Osteogenesis Imperfecta (OI) is a heritable bone disorder characterized by bone fragility and often caused by mutations in the Type I collagen-encoding genes COL1A1 and COL1A2. The pathophysiology of OI, particularly at the cellular level, is still not well understood. This contributes to the lack of a cure for this disorder as well as an effective preventive or management options of its complications. In the bone environment, mesenchymal stem cells (MSCs) and osteoblasts (Ob) exert their function, at least partially, through the secretion of extracellular vesicles (EV). EV is a heterogeneous group of nanosized membrane-enclosed vesicles that carry/transfer a cargo of proteins, lipid and nucleic acids from the secreting cell to its target cells. Our objective is to characterize EVs secreted by human control (HC)- and OI-MSCs and their derived Obs, with focus on their protein content. We hypothesize that there will be differences in the protein content of EVs secreted by OI-Obs compared to HC-Ob, which may indicate a deviation from healthy Ob behavior and, thus, a role in OI pathophysiology. MSCs were harvested from the adipose tissue of four COL1A1-OI and two HC patients. They were proliferated in an EV-depleted media, then induced to differentiate to extracellular matrix (ECM)-producing osteoblasts, which then gets mineralized. EVs secreted by MSCs (MSC-EV) and Obs (Ob-EV) were then purified and concentrated. Using liquid chromatography- tandem mass spectrometry, proteomic analysis of the EV groups was done. A total of 384 unique proteins were identified in all EVs, 373 were found in Vesiclepedia indicating a good enrichment of our samples with EV proteins. 67 proteins of the total 384 were exclusively or significantly upregulated (p-value < 0 .05) in OI-Ob-EV and 28 proteins in the HC-Ob-EVs, relative to each other. These two groups of differentially expressed proteins were compared by Gene Ontology (GO) analysis of their cellular compartment, molecular functions and biological processes. We observed that there were differences in the cellular origin of EV-proteins, which may indicate heterogeneity of the isolated EVs. Molecular function and biological process analyses of the HC-Ob-EV proteins showed, as expected, predominantly calcium-related activities such as extracellular matrix (ECM) mineralization. OI-Ob-EV proteins were still predominantly exhibiting ECM organization and formation functions. Annexins A1,2,4,5 and 6 were differentially and significantly upregulated by the HC-Ob-EVs.
The fixation of titanium or titanium alloy implants is related to their surface composition and topography. Osteoconductive calcium phosphate coatings promote bone healing and apposition, leading to the rapid biological fixation of implants. It’s no doubt that the addition of certain biologically active protein with biomaterial will improve the bioactivity of the material. Previously, we examined the biocompatibility of basic fibroblast growth factor (bFGF) incorporation with titanium implants. Now we investigate the effect of
In a healthy joint, mechanical loading increases matrix synthesis and maintains cell phenotype, while reducing catabolic activities. It activates several pathways, most of them yet largely unknown, with integrins, TGF-β, canonical (Erk 1/2) and stress-activated (JNK) MAPK playing a key role. Degenerative joint diseases are characterized by Wnt upregulation and by the presence of proteolytic
Objective. High molecular weight hyaluronan (HA) is widely used in the treatment of osteoarthritis (OA) and rheumatoid arthritis (RA) by intra-articular injection. However, comparative studies of HA actions on catalytically activated cartilages in different pathologic conditions have rarely been investigated.
Senescent chondrocyte and subchondral osteoclast overburden aggravate inflammatory cytokine and pro-catabolic proteinase overproduction, accelerating extracellular matrix degradation and pain during osteoarthritis (OA).
Material-based strategies seek to engineer synthetic microenvironments that mimic the characteristics of physiological extracellular matrices for applications in regenerative therapies, including bone repair and regeneration. In our group, we identified a specific chemistry, poly(ethyl acrylate) (PEA), able to induce the organization of
The presence of the connective tissue components
The success of long-term transcutaneous implants
depends on dermal attachment to prevent downgrowth of the epithelium
and infection. Hydroxyapatite (HA) coatings and
Regeneration of bone defects in elderly patients is limited due to the decreased function of bone forming cells and compromised tissue physiology. Previous studies suggested that the regenerative activity of stem cells from aged tissues can be enhanced by exposure to young systemic and tissue microenvironments. The aim of our project was to investigate whether extracellular matrix (ECM) engineered from human induced pluripotent stem cells (hiPSCs) can enhance the bone regeneration potential of aged human bone marrow stromal cells (hBMSCs). ECM was engineered from hiPSC-derived mesenchymal-like progenitors (hiPSC-MPs), as well as young (<30 years) and aged (>70 years) hBMSCs. ECM structure and composition were characterized before and after decellularization using immunofluorescence and biochemical assays. Three hBMSCs of different ages were cultured on engineered ECMs. Growth and differentiation responses were compared to tissue culture plastic, as well as to collagen and
Background: Osseointegrated amputation prostheses avoid soft tissue complications associated with traditional socket prostheses. Forces are transmitted directly to the skeleton resulting in improved function. However, approximately 50% of transcutaneous implants become infected due to the lack of a successful skin-implant seal. Intraosseous Transcutaneous Amputation Prostheses (ITAP) are designed to integrate with the skin preventing epithelial downgrowth and infection.
The anterior cruciate ligament (ACL) is the connective tissue located at the end of long bones providing stability to the knee joint. After tear or rupture clinical reconstruction of the tissue remains a challenge due to the particular mechanical properties required for proper functioning of the tissue. The outstanding mechanical properties of the ACL are characterized by a viscoelastic behavior responsible of the dissipation of the loads that are transmitted to the bone. These mechanical properties are the result of a very specialized graded extracellular matrix that transitions smoothly between the heterotypic cells, stiffness and composition of the ACL and the adjacent bone. Thus, mimicking the zonal biochemical composition, cellular phenotype and organization are key to reset the proper functioning of the ACL. We have previously shown how the biochemical composition presented to cells in electrospun scaffolds results in haptokinesis, reverting contact-guidance effects. [1]. Here, we demonstrate that contact guidance can also be disrupted by structural parameters in aligned wavy scaffolds. The presentation of a wavy fiber arrangement affected the cell organization and the deposition of a specific ECM characteristic of fibrocartilage. Cells cultured in wavy scaffolds grew in aggregates, deposited an abundant ECM rich in
Chondrocytic activity is downregulated by compromised autophagy and mitochondrial dysfunction to accelerate the development of osteoarthritis (OA). Irisin is a cleaved form of
Backgrounds and aim. Low back pain resulting from Intervertebral disc (IVD) degeneration is a serious worldwide problem, with poor treatment options available. Notochordal (NC) cells, are a promising therapeutic cell source with anti-catabolic and regenerative effect, however, their behaviour in the harsh degenerate environment is unknown. Thus, we aimed to investigate and compare their physiological behaviour in in vitro niche that mimics the healthy and degenerated intervertebral disc environment. Methodology. Porcine NC cells were encapsulated in 3D alginate beads to maintain their phenotype then cultured in media to mimic the healthy and degenerate disc environment, together with control NC media for 1 week. Following which viability using PI and Calcein AM, RNA extraction and RT-PCR for NC cell markers, anabolic and catabolic genes analysed. Proteomic analysis was also performed using Digiwest technology. Results. A small increase in cell death was observed in degenerated media compared to standard and healthy media, with a further decrease seen when cultured with IL-1β. Whilst no significant differences were seen in phenotypic marker expression in NCs cultured in any media at gene level (ACAN, KRT8, KRT18, FOXA2, COL1A1 and Brachyury). Preliminary Digiwest analysis showed increased protein production for Cytokeratin 18, src and phosphorylated PKC but a decrease in
Low back pain resulting from Interertebral disc (IVD) degeneration is a serious worldwide problem, with poor treatment options available. Notochordal (NC) cells, are a promising therapeutic cell source with anti-catabolic and regenerative effect. However, their behaviour in the harsh degenerate environment is unknown. Porcine NC cells (pNCs), and Human NP cells from degenerate IVDs were cultured in alginate beads to maintain phenotype. Cells were cultured alone or in combination, or co-stimulated with notochordal cell condition media (NCCM), in media to mimic the healthy and degenerate disc environment, together with controls for up to 1 week. Following culture viability, qPCR and proteomic analysis using Digiwest was performed. A small increase in pNC cell death was observed in degenerated media compared to standard and healthy media, with a further decrease seen when cultured with IL-1β. Whilst no significant differences were seen in phenotypic marker expression in pNCs cultured in any media at gene level (ACAN, KRT8, KRT18, FOXA2, COL1A1 and Brachyury). Preliminary Digiwest analysis showed increased protein production for Cytokeratin 18, src and phosphorylated PKC but a decrease in
Neoangiogenesis drives the replacement of mineralised cartilage by trabecular bone during bone growth regulated by molecules like e.g. VEGF, OPG and RANKL. The Heparan sulfate proteoglycan Syndecan-1 (Sdc1) plays a role in the interaction of osteoclasts and osteoblasts and the development of blood vessels. We expected Sdc1 to have an influence on bone structure and vessel development. Therefore, bone structure and angiogenesis at the growth plate in mice was compared and the influence of Syndecan-1 deficiency was characterised. Animals: Femura of male and female C57BL/6 WT (5♀, 6♂) and Sdc1-/- (9♀, 5♂) mice were used for native bone analysis at 4 month age. Histology: Bone structure was analysed using microCT scans with a resolution of 9µm. Vascularisation was visualised using an anti-Endomucin antibody in 80µm thick cryosections. In vitro angiogenesis: Bone marrow isolates were used to generate endothelial progenitor cells by sequential cultivation on
Introduction. Intraosseous transcutaneous amputation prostheses (ITAP) provide an alternative means of attaching artificial limbs for amputees. Conventional stump-socket devices are associated with soft tissue complications including; pressure sores and tissue necrosis. ITAP resolves these problems by attaching the exo-prosthesis transcutaneously to the skeleton. The aim of this study is to increase the attachment of dermal fibroblasts to titanium alloy in vitro.
Dupuytren’s disease is a chronic inflammatory process which produces contractures of the fingers. The nodules present in Dupuytren’s tissue contain inflammatory cells, mainly lymphocytes and macrophages. These express a common integrin known as VLA4. The corresponding binding ligands to VLA4 are vascular cell adhesion molecule-1 (VCAM-1) present on the endothelial cells and the CS1 sequence of the
Mesenchymal stem cells (MSC) have a well recognised potential for tissue repair. This potential is two pronged: they can differentiate into the functional cell types of the damaged tissues and they can support tissue recovery by secreting trophic factors, depositing an extracellular matrix (ECM) and dampening inflammation. Three-dimensional microscopy recently shown that MSCs in the bone marrow create an intricate proteo-cellular scaffold with the ECM forming an interconnected cellular continuum whose structure is guided by the deposited ECM. This proteo-cellular scaffold controls bone marrow functions from hematopoiesis to osteogenesis. In the current study we aimed to optimise ECM production under in vitro conditions by immortalised MSCs with the view that the generated ECM can be utilised for tissue repair. With immunocytochemistry we determined the deposition of bone marrow-characteristic ECM proteins: collagen I, III, IV, V, VI, laminin and
Introduction and Objective. Chronic tendinopathy is a multifactorial disease and a common problem in both, athletes and the general population. Mechanical overload and in addition old age, adiposity, and metabolic disorders are among the risk factors for chronic tendinopathy but their role in the pathogenesis is not yet unequivocally clarified. Materials and Methods. Achilles tendons of young (10 weeks) and old (100 weeks) female rats bred for high (HCR) and low (LCR) intrinsic aerobic exercise capacity were investigated. Both Achilles tendons of 28 rats were included and groups were young HCR, young LCR, old HCR, and old LCR (n = 7 tendons per group/method). In this rat model, genetically determined aerobic exercise capacity is associated with a certain phenotype as LCR show higher body weight and metabolic dysfunctions in comparison to HCR. Quantitative real-time PCR (qPCR) was used to evaluate alterations in gene expression. For histological analysis, semi-automated image analysis and histological scoring were performed. Results. Age-related downregulation of tenocyte marker genes (Tenomodulin), genes related to matrix modelling and remodeling (Collagen type 1, Collagen type 3, Elastin, Biglycan,
Introduction. Following amputation, residual stumps used to attach the external prostheses can be associated with sores, infection and skin necrosis. These problems could be overcome by off loading the soft tissues. Intraosseous transcutaneous amputation prostheses (ITAP) attach external implants directly to residual bone reducing these complications. However, a tight seal at the skin implant interface is crucial in preventing epithelial down-growth and infection.
The August 2014 Research Roundup. 360 . looks at: Antibiotic loaded ceramic of use in osteomyelitis;
Regeneration of bone defects in elderly patients is limited due to the decreased function of bone forming cells and compromised tissue physiology. Previous studies suggested that the regenerative activity of stem cells from aged tissues can be enhanced by exposure to young systemic and tissue microenvironments. The aim of our project was to investigate whether extracellular matrix (ECM) engineered from human induced pluripotent stem cells (hiPSCs) can enhance the bone regeneration potential of aged human bone marrow stromal cells (hBMSCs). ECM was engineered from hiPSC-derived mesenchymal-like progenitors (hiPSC-MPs), as well as young (70 years) hBMSCs. ECM structure and composition were characterized before and after decellularization using immunofluorescence and biochemical assays. Three hBMSCs of different ages were cultured on engineered ECMs. Growth and differentiation responses were compared to tissue culture plastic controls. Decellularized ECMs contained collagens type I and IV,
Background. Osteoarthritis (OA), a common degenerative disorder of synovial joints, is characterized by disruption of the extracellular matrix (ECM) homeostasis with an overall misbalance towards cartilage catabolism. Integrins are alpha/beta heterodimeric transmembrane proteins transmitting chemical and biomechanical signals into the cells. There is a growing consensus that changes of ECM composition by proteolytic degradation of matrix constituents, or alteration of the biomechanical microenvironment of chondrocytes caused by chronic stress or injury significantly increase the risk of OA through the perturbation of integrin signaling. In order to further investigate the role of the b1 integrin subfamily in OA, we have challenged hip cartilage explants dissected for mice lacking beta1 integrins in chondrocytes by cytokines, ECM degradation products or mechanical stimulation. Methods. Femoral articular cartilages were avulsed from hip joints of 6 weeks old wild type (WT) and b1fl/fl-PrxCre mutant (MT) mice. For the chemically-induced OA-like stimulation, femoral caps were cultured for 3 days in serum-free DMEM/F12 with or without the supplementation of interleukin-1a (IL1a), 120kDa cell-binding
The steric and electrostatic complementarity of natural proteins and other macromolecules are a result of evolutionary processes. The role of such complementarity is well established in protein-protein interactions, accounting for the known protein complexes. To our knowledge, non-biological systems have not been a part of such evolutionary processes. Therefore, it is desirable to design and develop nonbiological surfaces, such as implant devices (e.g. bone growth for non-cemented fixation), that exhibit such complementarity effects with the natural proteins. Cell attachment and spreading in vitro is generally mediated by adhesive proteins such as
The main obstacle for tissue engineering is the difficulty in producing structurally and functionally well-organized tissues from in vitro cultured cells. Thus, on one hand the research is focusing towards bioactive three-dimensional materials (scaffolds) able to stimulate specific cellular processes. In fact the problem exists that cells cultured in scaffolds have great difficulty to adhere and proliferate if they don’t recognize bioactive molecules. In this respect biological polymers are used in the preparation of synthetic matrices to be used as tissue engineering scaffolds. On the other hand biological research is focusing on morphological and functional properties of cells seeded onto bioactive materials to evaluate their viability, adherence and proliferation, fundamental steps for successful tissue engineering. Surgical specimens were treated with type Ia collagenase and cultured in FCS/EGF supplemented DMEM. Cellular characterization was carried out on 3rd passage cells. Fibroblasts were seeded on Matri-cell, a substrate rich in basal lamina constituents, or PVA-gelatin sponges. Pulmonar ovine fibroblasts were also employed to set up the experimental procedures of cell seeding on scaffolds and histological methods. Immunocytochemistry was carried out to evaluate the presence of cytokeratin, fibroblast antigen, S-100 protein, TGF-beta1,
Aberrant infrapatellar fat metabolism is a notable feature provoking inflammation and fibrosis in the progression of osteoarthritis (OA). Irisin, a secretory subunit of
Osteoinductive bone substitutes are in their developmental infancy and a paucity of effective grafts options persists despite clinical demand. Bone mineral substitutes such as hydroxyapatite cause minimal biological activity when compared to osteoinductive systems present biological growth factors in order to drive bone regeneration. We have previously demonstrated the in-vitro efficacy of a bioengineered system at presenting growth factors at ultra low-doses. This study aimed to translate this growth factor delivery system towards a clinically applicable implant. Osteoinductive surfaces were engineered using plasma polymerisation of poly(ethyl acrylate) onto base materials followed by adsorption of
Cellular therapies play an important role in tendon tissue engineering with tenocytes being described as the most prominent cell population if available in large numbers. However, in vitro expansion of tenocytes in standard culture leads to phenotypic drift and cellular senescence. Recent work suggests that maintenance of tenogenic phenotype in vitro can be achieved by recapitulating different aspects of the native tendon microenvironment. One approach used to modulate the in vitro microenvironment and enhance extracellular matrix (ECM) deposition is macromolecular crowding (MMC). MMC is based on the addition of inert macromolecules to the culture media mimicking the dense extracellular matrix. In addition, as tendon has been described to be a relatively avascular and hypoxic tissue and low oxygen tension can stimulate collagen synthesis and cross-linking, we venture to assess the synergistic effect of MMC and low oxygen tension on human tenocyte phenotype maintenance by enhancing synthesis and deposition of tissue-specific ECM. Human tendons were kindly provided from University Hospital Galway, after obtaining appropriate licenses, ethical approvals and patient consent. Afterwards, tenocytes were extracted using the migration method. Experiments were conducted at passage three. Optimization of MMC conditions was assessed using 50 to 500 μg/ml carrageenan (Sigma Aldrich, UK). For variable oxygen tension cultures, tenocytes were incubated in a Coy Lab (USA) hypoxia chamber. ECM synthesis and deposition were assessed using SDS-PAGE (BioRad, UK) and immunocytochemistry (ABCAM, UK) analysis. Protein analysis for Scleraxis (ABCAM, UK) was performed using western blot. Gene analysis was conducted using a gene array (Roche, Ireland). Cell morphology was assessed using bright-field microscopy. All experiments were performed at least in triplicate. MINITAB (version 16, Minitab, Inc.) was used for statistical analysis. Two-sample t-test for pairwise comparisons and ANOVA for multiple comparisons were conducted. SDS-PAGE and immunocytochemistry analysis demonstrated that human tenocytes treated with the optimal MMC concentration at 2% oxygen tension showed increased synthesis and deposition of collagen type I, the major component of tendon ECM. Moreover, immunocytochemistry for the tendon-specific ECM proteins collagen type III, V, VI and
While new biomaterials for regenerative therapies are being reported in the literature, clinical translation is slow. Existing regenerative approaches rely on high doses of growth factors, such as BMP-2 in bone regeneration, which can cause serious side effects. We describe an ultra-low-dose growth factor technology yielding high bioactivity based on a simple polymer, poly (ethyl acrylate) (PEA), and report its translation to a clinical veterinary setting. This polymer-based technology triggers spontaneous
INTRODUCTION: We have previously demonstrated the efficacy of a modified Ti-surface tethered with antibiotics in preventing bacterial colonization. It is not known if coverage of this surface with serum or other physiological material may hinder the bactericidal properties of such a surface.. The in vitro activity and efficacy of such a surface against S. aureus and S. epidermidis was tested following coverage of the surface with serum. METHODS: Vancomycin was coupled to Ti6Al4V pins by aminopropylation, linker addition, and vancomycin coupling (VancTi). Bactericidal activity was tested in solutions of bacteria (Ci=1×104cfu/ml) incubated with pins±pre-incubation with fetal bovine serum (FBS). Anti
The study describes the changes of condrocytes and extracellular matrix occurring in Hip OA. 16 femoral heads were included in the study. Cartilage explants were removed from 3 anatomical sites over the surface of 14 OA and 2 non-OA patients. Cartilage sections were evaluated with histological (EE, Alcian Blu and Mallory-Azan stainings) and immuno-histochemichal (antibodies directed against
Osteoarthritis (OA) is the most common form of joint disease leading to disability and dependence. In severe cases of knee OA, the joint is deemed irrecoverable and total knee replacements are indicated. Tissue engineering is a possible solution for this pathology and previous work from our laboratory has demonstrated that it is possible to isolate and expand chondroprogenitor cells in vitro from healthy knee-joint articular cartilage. Work presented here describes the detection and isolation of chondroprogenitor cells derived from osteoarthritic cartilage following total knee replacement in patients with severe OA, suggesting a pool of viable cells from this degenerate region which has been previously deemed non-recoverable. Human articular cartilage was excised from tibial plateaux (TP's) obtained from total knee replacements following the diagnoses of severe OA. Cells were isolated by a sequential pronase and collagenase digestion and subject to a
Summary. Attachment, proliferation and osteogenic maturation of hMSCs are enhanced on a sub-micron grooved Ti6Al4V alloy, while osteoblasts are less sensitive. These effects are attributed to their different maturation stage and may be mediated through differential activation of the RhoA/ROCK pathway. Introduction. Ti6Al4V alloy is the most widely used titanium-based biomaterial for manufacturing bone-anchoring devices. We report on the interactions of human bone-forming cells, mesenchymal stem cells from bone marrow (hMSCs) and primary osteoblasts (hOBs), with an anisotropic Ti6Al4V alloy that displays submicron grooves. Materials. Submicrometric Ti6Al4V surfaces (GV) with parallel grooves and mean average roughness values around 200 nm were generated by mechanical abrasion. A polished Ti6Al4V surface (PL) was used for comparative purposes. hMSCs were phenotypically characterised as progenitors and hOBs as committed osteogenic cells at a late stage of maturation. Cell attachment, proliferation, cytoskeleton organisation, adhesion sites and
Cellular therapies play an important role in tendon tissue engineering with tenocytes being described as the most prominent cell population if available in large numbers. In vitro expansion of tenocytes in standard culture leads to phenotypic drift and cellular senescence. Maintenance of tenogenic phenotype in vitro can be achieved by recapitulating different aspects of the tendon microenvironment. One approach used to modulate in vitro microenvironment and enhance extracellular matrix (ECM) deposition is macromolecular crowding (MMC). In addition, as tendon has been described to be a relatively avascular and hypoxic tissue and low oxygen tension can stimulate collagen synthesis and cross-linking through the activation of hypoxia-inducible factor 1-alpha (HIF1-α), we venture to assess the synergistic effect of MMC and low oxygen tension on human tenocyte phenotype maintenance. SDS-PAGE and immunocytochemistry analysis demonstrated that human tenocytes treated with MMC at 2 % oxygen tension showed increased synthesis and deposition of collagen type I. Moreover, immunocytochemistry for the tendon-specific ECM proteins collagen type III, V, VI and
In orthopedic surgery, sterilization of bone used for reconstruction of osteoarticular defects caused by malignant tumors is carried out in different ways. At present, to devitalize tumor-bearing osteochondral segments, mainly extracorporal irradiation or autoclaving is used. Both methods have substantial disadvantages, e.g. loss of biomechanical and biological integrity of the bone. In particular integration at the autograft-host junction after reimplantation is often impaired due to alterations of the osteoinductivity following irradiation or autoclaving. As an alternative approach, high hydrostatic pressure (HHP) treatment of bone is a new technology, now being used in preclinical testing to inactivate tumor cells without alteration of biomechanical properties of bone, cartilage and tendons. The aim of this study was to investigate the influence of HHP on
Aim of study: The development of tissue engineering techniques evidenced that the healing of injured ligaments require the interactions of different cell types, local cellular environment and the use of devices. In order to gain new information on the complex interactions between mesenchymal stem cells (MSCs) and biodegradable scaffold, we analysed in vitro the proliferation, vitality and phenotype of MSCs grown onto a multilayered-woven-cylindric-array of Hyaff-11A8 fiber configured as ligament scaffold. Methods: Sheep MSCs were isolated from bone marrow aspirates and grown at two different density (7,5x106/cm and 15x106/cm) in the scaffold. At different time points (2, 4, 6 days) cellular proliferation was analysed by MTT test and cellular viability by calcein-AM immunofluorescence dye and confocal microscopy analysis. Moreover, hyaluronic acid receptor (CD44) and typical matrix ligament proteins (collagen type I, III, laminin,
Introduction. Despite the high regenerative capacity of bone, large bone defects often require treatment involving bone grafts. Conventional autografting and allografting treatments have disadvantages, such as donor site morbidity, immunogenicity and lack of donor material. Bone tissue engineering offers the potential to achieve major advances in the development of alternative bone grafts by exploiting the bone-forming capacity of osteoblastic cells. However, viable cell culture models are essential to investigate osteoblast behavior. Three-dimensional (3D) cell culture systems have become increasingly popular because biological relevance of 3D cultures may exceed that of cell monolayers (2D) grown in standard tissue culture. However, only few direct comparisons between 2D and 3D models have been published. Therefore, we performed a pilot study comparing 2D and 3D culture models of primary human osteoblasts with regard to expression of transcription factors RUNX2 and osterix as well as osteogenic differentiation. Patients and Methods. Primary human osteoblasts were extracted from femoral neck spongy bone obtained during surgery procedures. Primary human osteoblasts of three donor patients were cultured in monolayers and in three different 3D culture models: 1) scaffold-free cultures, also referred to as histoids, which form autonomously after multilayer release of an osteoblast culture; 2) short-term (10-day) collagen scaffolds seeded with primary human osteoblasts (HOB); 3) long-term (29-day) collagen scaffolds seeded with HOB. Expression levels of transcription factors RUNX2 and osterix, both involved in osteoblast differentiation, were investigated using quantitative PCR and immunohistochemical staining. Furthermore, markers of osteogenic differentiation were evaluated, such as alkaline phosphatase activity, osteocalcin expression, and mineral deposition, as well as the expression of collagen type I and
Purpose: Bone allografting appears to be optimised by in situ stromal cells which have potential to evolve into a bone line. The purpose of this study was to test the bio-compatibility of stromal cells and an allogenic human bone support treated with stromal cells as well as their evolutive potential. Material and methods: The bone support was a human femoral head allograft harvested during total hip arthroplasty. After validation of the safety of the femoral heads by the bone bank, they were treated using the Osteopure(r) method. Human stromal cells were harvested during cardiac surgery from the sternotomy. The in vitro study was conducted in a sterile atmosphere in an incubator. Different adhesion molecules were used: collagen, gelatin,
Osteoarthritis (OA) is a common degenerative joint disease worldwide, which is characterized by articular cartilage lesions. With more understanding of the disease, OA is considered to be a disorder of the whole joint. However, molecular communication within and between tissues during the disease process is still unclear. In this study, we used transcriptome data to reveal crosstalk between different tissues in OA. We used four groups of transcription profiles acquired from the Gene Expression Omnibus database, including articular cartilage, meniscus, synovium, and subchondral bone, to screen differentially expressed genes during OA. Potential crosstalk between tissues was depicted by ligand-receptor pairs.Aims
Methods
Introduction: The highest goal after meniscus damage is the preservation of the meniscus, which is often not possible due to the bad healing of meniscus lesions in the avascular zone. Therefore, the goal of our investigations was the analysis of expression of different angiogenic factors, growth hormones and cytokines in human meniscus cells (fibrochondrocytes). The mutual influence of the fibrochondrocytes by endothelial cell cocultures was analyzed, in order to examine the molecular bases of the healing of meniscus tears in vascularized zones more exactly. For this purpose, commercially available HUVEC [human umbilical vein endothelial cells] were used as well established and stable endothelial cell model. Material and Methods: Meniscal fibrochondrocytes were expanded in DMEM medium enriched with antibiotics and 10 % FCS. Cocultures of mensical cells and HUVEC were incubated in transwells over four and twelve days, separated by a semipermeable membrane. The expression of Angiopoietin-1, Angiopoietin-2, End-ostatin, VEGF, SMAD-4, Thrombospondin-1, Aggrecan, Biglycan,
Cellular therapies play an important role in tendon tissue engineering and regenerative medicine with tenocytes being described as the most prominent cell population for these applications if available in large numbers. However, this is difficult to achieve, because in vitro expansion of tenocytes leads to phenotypic drift and loss of function. Recent work suggests that maintenance of tenogenic phenotype in vitro can be achieved by recapitulating different aspects of the native tendon microenvironment. One approach used to modulate in vitro microenvironment and enhance extracellular matrix (ECM) deposition is macromolecular crowding (MMC). MMC is based on the addition of inert macromolecules to the culture media to mimic the dense extracellular matrix and accelerate the production of ECM-rich substitutes. In addition, as tendon has been described to be a relatively avascular and hypoxic tissue and low oxygen tension can stimulate collagen synthesis and cross-linking through the activation of hypoxia-inducible factor 1-alpha (HIF1-α), we venture to assess the synergistic effect of MMC and low oxygen tension on human tenocyte phenotype maintenance by enhancing deposition of tissue-specific extracellular matrix. SDS-PAGE and immunocytochemistry analysis, demonstrated that human tenocytes treated with the optimal MMC concentration at 2% oxygen tension showed increased collagen type I synthesis and deposition after 7 days. Moreover, immunocytochemistry for collagen type III, type V, VI, elastin and
This study aimed, through bioinformatics analysis and in vitro experiment validation, to identify the key extracellular proteins of intervertebral disc degeneration (IDD). The gene expression profile of GSE23130 was downloaded from the Gene Expression Omnibus (GEO) database. Extracellular protein-differentially expressed genes (EP-DEGs) were screened by protein annotation databases, and we used Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) to analyze the functions and pathways of EP-DEGs. STRING and Cytoscape were used to construct protein-protein interaction (PPI) networks and identify hub EP-DEGs. NetworkAnalyst was used to analyze transcription factors (TFs) and microRNAs (miRNAs) that regulate hub EP-DEGs. A search of the Drug Signatures Database (DSigDB) for hub EP-DEGs revealed multiple drug molecules and drug-target interactions.Aims
Methods
Background. Intervertebral disc degeneration is implicated as a major cause of chronic lower back pain. Current therapies for lower back pain are aimed purely at relieving the symptoms rather than targeting the underlying aberrant cell biology. As such focus has shifted to development of cell based alternatives. Notochordal cells are progenitors to the adult nucleus pulposus that display therapeutic potential. However, notochordal cell phenotype and suitable culture conditions for research or therapeutic application are poorly described. This study aims to develop a suitable culture system to allow comprehensive study of the notochordal phenotype. Methods & Results. Porcine notochordal cells were isolated from 6 week post natal discs using dissection and enzymatic digestion and cultured in vitro under different conditions: (1)DMEM vs αMEM (2)laminin-521,
Introduction: Cell adhesion to titanium alloy implants is important in osseointegration [1,2] and attachment of the soft tissues to skin penetrating implants e.g. external fixator pins and Intraosseous Transcutaneous Amputation Prostheses [3,4]. Cell adhesion can be assessed using cell area data and immunolocalisation of focal contact proteins e.g. vinculin; however no method of assessing biophysical attachment is performed routinely. Cell adhesion can be enhanced with adhesion proteins including
Introduction: The knee meniscus is prone to injury and has limited intrinsic healing potential despite surgical repair. Methods to enhance fibrochondrocyte function and augment meniscal repair would be invaluable in the treatment of meniscal injuries. Ultraviolet Ozone (UVO) modified surfaces have been characterised chemically and topographically. These surfaces have been shown to promote the function of certain cell types. This study investigated the attachment, proliferation and extracellular matrix production of fibrochondrocytes cultured on UVO modified polystyrene surfaces. Interest was paid to the integrins, a group of transmembrane extracellular matrix attachment glycoproteins. In particular the subunits alpha2 and alpha5, as they specifically bind to the ligands Collagen Type I and
Introduction: MEPE was identified in patients with tumors and oncogenic hypophosphatemic osteomalacia (OHO), and therefore thought to inhibit osteoblast differentiation and proliferation. However when looking at the structure of MEPE in detail a number of important domains are observed, including a glycosamino-glycan-attachment site, and a RGD cell-attachment motif. The RGD motif is by far the best characterized peptide sequence for stimulating cell adhesion on synthetic surfaces. Glycosaminoglycan attached to MEPE also has the potential to interact with numerous growth factors, proteases and cell surface receptors. MEPE shares molecular similarities with several dentin-bone phosphoglycoproteins which exhibit an ASARM motif shown to potently inhibit calcium crystallization and crystal growth in the salivary duct system. More recently the ASARM peptide sequence has been shown to be a inhibitor of osteoblast mineralization. Method: To test the hypothesis that MEPE has multiple functional sites, PCR Primers were designed to provide a truncated MEPE protein, which contained pro-osteogenic motifs and had the anti-osteogenic ASARM motif removed. PCR products were cloned using the pBAD TOPO® TA Expression Kit. MEPE was than expressed in E. coli and purified by HIS column chromatography. Expression of truncated MEPE was confirmed by coomassie staining, Western blot with an antibody to an epitope tag and sequence analysis. Truncated MEPE was passively absorbed overnight at 4 oC in a 96 well plate (0.3–50 micrograms) and
Background. Auxetic materials have a negative poisons ratio, and a number of native biological tissues are proposed to possess auxetic properties. One such tissue is annulus fibrosus (AF), the fibrous outer layers of the intervertebral disc (IVD). However, few studies to date have investigated the potential of these materials as tissue engineering scaffolds. Here we describe the potential of manually converted polyurethane (PU) foams as three dimensional cellular scaffolds for AF repair. Methods. Rat MSCs were seeded onto
Polyether ether ketone (PEEK) has been increasingly employed as biomaterials for trauma, orthopeadic, and spinal implants. However, concern has been raised about the inertness of PEEK which limits bone integration. In this study, we have coated PEEK with a functional material seeking to promote osteogenic differentiation of human mesenchymal stem cells (hMSC). We have used spray drying to coat poly(ethyl acrylate) (PEA) as a coating on PEEK. This technique is simple, allows a range of controlled coating thicknesses (from hundred nm to a few um), cost effective and easily translatable to scaffolds or implant surfaces for existing or new orthopaedic applications. PEA induces the organisation of
Adenosine, lidocaine, and Mg2+ (ALM) therapy exerts differential immuno-inflammatory responses in males and females early after anterior cruciate ligament (ACL) reconstruction (ACLR). Our aim was to investigate sex-specific effects of ALM therapy on joint tissue repair and recovery 28 days after surgery. Male (n = 21) and female (n = 21) adult Sprague-Dawley rats were randomly divided into ALM or Saline control treatment groups. Three days after ACL rupture, animals underwent ACLR. An ALM or saline intravenous infusion was commenced prior to skin incision, and continued for one hour. An intra-articular bolus of ALM or saline was also administered prior to skin closure. Animals were monitored to 28 days, and joint function, pain, inflammatory markers, histopathology, and tissue repair markers were assessed.Aims
Methods
Background. The cartilaginous growth plate (GP) is a zonal structure, in which chondrocytes are organized into columns and drive the longitudinal elongation of the endochondral bones. In the proliferative zone (PZ), cells exhibit high mitotic activity, are flattened and oriented along the mediolateral (ML) axis of the GP. Mitotic figures in the elongated chondrocytes lie perpendicular to the proximo-distal (PD) direction of growth, while cell divisions occur parallel to the columns followed by a gliding movement of the daughter cells. The mechanisms responsible for the geometrical anisotropy and columnar arrangement of PZ chondrocytes are poorly understood. Here, we assessed the function of the adhesive receptor β1 integrins on spindle and division geometry in chondrocytes using mouse genetics. Methods. GP slices were prepared from wild type (wt) and β1fl/fl-Col2a1cre mice. Primary rib chondrocytes were cultured on substrate-coated glass slides and fluorescently stained with anti-alpha-tubulin and anti-pericentrin antibodies, with phalloidin and DAPI. Confocal stacks were built from images acquired by confocal microscopy. Cell and spindle orientation relative to the PD axis (in vivo) or to the substrate plane (SP) in vitro were determined by geometric functions. Shape indexes (SI) were calculated as the ratio of the length and height of the cell. Results. During GP morphogenesis, aggregating mesenchymal cells (E11) were polygonal (SI=1.43) and nonoriented. Upon chondrogenic differentiation at E12, wt GP chondrocytes showed moderate flattening (SI=1.93) and tend to align perpendicular to the PD axis. At E13, PZ chondrocytes further flattened (SI=3.41) and largely organized into lines along the ML axis. At E14, the first vertical stacks formed, which were gradually elongated along the PD axis at later stages and composed of extremely flat (SI=4.91), ML-oriented chondrocytes. Early spindles were randomly oriented at all stages, whereas late spindles were aligned along the long axis of the cell. In contrast, β1 integrin null PZ chondrocytes were rounded (SI=1.37), displayed random orientation of both early and late spindles, and failed to organize into columns. On collagen II, both wt and β1-null primary chondrocytes remained rounded and displayed random spindle orientation relative to the SP. On
To investigate whether idiopathic osteonecrosis of the femoral head (ONFH) is related to impaired osteoblast activities. We cultured osteoblasts isolated from trabecular bone explants taken from the femoral head and the intertrochanteric region of patients with idiopathic ONFH, or from the intertrochanteric region of patients with osteoarthritis (OA), and compared their viability, mineralization capacity, and secretion of paracrine factors.Aims
Methods
The antidiabetic agent metformin inhibits fibrosis in various organs. This study aims to elucidate the effects of hyperglycaemia and metformin on knee joint capsule fibrosis in mice. Eight-week-old wild-type (WT) and type 2 diabetic (db/db) mice were divided into four groups without or with metformin treatment (WT met(-/+), Db met(-/+)). Mice received daily intraperitoneal administration of metformin and were killed at 12 and 14 weeks of age. Fibrosis morphology and its related genes and proteins were evaluated. Fibroblasts were extracted from the capsules of 14-week-old mice, and the expression of fibrosis-related genes in response to glucose and metformin was evaluated in vitro.Aims
Methods
Control of stem cell fate and function is critical for clinical and academic work. By combining surface chemistry-driven extracellular matrix (ECM) assembly with mesenchymal stem cells (MSCs) we are developing a system which can be used to regulate the behaviour of MSCs. The conformation of the ECM glycoprotein
Orthopaedic surgery requires grafts with sufficient mechanical strength. For this purpose, decellularized tissue is an available option that lacks the complications of autologous tissue. However, it is not widely used in orthopaedic surgeries. This study investigated clinical trials of the use of decellularized tissue grafts in orthopaedic surgery. Using the ClinicalTrials.gov (CTG) and the International Clinical Trials Registry Platform (ICTRP) databases, we comprehensively surveyed clinical trials of decellularized tissue use in orthopaedic surgeries registered before 1 September 2022. We evaluated the clinical results, tissue processing methods, and commercial availability of the identified products using academic literature databases and manufacturers’ websites.Aims
Methods
Introduction. Tendon is prone to degeneration through ageing and injury and current therapies are largely ineffective. The recent identification of a cell population within tendon with stem cell-like characteristics holds potential for regeneration of tendon. The local stem cell environment (niche) is important for stem cell maintenance and function. This study aims to characterize extracellular matrix (ECM) components of the stem cell niche in equine tendon, which is prone to age-related degeneration and rupture. Materials and Methods. Putative tendon stem cells (TSCs) were isolated from equine superficial digital flexor tendon by low-density plating and differential adhesion to
Rheumatoid arthritis (RA) is an autoimmune disease that involves T and B cells and their reciprocal immune interactions with proinflammatory cytokines. T cells, an essential part of the immune system, play an important role in RA. T helper 1 (Th1) cells induce interferon-γ (IFN-γ), tumour necrosis factor-α (TNF-α), and interleukin (IL)-2, which are proinflammatory cytokines, leading to cartilage destruction and bone erosion. Th2 cells primarily secrete IL-4, IL-5, and IL-13, which exert anti-inflammatory and anti-osteoclastogenic effects in inflammatory arthritis models. IL-22 secreted by Th17 cells promotes the proliferation of synovial fibroblasts through induction of the chemokine C-C chemokine ligand 2 (CCL2). T follicular helper (Tfh) cells produce IL-21, which is key for B cell stimulation by the C-X-C chemokine receptor 5 (CXCR5) and coexpression with programmed cell death-1 (PD-1) and/or inducible T cell costimulator (ICOS). PD-1 inhibits T cell proliferation and cytokine production. In addition, there are many immunomodulatory agents that promote or inhibit the immunomodulatory role of T helper cells in RA to alleviate disease progression. These findings help to elucidate the aetiology and treatment of RA and point us toward the next steps. Cite this article:
Introduction. The hierarchical structure of tendon results in a complex mechanical strain environment, with tenocytes experiencing both tension and shear during loading. The mechanotransduction mechanisms involved in sensing these environments is currently unclear. To better understand the effects of shear and tension on cell behaviour, a fibre composite system able to recapitulate the physiological shear-tension ratio found in tendons, was used. Cell attachment within the composite was achieved by using either a collagen type I mimetic peptide, DGEA, or a
Introduction. The ability of tendons to withstand stress generally decreases with age, often resulting in increased tissue degeneration and decreased regeneration capacity. However, the underlying molecular and cellular mechanisms of tendon senescence remain poorly characterized. Therefore, the aim of the current study was to identify genes showing an age-dependent altered expression profile in tendons. Materials and Methods. A suppression-subtractive-hybridization (SSH) screen comparing cDNA libraries generated from Achilles tendons of mature-adult (3 months) and old (18 months) female C57BL/6 mice was conducted. Subsequently, the differential expression of the identified genes was validated by RT-qPCR and selected genes were then further analysed by immunohistochemistry and Western blot. To investigate age-related structural alterations in the collagenous extracellular matrix we applied SHG-microscopy and TEM. In vitro experiments with young and old tendon derived stem/progenitor cells (TDSCs) involved wounding assays, tendon-like constructs as well as collagen gel contraction assays. Results. Among 168 identified genes, several ECM genes showed a differential expression, including Col1a1, Col3a1,
The purpose of this study was to explore a simple and effective method of preparing human acellular amniotic membrane (HAAM) scaffolds, and explore the effect of HAAM scaffolds with juvenile cartilage fragments (JCFs) on osteochondral defects. HAAM scaffolds were constructed via trypsinization from fresh human amniotic membrane (HAM). The characteristics of the HAAM scaffolds were evaluated by haematoxylin and eosin (H&E) staining, picrosirius red staining, type II collagen immunostaining, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Human amniotic mesenchymal stem cells (hAMSCs) were isolated, and stemness was verified by multilineage differentiation. Then, third-generation (P3) hAMSCs were seeded on the HAAM scaffolds, and phalloidin staining and SEM were used to detect the growth of hAMSCs on the HAAM scaffolds. Osteochondral defects (diameter: 3.5 mm; depth: 3 mm) were created in the right patellar grooves of 20 New Zealand White rabbits. The rabbits were randomly divided into four groups: the control group (n = 5), the HAAM scaffolds group (n = 5), the JCFs group (n = 5), and the HAAM + JCFs group (n = 5). Macroscopic and histological assessments of the regenerated tissue were evaluated to validate the treatment results at 12 weeks.Aims
Methods
Bone regeneration during treatment of staphylococcal bone infection is challenging due to the ability of The human osteoblast-like Saos-2 cells infected with Aims
Methods
To try and aid the formation of a soft tissue seal to promote dermal and epidermal attachment to Intraosseous Transcutaneous Amputation Prostheses we compared the effect of titanium surfaces functionalised with
This review provides a concise outline of the advances made in the care of patients and to the quality of life after a traumatic spinal cord injury (SCI) over the last century. Despite these improvements reversal of the neurological injury is not yet possible. Instead, current treatment is limited to providing symptomatic relief, avoiding secondary insults and preventing additional sequelae. However, with an ever-advancing technology and deeper understanding of the damaged spinal cord, this appears increasingly conceivable. A brief synopsis of the most prominent challenges facing both clinicians and research scientists in developing functional treatments for a progressively complex injury are presented. Moreover, the multiple mechanisms by which damage propagates many months after the original injury requires a multifaceted approach to ameliorate the human spinal cord. We discuss potential methods to protect the spinal cord from damage, and to manipulate the inherent inhibition of the spinal cord to regeneration and repair. Although acute and chronic SCI share common final pathways resulting in cell death and neurological deficits, the underlying putative mechanisms of chronic SCI and the treatments are not covered in this review.
Summary. Osseointegrated Amputation Prostheses can be functionalised by both biological augmentation and structural augmentation. These augmentation techniques may aid the formation of a stable skin-implant interface. Introduction. Current clinical options are limited in restoring function to amputees, and are associated with contact dermatitis and infection at the stump-socket interface. Osseointegrated Amputation Prosthesis attempts to solve issues at the stump-socket interface by directly transferring axial load to the prosthesis, via a skin-penetrating abutment. However, development is needed to achieve a seal at the skin-implant interface to limit infection.
Unique progenitor cells have been identified recently and successfully cultured in vitro from human articular cartilage. These cells are able to maintain chondrogenic potential upon extensive expansion. In this study, we have developed a sheep, ex-vivo model of cartilage damage and repair, using these progenitor cells. This study addresses the question can such a model be used to determine factors required for progenitor cell proliferation, differentiation and integration of matrix onto bone. The hypothesis was that sheep allogenic cartilage derived progenitor cells could regenerate artificially damaged sheep articular cartilage in an osteochondral culture model. Progenitor cells were derived from ovine articular cartilage using a differential adhesion assay to
Summary Statement. The Dkk3-derived cells represent a branch of the periosteal mesenchymal lineage that produces fibrocartilage as well as regenerating the periosteal structures. Introduction. Mesenchymal progenitor cells are capable of generating a wide variety of mature cells that constitute the connective tissue system. Our Laboratory has been developing SMAA GFP reporter mice to prove to be an effective tool for identifying these cells prior to the expression of markers of differentiation characteristic of bone, fat, muscular blood vessels or fibrocartilage. Dkk3 was chosen as a candidate reporter because microarray of SMAA-sorted cells culture indicated high expression of this non-canonical anti-Wnt factor, which was not anticipated in a culture with strong osteogenic potential. Material and Methods. Fracture healing process was evaluated in 12 week old male mice at 3, 5, 7, 14, 21 and 28days post fracture. A 3 color reporter mouse was generated by crossing SMAA-GFPcherry × Col3.6GFPcyan × Dkk3-eGFP and subjected to tibial fracture. A closed transverse fracture was performed by Einhorn device under isoflurane anesthesia after insertion of intramedullary pinning. Longitudinal 5 mm non-calcified cryosections were stabilised with Cryofilm tape. Results. Three days post fracture, the proliferating SMAA-red cells were also beginning to express either Dkk3 or Col3.6. By day 5 the two populations had diverged with the Dkk3 cells being on the outer surface of the developing callus while the Col3.6 cells were forming bone at the base of the callus. By day 7 when the callus is filled with cartilage, Dkk3 is active in cells that are in transition from elongated cells on the external surface of the callus to fibrocartilagenous cells that now express low levels of Col3.6. The zone of cells that express Dkk3 appear to block the passage of the surrounding vasculature into the underlying cartilage and does not deposit
Mesenchymal stem cells (MSCs) have potential for therapeutic repair of cartilage and bone but still require optimization in terms of their capacity to deposit an appropriate extracellular matrix (ECM). Adult human cartilage has a limited capacity for repair and is unusual in that it is one of the few tissues where injury is not followed by an influx of monocytes. We are studying the effects of co-culturing primary monocytes with MSCs differentiating along chondrogenic lineage but in addition we needed to investigate the effects of the monocytes on the mature chondrocytes that will result from the MSCs and will also be present in the host tissue. Human articular cartilage chondrocytes were isolated from human donors undergoing knee replacement surgery for osteoarthritis (OA) with full ethical consent. Cultures were expanded and cells used below passage five for co-culture experiments. Monocytes were prepared from fresh heparinized human blood samples by Ficoll gradient. Co-cultures consisted of either chondrocyte micromasses overlaid with monocytes, or chondrocytes and monocytes seeded together within a collagen/glycosaminoglycan scaffold (Chondromimetic, Tigenix UK). Media, cell pellets and scaffolds were analysed for extracellular matrix (ECM) proteins and proteases by dot blot, western blot, zymography and immunohistochemistry. Human chondrocytes maintained stable micromasses and laid down an ECM for at least 40 days. Human monocytes eventually formed a proliferating cell population with a rounded morphology on top of the chondrocyte micromasses. These cells established an adherent population with a fibroblastic morphology when replated on plastic. Analysis of chondrocyte ECM proteins indicated that monocytes affected deposition of types I and II collagen, decorin and
Prosthetic joint infection (PJI) is an increasing problem and management commonly involves prosthesis removal with serious consequences. Biofilm-forming staphylococci are the most common causative organisms with Staphylococcus aureus being most virulent and methicillin-resistant Staphylococcus aureus (MRSA) more than doubling the infection mortality rate. Bacterial adhesion is an essential primary event in biofilm formation and infection establishment. The development of a novel combination vaccine programme to prevent staphylococcal PJI by directing antibody against factors involved in adhesion and biofilm formation, and investigation of S. aureus binding-domains as potential vaccine components for adhesion inhibition is described. Selected target antigens included the S. aureus fibronectin-binding protein (FnBP) and iron-regulated surface determinant (IsdA), which have been shown to be important for infection establishment and predominantly bind to host
Background: Circulating endothelial precursor cells (CEPS) are thought to play a role in postnatal angiogenesis. We investigated the angiogenic stress of musculoskeletal trauma on CEP kinetics in trauma patients and their bone marrow progenitor populations in a murine model. Methods: Peripheral blood mononuclear cells (PB-MNCs) were isolated from patients (n=12) on consecutive days following closed lower-limb diaphyseal fractures. CEP levels, defined by the surface expression patterns of VEGFR2, CD34 and AC133 were determined and cytokine analysis of collected serum was performed. Bone marrow precursors defined by Ly-6A/E and c-Kit expression were harvested following traumatic insult from the murine model and quantified on flow cytometry. Human and murine progenitor populations were cultured on
Study Design: Experimental in vivo study on New Zealand White Rabbits. Summary of Background Data: We have developed an in-vivo rabbit model of lumbar disc degeneration. This model provides a defined loading of one single disc. However, the molecular mechanism that leads to mechanically-induced disc degeneration remains unclear. Objective: To investigate the process of mechanically induced disc degeneration in New Zealand White Rabbits with respect to remodeling on the gene and the level of protein expression. Subjects: Seven animals were treated with an external compression-device applying 200N on segment L3/4. Eight animals underwent sham surgery. Outcome Measures: After 28 days discs were harvested and cut into two pieces in a sagittal plain. One piece was used for protein analysis utilizing immunohistochemical protocols for collagen I, II and aggrecan. The other half of the disc was used for quantitative real-time RT-PCR to determine gene expression of selected matrix genes. Results: In the compression group matrix genes were upregulated: collagen I (6.46x; p=0,018), collagen II (2.14x), biglycan (2.97x; p=0,049), decorin (4.64x; p=0,043), aggrecan (1.2x), osteonectin (2.03x),
The changes occurring in ligamentum flavum in lumbar spine stenosis are a matter of long–standing controversy. More recently, some studies showed that the posterior spinal structures, including hypertrophied ligamentum flavum, play a major role in the pathogenesis of the lumbar stenosis. To investigate the pathogenesis of the degenerative changes of the ligamentum flavum occurring in lumbar spine stenosis, yellow ligament cells from patients with lumbar spine stenosis were cultured for the first time and subjected to biochemical, histochemical and immunohistochemical study. Samples of ligamentum flavum were collected from 4 patients undergoing surgery for lumbar stenosis (mean age 47.2 years). Cell cultures were obtained from each patient and maintained in Dulbecco’s modified essential medium-10% fetal calf serum. Cell characterization was histochemically (Gomori’s and von Kossa staining), immunohistochemically (anti-type I, -type II, -type III and -type X collagen, anti-S100 protein, anti-fibronectin, anti-osteonectin and anti-osteocalcin), biochemically (cAMP activity after human parathyroid hormone stimulation) assessed. Samples collected from 2 age-matched patients who underwent surgery for lumbar fractures were used as controls. Stenotic ligamentum flavum cells expressed high levels of alkaline phosphatase activity and produced a mineralized matrix rich in type I, type III and type X collagen,
Transforming growth factor-beta2 (TGF-β2) is recognized as a versatile cytokine that plays a vital role in regulation of joint development, homeostasis, and diseases, but its role as a biological mechanism is understood far less than that of its counterpart, TGF-β1. Cartilage as a load-resisting structure in vertebrates however displays a fragile performance when any tissue disturbance occurs, due to its lack of blood vessels, nerves, and lymphatics. Recent reports have indicated that TGF-β2 is involved in the physiological processes of chondrocytes such as proliferation, differentiation, migration, and apoptosis, and the pathological progress of cartilage such as osteoarthritis (OA) and rheumatoid arthritis (RA). TGF-β2 also shows its potent capacity in the repair of cartilage defects by recruiting autologous mesenchymal stem cells and promoting secretion of other growth factor clusters. In addition, some pioneering studies have already considered it as a potential target in the treatment of OA and RA. This article aims to summarize the current progress of TGF-β2 in cartilage development and diseases, which might provide new cues for remodelling of cartilage defect and intervention of cartilage diseases.
Enzymes that breakdown components of the extracellular matrix (ECM) are of fundamental importance, not only in normal bone physiology but also in pathological processes. For instance the temporal and spatial distribution of proteoglycans is not only critical for the mineralisation of bone but is also believed to be responsible for dictating the local bioavailability of glycosaminoglycan-binding growth factors. A sub-family of the ADAMs (a disintegrin and metalloproteinase) has been identified, that contains thrombospondin-like motifs (ADAMTS), and ADAMTS1, 4 and 5 have recently been shown to cleave the major proteoglycan of cartilage, aggrecan. We propose that ADAMTS family members play a novel role in regulating osteoblast function by determining the distribution of proteoglycan in bone. RT-PCR and Northern blotting experiments have shown expression of ADAMTS1, 3, 4 and 5 in primary rat osteoblasts and in the osteosarcoma cell lines, MG63, TE85 and SaOS-2. ADAMTS1 transcript levels increased with time in primary rat osteoblasts driven by dexamethasone, beta-glycerophosphate and ascorbic acid phosphate to produce bone-like nodules in vitro. Whereas levels of ADAMTS4 that were initially raised in this culture system then became undetectable as mineralisation proceeded. Since we are interested in the relationship between the osteoblast and matrix molecules, we plated TE85 cells onto an ECM synthesised by MG63 cells and isolated RNA at 1, 24 and 48 hours. Northern analysis showed a transient upregulation of mRNA for both ADAMTS1 and 5 at 1h that was reduced to control levels at 24 and 48h. Transcripts for ADAMTS1 and 3 were also upregulated in primary rat osteoblasts when seeded on ECM molecules like
Purpose: To evaluate the role of myofibroblasts in post-traumatic contractures, studies were performed on the myofibroblast marker &
#945;-SMA and myofibroblast up-regulators TGF-&
#946;1 and the ED-A domain of
Rotator cuff (RC) tears are common musculoskeletal injuries which often require surgical intervention. Noninvasive pulsed electromagnetic field (PEMF) devices have been approved for treatment of long-bone fracture nonunions and as an adjunct to lumbar and cervical spine fusion surgery. This study aimed to assess the effect of continuous PEMF on postoperative RC healing in a rat RC repair model. A total of 30 Wistar rats underwent acute bilateral supraspinatus tear and repair. A miniaturized electromagnetic device (MED) was implanted at the right shoulder and generated focused PEMF therapy. The animals’ left shoulders served as controls. Biomechanical, histological, and bone properties were assessed at three and six weeks.Aims
Methods
Introduction: It is well known that the fate of biomaterials is determined by the distribution of proteins attached to the surface from the initial contact with blood or serum. This profile determines wether a material is inert, creates a foreign body response or is bioactive. Bioinert materials, such as polyethylene completely denature surface proteins, whilst materials inducing inflammatory responses are predisposed to complement protein attachment. Bioactive materials such autologous tissue grafts adsorb, but do not denature serum proteins such as
Articular cartilage has a limited regenerative capacity. Tissue engineering strategies adopting seeding and differentiation of individual chondrocytes on porous 3D scaffolds of clinically relevant size remains a considerable challenge. A well documented method to produce small samples of differentiated cartilage tissue in vitro is via micro-mass (pellet) culture, whereby, high concentrations of chondrocytes coalesce to form. a spherical tissue pellet. However, pellet culture techniques are not applied clinically as it is only possible to produce small amounts of tissue (1–2mm). The aims of this study were to develop a method for mass-production of pellets, and investigate whether an alternative “pellet seeding” approach using smart 3D scaffold design would allow large numbers of spherical pellets to be fixed in place. Chondrocytes were isolated from bovine articular cartilage via enzymatic digestion. Freshly isolated and expanded (passage 2) chondrocytes were placed in 96-well plates with round- or v-shaped wells at a range of densities from 0.1, 0.25 and 0.5 million cells per pellet, and centrifuged at 500g for 2 min. In order to assess pellet forming conditions, cells were treated with or without 300 mg/mL
Limb salvage in bone tumour patients replaces the bone with massive segmental prostheses where achieving bone integration at the shoulder of the implant through extracortical bone growth has been shown to prevent loosening. This study investigates the effect of multidrug chemotherapy on extracortical bone growth and early radiological signs of aseptic loosening in patients with massive distal femoral prostheses. A retrospective radiological analysis was performed on adult patients with distal femoral arthroplasties. In all, 16 patients were included in the chemotherapy group with 18 patients in the non-chemotherapy control group. Annual radiographs were analyzed for three years postoperatively. Dimensions of the bony pedicle, osseointegration of the hydroxyapatite (HA) collar surface, bone resorption at the implant shoulder, and radiolucent line (RLL) formation around the cemented component were analyzed.Aims
Methods
Biofilm formation is one of the primary reasons for the difficulty in treating implant-related infections (IRIs). Focused high-energy extracorporeal shockwave therapy (fhESWT), which is a treatment modality for fracture nonunions, has been shown to have a direct antibacterial effect on planktonic bacteria. The goal of the present study was to investigate the effect of fhESWT on
Aims
Methods
Here we introduce a wide and complex study comparing effects of growth factors used alone and in combinations on human mesenchymal stem cell (hMSC) proliferation and osteogenic differentiation. Certain ways of cell behaviour can be triggered by specific peptides – growth factors, influencing cell fate through surface cellular receptors. In our study transforming growth factor β (TGF-β), basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), insulin-like growth factor 1 (IGF-1), and vascular endothelial growth factor (VEGF) were used in order to induce osteogenesis and proliferation of hMSCs from bone marrow. These cells are naturally able to differentiate into various mesodermal cell lines. Effect of each factor itself is pretty well known. We designed experimental groups where two and more growth factors were combined. We supposed cumulative effect would appear when more growth factors with the same effect were combined. The cellular metabolism was evaluated using MTS assay and double-stranded DNA (dsDNA) amount using PicoGreen assay. Alkaline phosphatase (ALP) activity, as early osteogenesis marker, was observed. Phase contrast microscopy was used for cell morphology evaluation.Aims
Methods
Re-rupture is common after primary flexor tendon repair. Characterization of the biological changes in the ruptured tendon stumps would be helpful, not only to understand the biological responses to the failed tendon repair, but also to investigate if the tendon stumps could be used as a recycling biomaterial for tendon regeneration in the secondary grafting surgery. A canine flexor tendon repair and failure model was used. Following six weeks of repair failure, the tendon stumps were analyzed and characterized as isolated tendon-derived stem cells (TDSCs).Objectives
Methods
The Intraosseous Transcutaneous Amputation Prosthesis (ITAP)
may improve quality of life for amputees by avoiding soft-tissue
complications associated with socket prostheses and by improving
sensory feedback and function. It relies on the formation of a seal
between the soft tissues and the implant and currently has a flange
with drilled holes to promote dermal attachment. Despite this, infection
remains a significant risk. This study explored alternative strategies
to enhance soft-tissue integration. The effect of ITAP pins with a fully porous titanium alloy flange
with interconnected pores on soft-tissue integration was investigated.
The flanges were coated with fibronectin-functionalised hydroxyapatite
and silver coatings, which have been shown to have an antibacterial
effect, while also promoting viable fibroblast growth Aims
Materials and Methods
Options for the treatment of intra-articular ligament injuries are limited, and insufficient ligament reconstruction can cause painful joint instability, loss of function, and progressive development of degenerative arthritis. This study aimed to assess the capability of a biologically enhanced matrix material for ligament reconstruction to withstand tensile forces within the joint and enhance ligament regeneration needed to regain joint function. A total of 18 New Zealand rabbits underwent bilateral anterior cruciate ligament reconstruction by autograft, FiberTape, or FiberTape-augmented autograft. Primary outcomes were biomechanical assessment (n = 17), microCT (µCT) assessment (n = 12), histological evaluation (n = 12), and quantitative polymerase chain reaction (qPCR) analysis (n = 6).Aims
Materials and Methods
To assess the structure and extracellular matrix molecule expression of osteogenic cell sheets created via culture in medium with both dexamethasone (Dex) and ascorbic acid phosphate (AscP) compared either Dex or AscP alone. Osteogenic cell sheets were prepared by culturing rat bone marrow stromal cells in a minimal essential medium (MEM), MEM with AscP, MEM with Dex, and MEM with Dex and AscP (Dex/AscP). The cell number and messenger (m)RNA expression were assessed Objectives
Methods
The aim of this study was to provide a comprehensive understanding of alterations in messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) in cartilage affected by osteoarthritis (OA). The expression profiles of mRNAs, lncRNAs, and circRNAs in OA cartilage were assessed using whole-transcriptome sequencing. Bioinformatics analyses included prediction and reannotation of novel lncRNAs and circRNAs, their classification, and their placement into subgroups. Gene ontology and pathway analysis were performed to identify differentially expressed genes (DEGs), differentially expressed lncRNAs (DELs), and differentially expressed circRNAs (DECs). We focused on the overlap of DEGs and targets of DELs previously identified in seven high-throughput studies. The top ten DELs were verified by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in articular chondrocytes, both Objectives
Methods
The placement of orthopaedic, as well as dental, oral and craniofacial implants, are common practices in medicine and denstistry today. Challenges to the successful outcome of such implants include loosening of the device and inadequate filling of bone defects. The engineering of bone tissue is a recent strategy to provide new solutions to such problems. Since skeletal tissue regeneration requires three components, i.e. cells, growth and differentiation factors, and extracellular matrix, the approach of bone engineering is to mimic the biological process by delivering to the injured site: 1. cells capable of differentiating into osteoblasts, 2. inductive factors, and 3. a scaffold, biodegradable or not, to support cells. Prior to experimental and clinical application of the innovative surfaces or scaffolds, the three components have to be tested in the Labs using reliable in vitro methods. 1. Cells. The source of cells is a key point: osteoblast is the differentiated cell able to form bone in vivo and in vitro, and should be used, but primary human osteoblasts (hOB) are seldom available to the Labs, whereas osteoblast-like cell lines and bone cells from animals are an easy source, but may give different responses. An additional aspect which cannot be disregarded is the source of the bone cells, since the age and gender of the donor, as well as the site of retrieval and the method of isolation, have been shown to affect the yield of cells, the proliferation rate and their ability to form bone in vitro. Stromal cells from bone marrow (MSC), and other sites, have been shown to be a promising source of cells with high replicative and bone-forming potential. The same drawbacks outlined for osteoblasts apply to MSC. In our lab human osteoblasts are mainly obtained from trabecular bone fragments and stromal cells from bone marrow of patients undergoing surgical revision of hip implants. HOB are usually isolated by seeding minced bone chips in culture plates to get outgrowth of single cells from fragments, as the isolation technique (mechanical vs enzymatic) appeared to have no effect on the differentiation process. Confluence of the cell layer is reached in approximately four weeks (14–40 dd) and the bone phenotype is assessed by alkaline phosphatase (ALP) cytochemistry and morphology, as well as mineralization after addition of ascorbic acid and b-glycerophosphate. MSC are isolated by gradient centrifugation and adherence to culture plastic; their replicative potential is evaluated by the colony forming assay, and ALP staining provides the test for differentiation toward bone-forming cells. Preliminary evaluation of our cell isolates from orthopaedic patients showed that there is no direct correlation between the age of donor and the yield of hOB in terms of proliferation rate and ALP activity. As far as MSC are concerned, the addition of dexamethasone during cell expansion stimulated only a small increase in the number of colonies and ALP positive staining. 2. Inductive factors include growth factors, cytokines, peptide sequences and angiogenetic factors. The experience of our Lab will be given in a different presentation. 3. Specifically tailored biomaterials are crucial tools in tissue engineering: our experience is concerning in vitro testing of artificial materials developed by material scientists to replace bone. Such materials have to provide biocompatibility, i.e. no inflammatory reaction or immunorejection, controlled biodegradation if necessary, and biomechanical features to comply with the anatomical requirements. From a methodological point of view, the ‘engineered’ biomaterials can be classifieded as bi-dimensional (2D) materials or three-dimensional (3D) scaffolds. 2D surfaces are often well known materials already in clinical use, but innovations concern the ‘biomimetic approach’ applied to their surface. This means to recreate the ‘nanotopography’ of natural tissues, by modifying the roughness, or by mimicking the extracellular matrix (ECM) on the surface: both strategies aim to recruit bone cells and to promote bone formation. In the framework of a national research project both 2D and 3D materials were assayed in our Lab. Two types of titanium with different surfaces were tested with human osteoblasts, and compared to a commercial titanium with smooth surface. At 4 hours from seeding onto surfaces, hOB on smooth Ti were elongated, with evident spreading. On the rougher surfaces small focal contact patches were evident, and hOB showed a more rounded morphology whereas stitching to the irregular surface. By prolonging the culture time, all the surfaces were covered by cells, and differences were less evident. Therefore early osteoblast adhesion seems to be different on micro-rough and smooth titanium, but then hOB exhibited a similar proliferation rate. Our results show that surface roughness is not always increasing cell adhesion, and primary cells do require specific micro or nano-topography to spread and proliferate, unlike continuous cell lines which are easily growing on any substrate. A second approach to control cell adhesion and spreading onto surfaces is the deposition of RGD sequence (Arg-Gly-Asp), the cell-binding domain shared by a number of bone related proteins, including collagen,
The success of anterior cruciate ligament reconstruction (ACLR)
depends on osseointegration at the graft-tunnel interface and intra-articular
ligamentization. Our aim was to conduct a systematic review of clinical
and preclinical studies that evaluated biological augmentation of
graft healing in ACLR. In all, 1879 studies were identified across three databases.
Following assessment against strict criteria, 112 studies were included
(20 clinical studies; 92 animal studies). Aims
Materials and Methods
The purpose of this study was to create a novel The metatarsophalangeal joints of 12 fresh cadaveric bovine feet were skinned and dissected aseptically, and cultured for up to four weeks. Dynamic movement was applied using a custom-made machine on six joints, with the others cultured under static conditions. Chondrocyte viability and matrix glycosaminoglycan (GAG) content were evaluated by the cell viability probes, 5-chloromethylfluorescein diacetate (CMFDA) and propidium iodide (PI), and dimethylmethylene blue (DMMB) assay, respectively.Objectives
Methods
Nanotechnology is the study, production and controlled
manipulation of materials with a grain size <
100 nm. At this
level, the laws of classical mechanics fall away and those of quantum
mechanics take over, resulting in unique behaviour of matter in
terms of melting point, conductivity and reactivity. Additionally,
and likely more significant, as grain size decreases, the ratio
of surface area to volume drastically increases, allowing for greater interaction
between implants and the surrounding cellular environment. This
favourable increase in surface area plays an important role in mesenchymal
cell differentiation and ultimately bone–implant interactions. Basic science and translational research have revealed important
potential applications for nanotechnology in orthopaedic surgery,
particularly with regard to improving the interaction between implants
and host bone. Nanophase materials more closely match the architecture
of native trabecular bone, thereby greatly improving the osseo-integration
of orthopaedic implants. Nanophase-coated prostheses can also reduce
bacterial adhesion more than conventionally surfaced prostheses.
Nanophase selenium has shown great promise when used for tumour
reconstructions, as has nanophase silver in the management of traumatic
wounds. Nanophase silver may significantly improve healing of peripheral
nerve injuries, and nanophase gold has powerful anti-inflammatory
effects on tendon inflammation. Considerable advances must be made in our understanding of the
potential health risks of production, implantation and wear patterns
of nanophase devices before they are approved for clinical use.
Their potential, however, is considerable, and is likely to benefit
us all in the future. Cite this article:
The pathogenesis of rotator cuff disease (RCD) is complex and
not fully understood. This systematic review set out to summarise
the histological and molecular changes that occur throughout the
spectrum of RCD. We conducted a systematic review of the scientific literature
with specific inclusion and exclusion criteria.Introduction
Methods
Pathological assessment of periprosthetic tissues is important, not only for diagnosis, but also for understanding the pathobiology of implant failure. The host response to wear particle deposition in periprosthetic tissues is characterised by cell and tissue injury, and a reparative and inflammatory response in which there is an innate and adaptive immune response to the material components of implant wear. Physical and chemical characteristics of implant wear influence the nature of the response in periprosthetic tissues and account for the development of particular complications that lead to implant failure, such as osteolysis which leads to aseptic loosening, and soft-tissue necrosis/inflammation, which can result in pseudotumour formation. The innate response involves phagocytosis of implant-derived wear particles by macrophages; this is determined by pattern recognition receptors and results in expression of cytokines, chemokines and growth factors promoting inflammation and osteoclastogenesis; phagocytosed particles can also be cytotoxic and cause cell and tissue necrosis. The adaptive immune response to wear debris is characterised by the presence of lymphoid cells and most likely occurs as a result of a cell-mediated hypersensitivity reaction to cell and tissue components altered by interaction with the material components of particulate wear, particularly metal ions released from cobalt-chrome wear particles. Cite this article: Professor N. A. Athanasou. The pathobiology and pathology of aseptic implant failure.
Although mechanical stabilisation has been a hallmark of orthopaedic surgical management, orthobiologics are now playing an increasing role. Platelet-rich plasma (PRP) is a volume of plasma fraction of autologous blood having platelet concentrations above baseline. The platelet α granules are rich in growth factors that play an essential role in tissue healing, such as transforming growth factor-β, vascular endothelial growth factor, and platelet-derived growth factor. PRP is used in various surgical fields to enhance bone and soft-tissue healing by placing supraphysiological concentrations of autologous platelets at the site of tissue damage. The easily obtainable PRP and its possible beneficial outcome hold promise for new regenerative treatment approaches. The aim of this literature review was to describe the bioactivities of PRP, to elucidate the different techniques for PRP preparation, to review animal and human studies, to evaluate the evidence regarding the use of PRP in trauma and orthopaedic surgery, to clarify risks, and to provide guidance for future research.
We compared the biological characteristics of extrinsic fibroblasts infiltrating the patellar tendon with those of normal, intrinsic fibroblasts in the normal tendon Proliferation and invasive migration into the patellar tendon was significantly slower for infiltrative fibroblasts than for normal tendon fibroblasts. Flow-cytometric analysis indicated that expression of α5β1 integrin at the cell surface was significantly lower in infiltrative fibroblasts than in normal tendon fibroblasts. The findings suggest that cellular proliferation and invasive migration of fibroblasts into the patellar tendon after necrosis are inferior to those of the normal fibroblasts. The inferior intrinsic properties of infiltrative fibroblasts may contribute to a slow remodelling process in the grafted tendon after ligament reconstruction.
The aim of this study was to examine whether asymmetric loading
influences macrophage elastase (MMP12) expression in different parts
of a rat tail intervertebral disc and growth plate and if MMP12
expression is correlated with the severity of the deformity. A wedge deformity between the ninth and tenth tail vertebrae
was produced with an Ilizarov-type mini external fixator in 45 female
Wistar rats, matched for their age and weight. Three groups were
created according to the degree of deformity (10°, 30° and 50°).
A total of 30 discs and vertebrae were evaluated immunohistochemically
for immunolocalisation of MMP12 expression, and 15 discs were analysed
by western blot and zymography in order to detect pro- and active
MMP12.Objectives
Methods
The aim of this experimental study on New Zealand’s white rabbits
was to investigate the transplantation of autogenous growth plate
cells in order to treat the injured growth plate. They were assessed
in terms of measurements of radiological tibial varus and histological
characteristics. An experimental model of plate growth medial partial resection
of the tibia in 14 New Zealand white rabbits was created. During
this surgical procedure the plate growth cells were collected and
cultured. While the second surgery was being performed, the autologous
cultured growth plate cells were grafted at the right tibia, whereas
the left tibia was used as a control group. Objectives
Methods
Injury to the anterior cruciate ligament (ACL)
is one of the most devastating and frequent injuries of the knee. Surgical
reconstruction is the current standard of care for treatment of
ACL injuries in active patients. The widespread adoption of ACL
reconstruction over primary repair was based on early perception
of the limited healing capacity of the ACL. Although the majority
of ACL reconstruction surgeries successfully restore gross joint stability,
post-traumatic osteoarthritis is commonplace following these injuries,
even with ACL reconstruction. The development of new techniques
to limit the long-term clinical sequelae associated with ACL reconstruction
has been the main focus of research over the past decades. The improved
knowledge of healing, along with recent advances in tissue engineering
and regenerative medicine, has resulted in the discovery of novel
biologically augmented ACL-repair techniques that have satisfactory
outcomes in preclinical studies. This instructional review provides
a summary of the latest advances made in ACL repair. Cite this article:
Treatment strategies for osteoarthritis most commonly involve the removal or replacement of damaged joint tissue. Relatively few treatments attempt to arrest, slow down or reverse the disease process. Such options include peri-articular osteotomy around the hip or knee, and treatment of femoro-acetabular impingement, where early intervention may potentially alter the natural history of the disease. A relatively small proportion of patients with osteoarthritis have a clear predisposing factor that is both suitable for modification and who present early enough for intervention to be deemed worthwhile. This paper reviews recent advances in our understanding of the pathology, imaging and progression of early osteoarthritis.
Conventional amputation prostheses rely on the attachment of the socket to the stump, which may lead to soft-tissue complications. Intraosseous transcutaneous amputation prostheses (ITAPs) allow direct loading of the skeleton, but their success is limited by infection resulting from breaching of the skin at the interface with the implant. Keratinocytes provide the skin’s primary barrier function, while hemidesmosomes mediate their attachment to natural ITAP analogues. Keratinocytes must attach directly to the surface of the implant. We have assessed the proliferation, morphology and attachment of keratinocytes to four titaniumalloy surfaces in order to determine the optimal topography We have shown that the proliferation, morphology and attachment of keratinocytes are affected by the surface topography of the biomaterials used to support their growth. Smoother surfaces improved adhesion. We postulate that a smooth topography at the point of epithelium-ITAP contact could increase attachment
Biofilm-associated infections in wounds or on implants are difficult to treat. Eradication of the bacteria is nearly always impossible, despite the use of specific antibiotics. The bactericidal effects of high-energy extracorporeal shock waves on The biofilm-cultured washers were exposed to low-energy shock waves at 0.16 mJ/mm2 for 500 impulses. The washers were then treated with cefuroxime, rifampicin and fosfomycin, both alone and in combination. All tests were carried out in triplicate. Viable cells were counted to determine the bactericidal effect. The control groups of We conclude that shock waves combined with antibiotics could be tested in an
Between November 1994 and June 1999, 35 patients referred to our Problem Fracture Service with chronic diaphyseal osteomyelitis were treated using a closed double-lumen suction irrigation system after reaming and arthroscopic debridement of the intramedullary canal. This is a modified system based on that of Lautenbach. Between June and July 2007 the patients were reviewed by postal questionnaire and telephone and from the case notes. At a mean follow-up of 101 months (2 to 150), 26 had no evidence of recurrence and four had died from unrelated causes with no evidence of recurrent infection. One had been lost to follow-up at two months and was therefore excluded. Four had persisting problems with sinus discharge and one had his limb amputated for recurrent metaplastic change. Our results represent a clearance of infection of 85.3% (29 of 34), with recurrence in 11.8% (4 of 34). They are comparable to the results of the Papineau and Belfast techniques, but with considerably less surgical insult to the patient.
