Abstract. Osteoarthritis (OA) is a degenerative disorder associated with cartilage loss and is a leading cause of disability around the world. In old age, the capacity of cartilage to regenerate is diminished. With an aging population, the burden of OA is set to rise. Currently, there is no definitive treatment for OA. However,
Adipose derived mesenchymal stromal cells (ASC) are adult stem cells exhibiting functional properties that have open the way for
Bone regeneration and repair are crucial to ambulation and quality of life. Factors such as poor general health, serious medical comorbidities, chronic inflammation, and ageing can lead to delayed healing and nonunion of fractures, and persistent bone defects. Bioengineering strategies to heal bone often involve grafting of autologous bone marrow aspirate concentrate (BMAC) or mesenchymal stem cells (MSCs) with biocompatible scaffolds. While BMAC shows promise, variability in its efficacy exists due to discrepancies in MSC concentration and robustness, and immune cell composition. Understanding the mechanisms by which macrophages and lymphocytes – the main cellular components in BMAC – interact with MSCs could suggest novel strategies to enhance bone healing. Macrophages are polarized into pro-inflammatory (M1) or anti-inflammatory (M2) phenotypes, and influence cell metabolism and tissue regeneration via the secretion of cytokines and other factors. T cells, especially helper T1 (Th1) and Th17, promote inflammation and osteoclastogenesis, whereas Th2 and regulatory T (Treg) cells have anti-inflammatory pro-reconstructive effects, thereby supporting osteogenesis. Crosstalk among macrophages, T cells, and MSCs affects the bone microenvironment and regulates the local immune response. Manipulating the proportion and interactions of these cells presents an opportunity to alter the local regenerative capacity of bone, which potentially could enhance clinical outcomes. Cite this article:
To analyse the efficacy and safety of cellular therapy utilizing Mesenchymal Stromal Cells (MSCs) in the management of rotator cuff(RC) tears from clinical studies available in the literature. We conducted independent and duplicate electronic database searches including PubMed, Embase, Web of Science, and Cochrane Library on August 2021 for studies analyzing the efficacy and safety of cellular therapy (CT) utilizing MSCs in the management of RC tears. VAS for pain, ASES Score, DASH Score, Constant Score, radiological assessment of healing and complications and adverse events were the outcomes analyzed. Analysis was performed in R-platform using OpenMeta [Analyst] software. 6 studies involving 238 patients were included for analysis. We noted a significant reduction in VAS score for pain at 3 months (WMD=-2.234,p<0.001) and 6 months (WMD=-3.078,p<0.001) with the use of CT. Concerning functional outcomes, utilization of CT produced a significant short-term improvement in the ASES score (WMD=17.090,p<0.001) and significant benefit in functional scores such as Constant score (WMD=0.833,p=0.760) at long-term. Moreover, we also observed a significantly improved radiological tendon healing during the long-term follow-up (OR=3.252,p=0.059). We also noted a significant reduction in the retear rate upon utilization of CT in RC tears both at short- (OR=0.079,p=0.032) and long-term (OR=0.434,p=0.027). We did not observe any significant increase in the adverse events as compared with the control group (OR=0.876,p=0.869). Utilization of CT in RC tear is safe and it significantly reduced pain severity, improved functional outcome, enhanced radiological tendon healing, and mitigated retear rates at short- and long-term follow-up.RESULTS:
The purpose of this study was to develop a cell-based VEGF gene therapy in order to accelerate fracture healing and investigate the effect of VEGF on bone repair in vivo. Twenty-one rabbits were studied. A ten millimeter segmental bone defect was created after twelve millimeter periosteal excision in the middle one third of each tibia and each tibia was plated. Primary cultured rabbit fibroblasts were transfected by use of SuperFect (Qiagen Inc) with pcDNA-VEGF. 5.0 X 106 cells in 1ml PBS were delivered via impregnated gelfoam into the fracture site. Experimental groups were:
Transfected fibroblasts with VEGF (n=7), Fibroblasts alone (n=7), and PBS only (n=7). The animals were sacrificed and fracture healing specimens collected at ten weeks post surgery Radiology: Fracture healing was defined as those with bone bridging of the fracture defect. After ten weeks, fourteen tibial fractures were healed in total including six in group one, four in group two and four in group three. The VEGF group had an earlier initial sufficient volume of bridging new bone formation. Histological evaluation demonstrated ossification across the entire defect in response to the VEGF gene therapy, whereas the defects were predominantly fibrotic and sparsely ossified in groups two and three. Numerous positively stained (CD31) vessels were shown in the VEGF group. MicroCT evaluation showed complete bridging for the VEGF group, but incomplete healing for groups two and three. Micro-CT evaluation of the new bone structural parameters showed that the amount of new bone (volume of bone (VolB) x bone mineral density (BMD)), bone volume fractions (BVF), bone volume/tissues (BV/TV), trabecular thickness (Tb.Th), number (Tb.N) and connectivity density (Euler number) were higher; while structure model index (SMI), bone surface/bone volume (BS/BV), and trabecular separations (Tb.Sp) were lower in the VEGF group than the other groups. P-Values <
0.05 indicated statistical significance (ANOVA, SPSS) in all parameters except for SMI (0.089) and VolBx-BMD (0.197). These results indicate that cell-based VEGF gene delivery has significant osteogenic and angiogenic effects and demonstrates the ability of cell based VEGF gene therapy to enhance healing of a critical sized defect in a long bone in rabbits.
Meniscus tears have been treated using partial meniscectomy to relieve pain in patients, although this leads to the onset of early osteoarthritis (OA).
Intervertebral disc degeneration can lead to physical disability and significant pain, while the present therapeutics still fail to biochemically and biomechanically restore the tissue. Stem
By combining cells, biological factors, and biomaterials the field of tissue engineering has generated technologies capable of supporting regeneration. However, the regulatory hurdles associated with the use of
Spontaneous muscle regenerative potential is limited, as severe injuries incompletely recover and result in chronic inflammation. Current therapies are restricted to conservative management, not providing a complete restitutio ad integrum; therefore, alternative therapeutic strategies are welcome, such as
Osteoarthritis is a common articular cartilage disorder and causes a significant global disease burden. Articular cartilage has a limited capacity of repair and there is increasing interest in the use of
The application of immune regenerative strategies to deal with unsolved pathologies, such as tendinopathies, is getting attention in the field of tissue engineering exploiting the innate immunomodulatory potential of stem cells [1]. In this context, Amniotic Epithelial Cells (AECs) represent an innovative immune regenerative strategy due to their teno-inductive and immunomodulatory properties [2], and because of their high paracrine activity, become a potential stem cell source for a cell-free treatment to overcome the limitations of traditional
Mesenchymal stem cells (MSC) have potent immunomodulatory and regenerative effects via soluble factors. One approach to improve stem
Aims. Extracellular vesicles (EVs) are nanoparticles secreted by all cells, enriched in proteins, lipids, and nucleic acids related to cell-to-cell communication and vital components of
Within the field of disc degeneration-related low back pain, the spine community has been increasingly acknowledging the regenerative potential of extracellular vesicles (EVs). EVs are small lipid bilayer-delimited particles naturally released by cells, involved in intercellular signaling. They do so by interacting with recipient cells and releasing their biological cargo (e.g., mRNA, miRNA, DNA, protein, lipid). EVs derived from mesenchymal stromal cells and, more recently, also EVs from notochordal cells, the cells residing within the core of the juvenile human disc, are being actively studied. In general, they have been proposed to mitigate inflammation/catabolic processes, reduce apoptosis, stimulate proliferation and even improve the matrix producing capacity of the treated cells. Within this context, appropriate characterization of EVs is essential to increase the level of evidence that the reported effects are indeed EV-associated. To analyze the purity and biochemical composition of EV preparations the International Society for Extracellular Vesicles (ISEV) has prepared guidelines recommending the analysis of multiple (EV) markers, as well as proteins co-isolated/recovered with EVs. Alongside, to prove that the effects are EV-associated and not due to co-isolated factors from the tissue or cells used to derive the EVs, appropriate technical controls need to be taken along (during cell/tissue culture). As such the question arises: “what is the evidence so far?”. While from a fundamental perspective EVs are very appealing, the use of natural EVs in clinical applications is challenging. It comes with drawbacks, including biologic variability, yield, cumbersome isolation, and challenging upscaling and storage to achieve industrial levels. To date there is no FDA-approved EV-based therapy for disc-related lower back pain. Nonetheless, EV-based therapeutic approaches have unique advantages over the use of (pluripotent) stem
Abstract. Objectives. Osteoarthritis is a common articular cartilage disorder and causes a significant global disease burden. Articular cartilage has a limited capacity of repair and there is increasing interest in the use of
Abstract. Osteoarthritis is a common articular cartilage disorder and causes a significant global disease burden. Articular cartilage has a limited capacity of repair and there is increasing interest in the use of
Introduction and Objective. The meniscus is composed of two distinct regions, a vascular outer zone and an avascular inner zone. Due to vascularization, tears within the vascular zone can be treated by suturing. However, tears in the avascular zone have a poor healing capacity and partial meniscectomy is used to prevent further pain, although this leads to early osteoarthritis. Previous studies have demonstrated that the vascular zone contains a progenitor population with multilineage differentiation potential. Isolation and propagation of these progenitors can be used to develop
Objectives. In order to ensure safety of the
Objectives. The present study describes a novel technique for revitalising allogenic intrasynovial tendons by combining
Intervertebral disc (IVD) degeneration presents a harsh microenvironment characterised by low glucose, low oxygen and matrix acidity posing a significant challenge for
Tendon injuries are common and current therapies often are unsuccessful.
The World Health Organisation (WHO) has included low back pain in its list of twelve priority diseases. Notably, Degenerative disc disease (DDD) presents a large, unmet medical need which results in a disabling loss of mechanical function. Today, no efficient therapy is available. Chronic cases often receive surgery, which may lead to biomechanical problems and accelerated degeneration of adjacent segments. Our consortium partners have developed and studied mesenchymal stem
Abstract. Focal articular cartilage defects do not heal and, left untreated, progress to more widespread degenerative changes. A promising new approach for the repair of articular cartilage defects is the application of
Introduction. Stem cells are widely known in the state of the art of
Introduction.
Tendon detachment from its bony insertion is one of the most frequent injuries occurring in the musculoskeletal interface, constituting an unmet challenge in orthopaedics. Tendon-to-bone integration occurs at the enthesis, which is characterized by a complex structure organized in a gradient of cells and microenvironments. Hence, the maintenance of a heterotypic cellular niche is critical for tissue functionality and homeostasis. Replicating this unique complexity constitutes a challenge when addressing tendon-to-bone regeneration and interfacial tissue engineering strategies. Currently, mechanisms presiding to tendon-to-bone interface healing are not yet fully understood, particularly the interactions between tendon and bone cells in the orchestration of interfacial repair versus regeneration. Therefore, this study focused on the hypothesis that interactions between human tendon-derived cells (hTDCs) and pre-osteoblasts (pre-OB) can initiate a cascade of events, potentially leading to interfacial regeneration. Thus, hTDCs and pre-OB (pre-differentiated human adipose-derived stem cells) were used. Herein, five different ratios between basal and osteogenic media (100:0,75:25,50:50,25:75,0:100) were assessed to estimate their influence on cell behaviour and identify the ideal parameters for simultaneously supporting tenogenic and osteogenic differentiation before establishing a co-culture. Tenogenic and osteogenic differentiation were assessed through the expression of tendon and bone markers, mineralization (alizarin red, AZ) and alkaline phosphatase (ALP) quantification. Results showed that hTDCs exhibited osteogenic differentiation potential when cultured in the presence of osteogenic media, as demonstrated by an increase in ALP activity and mineralization. Pre-OB expressed osteogenic markers (OCN, OPN) in all media conditions confirming osteogenic commitment, which was simultaneously confirmed by ALP levels and AZ staining. Thus, three different conditions (100:0, 50:50, 0:100) were chosen for further studies in a direct contact co-culture system. Similarly to single cultures, a significant proliferation was observed in all conditions and mineralization was increased as soon as 7 days of culture. Additionally, osteogenic, tenogenic and interface-relevant markers will be assessed to study the effect of co-culture on phenotype maintenance. In summary, the present work addresses major limitations to clinical translation of
Introduction.
As cartilage has poor intrinsic repair capacity, in vitroexpansion of human articular chondrocytes (HACs) is required for
Introduction. Nonunion is a common and costly fracture outcome. Intricate reciprocity between angiogenesis and osteogenesis means vascular
Summary. Tissue grafts fail to recapitulate native tendon function, imposing the need for development of functional regeneration strategies. Herein, we describe advancements in tendon repair and regeneration using functionalised natural and synthetic devices and scaffold-free
Summary. The donor-matched comparison between mesenchymal stem cells from knee infrapatellar and subcutaneous adipose tissue revealed their preferential commitment towards the chondrogenic and osteogenic lineage, respectively. These peculiarities could be relevant for the development of successful bone and cartilage cell-based applications. Introduction. Mesenchymal stem cells (MSCs) have been proposed in bone and cartilage tissue engineering applications as an alternative to terminally differentiated cells. In the present study we characterised and performed a donor-matched comparison between MSCs resident within the infrapatellar fat pad (IFP-MSCs) and the knee subcutaneous adipose tissue (ASCs) of osteoarthritic patients. These two fat depots, indeed, can be considered appealing candidates for orthopaedic
Study Design: Experimental study in dogs:. Objective: To assess the efficiency of disc chondrocyte transplantation in a canine model. Summary of Background Data: Conventional clinical treatments of intervertebral disc herniation and degeneration are focused on excision of damaged tissue, stabilization, and spinal fusion. The development and refinement of cell-based therapeutics for tissue regeneration and repair have spawned a multitude of applications including autologous disc chondrocyte transplantation. For clinical application the efficiency of disc chondrocyte transplantation was assessed using a pre-clinical canine model to show the technical feasibility and biological relevance for disc repair and retardation of disc degeneration. This report examined the protein expression of transplanted disc chondrocytes and their role in the clinically observed disc repair following autologous disc chondrocyte transplantation. Methods: The nucleus and inner annulus were sampled from four skeletally-mature dogs by micro-discectomy. Disc chondrocytes were isolated and propagated under GMP validated conditions including completely autologous serum conditions. Two months later, the cultured cells were transplanted through the contralateral side of experimental discs after testing complete healing of the annulus by measuring intradiscal pressure stability. After seven months the animals were humanely killed. One half of the vertically halved lumbar spines were embedded in paraffin and sections were analysed histologically and immunohistochemically. Results: Histological examinations revealed large clusters of cells within the nucleus area of the treated discs. Cells within these cell clones were found to be viable and surrounded by de novo synthesized matrix as evidenced by a distinct histological staining and immunohistochemical expression pattern. A disc-specific expression of collagen type I and II and hyaline-specific proteoglycans was observed indicating the regenerative and reconstructive capacity of the transplanted disc chondrocytes. Conclusions: These results indicate the contribution of transplanted disc chondrocytes to the observed clinical success of this
A major challenge to be faced in order to introduce
Purpose: The purpose of this study was to compare the effects of two types of stem/progenitor cells on the healing of critical sized bone defects in a rat model. Endothelial Progenitor Cells (EPCs), a novel cell type with previously demonstrated effects on angiogenesis in animal models of vascular disease, were compared to both a control group of no cell therapy, and a treatment group of Mesenchymal Stem Cells (MSCs). The hypothesis was that EPCs would demonstrate both superior bone healing and angiogenesis, when compared to the control group and MSC group. Method: EPCs and MSCs were isolated from the bone marrow of syngeneic rats by differential culture and grown ex vivo for 10 days. Subsequently the cells were harvested, seeded on a gelfoam scaffold, and implanted into a 5mm segmental defect in a rat femur that had been stabilized with a plate and screws. Bone healing was assessed radiographically and by microCT. Angiogenesis was assessed by histology and physiologically, using laser doppler to assess blood flow in the bone and soft tissues. All animal protocols were approved by and performed in accordance with the St. Michael’s Hospital Animal Care Committee. ANOVA was used to test for significant differences between the groups, and a p-value of <
0.05 was considered statistically significant. Results: The EPC (n=14) group demonstrated radiographic evidence of healing of the bone defect as early as 2 weeks, and all specimens were radiographically healed at 6 weeks. Both the control group (n=14) and the MSC group (n=14) showed no radiographic evidence of healing at 10 weeks. MicroCT comparison of the EPC group versus the control group showed significantly greater bone volume and density at the defect site (p<
0.001). More blood vessel formation was observed in the EPC group versus the control group on histology at 2 weeks. Laser Doppler assessment showed significantly more soft tissue and bone blood flow at 2 and 3 weeks in the EPC group versus the control group (p=0.021). Conclusion: The results of this study demonstrate that EPCs are effective as
Summary Statement. This work raises the potential of utilizing stem cells to catalyze cartilage regeneration by a minimal number of neonatal chondrocytes via controlling cell distribution in 3D matrices, and may solve the challenge of scarce donor availability associated with
Introduction: Articular cartilage has limited capacity for regeneration. Tissue engineering strategies offer future hope for cartilage replacement and repair. In an attempt to mimic functional native cartilage for tissue repair, current research focuses on construct/implant designs that simulate an embryonic like microenvironment to promote cellular differentiation along a chondrogenic lineage. The aim of the present study was, for the first time, to illustrate the differences between human neonatal and adult chondrocytes along with bone marrow stromal cells (HBMSCs) to differentiate the factors that promote chondrogenesis and maintain functional homeostasis. Material and Methods: Adult chondrocytes, neonatal chondrocytes and HBMSCs were cultured in monolayers for 1, 2 and 3 weeks in basal or chondrogenic media. Expression of transcription factor Sox9, Aggrecan (ACAN) and Collagen type II (COL2A)was compared via real time polymerase chain reaction (q-PCR). Alternatively, cells were seeded onto 3D PLGA scaffolds and cultured in vitro for 3 and 6 weeks in basal or chondrogenic media. Paraffin sections of the constructs were stained with Alcian blue/ Sirius red and expression of Collagen type II and Aggrecan was visualised via immunohistochemistry. Results: For monolayer cultures of all three cell types, at week 1, expression of all three genes was down regulated in basal medium compared to levels in chondrogenic medium. By week 2, q-PCR revealed an increased expression of Col2A in chondroinduced neonatal chondrocytes compared to adult chondrocytes and HBMSCs. A steady increase in SOX9 expression was observed with time in all three cell types in chondrogenic medium. However, SOX9 expression in week 2 was higher for each cell type in basal medium compared with chondrogenic medium. ACAN expression by HBMSCs was greatly enhanced compared with that of neonatal and adult chondrocytes after 2 weeks in chondrogenic medium. By week 3, basal cultures of all cell types showed an overall lower level of gene expression compared with chondroinduced cells. 3D constructs revealed the formation of cartilage like tissue for all three cell types with the presence of a prominent superficial layer and middle zone in the chondroinduced constructs. A superficial layer was also observed in constructs cultured in basal media but there was no evidence of any other characteristic zones. A fibrous capsule had formed around the chondroinduced tissue by week 6. Thinnest capsules were observed for constructs seeded with neonatal cells, with thickest capsules in constructs seeded with HBMSCs. Immunohistochemistry revealed a greater presence of aggrecan and type II collagen in the chondroinduced constructs compared to those cultures in basal media. Conclusion: This comparative study indicates a major difference between the microenvironment of human neonatal chondrocytes, adult chondrocytes and HBMSCs. The expression of high amounts of COL2A and ACAN (considered to be middle to late markers in chondrogenesis) in week 1 in neonatal chondrocytes indicates a difference in temporal gene expression during chondrogenesis or in maintaining cartilage homeostasis. The study provides potentially useful information to inform
Cite this article:
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.
Implantation of ultra-purified alginate (UPAL) gel is safe and effective in animal osteochondral defect models. This study aimed to examine the applicability of UPAL gel implantation to acellular therapy in humans with cartilage injury. A total of 12 patients (12 knees) with symptomatic, post-traumatic, full-thickness cartilage lesions (1.0 to 4.0 cm2) were included in this study. UPAL gel was implanted into chondral defects after performing bone marrow stimulation technique, and assessed for up to three years postoperatively. The primary outcomes were the feasibility and safety of the procedure. The secondary outcomes were self-assessed clinical scores, arthroscopic scores, tissue biopsies, and MRI-based estimations.Aims
Methods
To explore the efficacy of extracorporeal shockwave therapy (ESWT) in the treatment of osteochondral defect (OCD), and its effects on the levels of transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, -3, -4, -5, and -7 in terms of cartilage and bone regeneration. The OCD lesion was created on the trochlear groove of left articular cartilage of femur per rat (40 rats in total). The experimental groups were Sham, OCD, and ESWT (0.25 mJ/mm2, 800 impulses, 4 Hz). The animals were euthanized at 2, 4, 8, and 12 weeks post-treatment, and histopathological analysis, micro-CT scanning, and immunohistochemical staining were performed for the specimens.Aims
Methods
The aim of the HIPGEN consortium is to develop the first cell therapy product for hip fracture patients using PLacental-eXpanded (PLX-PAD) stromal cells. HIPGEN is a multicentre, multinational, randomized, double-blind, placebo-controlled trial. A total of 240 patients aged 60 to 90 years with low-energy femoral neck fractures (FNF) will be allocated to two arms and receive an intramuscular injection of either 150 × 106 PLX-PAD cells or placebo into the medial gluteal muscle after direct lateral implantation of total or hemi hip arthroplasty. Patients will be followed for two years. The primary endpoint is the Short Physical Performance Battery (SPPB) at week 26. Secondary and exploratory endpoints include morphological parameters (lean body mass), functional parameters (abduction and handgrip strength, symmetry in gait, weightbearing), all-cause mortality rate and patient-reported outcome measures (Lower Limb Measure, EuroQol five-dimension questionnaire). Immunological biomarker and in vitro studies will be performed to analyze the PLX-PAD mechanism of action. A sample size of 240 subjects was calculated providing 88% power for the detection of a 1 SPPB point treatment effect for a two-sided test with an α level of 5%.Aims
Methods
Osteoporosis (OP) is a metabolic bone disease, characterized by a decrease in bone mineral density (BMD). However, the research of regulatory variants has been limited for BMD. In this study, we aimed to explore novel regulatory genetic variants associated with BMD. We conducted an integrative analysis of BMD genome-wide association study (GWAS) and regulatory single nucleotide polymorphism (rSNP) annotation information. Firstly, the discovery GWAS dataset and replication GWAS dataset were integrated with rSNP annotation database to obtain BMD associated SNP regulatory elements and SNP regulatory element-target gene (E-G) pairs, respectively. Then, the common genes were further subjected to HumanNet v2 to explore the biological effects.Aims
Methods
This study aimed to investigate whether human umbilical cord mesenchymal stem cells (UC-MSCs) can prevent articular cartilage degradation and explore the underlying mechanisms in a rat osteoarthritis (OA) model induced by monosodium iodoacetate (MIA). Human UC-MSCs were characterized by their phenotype and multilineage differentiation potential. Two weeks after MIA induction in rats, human UC-MSCs were intra-articularly injected once a week for three weeks. The therapeutic effect of human UC-MSCs was evaluated by haematoxylin and eosin, toluidine blue, Safranin-O/Fast green staining, and Mankin scores. Markers of joint cartilage injury and pro- and anti-inflammatory markers were detected by immunohistochemistry.Aims
Methods
Minimally manipulated cells, such as autologous bone marrow concentrates (BMC), have been investigated in orthopaedics as both a primary therapeutic and augmentation to existing restoration procedures. However, the efficacy of BMC in combination with tissue engineering is still unclear. In this study, we aimed to determine whether the addition of BMC to an osteochondral scaffold is safe and can improve the repair of large osteochondral defects when compared to the scaffold alone. The ovine femoral condyle model was used. Bone marrow was aspirated, concentrated, and used intraoperatively with a collagen/hydroxyapatite scaffold to fill the osteochondral defects (n = 6). Tissue regeneration was then assessed versus the scaffold-only group (n = 6). Histological staining of cartilage with alcian blue and safranin-O, changes in chondrogenic gene expression, microCT, peripheral quantitative CT (pQCT), and force-plate gait analyses were performed. Lymph nodes and blood were analyzed for safety.Aims
Methods
Ageing-related incompetence becomes a major hurdle for the clinical translation of adult stem cells in the treatment of osteoarthritis (OA). This study aims to investigate the effect of stepwise preconditioning on cellular behaviours in human mesenchymal stem cells (hMSCs) from ageing patients, and to verify their therapeutic effect in an OA animal model. Mesenchymal stem cells (MSCs) were isolated from ageing patients and preconditioned with chondrogenic differentiation medium, followed by normal growth medium. Cellular assays including Bromodeoxyuridine / 5-bromo-2'-deoxyuridine (BrdU), quantitative polymerase chain reaction (q-PCR), β-Gal, Rosette forming, and histological staining were compared in the manipulated human mesenchymal stem cells (hM-MSCs) and their controls. The anterior cruciate ligament transection (ACLT) rabbit models were locally injected with two millions, four millions, or eight millions of hM-MSCs or phosphate-buffered saline (PBS). Osteoarthritis Research Society International (OARSI) scoring was performed to measure the pathological changes in the affected joints after staining. Micro-CT analysis was conducted to determine the microstructural changes in subchondral bone.Aims
Methods
Hyaline cartilage defects are a significant clinical problem for which a plethora of cartilage repair techniques are used. One such technique is cartilage replacement therapy using autologous chondrocyte or mesenchymal stem cell (MSC) implantation (ACI). Mesenchymal stem cells are increasingly being used for these types of repair technique because they are relatively easy to obtain and can be expanded to generate millions of cells. However, implanted MSCs can terminally differentiate and produce osteogenic tissue which is highly undesirable, also, MSCs generally only produce fibrocartilage which does not make biomechanically resilient repair tissue, an attribute that is crucial in high weight-bearing areas. Tissue-specific adult stem cells would be ideal candidates to fill the void, and as we have shown previously in animal model systems [Dowthwaite et al, 2004, J Cell Sci 117;889], they can be expanded to generate hundreds of millions of cells, produce hyaline cartilage and they have a restricted differential potential. Articular chondroprogenitors do not readily terminally differentiate down the osteogenic lineage. At present, research focused on isolating tissue-specific stem cells from articular cartilage has met with modest success. Our results demonstrate that using differential adhesion it is possible to easily isolate articular cartilage progenitor populations from human hyaline cartilage and that these cells can be subsequently expanded in vitro to a high population doubling whilst maintaining a normal karyotype. Articular cartilage progenitors maintain telomerase activity and telomere length that are a characteristic of progenitor/stem cells and differentiate to produce hyaline cartilage. In conclusion, we propose the identification and characterisation of a novel articular cartilage progenitor population, resident in human cartilage, which will greatly benefit future
Hyaline cartilage defects are a significant clinical problem for which a plethora of cartilage repair techniques are used. One such technique is cartilage replacement therapy using autologous chondrocyte or mesenchymal stem cell (MSC) implantation (ACI). Mesenchymal stem cells are increasingly being used for these types of repair technique because they are relatively easy to obtain and can be expanded to generate millions of cells. However, implanted MSCs can terminally differentiate and produce osteogenic tissue which is highly undesirable, also, MSCs generally only produce fibrocartilage which does not make biomechanically resilient repair tissue, an attribute that is crucial in high weight-bearing areas. Tissue-specific adult stem cells would be ideal candidates to fill the void, and as we have shown previously in animal model systems [Dowthwaite et al, 2004, J Cell Sci 117;889], they can be expanded to generate hundreds of millions of cells, produce hyaline cartilage and they have a restricted differential potential. Articular chondroprogenitors do not readily terminally differentiate down the osteogenic lineage. At present, research focused on isolating tissue-specific stem cells from articular cartilage has met with modest success. Our results demonstrate that using differential adhesion it is possible to easily isolate articular cartilage progenitor populations from human hyaline cartilage and that these cells can be subsequently expanded in vitro to a high population doubling whilst maintaining a normal karyotype. Articular cartilage progenitors maintain telomerase activity and telomere length that are a characteristic of progenitor/stem cells and differentiate to produce hyaline cartilage. In conclusion, we propose the identification and characterisation of a novel articular cartilage progenitor population, resident in human cartilage, which will greatly benefit future