Aims. Given the possible radiation damage and inaccuracy of radiological investigations, particularly in children, ultrasound and superb microvascular imaging (SMI) may offer alternative methods of evaluating new
Alcoholism is a well-known detrimental factor in fracture healing. However, the underlying mechanism of alcohol-inhibited fracture healing remains poorly understood. MicroRNA (miR) sequencing was performed on bone mesenchymal stem cells (BMSCs). The effects of alcohol and miR-19a-3p on vascularization and osteogenic differentiation were analyzed in vitro using BMSCs and human umbilical vein endothelial cells (HUVECs). An in vivo alcohol-fed mouse model of femur fracture healing was also established, and radiological and histomorphometric analyses were used to evaluate the role of miR-19a-3p. The binding of miR-19a-3p to forkhead box F2 (FOXF2) was analyzed using a luciferase reporter assay.Aims
Methods
Introduction: The mechanobiology and response of
Heterotopic ossification (HO) is defined as aberrant
Polyetheretherketone (PEEK) interbody fusion cages combined with autologous bone graft is the current clinical gold standard treatment for spinal fusion, however, bone graft harvest increases surgical time, risk of infection and chronic pain. We describe novel low-stiffness 3D Printed titanium interbody cages without autologous bone graft and assessed their biological performance in a pre-clinical in vivo interbody fusion model in comparison to the gold standard, PEEK with graft. Titanium interbody spacers were 3D Printed with a microporous (Ti1: <1000μm) and macroporous (Ti2: >1000μm) design. Both Ti1 and Ti2 had an identical elastic modulus (stiffness), and were similar to the elastic modulus of PEEK. Interbody fusion was performed on L2-L3 and L4-L5 vertebral levels in 24 skeletally mature sheep using Ti1 or Ti2 spacers, or a PEEK spacer filled with iliac crest autograft, and assessed at 8 and 16 weeks. We quantitatively assessed bone fusion, bone area, mineral apposition rate and
Aims. Several artificial bone grafts have been developed but fail to achieve anticipated osteogenesis due to their insufficient neovascularization capacity and periosteum support. This study aimed to develop a vascularized bone-periosteum construct (VBPC) to provide better angiogenesis and osteogenesis for bone regeneration. Methods. A total of 24 male New Zealand white rabbits were divided into four groups according to the experimental materials. Allogenic adipose-derived mesenchymal stem cells (AMSCs) were cultured and seeded evenly in the collagen/chitosan sheet to form cell sheet as periosteum. Simultaneously, allogenic AMSCs were seeded onto alginate beads and were cultured to differentiate to endothelial-like cells to form vascularized bone construct (VBC). The cell sheet was wrapped onto VBC to create a vascularized bone-periosteum construct (VBPC). Four different experimental materials – acellular construct, VBC, non-vascularized bone-periosteum construct, and VBPC – were then implanted in bilateral L4-L5 intertransverse space. At 12 weeks post-surgery, the bone-forming capacities were determined by CT, biomechanical testing, histology, and immunohistochemistry staining analyses. Results. At 12 weeks, the VBPC group significantly increased new
Aims. Acquired heterotopic ossification (HO) is a debilitating disease characterized by abnormal extraskeletal
Aims. To develop an early implant instability murine model and explore the use of intermittent parathyroid hormone (iPTH) treatment for initially unstable implants. Methods. 3D-printed titanium implants were inserted into an oversized drill-hole in the tibiae of C57Bl/6 mice (n = 54). After implantation, the mice were randomly divided into three treatment groups (phosphate buffered saline (PBS)-control, iPTH, and delayed iPTH). Radiological analysis, micro-CT (µCT), and biomechanical pull-out testing were performed to assess implant loosening,
Aim. Bone regeneration following the treatment of Staphylococcal bone infection or osteomyelitis is challenging due to the ability of Staphylococcus aureus to invade and persist within bone cells, which could possibly lead to antimicrobial tolerance and incessant bone destruction. Here, we investigated the influence of Staphylococcal bone infection on osteoblasts metabolism and function, with the underlying goal of determining whether Staphylococcus aureus-infected osteoblasts retain their ability to produce extracellular mineralized organic matrix after antibiotic treatment. Method. Using our in vitro infection model, human osteoblasts-like Saos-2 cells were infected with high-grade Staphylococcus aureus EDCC 5055 strain, and then treated with 8 µg/ml rifampicin and osteogenic stimulators up to 21-days. Results. Immunofluorescence and transmission electron microscopic (TEM) imaging demonstrated the presence of intracellular bacteria within the infected osteoblasts as early as 2 hours post-infection. TEM micrographs revealed intact intracellular bacteria with dividing septa indicative of active replication. The infected osteoblasts showed significant amounts of intracellular bacteria colonies and alteration in metabolic activity compared to the uninfected osteoblasts (p≤0.001). Treatment of S. aureus-infected osteoblasts with a single dose of 8 µg/ml rifampicin sufficiently restored the metabolic activity comparative to the uninfected groups. Alizarin red staining and quantification of the rifampicin-treated infected osteoblasts revealed significantly lower amount of mineralized extracellular matrix after 7-days osteogenesis (p<0.05). Interestingly, prolonged osteogenic stimulation and rifampicin-treatment up to 21 days improved the extracellular matrix mineralization level comparable to the rifampicin-treated uninfected group. However, the untreated (native) osteoblasts showed significantly more quantity of mineral deposits (p≤0.001). Ultrastructural analysis of the rifampicin-treated infected osteoblasts at 21-days osteogenesis revealed active osteoblasts and newly differentiated osteocytes, with densely distributed calcium crystal deposits within the extracellular organic matrix. Moreover, residual colony of dead bacteria bodies and empty vacuoles of the fully degraded bacteria embedded within the mineralized extracellular matrix. Gene expression level of prominent
Aim. Antibiotic-loaded biomaterials are often used in dead space management after excision of infected bone. This study assessed the chronological progression of new
Growing evidence has suggested that paracrine mechanisms of Mesenchymal stem cell (MSC) may be involved in the underlying mechanism of MSC after transplantation, and extracellular vesicles (EVs) are an important component of this paracrine role. The aim of this study was to investigate the in vitro osteogenic effects of EVs derived from undifferentiated mesenchymal stem cells and from chemically induced to differentiate into osteogenic cells for 7 days. Further, the osteoinductive potential of EVs for bone regeneration in rat calvarial defects was assessed. We could isolate and characterize EVs from naïve and osteogenic-induced MSCs. Proteomic analysis revealed that EVs contained distinct protein profiles, with Osteo-EVs having more differentially expressed proteins with osteogenic properties. EVs were found to enhance the proliferation and migration of cultured MSC. In addition, the study found that Osteo-EVs/MEM combination scaffolds could enhance greater
1. In two dogs, approximately one to two years and three to four months of age, an experimental comparison was made between the calcium accretion rate as defined by the Bauer-Carlsson-Lindquist equation, and the
Aims. To verify whether secretory leucocyte protease inhibitor (SLPI) can promote early tendon-to-bone healing after anterior cruciate ligament (ACL) reconstruction. Methods. In vitro: the mobility of the rat bone mesenchymal stem cells (BMSCs) treated with SLPI was evaluated by scratch assay. Then the expression levels of osteogenic differentiation-related genes were analyzed by real-time quantitative PCR (qPCR) to determine the osteogenic effect of SLPI on BMSCs. In vivo: a rat model of ACL reconstruction was used to verify the effect of SLPI on tendon-to-bone healing. All the animals of the SLPI group and the negative control (NC) group were euthanized for histological evaluation, micro-CT scanning, and biomechanical testing. Results. SLPI improved the migration ability of BMSCs and upregulated the expression of genes related to osteogenic differentiation of BMSCs in vitro. In vivo, the SLPI group had higher histological scores at the tendon-bone interface by histological evaluation. Micro-CT showed more new
Aims. Bone regeneration during treatment of staphylococcal bone infection is challenging due to the ability of Staphylococcus aureus to invade and persist within osteoblasts. Here, we sought to determine whether the metabolic and extracellular organic matrix formation and mineralization ability of S. aureus-infected human osteoblasts can be restored after rifampicin (RMP) therapy. Methods. The human osteoblast-like Saos-2 cells infected with S. aureus EDCC 5055 strain and treated with 8 µg/ml RMP underwent osteogenic stimulation for up to 21 days. Test groups were Saos-2 cells + S. aureus and Saos-2 cells + S. aureus + 8 µg/ml RMP, and control groups were uninfected untreated Saos-2 cells and uninfected Saos-2 cells + 8 µg/ml RMP. Results. The S. aureus-infected osteoblasts showed a significant number of intracellular bacteria colonies and an unusual higher metabolic activity (p < 0.005) compared to uninfected osteoblasts. Treatment with 8 µg/ml RMP significantly eradicated intracellular bacteria and the metabolic activity was comparable to uninfected groups. The RMP-treated infected osteoblasts revealed a significantly reduced amount of mineralized extracellular matrix (ECM) at seven days osteogenesis relative to uninfected untreated osteoblasts (p = 0.007). Prolonged osteogenesis and RMP treatment at 21 days significantly improved the ECM mineralization level. Ultrastructural images of the mineralized RMP-treated infected osteoblasts revealed viable osteoblasts and densely distributed calcium crystal deposits within the extracellular organic matrix. The expression levels of prominent
Osteoporosis affects millions globally and current anti-catabolic treatments are limited by significant side-effects. Osteoporosis arises when skeletal stem cells (SSC) no longer sufficiently replenish osteoblasts, leading to net bone loss. A key regulator of SSC behaviour is physical loading, yet the mechanisms by which SSCs sense and respond to changes in their mechanical environment are virtually unknown. Primary cilia are nearly ubiquitous ‘antennae-like’ cellular organelles that have very recently emerged as extracellular chemo/mechano-sensors and thus, are strong candidates to play an important role in regulating SSC responses in bone. This paper will demonstrate that the SSC primary cilium plays an important role in loading-induced
Introduction and Objective. Calcium phosphates are among the most commonly used bone graft substitute materials. Compositions containing predominantly monetite (∼84.7%) with smaller additions of beta-tricalcium phosphate (β-TCP; ∼8.3%) and calcium pyrophosphate (Ca-PP; ∼6.8%) have previously been demonstrated to exhibit osteoinductive properties. Such a multi-component calcium phosphate bioceramic was fashioned in the form of hollowed-out, dome-shaped devices (15 mm diameter, 4 mm height), each reinforced with a 3D printed Ti6Al4V ELI frame. With the aim to induce
Purpose. Vitamin D is a key regulator of bone homeostasis. The enzyme CYP24A1 is responsible for transforming vitamin D into 24,25(OH)2vitD. The putative biological activity of 24,25(OH)2vitD remains unclear. Previous studies showed an increase in the circulating levels of this metabolite following a fracture in chicks. Our laboratory has engineered a mouse model deficient for the Cyp24a1 gene for studying the role of 24,25(OH)2vitD. We set out to study the role of 24,25(OH)2vitD in endochondral and intramembranous
Objectives. We have observed clinical cases where bone is formed in the overlaying muscle covering surgically created bone defects treated with a hydroxyapatite/calcium sulphate biomaterial. Our objective was to investigate the osteoinductive potential of the biomaterial and to determine if growth factors secreted from local bone cells induce osteoblastic differentiation of muscle cells. Materials and Methods. We seeded mouse skeletal muscle cells C2C12 on the hydroxyapatite/calcium sulphate biomaterial and the phenotype of the cells was analysed. To mimic surgical conditions with leakage of extra cellular matrix (ECM) proteins and growth factors, we cultured rat bone cells ROS 17/2.8 in a bioreactor and harvested the secreted proteins. The secretome was added to rat muscle cells L6. The phenotype of the muscle cells after treatment with the media was assessed using immunostaining and light microscopy. Results. C2C12 cells differentiated into osteoblast-like cells expressing prominent bone markers after seeding on the biomaterial. The conditioned media of the ROS 17/2.8 contained bone morphogenetic protein-2 (BMP-2 8.4 ng/mg, standard deviation (. sd. ) 0.8) and BMP-7 (50.6 ng/mg, . sd. 2.2). In vitro, this secretome induced differentiation of skeletal muscle cells L6 towards an osteogenic lineage. Conclusion. Extra cellular matrix proteins and growth factors leaking from a bone cavity, along with a ceramic biomaterial, can synergistically enhance the process of ectopic ossification. The overlaying muscle acts as an osteoinductive niche, and provides the required cells for
Bone morphogenetic proteins (BMPs) are able to induce osteogenic differentiation in many cells, including muscle cells. However, the actual contribution of muscle cells to
Summary. A promising approach to stimulate in vivo
Introduction. This study investigated the binding agent Calcium/Sodium Alginate fibre gel and the addition of autogenic bone marrow aspirate (BMA) on bone growth into a porous HA scaffold implanted in an ovine femoral condyle critical-sized defect. Our hypothesis was that Alginate fibre gel would have no negative effect on
Summary Statement. The present study demonstrates the beneficial effects of strontium (Sr) modified calcium phosphate cement to improve new
Objectives. An experimental rabbit model was used to test the null hypothesis,
that there is no difference in new
1. The effect of immobilisation on
The use of designer scaffolds to deliver biologically active osteogenic growth factors such as recombinant human bone morphogenetic protein-2 (rhBMP-2) to the sites of tissue regeneration in for example orthopaedics, has tremendous therapeutic implications. The aims of this study were to generate biomimetic biodegradable porous osteogenic scaffolds using a supercritical fluid process to encapsulate rhBMP-2, and to examine the ability of the scaffolds to promote human osteoprogenitor differentiation and
We used interconnected porous calcium hydroxyapatite ceramic to bridge a rabbit ulnar defect. Two weeks after inducing the defect we percutaneously injected rabbit bone marrow-derived mesenchymal stromal cells labelled with ferumoxide. The contribution of an external magnetic targeting system to attract these cells into the ceramic and their effect on subsequent
We measured the extent and rate of new
Introduction: The current practice of impaction allograft to fill large defects in revision total hip replacements is sometimes useful but clinical results are inconsistent. Other studies have shown that addition of mesenchymal stem cells (MSC) in blocks of hydroxyapatite (HA) scaffold can enhance new
Introduction: Current treatments for osteoporosis do not completely eliminate the risk of fracture and bone loss may continue even at a low level. Enhanced
The relationship between heterotopic
The purpose of this study was to determine the benefit and risk of NSAID-based prophylaxis for ectopic
Objective. Superior bone ingrowth and resistance to bacterial infection are ideal for orthopaedic implants. We compared new
Bone Morphogenetic Protein 7 (BMP7) is a powerful osteoinductive substance that could stimulate
1. Bones consist essentially of bundles of collagenous fibres united by a cementing substance in which the inorganic material lies in the form of minute plate-like crystals. 2. During weight bearing and muscle action bones as a whole are deformed to a variable extent. Periods of deformation are followed by periods of relaxed pressure during which the bones tend to return to their normal form. 3. These variations in deformation and elastic recoil set up alternating pressures and tensions within the bones along the bone cyrstal encrusted fibres which make up the trabeculae, lamellae and Haversian systems, and these alternating phases of compression and tension stimulate the activity of osteoblasts so that
1. A case of polyarteritis nodosa is reported, the presenting manifestation of which was subperiosteal new
1. Three patients with localised periosteal new
1 . Normal and diseased bone was obtained by biopsy from five patients suffering from Paget's disease. The tissue was studied by histology, microradiography and quantitative fluorescence microscopy using tetracycline markers. Study of the morphological changes showed that two of the biopsies could be regarded as normal, while one was osteoporotic; two biopsy specimens were in the porotic phase of Paget's disease and the remaining five were in the sclerotic phase. 2. The tetracycline markers were used to measure the linear rate at which bone was deposited on individual surfaces (appositional growth rate) in µ per day and the percentage volume of new bone added to the total volume of bone per day (bone formation rate). The values obtained for appositional growth rate in all the biopsies were of the order of 1 µ per day, but slightly higher values were obtained in the diseased tissue of each individual. The
1. A patient with ectopic bone in the upper arm associated with multiple congenital anomalies is reported. 2. The previous cases of congenital abnormalities in patients with ectopic
1. In five series of experiments in eighty-two rabbits we succeeded in causing rarefaction of the calcaneum of all the animals soon after it was relieved from muscular compressing forces; new bone was generated when the calcaneum was subjected again to the stresses and strains of muscle contraction. 2. We found evidence that during muscle action pressure forces are transmitted through the bone, and that the presence or absence of these pressure forces conditions the balance between
Introduction. Enhanced angiogenesis and osteogenesis may provide new strategies for the treatment of osteonecrosis. Methods. Synergistic effects of vascular endothelial growth factor (VEGF) and bone morphogenetic protein - 6 (BMP-6) on in vitro osteogenic differentiation and in vivo ectopic
Aim: To examine the effect of the bisphosphonate zoledronic acid in doses of 0.1mg/kg on new
Purpose: Previous studies have shown the utility of the bisphosphonate zoledronic acid (ZA) by systemic administration and local delivery for enhancing local
Aims: We tested the hypothesis whether vascular endothelial growth factor (VEGF-A) gene transfer is an appropriate way to enhance recruitment and activity of osteoblasts in vivo. Methods: We tested plasmid/ liposome and adenoviral gene transfer vectors in vitro and selected adenoviruses for in vivo experiments. Adenovirus vectors containing VEGF-A or lacZ genes (1.4x10. 10. pfu) were injected locally into right distal femurs of New Zealand White rabbits. Saline was injected into all contralateral distal femurs. One and three weeks after the gene transfers femurs were collected for analyzes. Trabecular bone hard tissue histo-morphometry was performed to analyze the effect of gene transfer on bone turnover. Results: X-Gal staining showed that up to twenty percent of the bone marrow cells were transfected. When compared to unilateral lacZ transfected trabecular bone at one week time point, VEGF-A bone had 8% less bone volume, 90% higher osteoblast number, 100% higher osteoblast surface, 125% higher osteoid volume and 70% less resorption surface. Corresponding parameters were 70% higher bone volume, 7% higher osteo-blast number, 30% higher osteoblast surface, 22% higher osteoid volume and 49% less resorption surface at week three. Conclusions: Our results suggest that adenovirus-mediated VEGF-A gene transfer induces
The thrombin-related peptide, TP508, is a synthetic 23 amino acid peptide, which represents the receptor binding domain of thrombin. TP508 mimics thrombin by interacting with receptors on cells involved in tissue repair. TP508 has been shown to enhance revascularization of injured tissue, and promote soft tissue wound healing, cartilage repair, and fracture repair. The aim of this study is to (1) test the effect of TP508 on bone regeneration during distraction osteogenesis; (2) study the chemotactic effect of TP508 on human osteoblasts. Unilateral tibial osteoectomies were performed and stabilized with MX100 Orthofix lengthener in 5 male adult NZW rabbits. After 7 days, distraction was initiated at rates of 1.4 mm / day for 6 days. TP508 (100 μg/ml, n=2; 10 μg/ml, n=1) or saline (300 μl, n=2) was injected into the osteotomy / lengthening gap at days 1, 7 and 14 post surgery. Animals were sacrificed at 2 weeks after leg lengthening.
Aims: The present study examined the effect of ade-novirus-mediated recombinant human BMP-2 (RAd-BMP-2) gene therapy combined with bioactive glass (BG) microspheres in promotion of new
In this study we investigated the effects of non-steroidal anti-inflammatory drugs (NSAIDs) with different cyclooxygenase (COX) selectivity on orthopaedic device-related infections (ODRIs) in a rat model. Specifically, we aimed to measure the impact of NSAID therapy on bone changes, bacterial load, and cytokine levels after treatment with antibiotics. In addition, we compared the effects of long vs short-term celecoxib (a COX-2 inhibitor) treatment on the same outcomes. Skeletally mature female Wistar rats were implanted with Aim
Method
We investigated the effects of non-steroidal anti-inflammatory drugs (NSAIDs) with different cyclooxygenase (COX) selectivity on orthopaedic device-related infections (ODRIs) in a rat model. We aimed to measure the impact of NSAID therapy on bone changes, bacterial load, and cytokine levels after treatment with antibiotics. We also compared the effects of long vs short-term celecoxib (a COX-2 inhibitor) treatment on the same outcomes. Skeletally mature female Wistar rats were implanted with Staphylococcus epidermidis- contaminated polyetheretherketone (PEEK) screws in the proximal right tibia and monitored for 7 days. All animals received subcutaneous antibiotics (rifampicin plus cefazolin) for two weeks from day 7 to 21. In phase I of the study, rats were randomly assigned to receive 28 days of oral treatment with acetylsalicylic acid, ibuprofen, celecoxib, or vehicle control. In phase II, an additional group received seven days of celecoxib treatment from day 0 to 7. Bone changes were monitored using in vivo micro-CT and histology. Quantitative bacteriology was performed at euthanasia. Plasma samples were collected to measure cytokine levels on days 0, 6, 20, and 28. Combination antibiotic therapy resulted in treatment success in 85.71% of cases, while the addition of long-term celecoxib treatment reduced it to 45.45%. Long-term celecoxib treatment significantly reduced bone loss (33.85% mean difference [95% CI 14.12–53.58], p=0.0004 on day 6 bone fraction) and periosteal reaction (0.2760 μm mean difference [95% CI 0.2073–0.3448], p<0.0001 on day 14 periosteal thickness) during early infection compared to the control group. Short- term celecoxib treatment showed similar radiological results without a reduction in treatment success (88.9%). No differences in the inflammatory markers were observed. Our findings highlight the potential benefits of short-term use of celecoxib in improving bone fraction during the early post-infection period without impairing the efficacy of antibiotic therapy
Several bisphosphonates are now available for the treatment of osteoporosis. Porous hydroxyapatite/collagen (HA/Col) composite is an osteoconductive bone substitute which is resorbed by osteoclasts. The effects of the bisphosphonate alendronate on the formation of bone in porous HA/Col and its resorption by osteoclasts were evaluated using a rabbit model. Porous HA/Col cylinders measuring 6 mm in diameter and 8 mm in length, with a pore size of 100 μm to 500 μm and 95% porosity, were inserted into a defect produced in the lateral femoral condyles of 72 rabbits. The rabbits were divided into four groups based on the protocol of alendronate administration: the control group did not receive any alendronate, the pre group had alendronate treatment for three weeks prior to the implantation of the HA/Col, the post group had alendronate treatment following implantation until euthanasia, and the pre+post group had continuous alendronate treatment from three weeks prior to surgery until euthanasia. All rabbits were injected intravenously with either saline or alendronate (7.5 μg/kg) once a week. Each group had 18 rabbits, six in each group being killed at three, six and 12 weeks post-operatively. Alendronate administration suppressed the resorption of the implants. Additionally, the mineral densities of newly formed bone in the alendronate-treated groups were lower than those in the control group at 12 weeks post-operatively. Interestingly, the number of osteoclasts attached to the implant correlated with the extent of
Type 1 diabetes mellitus (DM) is associated with a decreased