Ming Ding

Hip fractures are most commonly suffered by elderly patients, but 2–11% of hip fractures affect younger patients. In young adults with femoral neck f

The cytokine tumor necrosis factor (TNF), a major regulator of inflammatory responses, exists in both a membrane-bound form and a soluble form. We used the nonselective TNF inhibitor etanercept and the selective inhibitor XPro1595 and compared supraspinatus muscle cytokine levels, histology, and proteomic signatures in mice after supraspinatus tendon tear. The aim was to investigate the effect of anti-TNF treatment on the early inflammatory response in the muscle after tendon tear. In addition, the effect on body composition and bone mineral content was compared in naive mice after 2 months of treatment with either etanercept or XPro1595 using dual-energy X-ray absorptiometry (DEXA) and micro-CT. Inhibition of TNF did not significantly affect DEXA indexes of body composition nor bone microarchitecture, apart from increased structure model index and decreased bone surface density at 14 days, and bone surface to volume ratio at 2 months. Supraspinatus tendon tear caused extensive inflammatory changes in the supraspinatus muscle and initiated a regenerative response. However, TNF inhibition did not significantly affect these processes recorded as density in the lesioned supraspinatus muscle of macrophages and myogenin-positive nuclei. Although both inhibitors had an effect on mitochondrial proteins, particularly etanercept tended to modulate mitochondrial function, and eternacept also influenced NF-κB signaling. Modulation of the mitochondrial proteome and the influence on NF-κB signaling seen after etanercept treatment could correspond with its known effect on apoptosis.

Objective of this study This scoping-review aims to highlight the current modalities of sole use of stem cells in treating fracture nonunion updating a previous systematic review from 2013. We report solitary stem cell stimulation in literature in vivo studies to obtain current knowledge in understanding the crucial role of stem cells in enhancing fracture nonunion healing. Materials and methods This scoping review was conducted by systematical search in PubMed, Medline and clinicaltrials.gov with a timeframe from October 2012 to September 2024. Two authors independently screened all articles, and when included, the following information was extracted: type of nonunion, localization, type of stem cells, administered dose of stem cells, surgical information, type of scaffold, control group, evaluation method, time of evaluation post intervention, and adverse events. Results Of 4710 articles screened, 27 articles met the criteria for inclusion. In the reviewed articles, 2 out of 5 human studies, and 8 out of 12 animal studies with a control group reported a statistically significant effect of stem cells on bone healing when used in the treatment of fracture nonunion. Comparison of the studies was difficult due to heterogeneity. The administration of mesenchymal stem cells regarding adverse events was investigated in eight human studies. Conclusion Based on our reporting, the articles suggest that the perspectives of the sole use of mesenchymal stem cells in the management of fracture nonunion might be promising but remain inconclusive. Future research should be inspired by existing literature and focus on the development of well-standardized methodologies and results published.

There is an increasing demand for a suitable bone substitute to replace current clinical gold standard autografts or allografts. Majority of previous studies have focused on the early effects of substitutes on bone formation, while information on their long-term efficacies remains limited. This study investigated the efficacies of natural hydroxyapatite (nHA) derived from oyster shells and synthetic hydroxyapatite mixed with collagen (COL/HA) or chitosan (CS/HA) on bone regeneration and implant fixation in sheep. Titanium implants were inserted into critical-size defects in distal femur condyles bilaterally, and circumferential gaps around implants were filled with substitute materials or allografts (as control). 14 or 24 weeks post-operatively, the implant-bone blocks were harvested and evaluated using microarchitectural, histomorphometric, and mechanical methods. The nHA and COL/HA groups showed significant bone formation at both 14 and 24 weeks. There was a pronounced increase in bone tissue volume and ingrowth into titanium implant’s porous surfaces, significantly enhancing mechanical fixation strength at 24 weeks. CS/HA had a limited ability to induce bone formation and implant fixation. We conclude that nHA and COL/HA revealed long-term effects on enhancing bone formation and implant fixation that were at least as good as allograft after 24 weeks, and both nHA and COL/HA appear to be good alternative materials to bone allograft.

Introduction: Experimental bone research often generates large amounts of histology and histomorphometry data, and the analysis of these data can be time-consuming and trivial. Machine learning offers a viable alternative to manual analysis for measuring e.g. bone volume versus total volume.The objective was to develop a neural network for image segmentation, and to assess the accuracy of this network when applied to ectopic bone formation samples compared to a ground truth.Method: Thirteen tissue slides totaling 114 megapixels of ectopic bone formation were selected for model building. Slides were split into training, validation, and test data, with the test data reserved and only used for the final model assessment. We developed a neural network resembling U-Net that takes 512×512 pixel tiles. To improve model robustness, images were augmented online during training.The network was trained for 3 days on a NVidia Tesla K80 provided by a free online learning platform against ground truth masks annotated by an experienced researcher.Result: During training, the validation accuracy improved and stabilised at approx. 95%. The test accuracy was 96.1 %.Conclusion: Most experiments using ectopic bone formation will yield an inter-observer or inter-method variance of far more than 5%, so the current approach may be a valid and feasible technique for automated image segmentation for large datasets. More data or a consensus-based ground truth may improve training stability and validation accuracy.The code and data of this project are available upon request and will be available online as part of our publication.

Fucoidans are a heterogenous class of fucose-rich sulfated carbohydrates which have attracted increasing attention in cancer and inflammation research due to their bioactive properties. There are reports that fucoidans may have direct antibacterial effects and synergy with antibiotics. However, the literature is conflicting, potentially due to the limited reporting of origin, characteristics, and extraction methods of the fucoidans tested. Here we report the results of 18 defined fucoidans screened for direct, indirect, and synergistic antibacterial effects. 15 distinct fucoidan fractions, isolated from Laminaria hyperborea using a solvent-free extraction process, were characterised for molecular weight, pH, viscosity, and sulfur content. These, together with three commercially available crude fractions, were assessed at concentrations from 0.03125-24 mg mL^-1 for minimum inhibitory concentration against Staphylococcus aureus, Streptococcus mutans and Streptococcus sanguinis. Furthermore, we tested a selection of fucoidans for antibacterial synergy with vancomycin and indirect antibacterial effects in whole blood survival assays. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) was performed to assess the stress response in fucoidan-treated S. aureus cultures. We have identified one fucoidan fraction with bactericidal activity against diverse bacteria. This effect is dose-, fucoidan fraction- and bacteria-specific, and furthermore, not related to osmotic stress. No synergistic effects were observed with fucoidan in combination vancomycin. Fucoidans have exciting potential as antimicrobial agents. Further analysis is required to establish the precise molecular characteristics responsible for their potent bactericidal activity.

Diabetic foot ulcers are a common and severe complication of diabetes mellitus, and a risk factor for amputation. Because of the vessel insufficiency in diabetic foot ulcers (DFU), vascular endothelial growth factor (VEGF) that simulates angiogenesis is of interest to promote wound healing. This systematic review evaluates the last 16 years of in‐vivo studies with VEGF stimulation as a treatment for DFU, developed based on the last published systematic article. A total of 961 articles were identified through databases in two phases. 947 articles were excluded by exclusion criteria, and four articles met our inclusion criteria and were included. The effects of VEGF on wound healing were analysed in all four studies. In three studies, the VEGF‐treated wounds showed statistically faster healing than those not treated with VEGF. In one study, the VEGF‐treated wounds revealed a positive trend toward faster healing. Furthermore, all four studies were in favor of using VEGF, but concluded that further research is needed. These studies showed a positive trend towards faster healing and was safe when using VEGF topically on humans. Furthermore, viral particles of VEGF seem to have a systematic effect when a dose exceeding 5.0 × 10⁹ vp pr wound. Future research in using VEGF on DFU should focus on VEGF's relevant dosage, release rate, and specific mechanism. This review inspires further research, and a consistent study design is prerequisite such that results are more homogenic and comparable. Much effort is needed to translate the results into our clinical practice.

Aims: The primary outcome was investigating differences in wear, as measured by femoral head penetration, between cross-linked vitamin E-diffused polyethylene (vE-PE) and cross-linked polyethylene (XLPE) acetabular component liners and between 32 and 36 mm head sizes at the ten-year follow-up. Secondary outcomes included acetabular component migration and patient-reported outcome measures (PROMs) such as the EuroQol five-dimension questionnaire, 36-Item Short-Form Health Survey, Harris Hip Score, and University of California, Los Angeles Activity Scale (UCLA).Methods: A single-blinded, multi-arm, 2 × 2 factorial randomized controlled trial was undertaken. Patients were recruited between May 2009 and April 2011. Radiostereometric analyses (RSAs) were performed from baseline to ten years. Of the 220 eligible patients, 116 underwent randomization, and 82 remained at the ten-year follow-up. Eligible patients were randomized into one of four interventions: vE-PE acetabular liner with either 32 or 36 mm femoral head, and XLPE acetabular liner with either 32 or 36 mm femoral head. Parameters were otherwise identical except for acetabular liner material and femoral head size.Results: A total of 116 patients participated, of whom 77 were male. The median ages of the vE-PE 32 mm and 36 mm groups were 65 (interquartile range (IQR) 57 to 67) and 63 years (IQR 56 to 66), respectively, and of the XLPE 32 mm and 36 mm groups were 64 (IQR 58 to 66) and 61 years (IQR 54 to 66), respectively. Mean total head penetration was significantly lower into vE-PE acetabular liner groups than into XLPE acetabular liner groups (-0.219 mm (95% confidence interval -0.348 to -0.090); p = 0.001). There were no differences in wear according to head size, acetabular component migration, or PROMs, except for UCLA. There were no cases of aseptic loosening or failures requiring revision at long-term follow-up.Conclusion: Significantly lower wear was observed in vE-PE acetabular liners than in XLPE acetabular liners. No difference in wear was observed between different head size or PROMs except for the UCLA at ten years.Cite this article: Bone Joint J 2023;105-B(10):1052–1059.

Neovascularization plays an essential part in the progression of several diseases as well as recovery processes such as angiogenesis-guided neurogenesis after a spinal cord injury. To visualize and quantify neovascularization in an experimental setup, it is desirable to apply a noninvasive, repeatable, and harmless technique. Here, we apply a newly developed ultrasound-based technique to construct angiographies and quantify neovascularization in the regenerating spinal cord of a regeneration competent animal model, the Mexican axolotl. We measured vessel volume fraction prior to the induction of contusion and transection spinal cord injury and repeated this measurement directly after injury and at 3, 6, 12, and 63 days after injury. Although neither of the injury types resulted in statistically significant differences in vessel volume fraction relative to sham-operated animals, there was a statistically significant increase in neovascularization over time in all groups. Additionally, vessel volume fraction at the final time point (63 days after injury) was quantified with micro-CT imaging after vascular perfusion with a contrast agent, confirming no statistically significant difference in neovascularization between injury types. Ex vivo vessel volume fraction measured by micro-CT was significantly different from the in vivo ultrasound-based measurement at the same time point. This is likely a result of incomplete vascular perfusion with the contrast agent before micro-CT imaging, which was supported by subsequent histological evaluation. In summary, the results suggest that the ultrasound-based angiographic procedure, we demonstrate here, is applicable to visualize and quantify neovascularization in a noninvasive and harmless fashion in longitudinal experiments circumventing the limitations of contrast agent-dependent techniques.