Effects of Calcium Sulfate Combined with Platelet-rich Plasma on Restoration of Long Bone Defect in Rabbits / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The treatment for long bone defects has been a hot topic in the field of regenerative medicine. This study aimed to evaluate the therapeutic effects of calcium sulfate (CS) combined with platelet-rich plasma (PRP) on long bone defect restoration.</p><p><b>METHODS</b>A radial bone defect model was constructed through an osteotomy using New Zealand rabbits. The rabbits were randomly divided into four groups (n = 10 in each group): a CS combined with PRP (CS-PRP) group, a CS group, a PRP group, and a positive (recombinant human bone morphogenetic protein-2) control group. PRP was prepared from autologous blood using a two-step centrifugation process. CS-PRP was obtained by mixing hemihydrate CS with PRP. Radiographs and histologic micrographs were generated. The percentage of bone regenerated bone area in each rabbit was calculated at 10 weeks. One-way analysis of variance was performed in this study.</p><p><b>RESULTS</b>The radiographs and histologic micrographs showed bone restoration in the CS-PRP and positive control groups, while nonunion was observed in the CS and PRP groups. The percentages of bone regenerated bone area in the CS-PRP (84.60 ± 2.87%) and positive control (52.21 ± 4.53%) groups were significantly greater than those in the CS group (12.34 ± 2.17%) and PRP group (16.52 ± 4.22%) (P < 0.001). In addition, the bone strength of CS-PRP group (43.10 ± 4.10%) was significantly greater than that of the CS group (20.10 ± 3.70%) or PRP group (25.10 ± 2.10%) (P < 0.001).</p><p><b>CONCLUSION</b>CS-PRP functions as an effective treatment for long bone defects through stimulating bone regeneration and enhancing new bone strength.</p>

Hsa-miR-654-5p regulates osteogenic differentiation of human bone marrow mesenchymal stem cells by repressing bone morphogenetic protein 2 / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of hsa-miR-654-5p in repressing bone morphogenetic protein 2 (BMP2) mRNA and protein in human bone marrow mesenchymal stem cells (hBMSCs), and explore its regulatory role in osteogenic differentiation of hBMSCs.</p><p><b>METHODS</b>hBMSCs in the 4th passage were cultured for 16 h and transfected with hsa-miR-654-5p followed by further culture for 48 h. qRT-PCR and Western blotting were performed to detect the expressions of BMP2 mRNA and protein. Dual-luciferase?reporter gene assay was employed to examine the repression of the BMP2 gene.</p><p><b>RESULTS</b>BMP2 mRNA and protein expressions were significantly down-regulated in hBMSCs with hsa-miR-654-5p overexpression. Dualluci-ferase reporter gene assay indicated that the predicted target site of BMP2 was repressed directly by hsa-miR-654-5p, but this repression did not occur at the mutant predicted target site of BMP2.</p><p><b>CONCLUSION</b>hsa-miR-654-5p can directly repress the mRNA and protein expressions of BMP2 by binding to a specific target site. The changes in hsa-miR-654-5p can play an important role in osteogenic differentiation regulation of hBMSCs.</p>

New research progress on atrophic nonunion / 中国骨伤

Occurance of atrophic nonunion is a complex process. Previous studies suggested that atrophic nonunion was mainly due to lack of blood supply of fracture fragments, but recent studies found that blood supply was not deficiency in middle and late stages, indicating that decreased osteogenic factors and blood supply in early stages might play an important role in morbidity. Current effective treatment measures for atrophic nonunion mainly include bone graft and fixation,physical therapy, local injection therapy. All-round preventive could reduce incidence of atrophic nonunion. Atrophic nonunion is still a troublesome complication of fractures in orthopaedics, and more attention should be paid for its effective prevention and treatment. The paper summarized recent original articles about atrophic nonunion and reviewed the occurrence mechanisms, diagnosis, prevention and treatment measures of this disease.

Experimental study on preparation of decellularized artery vascular graft matrix and explantation of carotid artery allografts / 中华外科杂志

<p><b>OBJECTIVE</b>To set up a new process to access the preparation of decellularized artery grafts. And to evaluate the feasibility of decellularized artery allografts was evaluated.</p><p><b>METHODS</b>This study compared the effects of four extraction chemicals [1% t-octyl-phenoxypolyethoxyethanol (Triton X-100), 1% tri (n-butyl) phosphate (TnBP), and 1% sodium dodecyl sulfate (SDS) and trypsin (0.125, 0.25%) on thoracic artery vascular for 24 h (except trypsin for 2 h). At the base of it, a four-step process, including hypotonic, hypertonic solutions and combining with 1% Triton X-100 and 1% SDS detergents, were performed in rabbit thoracic artery vascular. Histological examination, tensile tests and expanding-burst tests were done on the samples. The decellularized carotid artery allografts were transplanted in other rabbits.</p><p><b>RESULTS</b>Treatment with 1% SDS or 1% Triton X-100 for 24 h could remove most cells with retention of near normal structure. A four-step process could remove all cells with the extracellular matrix well conserved. The pulling mechanical properties and burst pressure of decellularized carotid artery were similar to the control. The decellularized carotid artery allografts (diameter of 2 mm) were patent at explanting up to 2 months.</p><p><b>CONCLUSIONS</b>The acellular artery vascular graft matrix is well prepared with four-step process including detergents, such as TritonX-100, SDS without compromising the graft structure or mechanical properties significantly. The carotid artery allografts (diameter of 2 mm) decellularized by the process are patent at explanting up to 2 months.</p>