Bone tissue engineering by transplantation of culture expanded bone marrow cells and platelet rich plasma

1.骨特异性碱性磷酸酶（BAP）、I型胶原羧基末端前肽（P1CP）和骨钙素的分泌和mRNA表达均升高。体内骨形成（通过扩散室中钙化阳性面积百分比（%钙化）来量化）与BAP和P1CP的活性相关。骨钙素活性与钙化率无相关性。观察不同血小板浓度的PRP凝胶培养的骨髓细胞的成骨分化和增殖能力。PRP凝胶的增殖能力与血小板浓度呈正相关，而在骨髓细胞成骨分化方面，两种凝胶间无显著差异。将GFP（绿色荧光蛋白）转基因大鼠收获的细胞，在延长终止后，移植到大鼠延长模型的分散区，验证移植细胞的定位。移植后21天的组织学检查显示，GFP标记的细胞定位在新形成的小梁骨内。我们对牵张成骨进行了细胞移植和未进行细胞移植的骨的回顾性比较研究，以评估这种细胞疗法的疗效。治疗组的平均愈合指数明显低于未治疗组。治疗组并发症发生率明显低于对照组。细胞移植后股骨延长的愈合速度明显快于胫骨延长。

1.The secretion and mRNA expression of bone-specific alkaline phosphatase (BAP), carboxy-terminal propeptide of type I collagen (P1CP), and osteocalcin were elevated in the cells cultured with and without osteogenic supplements. In vivo bone formation, which was quantified by the percentage of area that was positive for calcification (% calcification) in the diffusion chamber, was correlated with the activity of BAP and P1CP. There was no correlation between the osteocalcin activity and the % calcification.2.Osteogenic differentiation and proliferation capability were examined among the bone marrow cells cultured within the PRP gel with different platelet concentration. Positive correlation was demonstrated between the proliferation capability and the platelet concentration of PRP gel, whereas, there were no significant differences in osteogenic differentiation of bone marrow cells among the gels.3.The cells harvested from GFP (green fluorescent protein) transgenic rats were transplanted into the distracted area of the rat lengthening model after the termination of lengthening to verify the localization of the transplanted cells. Histological examinations of the 21 days after transplantation showed that the GFP labeled cells were localized within the newly formed trabecular bone.4.Retrospective comparative study was conducted between the bones treated with and without cell transplantation in distraction osteogenesis to assess the efficacy of this cell therapy. The average healing index of the treated group was significantly lower than that of the untreated group. The rate of complications was also significantly lower in the treated group. The femoral lengthening showed significantly faster healing than the tibial lengthening by the cell transplantation.