复合细胞和人工骨的富血小板血浆成骨能力研究

目的探讨复合细胞和人工骨的富血小板血浆（platelet—rich plasma，PRP）促进骨缺损修复的能力。方法取新西兰大白兔骨髓，分离培养骨髓基质干细胞（marrow stromal stem cells，MSCs）；取兔全血体外诱导培养为类成骨样细胞，应用低密度两次离心法制备PRP。取48只1岁左右新西兰大白兔建立双侧桡骨1．2cm骨缺损模型，根据缺损中植入材料的不同随机分为4组，每组12只。A组：左侧PRP／Mscs／β-磷酸三钙（β-tricalcium phosphate，pTCP），右侧MSCs／β-TCP；B组：左侧自体骨，右侧PRP／Mscs／β-TCP；C组：左侧自体骨，右侧MSCs／β-TCP；D组：左侧PRP／β-TCP，右侧β-TCP。术后2、6及12周通过大体观察、X线片、组织学及生物力学观察桡骨缺损的愈合情况。结果制备的PRP血小板浓度稳定，约为全血的5．45±0．23倍。大体标本与X线片显示2、6周时PRP／MSCs／β-TCP在缺损处桥接及新生骨外形较自体骨差，与MSCs／β-TCP无明显区别；12周，PRP／MSCs／β-TCP在缺损处桥接及新生骨外形接近于自体骨，优于MSCs／β-TCP。组织学观察，在新生骨数量及成熟度方面，术后各时间点PRP／MSCs／β-TCP明显优于MSCs／β-TCP（P〈0．05），PRP／MSCs／β-TCP与自体骨无差异（P〉0．05）；2、6周PRP／β-TCP与β-TCP无差异（P〉0．05）；12周PRP／β-TCP优于β-TCP（P〈0．05）。新生骨生物力学强度检测，6、12周PRP／MSCs／阻TCP优于MSCs／β-TCP（P〈0．05）；6周PRP／MSCs／β-TCP小于自体骨（P〈0．05），但12周与自体骨无差异（P〉0．05）；12周PRP／β-TCP与β-TCP无差异（P〉0．05）。结论PRP复合MSCs和β-TCP显示出了良好的成骨能力，PRP可通过提高MSCs和成骨细胞的增殖与分化活性，促进骨缺损的修复。

OSTEOGENIC POTENTIAL OF PLATELET-RICH PLASMA COMBINED WITH CELLS AND ARTIFICIAL BONE

OBJECTIVE: To investigate the ability of platelet-rich plasma(PRP) combined with cells and artificial bone in accelerating the repair of bone defect. METHODS: The marrow stromal stem cells (MSCs) of rabbit were cultured and induced into the osteoblast-like cells in vitro. PRP was produced with low-density twice centrifugations. Forty-eight New Zealand rabbits were made 1.2 cm bilateral radius defect models and divided into 4 groups averagely at random: group A (left:PRP/MSCs/beta-tricalcium phosphate (beta-TCP), right: MSCs/beta-TCP), group B (left:auto-radius, right: PRP/MSCs/beta-TCP); group C (left:auto-radius, right: MSCs/beta-TCP), and group D (left:PRP/beta-TCP; right:beta-TCP). At 2, 6 and 12 weeks after operation, the repair of bone defect was evaluated by the general observation, histology, biomechanics and histomorphology. RESULTS: There was a stable platelet concentration in PRP and it was about 5.45+/-0. 23 times of whole blood. In the aspect of bone bridge and conture of the defects, at 2 and 6 weeks, PRP/MSCs/ beta-TCP and MSCs/beta-TCP displayed a similar outcome and were less than auto in general sample and X-ray; at 12 weeks, PRP/MSCs/beta-TCP was similar to auto-radius and better than MSCs/beta-TCP. in the aspect of quantity and quality of bone formation, histology showed that PRP/MSCs/beta-TCP and auto-radius were better than MSCs/beta-TCP (P < 0.05), and there was no significant difference between PRP/MSCs/beta-TCP and auto-radius (P>0.05). At 2 and 6 weeks, there was no significant difference between PRP/beta-TCP and beta-TCP (P>0.05). At 12 weeks, PRP/beta-TCP was better than beta-TCP (P<0.05). In the aspect of intensity of bone formation, at 6 and 12 weeks, PRP/MSCs/beta-TCP and auto-radius were better than MSCs/beta-TCP (P<0.05). At 6 weeks, auto-radius was better than PRP/MSCs/beta-TCP (P < 0.05). At 12 weeks, there was no significant difference between PRP/MSCs/beta-TCP and auto (P>0.05). PRP/TCP and beta-TCP had no significant difference at 12 weeks (P> 0.05). CONCLUSION: PRP/MSCs/beta-TCP demonstrated excellent ability of forming bone in experiment. PRP was most likely to accelerate the repair of bone defect through increasing the activity of proliferation and differentiation of MSCs and osteoblasts.