Objective. Repair of bone defects represents a grave clinical challenge because of the tremendous difficulties in the recovery of bone function and regeneration of bone loss. Therefore, we investigated the effects of platelet-rich plasma-loaded (PRP) porous chitosan microspheres (PCMs) on the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and the proliferation and differentiation potential of BMSCs loaded by PCMs in vitro. We also established the model of bone defect repair in rat tibia to further explore the effects of PCMs loaded with PRP and BMSCs on bone regeneration. Methods. MTT assay was used to detect the proliferative ability of BMSCs after hypoxia/reoxygenation (H/R) treatment and the proliferative ability of BMSCs loaded by PCMs; polymerase chain reaction (PCR) was used to detect the expression of alkaline phosphatase (ALP), type I collagen (Col I), and type II collagen (Col II) in BMSCs after hypoxia and in BMSCs induced by PRP-loaded PCMs; PCR was used to detect the expression of Runt-associated transcription factor 2 (Runx2) and osteocalcin (OC) in the newly generated bone tissue; micro-CT scanning was applied to measure the bone mineral density and bone volume of the newly generated bone tissue in rats. Results. BMSCs still have the normal potential of proliferation and differentiation after H/R treatment. PCMs can provide a larger surface for the attachment of BMSCs, facilitating cell proliferation. Loaded by PCMs, PRP can be slowly released, effectively stimulating the differentiation of BMSCs. PCM/PRP/BMSC composites increased the expression levels of Runx2 and OC in the newly generated bone in rat tibia defect and the bone mineral density. Moreover, the composites improved the rate of regenerated bone volume. Conclusion. The application of PCM/PRP/BMSC composites is promising in the repair of tibia defects.

中文翻译：

---

富含血小板血浆和骨髓源性间充质干细胞的多孔壳聚糖微球对胫骨缺损再生的影响

目标。骨缺损的修复代表着严峻的临床挑战，因为骨功能的恢复和骨质流失的再生面临巨大困难。因此，我们研究了富血小板血浆（PRP）多孔壳聚糖微球（PCM）对骨髓来源的间充质干细胞（BMSCs）的分化以及PCM负载的BMSCs体外增殖和分化潜能的影响。我们还建立了大鼠胫骨骨缺损修复模型，以进一步探讨装载PRP和BMSC的PCM对骨再生的影响。方法。MTT法检测缺氧/复氧（H / R）处理后的骨髓间充质干细胞的增殖能力和PCM加载的骨髓间充质干细胞的增殖能力。聚合酶链反应（PCR）用于检测缺氧后BMSC和加载PRP的PCM诱导的BMSC中碱性磷酸酶（ALP），I型胶原（Col I）和II型胶原（Col II）的表达；PCR检测新生骨组织中Runt相关转录因子2（Runx2）和骨钙素（OC）的表达。显微CT扫描用于测量大鼠新产生的骨组织的骨矿物质密度和骨体积。结果。经H / R处理后，BMSC仍具有正常的增殖和分化潜能。PCM可以为BMSC的附着提供更大的表面，从而促进细胞增殖。通过PCM加载，PRP可以缓慢释放，有效刺激BMSC的分化。PCM / PRP / BMSC复合材料增加了大鼠胫骨缺损新生骨中Runx2和OC的表达水平以及骨矿物质密度。而且，复合材料提高了骨体积的再生率。结论。PCM / PRP / BMSC复合材料的应用有望修复胫骨缺损。