Chen Linwei, Lu Xiaolang, Li Shi, Sun Qizhi, Li Wanli, Song Dianwen
Department of Orthopaedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
Orthopedics. 2012 Sep;35(9):e1402-9. doi: 10.3928/01477447-20120822-29.
Platelet-rich plasma (PRP) has a pool of multiple growth factors efficient at inducing the proliferation and osteogenic differentiation of human adipose-derived stem cells (hADSCs). Bone morphogenetic protein (BMP)-2 is a strong stimulator for the osteogenic differentiation of hADSCs. The purpose of this study was to verify the effect of PRP-released growth factors and microsphere-encapsulated BMP-2 on the proliferation and osteoblastic differentiation of hADSCs and to construct a novel tissue-engineered bone. The BMP-2-loaded microspheres and hADSCs were embedded in activated PRP gel. Another 5 composites (hADSCs/platelet-poor plasma [PPP]; hADSCs/PRP; hADSCs/BMP-2/PPP; hADSCs/BMP-2/PRP; and hADSCs/BMP-2+microspheres/PPP) were also constructed. The DNA content, alkaline phosphatase activity, mRNA expression of alkaline phosphatase, osteopontin, osteocalcin, and mineralization of hADSCs in each composite were compared. The DNA content was higher in all PRP-containing composites, meaning that PRP-released growth factors stimulated proliferation of hADSCs. Alkaline phosphatase increased in BMP-2/PRP and BMP-2+microspheres/PRP composites in the first 7 days, meaning that BMP-2 had a synergistic effect with PRP in the early differentiation of hADSCs. Osteopontin, osteocalcin, and mineralization assays were higher in BMP-2+microspheres/PRP composite than in the BMP-2/PRP composite up to 21 days, meaning that a continuous delivery of BMP-2 stimulates osteoblastic differentiation of hADSCs at the early stage and the final maturation stage. These results suggest that sustained delivery of BMP-2 in combination with PRP is better than a single administration of PRP or BMP-2 in the osteogenic differentiation of hADSCs.
富血小板血浆（PRP）含有多种生长因子，能有效诱导人脂肪来源干细胞（hADSCs）的增殖和成骨分化。骨形态发生蛋白（BMP）-2是hADSCs成骨分化的强刺激因子。本研究的目的是验证PRP释放的生长因子和微球包裹的BMP-2对hADSCs增殖和成骨细胞分化的影响，并构建新型组织工程骨。将负载BMP-2的微球和hADSCs嵌入活化的PRP凝胶中。还构建了另外5种复合材料（hADSCs/贫血小板血浆[PPP]；hADSCs/PRP；hADSCs/BMP-2/PPP；hADSCs/BMP-2/PRP；以及hADSCs/BMP-2+微球/PPP）。比较了每种复合材料中hADSCs的DNA含量、碱性磷酸酶活性、碱性磷酸酶、骨桥蛋白、骨钙素的mRNA表达以及矿化情况。所有含PRP的复合材料中DNA含量均较高，这意味着PRP释放的生长因子刺激了hADSCs的增殖。在最初7天，BMP-2/PRP和BMP-2+微球/PRP复合材料中的碱性磷酸酶增加，这意味着BMP-2在hADSCs的早期分化中与PRP具有协同作用。在长达21天的时间里，BMP-2+微球/PRP复合材料中的骨桥蛋白、骨钙素和矿化检测结果均高于BMP-2/PRP复合材料，这意味着BMP-2的持续释放刺激了hADSCs在早期阶段和最终成熟阶段的成骨细胞分化。这些结果表明，在hADSCs的成骨分化中，BMP-2与PRP联合持续递送优于单独施用PRP或BMP-2。
