Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Biomaterials. 2010 Nov;31(33):8674-83. doi: 10.1016/j.biomaterials.2010.07.096. Epub 2010 Aug 16.
Recent studies have shown that alendronate (Aln) enhances the osteogenesis of osteoblasts and bone marrow mesenchymal stem cells. In this study, we hypothesize that Aln may act as an osteo-inductive factor to stimulate the osteogenic differentiation of human adipose-derived stem cells (hADSCs) for bone regeneration. The in vitro effect of Aln (1-10 μM) on the osteogenic ability of hADSCs was evaluated by examining mineralization and alkaline phosphatase (ALP) activity. Bone morphogenetic protein 2 (BMP2) expression was measured using a real-time polymerase chain reaction and western blot analysis. Our results indicated that 5 μM Aln was sufficient to enhance BMP2 expression, ALP activity and mineralization in hADSCs. The in vivo effect of locally administered Aln on bone repair was examined in a rat critical-sized (7-mm) calvarial defect that was implanted with a hADSC-seeded poly(lactic-co-glycolic acid) (PLGA) scaffold. Aln (5 μM/100 μl/day) was injected locally into the defect site for one week. New bone formation was evaluated by radiographic and histological analyses at 8 and 12 weeks post-implantation. The expression levels of human BMP2 (hBMP2) and hADSC localization in defect sites were examined using immunohistochemistry analysis and fluorescent in situ hybridization, respectively. Results showed that local treatment of Aln on hADSC-seeded PLGA scaffolds at week 12 had a maximal effect on bone regeneration, enhancing mineralization and bone matrix formation. In addition, hADSCs and hBMP2 were also detected at the defect sites. These results demonstrated that local delivery of Aln, a potent osteo-inductive factor, enhances hADSC osteogenesis and bone regeneration.
最近的研究表明，阿仑膦酸钠（Aln）能增强成骨细胞和骨髓间充质干细胞的成骨作用。在本研究中，我们假设 Aln 可能作为一种骨诱导因子，刺激人脂肪来源干细胞（hADSCs）的成骨分化，从而促进骨再生。通过检测矿化和碱性磷酸酶（ALP）活性，评估 Aln（1-10 μM）对 hADSCs 成骨能力的体外影响。采用实时聚合酶链反应和 Western blot 分析检测骨形态发生蛋白 2（BMP2）的表达。结果表明，5 μM Aln 足以增强 hADSCs 中 BMP2 的表达、ALP 活性和矿化。通过将负载 hADSCs 的聚乳酸-共-羟基乙酸（PLGA）支架植入大鼠 7mm 临界大小颅骨缺损模型，评估局部给予 Aln 对骨修复的体内影响。在植入后 1 周内，每天将 Aln（5 μM/100 μl）局部注射到缺损部位。植入后 8 和 12 周时，通过影像学和组织学分析评估新骨形成。采用免疫组化分析和荧光原位杂交分别检测缺损部位 hBMP2（hBMP2）的表达水平和 hADSC 的定位。结果表明，在第 12 周时，局部给予 Aln 对负载 hADSCs 的 PLGA 支架的处理对骨再生有最大的影响，增强了矿化和骨基质形成。此外，还在缺损部位检测到 hADSCs 和 hBMP2。这些结果表明，局部递送强骨诱导因子 Aln 可增强 hADSC 成骨和骨再生。
