Xia Yuan-Jun, Xia Hong, Chen Ling, Ying Qing-Shui, Yu Xiang, Li Li-Hua, Wang Jian-Hua, Zhang Ying
Department of Trauma Orthopedics, Hospital of Orthopaedics, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou, Guangdong 510010, P.R. China.
Department of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
Exp Ther Med. 2018 Apr;15(4):3265-3272. doi: 10.3892/etm.2018.5849. Epub 2018 Feb 7.
Bone morphogenetic protein-2 (BMP-2) serves an important role in the development of bone and cartilage. However, administration of BMP-2 protein alone by intravenous delivery is not very effective. Sustained delivery of stabilized BMP-2 by carriers has been proven necessary to improve the osteogenesis effect of BMP-2. The present study constructed a novel drug delivery system using dextran sulfate (DS)-chitosan (CS) microspheres and investigated the efficiency of the delivery system on recombinant human bone morphogenetic protein (rhBMP-2). The microsphere morphology, optimal ratio of DS/CS/rhBMP-2, and drug loading rate and entrapment efficiency of rhBMP-2 CS nanoparticles were determined. L929 cells were used to evaluate the cytotoxicity and effect of DS/CS/rhBMP-2 microspheres on cell proliferation. Differentiation study was conducted using bone marrow mesenchymal stem cells (BMSCs-C57) cells treated with DS/CS/rhBMP-2 microspheres or the control microspheres. The DS/CS/rhBMP-2 microspheres delivery system was successfully established. Subsequent complexation of rhBMP-2-bound DS with polycations afforded well defined microspheres with a diameter of ~250 nm. High protein entrapment efficiency (85.6%) and loading ratio (47.245) µg/mg were achieved. Release of rhBMP-2 from resultant microspheres persisted for over 20 days as determined by ELISA assay. The bioactivity of rhBMP-2 encapsulated in the CS/DS microsphere was observed to be well preserved as evidenced by the alkaline phosphatase activity assay and calcium nodule formation of BMSCs-C57 incubated with rhBMP-2-loaded microspheres. The results demonstrated that microspheres based on CS-DS polyion complexes were a highly efficient vehicle for delivery of rhBMP-2 protein. The present study may provide novel orientation for bone tissue engineering for repairing and regenerating bone defects.
骨形态发生蛋白-2（BMP-2）在骨骼和软骨发育中起重要作用。然而，单独通过静脉注射给予BMP-2蛋白的效果并不理想。已证明通过载体持续递送稳定化的BMP-2对于提高BMP-2的成骨效果是必要的。本研究构建了一种使用硫酸葡聚糖（DS）-壳聚糖（CS）微球的新型药物递送系统，并研究了该递送系统对重组人骨形态发生蛋白（rhBMP-）的递送效率。测定了微球形态、DS/CS/rhBMP-2的最佳比例以及rhBMP-2 CS纳米颗粒的载药率和包封率。使用L929细胞评估DS/CS/rhBMP-2微球的细胞毒性及其对细胞增殖的影响。使用经DS/CS/rhBMP-2微球或对照微球处理的骨髓间充质干细胞（BMSCs-C57）细胞进行分化研究。成功建立了DS/CS/rhBMP-2微球递送系统。随后，将与rhBMP-2结合的DS与聚阳离子复合，得到直径约为250 nm的明确微球。实现了高蛋白包封率（85.6%）和载药率（47.245）μg/mg。通过ELISA测定法确定，rhBMP-2从所得微球中的释放持续超过20天。通过碱性磷酸酶活性测定和与负载rhBMP-2的微球孵育的BMSCs-C57的钙结节形成证明，封装在CS/DS微球中的rhBMP-2的生物活性得到了良好保留。结果表明，基于CS-DS聚离子复合物的微球是递送rhBMP-2蛋白的高效载体。本研究可能为骨组织工程修复和再生骨缺损提供新的方向。
