摘要:
本研究以胰蛋白酶(Try)为模型蛋白，将壳聚糖缓释微球与可降解多孔支架复合，构建可次第释放不同生长因子的骨组织工程支架。首先，制备载胰蛋白酶的壳聚糖微球(Try-CMs)，然后将微球与纳米羟基磷灰石/羟基乙酸(nHA/PLGA)按照一定的比例混合，通过粒子沥虑–冷冻干燥复合工艺制备Try-CMs/ nHA/PLGA复合支架。结果表明，制备的Try-CMs呈规则球形，粒径分布在4~10 μm之间，胰蛋白酶包封率为61.33%，载药量为25.69%。制备的Try-CMs/nHA/PLGA复合支架孔径为100~200 μm，孔隙率为53.24%，抗压强度为7.31 MPa，8周降解率为19.92%。48 h，Try-nHA/PLGA、Try-CMs、Try-CMs/nHA/ PLGA复合支架累计释放率分别57.31%、69.32%和26.03%；14天时，Try-nHA/PLGA、Try-CMs和Try-CMs/nHA/PLGA复合支架的累计释放率分别为77.89%、85.73%和54.53%。Try-CMs/nHA/PLGA复合支架对蛋白药物具有良好的缓释作用，有望作为具有蛋白类药物缓释作用的组织工程支架。
Abstract:
In order to construct a bone regeneration scaffold that different growth factors controlled release at proper stage, Trypsin (Try) was selected as the model protein. The composite of sustained-re- lease microspheres and biodegradable porous scaffolds was prepared in this study. Firstly, Tryp-sin-chitosan microspheres (CMs) were prepared. Then, Trypsin-CMs were compounded to the nano hydroxyapatite/poly lactic-co-glycolic acid (nHA/PLGA) to build a scaffold that could release growth factors sequentially. The results showed that the Try-CMs were spherical shape with diameters of 4 - 10 μm. The encapsulation efficiency of the Trypsin in CMs was 61.33%, and the loading capacity was 25.699%. The prepared Try-CMs/nHA/PLGA scaffold possessed 100 - 200 μm pore diameter, 53.24% porosity, 7.31 MPa compressive strength, and 19.92% degradation at 8 weeks. The cumulative releases of Trypsin from Try-nHA/PLGA, Try-CMs and Try-CMs/nHA/PLGA scaffolds were respectively about 57.31%, 69.32% and 26.03% at 48 hours, 77.89%, 85.73% and 54.53% at 14 days. The results demonstrated that Try-CMs/nHA/PLGA scaffolds had excellent drug sustained-release performance, which would be used as tissue engineering scaffolds with protein controlled delivery.