人工软骨支架中TGF-β1缓释壳聚糖微球对ATDC-5细胞生长的促进作用

ATDC-5 growth promoted by sustained-releasing chitosan microspheres loading TGF-β1 in artificial cartilage scaffolds

摘要:

为了提高本课题组前期构建的Ⅱ型胶原蛋白-透明质酸-硫酸软骨素的人工三维软骨支架对软骨细胞生长的促进作用，采用乳化交联法以壳聚糖为原料，加入细胞转化生长因子TGF-β1，并通过真空冷冻干燥技术制备了包裹TGF-β1的壳聚糖微球。然后分别将其与空白壳聚糖微球整合进软骨支架中，并接种小鼠软骨细胞ATDC-5，通过观察细胞生长状态来评价缓释微球在人工软骨支架中对软骨细胞生长是否具有促进作用。结果显示所制得的壳聚糖微球球体表面光滑，分散均匀，直径在100 nm左右，吸水率良好可达983.73%±4.38%，抗酶解作用较强，第28天时降解率仅达到51.0%±1.8%。由TGF-β1累积释放曲线可知TGF-β1在开始的24 h内释放最快，之后逐渐减慢，在120 h之后进入平台期，具有缓释效果。MTT试验以及荧光染色试验充分表明，由Ⅱ型胶原蛋白、透明质酸以及硫酸软骨素构建的三维软骨支架适合ATDC-5细胞的生长增殖，并且壳聚糖微球对TGF-β1的缓释能够显著促进细胞的生长。

Abstract:

In order to promote the growth of chondrocyte ATDC-5 in collagen type II-hyaluronic acid-chondroitin sulfate composite scaffolds constructed previously in vitro, the sustained-releasing chitosan microspheres loading TGF-β1 were prepared by emulsification and cross-linking. In addition, ATDC-5 was inoculated into the scaffolds incorporating the chitosan microspheres with TGF-β1. Results show that the morphology of microsphere was round and uniform, mean diameter was about 100 nm, absorption rate was up to 983.7%±4.38%.When the microsphere was incubated under the condition of 107 U/L lysozyme, the degradation rate was only 51.0%±1.8% on day 28. Moreover, to compare the effect of TGF-β1, the growth of ATDC-5 in different scaffolds was observed by MTT assay and fluorescence staining test. According to the cumulative release curve, TGF-β1 was released quickly at initial 24 h, then gradually decelerated, finally reached the plateau after 120 h. MTT assay and fluorescence staining test demonstrated that the scaffolds were suitable for ATDC-5 growth and proliferation, as well as, suggested that the sustained-releasing chitosan microspheres loading TGF-β1 could significantly promote the growth of ATDC-5.