Huang Hongjie, Zhang Xin, Hu Xiaoqing, Dai Linghui, Zhu Jingxian, Man Zhentao, Chen Haifeng, Zhou Chunyan, Ao Yingfang
Institute of Sports Medicine, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, People's Republic of China.
Biomed Mater. 2014 Jun;9(3):035008. doi: 10.1088/1748-6041/9/3/035008. Epub 2014 Apr 25.
Hydrogels are attractive for cartilage tissue engineering because of their high plasticity and similarity with the native cartilage matrix. However, one critical drawback of hydrogels for osteochondral repair is their inadequate mechanical strength. To address this limitation, we constructed a solid-supported thermogel comprising a chitosan hydrogel system and demineralized bone matrix. Scanning electron microscopy, the equilibrium scanning ratio, the biodegradation rate, biomechanical tests, biochemical assays, metabolic activity tests, immunostaining and cartilage-specific gene expression analysis were used to evaluate the solid-supported thermogel. Compared with pure hydrogel or demineralized matrix, the hybrid biomaterial showed superior porosity, equilibrium swelling and degradation rate. The hybrid scaffolds exhibited an increased mechanical strength: 75% and 30% higher compared with pure hydrogels and demineralized matrix, respectively. After three days culture, bone-derived mesenchymal stem cells (BMSCs) maintained viability above 90% in all three materials; however, the cell retention of the hybrid scaffolds was more efficient and uniform than the other materials. Matrix production and chondrogenic differentiation of BMSCs in the hybrid scaffolds were superior to its precursors, based on glycosaminoglycan quantification and hyaline cartilage marker expression after three weeks in culture. Its easy preparation, favourable biophysical properties and chondrogenic capacity indicated that this solid-supported thermogel could be an attractive biomaterial framework for cartilage tissue engineering.
水凝胶因其高可塑性以及与天然软骨基质的相似性而在软骨组织工程中颇具吸引力。然而，水凝胶用于骨软骨修复的一个关键缺点是其机械强度不足。为解决这一局限性，我们构建了一种包含壳聚糖水凝胶系统和脱矿骨基质的固体支撑热凝胶。通过扫描电子显微镜、平衡扫描率、生物降解率、生物力学测试、生化分析、代谢活性测试、免疫染色以及软骨特异性基因表达分析来评估该固体支撑热凝胶。与纯水凝胶或脱矿基质相比，这种混合生物材料表现出更好的孔隙率、平衡溶胀和降解速率。混合支架的机械强度有所提高：分别比纯水凝胶和脱矿基质高出75%和30%。培养三天后，骨源性间充质干细胞（BMSCs）在这三种材料中均保持90%以上的活力；然而，混合支架对细胞的保留比其他材料更有效且更均匀。基于培养三周后的糖胺聚糖定量和透明软骨标志物表达，混合支架中BMSCs的基质产生和成软骨分化优于其前体材料。其易于制备、良好的生物物理性质和成软骨能力表明，这种固体支撑热凝胶可能是软骨组织工程中一种有吸引力的生物材料框架。
