卡拉胶/聚乙烯醇复合材料的制备及生物相容性评价

Preparation of polyvinyl alcohol/lota-carrageenan scaffolds and its biocompatibility

背景:聚乙烯醇水凝胶具有与天然关节软骨类似多孔结构和力学性能,适合于关节软骨修复的研究。但纯聚乙烯醇水凝胶不仅缺乏细胞黏附性,而且成型过程中容易出现形貌皱缩的现象,严重限制了其在组织工程领域中的应用。将活性聚合物添加到聚乙烯醇水凝胶体系中能够提高材料的细胞黏附能力。目的:制备含不同卡拉胶配比的聚乙烯醇/ι-卡拉胶复合材料,以血管内皮细胞评价其生物相容性。方法:制备含不同卡拉胶的聚乙烯醇/ι-卡拉胶二维复合膜材料,将血管内皮细胞与复合膜材料共培养,通过细胞黏附及增殖实验,扫描电镜观察细胞在材料上的生长及增殖状况,评价其生物相容性;在此基础上进一步制备不同卡拉胶配比的三维支架材料,根据医疗器械生物学评价标准进行溶血实验,扫描电镜观察复合支架材料的孔隙率、孔径。结果与结论:1体外细胞实验结果表明卡拉胶的加入可以显著提高聚乙烯醇水凝胶的生物活性,促进细胞在材料上的黏附和增殖;2不同卡拉胶配比的各实验组溶血率均小于公认的5%,说明材料符合医用材料的溶血实验要求;3卡拉胶质量分数为20%-30%的材料有适合细胞生长、增殖的孔径和有助于养料和代谢产物的输送孔隙率,可为进一步制备组织工程支架材料提供理论支持。

BACKGROUND： Polyvinyl alcohol（PVA） hydrogel with similar porous structure and mechanical properties to the natural cartilage is very suitable for the repair of articular cartilage. However, the pure PVA hydrogel after lyophilization will be accompanied by the shrinkage of the polymer network and the collapse of the pores, leading to the inhomogeneous performance of the material even in the state of re-swelling. Addition of the active polymer will increase the cell adhesion ability of PVA hydrogel.OBJECTIVE： To construct PVA/ lota-carrageenan（l-CA） composite materials with different mass fractions of l-CA and evaluate the biocompatibility with vascular endothelial cells. METHODS： PVA/l-CA composite films with different contents of l-CA were fabricated and then co-cultured with vascular endothelial cells. Attachment, proliferation and morphological changes of vascular endothelial cells on the composite were observed by scanning electron microscope and MTT assay to evaluate its biocompatibility. PVA/l-CA three-dimensional scaffold with different contents of l-CA were constructed, and hemolysis experiment was conducted according to the biological evaluation standards of medical devices, and the porosity and pore size were observed using scanning electron microscope. RESULTS AND CONCLUSION： In vitro experimental results showed that the addition of l-CA could significantly increase the biological activity of PVA hydrogel, and promote the cell attachment and proliferation on the scaffold. The hemolysis rate of each experimental group was less than 5%（the accepted safety standard）, suggesting that the composite materials were in accordance with the standard of medical devices for hemolysis experiment. These findings indicate that the composite scaffolds with 20%-30% l-CA possess the pore size suitable for cell growth and proliferation and the porosity beneficial for transportation of nutrients and metabolites, which can serve as an excellent scaffold for tissue engineering.