Cytodext-3微载体/藻酸钠水凝胶作为可注射性支架构建组织工程软骨的可行性

Constructing injectable tissue-engineered cartilage using cytodex-3 microcarrier and alginate hydrogel

背景:藻酸钠水凝胶和微载体均可作为注射性支架材料,但存在力学性能差和可塑性差等缺点。目的:探索Cytodext-3微载体与藻酸钠水凝胶复合体作为可注射性组织工程软骨支架的可行性。方法:制备可注射性Cytodext-3微载体/藻酸钠水凝胶复合支架、可注射藻酸钠水凝胶支架,检测两组支架的力学性能。将软骨细胞与Cytodext-3微载体置于生物反应中培养,获得负载软骨细胞的微载体,再与藻酸钠水凝胶复合,作为实验组;将软骨细胞与可注射藻酸钠水凝胶支架共培养,作为对照组,检测两组支架内的细胞活性、细胞合成DNA与糖胺聚糖的能力。结果与结论:(1)可注射性Cytodext-3微载体/藻酸钠水凝胶复合支架杨氏弹性模量高于可注射藻酸钠水凝胶支架(P<0.05);(2)对照组内软骨细胞呈圆形形状,均匀分布于藻酸钠凝胶中;实验组软骨细胞帖附于微载体表面,均匀分布于支架中;培养1 d后,两组支架内部可见,亦可见大量死亡的软骨细胞;14 d后,两组支架内均未发现死亡细胞,大量增殖软骨细胞保持较高的细胞活性,实验组细胞数量明显多于对照组;(3)随着时间的延长,两组细胞合成DNA与糖胺聚糖的含量逐渐增多,实验组DNA与糖胺聚糖含量高于对照组(P<0.05);(4)结果表明:Cytodext-3微载体/藻酸钠水凝胶复合体有望作为一种良好的具有可注射性的组织工程软骨支架。

BACKGROUND：Alginate hydrogel and microcarrierbothcan be used as injectable scaffolds, buttheir shortcomings such as poor mechanical property and poor plasticity remain unresolved. OBJIECTIVE：To explore the feasibility of constructing an injectable tissue-engineered cartilage with cytodex-3 microcarrier/alginate hydrogelcomposite. METHODS：Injectable cytodex-3 microcarrier/alginate hydrogel composite scaffold and injectable alginate hydrogel scaffold were established, and the mechanical properties of the two scaffolds were detected. Chondrocytes-seeded cytodex-3 microcarrier was obtained after incubatedin the bioreactor, and then composited with alginate hydrogel as experimental group; chondrocytes were co-cultured with alginate hydrogel as control group. Subsequently, cel viabilityandability ofDNA and glycosaminoglycansynthesis were detected. RESULTS AND CONCLUSION：The Young’s modulus of the experimental group was significantly higher than that of the control group （P〈 0.05）. And in the control group, chondrocytes were in a round shape and evenly distributed in the alginate hydrogel; in the experimental group, chondrocytes adhered on the scaffold surface and evenly distributed in the scaffold. After 1 day of culture,bothviable and numerous dead chondrocytes could be found in both two scaffolds; and after 14-day culture, there were no dead chondrocytes in both two scaffolds, abundant proliferating chondrocytes maintained a high cel viability, andthe number of chondrocytes in the experimental group was significantly higer than that of the control group. What’s more, the contents of DNA and glycosaminoglycans were in a rise with time in both two groups, which were significantly higher in the experimental groupthan the control group（P〈 0.05）. These results suggest that the cytodex-3 microcarrier/alginate hydrogel composite is a promising injectable scaffold in cartilage tissue engineering.