Brinkman William T, Nagapudi Karthik, Thomas Benjamin S, Chaikof Elliot L
Departments of Surgery and Biomedical Engineering, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
Biomacromolecules. 2003 Jul-Aug;4(4):890-5. doi: 10.1021/bm0257412.
The effectiveness of photomediated cross-linking of type I collagen gels in the presence of rat aortic smooth muscle cells (RASMC) as a method to enhance gel mechanical properties while retaining native collagen triple helical structure and maintaining high cell viability was investigated. Collagen was chemically modified to incorporate an acrylate moiety. Collagen methacrylamide was cast into gels in the presence of a photoinitiator along with RASMC. The gels were cross-linked using visible light irradiation. Neither acrylate modification nor the cross-linking reaction altered collagen triple helical content. The cross-linking reaction, however, moved the denaturation temperature beyond the physiologic range. A twelve-fold increase in shear modulus was observed after cross-linking. Cell viability in the range of 70% (n = 4, p > 0.05) was observed in the photo-cross-linked gels. Moreover the cells were able to contract the cross-linked gel in a manner commensurate with that observed for natural type I collagen. Methacrylate-mediated photo-cross-linking is a facile route to improve mechanical properties of collagen gels in the presence of cells while maintaining high cell viability. This enhances the potential for type I collagen gels to be used as scaffolds for tissue engineering.
研究了在大鼠主动脉平滑肌细胞（RASMC）存在的情况下，光介导的I型胶原凝胶交联作为一种增强凝胶机械性能同时保留天然胶原三螺旋结构并维持高细胞活力的方法的有效性。将胶原蛋白进行化学修饰以引入丙烯酸酯部分。在光引发剂存在下，将甲基丙烯酰胺胶原蛋白与RASMC一起浇铸到凝胶中。使用可见光照射使凝胶交联。丙烯酸酯修饰和交联反应均未改变胶原三螺旋含量。然而，交联反应使变性温度超出了生理范围。交联后观察到剪切模量增加了12倍。在光交联凝胶中观察到细胞活力在70%的范围内（n = 4，p > 0.05）。此外，细胞能够以与天然I型胶原相当的方式收缩交联凝胶。甲基丙烯酸酯介导的光交联是一种在细胞存在下改善胶原凝胶机械性能同时维持高细胞活力的简便途径。这增强了I型胶原凝胶用作组织工程支架的潜力。
