Department of Organic Biomaterials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062, Japan.
Department of Bionanotechnology and Bio-Convergence Engineering, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 54896, Republic of Korea.
ACS Biomater Sci Eng. 2022 Feb 14;8(2):588-597. doi: 10.1021/acsbiomaterials.1c01521. Epub 2022 Jan 7.
To improve the mechanical properties of collagen hydrogels, which are widely utilized as biomaterials, post-cross-linking of collagen hydrogels was performed using polyrotaxane (PRX) as a cross-linker. Herein, carboxymethyl group-modified PRXs (CMPRs) composed of carboxymethylated α-cyclodextrins (α-CDs) threaded along poly(ethylene glycol) (PEG) capped with bulky stoppers were used to cross-link via reaction with the amino groups in the collagen. Four series of CMPRs with different α-CD threading ratios and axle PEG molecular weights were used for the post-cross-linking of the collagen hydrogels to verify the optimal CMPR chemical compositions. The post-cross-linking of the collagen hydrogels with CMPRs improved the swelling ratios and mechanical properties, such as viscoelasticity and tensile strength. Among the tested CMPRs, CMPRs with an axle PEG molecular weight of 35,000 (PEG35k) resulted in better mechanical properties than CMPRs with a PEG10k axis. Additionally, the cell adhesion and proliferation were greatly improved on the surface of the collagen hydrogels post-cross-linked with CMPRs with the PEG35k axle. These findings suggest that the molecular weight of an axle polymer in CMPRs is a more important parameter than the α-CD threading ratios. Accordingly, the post-cross-linking of hydrogels with PRXs is promising for improving the mechanical properties and biomaterial functions of collagen hydrogels.
为了改善胶原水凝胶的机械性能，将其作为生物材料广泛应用，使用聚轮烷（PRX）作为交联剂对胶原水凝胶进行后交联。在此，使用由接枝有大体积止推剂的聚乙二醇（PEG）封端的羧甲基化α-环糊精（α-CD）贯穿的羧甲基化 PRX（CMPR）通过与胶原中的氨基反应进行交联。使用具有不同α-CD 贯穿比和轴 PEG 分子量的四个系列的 CMPR 对胶原水凝胶进行后交联，以验证最佳 CMPR 化学组成。CMPR 对胶原水凝胶的后交联提高了水凝胶的溶胀比和机械性能，如粘弹性和拉伸强度。在所测试的 CMPR 中，轴 PEG 分子量为 35,000（PEG35k）的 CMPR 产生的机械性能优于轴 PEG10k 的 CMPR。此外，在 CMPR 交联的胶原水凝胶表面，细胞黏附和增殖得到了极大改善。这些发现表明，CMPR 中轴聚合物的分子量比 α-CD 贯穿比更重要。因此，使用 PRX 对水凝胶进行后交联有望改善胶原水凝胶的机械性能和生物材料功能。
