作者:Shereen Tan、Anton Blencowe、Katharina Ladewig、Greg G. Qiao
DOI:10.1039/c3sm50638j
日期:——
Herein, we report the synthesis of sliding-ring (SR) hydrogel networks in a one-pot click-mediated approach using α,ω-dialkyne poly(ethylene glycol) (PEG) and azido-functionalised cyclodextrin, which acts as both sliding cross-link and end-capping agent. This novel approach resulted in polymeric networks that possess a combination of both SR and covalent (CV) cross-link points. The extent of inclusion complexation and the ratio of SR to CV cross-links in the hydrogels was found to be dependent on both the concentration of the precursors and the curing temperature. Based upon model studies where rotaxanes were synthesised from the same precursors, it was observed that an increase in the precursor concentration led to an increase in click efficiency and inclusion ratio, which in turn affects the overall hydrogel rigidity and elasticity. Hydrogels synthesised at higher curing temperatures led to more homogeneous networks that were significantly tougher as a result of the overall increase in cross-linking density and the extent of CV cross-links. We therefore present a facile one-pot method for the synthesis of SR networks with tunable physicochemical properties. Additionally, the resultant hydrogel networks are potentially capable of supporting post-modification with various (bio)molecules or therapeutics utilizing the remaining azide groups on the cyclodextrin cross-links. Preliminary cytotoxicity studies revealed that the hydrogels did not impede cell growth and demonstrate negligible toxicity. Thus, these networks may have potential for soft-tissue engineering or biomedical applications, including sustained release and drug-delivery systems.
在本文中,我们报告了利用α,ω-二炔聚乙二醇(PEG)和叠氮功能化环糊精(它既是滑动交联剂,又是端封剂),通过一锅点击介导法合成滑动环(SR)水凝胶网络的情况。这种新方法产生的聚合物网络同时具有 SR 交联点和共价(CV)交联点。研究发现,水凝胶中的包合物复合程度以及 SR 交联与 CV 交联的比例取决于前体的浓度和固化温度。根据用相同前体合成轮烷的模型研究,可以发现前体浓度的增加会导致点击效率和包合比的增加,进而影响水凝胶的整体刚性和弹性。在较高的固化温度下合成的水凝胶可形成更均匀的网络,由于交联密度和 CV 交联程度的整体提高,网络的韧性明显增强。因此,我们提出了一种简便的一锅法,用于合成具有可调理化特性的 SR 网络。此外,利用环糊精交联物上残留的叠氮基团,所生成的水凝胶网络还可能支持各种(生物)分子或疗法的后修饰。初步的细胞毒性研究表明,水凝胶不会阻碍细胞生长,其毒性可忽略不计。因此,这些网络可能具有软组织工程或生物医学应用的潜力,包括缓释和给药系统。