光响应性水凝胶的分子设计和仿生驱动

Molecular Design of Photoresponsive Hydrogels for Biomimetic Actuation

高分子水凝胶是一类具有高含水量的聚合物交联网络,可在外界环境刺激下通过吸水或失水过程产生体积溶胀或收缩,良好的生物相容性和可调的力学性能使其在组织工程、仿生形变以及智能驱动等领域备受关注。光作为一种无接触式、可快速开关和具备高时空分辨率的刺激信号,可通过光热效应、光化学反应或光异构化等途径来调控水凝胶的宏观结构和性能,其中光异构化方法因其光照条件温和、高度可逆等优势有着更加广阔的应用前景。本文从光响应性水凝胶的分子设计、制备以及仿生智能驱动等方面,综述了当前基于分子开关异构化的光响应性水凝胶,并对其发展现状、面临的挑战和应用前景进行了展望。

Hydrogels are a type of high-water content and crosslinked polymer networks,which can produce a volumetric expansion or contraction through a water absorption or loss process under external environmental stimulation.Due to their good biocompatibility and adjustable mechanical properties,hydrogels have attracted wide attentions and have been extensively applied in the fields of tissue engineering,biomimetic deformation and intelligent actuation.Light is a non-contact,fast switching and high spatiotemporal resolution stimulus,and therefore is used to regulate the macroscopic structure and properties of hydrogels through photothermal effects,photochemical reactions or photoisomerization.Among them,photoisomerization of molecular switches has a broader application potential because of its advantages of mild irradiation conditions and high reversibility.In this review,we summarize the state-of-the-art of photoresponsive hydrogels based on molecular photoisomerization,emphasizing the principle of molecular design as well as applications in biomimetic actuation,and eventually address their perspectives and challenges in the future development.