【摘要】 高分子水凝胶是一种具有极高含水量的软物质,一般由低交联度的聚合物构成。水凝胶结构和性质与人体软组织高度相似,因此水凝胶已被广泛应用于生物医学等领域。自我修复水凝胶是一种可以在受到损伤后,自动恢复其完整性和自身功能的一类新型水凝胶。迄今为止,研究者通过物理或动态化学键合成了多种自愈合水凝胶。物理交联水凝胶是通过多重氢键作用、主-客体相互作用、离子键、金属配位、疏水相互作用和超分子相互作用等合成的。化学交联水凝胶则是通过动态化学键合成的自愈合水凝胶,与物理自愈合水凝胶相比,其内部交联网络连接强度较高,从而导致其具有更快的自愈过程和更高的机械强度。因此,动态化学键,如亚胺键、酰腙键和二硫键已被广泛用于制备自愈合水凝胶。自愈合水凝胶作为一种新型智能材料,在医疗生物领域具有十分广泛的应用前景。然而,大部分水凝胶是响应外部刺激反应的亲水性交联三维体系。在体内,一旦外部机械力或生理侵蚀破坏了水凝胶结构的完整性,水凝胶的功能性就会丧失。因此,在使用过程中水凝胶的结构和功能完整性会受到外部机械力或化学侵蚀的影响,特别是在复杂的体内环境中。为解决这一问题,已经设计开发出的具有内在自愈合能力的自愈合水凝胶可以克服内外环境的破坏性因素。凭借自愈能力,水凝胶在有外界刺激或无外界刺激的情况下修复自身损伤并恢复其原有结构和性能,从而提高水凝胶的可靠性与安全性。与传统水凝胶相比,自愈合水凝胶具有更长的使用寿命和更好的力学性能,使得自愈合水凝胶尤其是在三维细胞培养、组织工程、药物传送等方面具有更广阔的应用前景。由于自愈合水凝胶的研究尚处于起步阶段,目前大多数研究还处于探索寻求新型自愈合水凝胶体系的阶段。本文重点介绍了自愈合水凝胶的最新研究进展,对目前报道的一些自愈合水凝胶的合成策略进行总结与分析并阐述其自愈机理,即非共价键(物理键)包括多重氢键作用、疏水相互作用和主-客体相互作用,动态共价键(化学键)包括亚胺键、酰腙键。此外,分析了影响水凝胶自愈合性能的主要因素及其在组织工程、药物传送等生物医学领域的广泛应用,以期为制备性能优异的新型水凝胶提供参考。更多还原

【Abstract】 Apolymer hydrogel is a soft material with high water content and generally composed of a polymer having a low degree of crosslinking. Hydro-gels have been widely used in biomedical fields due to their advantages such as the structure and properties of hydrogels and the extremely high similarity of human soft tissues. Self-healing hydrogels are a new class of hydrogels that automatically restore their integrity and function after injury. Self-healing properties are important for extending the life of the material that is difficult to manufacture. To date,a variety of self-healing hydrogels have been synthesized by physical or dynamic chemical bonding. Physically crosslinked hydrogels are generally synthesized by multiple hydrogen bonding,host-guest interactions,ionic bonds,metal coordination,hydrophobic interactions,and supramolecular interactions. Chemical cross-linked self-healing hydrogels synthesized by dynamic chemical bonding have higher internal crosslink network strength than physical selfhealing hydrogels,resulting in faster self-healing processes and higher mechanical strength. Therefore,dynamic chemical linkages such as imine bonds,hydrazide bonds and disulfide bonds,have been widely used to prepare self-healing hydrogels.As a new intelligent material,self-healing hydrogel has a wide application prospect in the field of medical biology. However,most hydrogels are three-dimensional systems of hydrophilic cross-linking in response to external stimuli. In vivo,once external mechanical forces or physiological erosion disrupts the structural integrity of the hydrogel,the functionality of the hydrogel is lost. Thus,the structural and functional integrity of the hydrogel during use may be affected by external mechanical forces or chemical attack,particularly in complex in vivo environments. In order to solve this problem,self-healing hydrogel with intrinsic self-healing ability can overcome internal and external environmental destructive factors that has been designed and developed. With self-healing capabilities,hydrogels can repair their damage and restore their original structure and performance with or without external stimuli,improving reliability and safety. Compared with traditional hydrogels,self-healing hydrogels have a longer service life and higher mechanical properties,which makes self-healing hydrogels have broader application prospects,especially in three-dimensional cell culture,tissue engineering and drug delivery.Since the research on self-healing hydrogels is still in its infancy,most of the research is still in the stage of exploring new self-healing hydrogel systems. In this review,the latest developments in self-healing hydrogels are highlighted,and the synthesis strategies of some self-healing hydrogels reported so far are summarized and analyzed,and the self-healing mechanism is described. Non-covalent bonds( physical bonds) include multiple hydrogen bonding,hydrophobic interactions,host-guest interactions,and dynamic covalent bonds( chemical bonds) include imine bonds and hydrazide bonds. In addition,the main factors affecting the self-healing properties of hydrogels and their extensive applications in biomedical fields such as tissue engineering and drug delivery were analyzed,which provide references for the preparation of novel self-healing hydrogels with superior performance.更多还原