环糊精衍生物水凝胶材料的研究进展

Advances in Hydrogel Materials Based on Cyclodextrin Derivatives

水凝胶是一种由化学或物理交联的高分子聚合材料,具有亲水性的三维网络结构,使其能够吸收并保持大量的水分。水凝胶相对其他材料有着明显优势,其具有含水量高、性质柔软、通透性高、生物相容性好等优点,这些优异的性质使水凝胶在工业、农业、生物医学乃至生活中都有着广泛的应用。近些年来国内外研究者都致力于开发新型水凝胶,以解决传统水凝胶存在的力学强度差、功能单一的问题。因此,涌现了大批多功能、高强度的新型水凝胶,如温度、pH、光、电磁刺激响应性水凝胶,双网络、互穿网络水凝胶,纳米复合水凝胶,自愈合性水凝胶。其中,环糊精及其衍生物的引入是改善水凝胶不足的重要方法之一。环糊精存在特殊的外缘亲水、内部疏水的环状分子结构以及疏水性空腔,能够通过主客体偶合作用稳定络合疏水性分子。近年来,研究者们充分利用环糊精独特的结构和性质,在设计更好的环糊精衍生物水凝胶结构和功能方面不断地进行尝试,取得了丰硕的研究成果,制备了一系列具有优异性能的环糊精及其衍生物高分子水凝胶。环糊精及其衍生物水凝胶不仅在力学性能方面表现出优势,还具有显著的功能性,如刺激响应性、自修复性、形状记忆性、可注射性等。目前,已报道的环糊精衍生物水凝胶结构多样、性质各异,按其网络结构可分为:(1)化学修饰环糊精作为交联剂合成水凝胶;(2)环糊精衍生物的主客体超分子水凝胶;(3)环糊精衍生物的物理/化学双交联水凝胶;(4)环糊精衍生物的滑环水凝胶。各种交联结构的环糊精衍生物水凝胶的开发,赋予了水凝胶不同的功能和性质,为突破传统水凝胶的应用瓶颈提供了思路,使其在催化工程、药物控释、骨/软骨组织修复和水污染物净化领域具有广阔的应用前景。本文归纳了环糊精衍生物高分子水凝胶的研究进展,按水凝胶的交联结构对环糊精衍生物水凝胶进行分类,分别对环糊精分子、环糊精衍生物水凝胶的结构、制备方法、应用等进行介绍,分析了环糊精衍生物高分子水凝胶所面临的问题并展望其前景,以期为制备多功能、高强度环糊精衍生物水凝胶提供参考。

Hydrogels are a kind of chemically or physically crosslinked polymer materials.The hydrophilic three-dimensional network structure endows hydrogels with the ability of absorbing and maintaining a large amount of water.Compared with other materials,hydrogels possess outstanding advantages including high water content,soft texture,excellent permeability and favorable biocompatibility,which enable the widespread application of hydrogels in industry,agriculture,biomedicine and even daily life.In recent years,researchers at home and abroad have devoted themselves to develop innovative hydrogels to overcome the poor mechanical strength and deficient function of traditional hydrogels.Therefore,numerous new hydrogels with multifunctional and high strength have emerged,such as temperature,pH,light,electromagnetic stimuli-responsive hydrogels,double networks,interpenetrating network hydrogels,nanocomposite hydrogels and self-healing hydrogel.It is worth mentioning that the introduction of cyclodextrin and its derivatives is one of the important strategies to solve the deficiency of hydrogels.Cyclodextrin molecules contain special structure with hydrophilic outer rim,hydrophobic inner ring and hydrophobic cavities,which can accommodate hydrophobic molecules through host and guest interaction.In recent years,researchers have taken advantage of the unique structure and properties of cyclodextrins and intensive research endeavors have been put into designing cyclodextrin derivative hydrogels with superior structures and functions.And impressive strides have achieved that a series of cyclodextrin derivatives based hydrogels with excellent properties were developed.Cyclodextrins derivatives based hydrogels not only show their superiority in terms of mechanical properties,but also have signi-ficant functions,like stimulus responsiveness,self-healing,shape memory,injectability,etc.Now,the reported cyclodextrin derivatives based hydrogels show diverse structures and various properties.They can be divided into four types according to their network structure:Ⅰ.mono-cyclodextrin crosslinked hydrogel;Ⅱ.host-guest supramolecular hydrogel;Ⅲ.cyclodextrin based double network hydrogel;Ⅳ.slide-ring hydrogel.The developments of cyclodextrin derivatives hydrogels with diverse cross-linked structures have create various functions and properties of hydrogels.Moreover,it provides a way to break through the bottlenecks of traditional hydrogels and broaden the application prospect in catalytic engineering,drug control release,bone/cartilage tissue repair and water pollutant purification.This review offers a retrospection of the research efforts to cyclodextrin polymer hydrogels.Cyclodextrin derivative hydrogels are classified according to the cross-linked structure.And the elaboration about the structure,preparation and application of cyclodextrin molecules and cyclodextrin derivatives hydrogels are provided respectively.The problems and prospects of cyclodextrin derivatives hydrogels were analyzed in order to provide reference for the preparation of multifunctional,high-strength cyclodextrin derivatives hydrogels.