Xu Xian, Jha Amit K, Harrington Daniel A, Farach-Carson Mary C, Jia Xinqiao
Department of Materials Science and Engineering, Delaware Biotechnology Institute, University of Delaware, Newark, DE 19716.
Soft Matter. 2012;8(12):3280-3294. doi: 10.1039/C2SM06463D.
Hyaluronic acid (HA) is one of nature's most versatile and fascinating macromolecules. Being an essential component of the natural extracellular matrix (ECM), HA plays an important role in a variety of biological processes. Inherently biocompatible, biodegradable and non-immunogenic, HA is an attractive starting material for the construction of hydrogels with desired morphology, stiffness and bioactivity. While the interconnected network extends to the macroscopic level in HA bulk gels, HA hydrogel particles (HGPs, microgels or nanogels) confine the network to microscopic dimensions. Taking advantage of various scaffold fabrication techniques, HA hydrogels with complex architecture, unique anisotropy, tunable viscoelasticity and desired biologic outcomes have been synthesized and characterized. Physical entrapment and covalent integration of hydrogel particles in a secondary HA network give rise to hybrid networks that are hierarchically structured and mechanically robust, capable of mediating cellular activities through the spatial and temporal presentation of biological cues. This review highlights recent efforts in converting a naturally occurring polysaccharide to drug releasing hydrogel particles, and finally, complex and instructive macroscopic networks. HA-based hydrogels are promising materials for tissue repair and regeneration.
透明质酸（HA）是自然界中用途最为广泛且迷人的大分子之一。作为天然细胞外基质（ECM）的重要组成部分，HA在多种生物过程中发挥着重要作用。HA具有固有的生物相容性、可生物降解性和非免疫原性，是构建具有所需形态、硬度和生物活性水凝胶的理想起始材料。虽然在HA块状凝胶中相互连接的网络延伸到宏观层面，但HA水凝胶颗粒（HGPs，微凝胶或纳米凝胶）将网络限制在微观尺寸。利用各种支架制造技术，已合成并表征了具有复杂结构、独特各向异性、可调粘弹性和所需生物学结果的HA水凝胶。水凝胶颗粒在二级HA网络中的物理包埋和共价整合产生了分层结构且机械坚固的混合网络，能够通过生物信号的空间和时间呈现来介导细胞活动。本综述重点介绍了将天然存在的多糖转化为药物释放水凝胶颗粒，最终转化为复杂且具有指导意义的宏观网络的最新研究成果。基于HA的水凝胶是用于组织修复和再生的有前途的材料。
