超快动态交联的可注射壳聚糖-透明质酸水凝胶及促创伤愈合研究

可注射动态水凝胶是近年研究的热点,而制备无催化剂体系的快速交联的可注射动态水凝胶是研究的难点之一。以甲基丙烯酰化壳聚糖(CHMA)和醛基化透明质酸(ALHA)为原料,利用CHMA分子上的氨基与ALHA分子上的醛基和羧基,分别形成可逆动态席夫碱键和静电相互作用,可快速制备一种水凝胶。通过动态流变分析仪表征其凝胶化速率、剪切变稀行为和自愈合特征,通过体外细胞三维培养实验评估其细胞相容性,并通过急性全层皮肤创伤修复实验对其创伤愈合速率进行评估。结果表明,只需5 s,CHMA和ALHA的混合溶液就能形成凝胶。此外,该凝胶具有剪切变稀和快速自愈合的可注射特征,当扫描频率从10^-1 s^-1增加至10² s^-1时,其复数黏度由0.4 kPa降低至8 Pa;当应变在1%~1000%之间交替变化时,储能模量与损耗模量的大小能够迅速切换,且模量没有显著性地降低。同时,体外细胞三维培养实验表明,该水凝胶还具有优异的细胞相容性(细胞存活率高于95%),并且在雄性ICR小鼠急性全层皮肤缺损模型实验中,水凝胶组的创伤愈合时间相比空白对照组缩短5～7 d,表现出较快的创伤愈合速率。综上可见,这种可注射壳聚糖-透明质酸水凝胶在生物医药、组织功能、临床医学等领域具有广阔的应用前景。

Ultra-Rapid Fabrication of Dynamic-Crosslinked Injectable Chitosan-Hyaluronate Hydrogel for Wound Healing

The development of injectable dynamic hydrogels has been one hot issue in recent years, and the preparation of catalyst-free fast-crosslinked injectable dynamic hydrogels is still one big challenge. In this paper, reversible dynamic Schiff base bonds and electrostatic interactions, formed by amine groups on methylacrylated chitosan (CHMA) molecules with aldehyde groups and carboxyl groups on Aldehyde hyaluronic acid (ALHA) molecules respectively, were utilized to prepare a novel catalyst-free hydrogel. The gelation rate, shear thinning behavior and self-healing characteristics of the hydrogel were characterized by dynamic rheological analyzer, the cytocompatibility was evaluated by the cell three-dimensional culture experiment, and the wound healing rate was evaluated through the acute full-thickness skin wound repair experiment. Results showed that the hydrogel quickly formed in 5 seconds the aqueous solution of CHMA and ALHA were mixed. In addition, the hydrogel was an injectable one with shear thinning and rapid self-healing. The complex viscosity gradually decreased from 0.4 kPa to 8 Pa, when the scanning frequency increased from 10^-1 s^-1 to 10² s^-1. Meanwhile, the values order of its storage modulus and loss modulus switched quickly between 1% and 1000% of the strain, yet the modulus had no significant decrease. The hydrogel also exhibited excellent cytocompatibility and fast wound healing rate, evidenced by the high cell survival rate (>95%) in the 3D culture of cells, and a reduction in the wound healing time of 5-7 days in the hydrogel group compared to the blank control based on a model of acute full-thickness skin defect in male ICR mice. The injectable chitosan-hyaluronate hydrogel showed broad application perspectives in the fields of regenerative medicine.