Department of Chemical Engineering, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0385, Japan.
Acta Biomater. 2012 Feb;8(2):686-93. doi: 10.1016/j.actbio.2011.10.005. Epub 2011 Oct 11.
Conventional chitosan hydrogels exhibit an acidic nature and contain unfavorable additives because (i) chitosan is soluble only in acidic solutions and (ii) toxic chemicals or proteins of non-human origin that serve as antigens are necessary for preparing chitosan hydrogels. These characteristics of the chitosan hydrogels limit their possibilities as wound dressings. In this study, a chitosan-gluconic acid conjugate is developed, soluble in an aqueous solution at neutral pH and gellable by freeze-thawing (cryogelation) without using additives. The viability of L929 fibroblasts cultured in the presence of the chitosan derivative for 24 h was >96%. The degradation rate of the corresponding chitosan cryogels by lysozyme was tunable via the derivative concentration in the gels. The gels had low cellular adhesiveness. The gels promoted the accumulation of inflammatory cells such as polymorphonuclear leukocytes, which have the potential to release chemical mediators effective for wound healing, in full-thickness skin wounds in rats and accelerated the healing of the wounds. These results demonstrate that cryogels are promising for wound care.
常规的壳聚糖水凝胶呈酸性，并且含有不利的添加剂，因为 (i) 壳聚糖仅在酸性溶液中溶解，以及 (ii) 为了制备壳聚糖水凝胶，需要使用有毒的化学物质或作为抗原的非人类来源的蛋白质。这些壳聚糖水凝胶的特性限制了它们作为伤口敷料的可能性。在这项研究中，开发了一种在中性 pH 条件下可溶于水溶液且可通过冻融（冰晶形成）凝胶化而无需添加物的壳聚糖-葡萄糖酸缀合物。在存在壳聚糖衍生物的情况下培养 24 小时的 L929 成纤维细胞的存活率>96%。通过凝胶中衍生物的浓度可调节溶菌酶对相应壳聚糖冰晶的降解速率。这些凝胶的细胞黏附性低。凝胶促进了炎症细胞（如多形核白细胞）的积累，这些细胞有可能释放对伤口愈合有效的化学介质，并加速伤口的愈合。这些结果表明，冰晶凝胶有望用于伤口护理。
