Takei Takayuki, Danjo So, Sakoguchi Shogo, Tanaka Sadao, Yoshinaga Takuma, Nishimata Hiroto, Yoshida Masahiro
Department of Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
Departent of Diagnostic Pathology, Nanpuh Hospital, 14-3 Nagata-cho, Kagoshima 891-8512, Japan.
J Biosci Bioeng. 2018 Apr;125(4):490-495. doi: 10.1016/j.jbiosc.2017.10.015. Epub 2017 Nov 20.
Moist wounds were known to heal more rapidly than dry wounds. Hydrogel wound dressings were suitable for the moist wound healing because of their hyperhydrous structure. Chitosan was a strong candidate as a base material for hydrogel wound dressings because the polymer had excellent biological properties that promoted wound healing. We previously developed physically-crosslinked chitosan cryogels, which were prepared solely by freeze-thawing of a chitosan-gluconic acid conjugate (CG) aqueous solution, for wound treatment. The CG cryogels were disinfected by immersing in 70% ethanol before applying to wounds in our previous study. In the present study, we examined the influence of autoclave sterilization (121°C, 20 min) on the characteristics of CG cryogel because complete sterilization was one of the fundamental requirements for medical devices. We found that optimum value of gluconic acid content of CG, defined as the number of the incorporated gluconic acid units per 100 glucosamine units of chitosan, was 11 for autoclaving. An increased crosslinking level of CG cryogel on autoclaving enhanced resistance of the gels to enzymatic degradation. Furthermore, the autoclaved CG cryogels retained favorable biological properties of the pre-autoclaved CG cryogels in that they showed the same hemostatic activity and efficacy in repairing full-thickness skin wounds as the pre-autoclaved CG cryogels. These results showed the great potential of autoclavable CG cryogels as a practical wound dressing.
众所周知，湿性伤口比干性伤口愈合得更快。水凝胶伤口敷料由于其高含水结构而适用于湿性伤口愈合。壳聚糖是水凝胶伤口敷料基础材料的有力候选者，因为该聚合物具有促进伤口愈合的优异生物学特性。我们之前开发了物理交联的壳聚糖冷冻凝胶，其仅通过壳聚糖 - 葡萄糖酸共轭物（CG）水溶液的冻融制备用于伤口治疗。在我们之前的研究中，CG冷冻凝胶在应用于伤口之前通过浸入70%乙醇进行消毒。在本研究中，我们研究了高压灭菌（121°C，20分钟）对CG冷冻凝胶特性的影响，因为完全灭菌是医疗器械的基本要求之一。我们发现，对于高压灭菌，CG中葡萄糖酸含量的最佳值（定义为每100个壳聚糖葡糖胺单元中掺入的葡萄糖酸单元数）为11。高压灭菌时CG冷冻凝胶交联水平的提高增强了凝胶对酶降解的抗性。此外，高压灭菌后的CG冷冻凝胶保留了灭菌前CG冷冻凝胶的良好生物学特性，即它们在修复全层皮肤伤口方面表现出与灭菌前CG冷冻凝胶相同的止血活性和功效。这些结果表明可高压灭菌的CG冷冻凝胶作为一种实用伤口敷料具有巨大潜力。
