电沉积制备具有抗菌活性的天然多糖水凝胶膜材料
摘要
本文主要研究使用电化学沉积方法获得具有抗菌活性的天然多糖水凝胶膜作为新一代抗菌敷料的可能性。主要研究了三种不同体系的电沉积天然多糖水凝胶及其复合材料，包括壳聚糖溴氧化膜，铜离子交联的碱式碳酸铜力学增强的海藻酸膜以及掺有纳米铜和无定形碳酸钙的海藻酸钙电沉积膜。我们使用扫描电子显微镜，能谱仪，傅里叶变换红外光谱仪，热重分析，碘量滴定法等理化性能表征手段观察沉积膜的表面形貌，元素组成及微观分子结构。使用大肠杆菌和甲氧西林耐受型金黄色葡萄球菌作为革兰氏阴性菌和阳性菌的代表，使用平板计数法，抑菌圈测试和活/死细菌染色对电沉积水凝胶膜的抗菌活性进行研究。使用小鼠成纤维细胞L929对铜离子交联的海藻酸膜的体外细胞毒性。我们还研究了铜离子交联海藻酸膜的体内创口愈合表现，以小鼠背部全创伤口作为模型，对创口进行抗菌水凝胶放置以及固定，在固定后1天，3天，7天和14天打开伤口拍照，计算伤口闭合率。14天对组织切片染色固定去表征创口愈合质量。实验结果表明，虽然铜作为有效地抗菌剂能够成功抑制细菌生长繁殖，但是同时，超过一定量的铜的加入会使铜敷料产生严重的细胞毒性和体内免疫反应。因此，我们需要使用一系列不同浓度的铜生物材料研究细胞毒性后，挑选不引起细胞强烈反应，又能有效抗菌的铜浓度实现抑制细菌生长和促进组织修复的平衡。
关键词：铜；纳米铜；电沉积；壳聚糖溴胺；海藻酸
Electrodeposition of Antimicrobial Natural Polysaccharide Hydrogel Film
Abstract
The electrodeposition for antimicrobial natural polysaccharide hydrogel film as new generation antimicrobial wound dressing was focused on. Three electrolyte systems, including chitosan bromamine film, copper ion crosslinked basic copper carbonate-alginate film and CuNPs incorporated calcium-crosslinked calcium carbonate alginate was tested. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transformed infrared spectroscopy (FTIR), thermogravity analysis (TG) and iodimetric titration were used to characterize the morphology, chemical elements and molecular structures. Escherichia Coli and Methicillin resistant Staphylococcus aureus were chosen as models of gram-positive and gram-negative bacteria. The antimicrobial efficiency of prepared films was tested by plate counting, halo tests and live/dead staining. The cytotoxicity of basic copper carbonate alginate film to mice fibroblasts L929 was tested. Furthermore, mice back full depth wound as animal model, the basic copper carbonate alginate film was fixed and postoperative time points 1 day, 3 days, 7 days and 14 days were chosen to take photos of film-free wound to determine wound closure rate. Histological analysis was utilized to characterize the wound closure quality. The results showed that though copper as efficient antimicrobial agent can inhibit the growth of bacteria, over-doped copper in wound dressing can lead to strong cell toxicity and immunological reaction in vivo. Different films with a series of copper amount need to be prepared to test cell viability to determine the proper copper concentration to achieve a balance between bacteria inhibition and tissue regeneration.
Keywords: copper; CuNPs; electrodeposition; chitosan bromamine; alginate