Radiation Effects on Hybrid-Type Medical Materials

在生物医学材料的发展过程中，由于材料受到细菌的污染，灭菌是必不可少的。因此，聚合物材料必须能够在不造成损害的情况下灭菌。灭菌技术分为物理灭菌和化学灭菌。物理方法包括干热、蒸汽和电离辐射。使用环氧乙烷的化学灭菌方法也被广泛使用。遗憾的是，传统的高压灭菌方法不能用于仿生材料，因为它们含有蛋白质等不耐热的生物活性成分。环氧乙烷气体熏蒸处理后残留在材料中的微量有毒和致癌气体会导致健康问题。电离辐射能够在不包括热量和物质的情况下杀死细菌，而不影响材料的质量和我们的健康。因此，已经应用于医疗用品的辐照灭菌应该是最终的坦率的…更多的ATE用于含蛋白质的杂交型生物医学材料的灭菌。为了将商业辐照灭菌技术应用于含有蛋白质的杂交型生物医用材料，需要在通常用于商业规模辐照的标准剂量25kGy处检查蛋白质和其他组分的辐射耐受性。到目前为止，对这些生物材料的辐射灭菌数据还很少。在本项目中，为了建立含有生物活性分子和人工聚合物的杂化生物医学材料的辐射灭菌方法，我们用60Co伽马射线进行了辐射耐受性检测。我们选择了酶作为蛋白质的模型。此外，我们还设计了各种类型的生物医学聚合物以及用于生物医学应用的杂化材料。最后得出结论，商业辐照灭菌法适用于干燥或冷冻等适宜条件下的酶去污。虽然水溶液中的酶发生了辐射灭活，但通过控制辐射条件可以抑制辐射灭活。固定化酶的辐照稳定性比游离酶高得多。这些发现表明，辐照灭菌在未来杂交型生物医学材料中将是有用的。较少

During the course of the development of biomedical materials, sterilization is essential since a material is contaminated with bacteria. Therefore, the polymeric material must be capable of being sterilized without detriment. Sterilization techniques are categorized as physical or chemical ones. Physical methods include dry heat, steam, and ionizing radiation. Chemical sterilization methods by using ethylene oxide is also used widely. Unfortunately, conventional autoclaving method cannot be used for biomimetic materials because they contain heat-labile bioactive components such as proteins. Ethylene oxide gas fumigation causes a health problem by traces of toxic and carcinogenic gas remaining in the material after treatment. Ionizing radiations are able to kill bacteria without including neither heat nor substances affecting the quality of the materials and our health. Thus the irradiation sterilization, which has already been applied to the medical supplies, should be the final candid … More ate for sterilization of the hybrid-type biomedical materials containing proteins. To apply commercial irradiation sterilization technique to the protein-containing hybrid-type biomadical materials, it is necessary to examine radiation torelance of proteins as well as other components at a standard doze of 25kGy generally used for commercial-scale irradiation. There are very few data available for these purpse until now.In this project, to establish irradiation sterilization method for hybrid-type biomedical materials containing bioactive molecules together with artificial polymers, we examined radiation tolerance with 6OCo gamma-rays. We selected enzymes as a model of proteins. Furthermore, we designed various types of-biomedical polymers as well as hybrid-type materials for biomedical applications. Finally, it is concluded that the commercial irradiation sterilization method is applica ble to decontamination of enzymes under an appropriate condition such as dry or frozen state. Although radiation inactivation of enzymes in the aqueous solution was occurred, it could be depressed by control of the irradiation conditions. It is also concluded that the immobilized enzymesare much more stable than free ones for irradiation. These findings suggest that the irradiation sterilization will be useful for hybrid-type biomedical materials in future. Less