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Molecular design of poly (amino acid) microspheres byemulsion polymerization to apply as a biomaterial

乳液聚合聚氨基酸微球的分子设计及其生物材料应用

基本信息

批准号：
12680840
负责人：
FURUTA Masakazu
金额：
$ 2.18万
依托单位：
Osaka Prefecture Unversity
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12680840/
关键词：
Emulsion polymerization Poly (amino acid)Microsphere Surface Surfactant Enzyme Immobilization

项目摘要

We investigated the emulsion polymerization of r-benzyl-L-glutamete N-carboxyanhydride, r-methyl-L-glutamete N-carboxyanhydride, and leucine N-carboxyanhydride in mixtures of organic solvents and various surface surfactants under various reaction conditions in order to establish the approbate condition to obtain high molecular weight ploy (α-amino acid) microspheres quantatively. Copolymer microspheres obtained by using polyethylene glycol (MW 200) as surface surfactant and their diameter was within the range of 50-60 micrometers confirmed by electron microscope. As a result of the further examinations changing the composition of monomers and surfactants in the reaction mixture, we succeeded in obtaining the microspheres whose diameter was within the order of 100-200 nm constantly.Lipase was immobilized onto These microspheres by water-soluble carbodiimid method and to check their capacity to enhance the thermal and storage stabilities of the enzyme after the incubation in water under different PH condition. While the free enzyme lost its activity after several hours under acidic PH, the immobilized enzyme retained 80 % of the initial activity under the same condition. The immobilized enzyme also displayed considerable thermal stability retaining 20 % of the initial activity even under 80ーC. Any activity loss was not observed at extremely high PH. These results suggested that the change of the conformation of the enzyme by storage, heating, and change of pH could be inhibited by immobilization and that the microsphere may function as a barrier against the deterioration by microorganisms and other factors.

本文研究了r-苄基-L-精氨酸-N-羧酸酐、r-甲基-L-精氨酸-N-羧酸酐和亮氨酸-N-羧酸酐在有机溶剂和各种表面活性剂的混合溶剂中的乳液聚合反应，以确定制备高分子量聚α-氨基酸微球的适宜条件。以分子量为200的聚乙二醇为表面活性剂，得到了粒径在50-60 μ m的共聚物微球。作为改变反应混合物中单体和表面活性剂组成的进一步研究的结果，我们成功地获得了直径在100-200 nm数量级的微球，并将脂肪酶固定化在微球上。用可溶性双马来酰亚胺法测定酶的热稳定性和贮存稳定性，并检测它们在不同pH值的水中孵育后提高酶的热稳定性和贮存稳定性的能力条件游离酶在酸性pH下几小时后失去活性，而固定化酶在相同条件下保留了80%的初始活性。该固定化酶在80 ℃下仍保持20%的初始酶活.在极高的pH值下没有观察到任何活性损失。这些结果表明，通过储存，加热和pH值的变化可以抑制酶的构象的变化，固定化和微球可以作为一个屏障，对微生物和其他因素的恶化。