SYNTHESIS of BIODEGRADABLE COLYMER OF LACTIC ACID HAVING THIOL GROUPS AND EVALUATION OF ITS CHARACTERIZATION

含硫醇基可生物降解乳酸聚合物的合成及其表征评价

基本信息

批准号：
10650874
负责人：
OUCHI Tatsuro
金额：
$ 1.92万
依托单位：
Kansai University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

To modify the properties of poly(lactic acid)[poly(LA)] and to introduce pendant thiol groups to poly(LA), the random terpolymer of L-LA, glycolic acid(Glc) and cysteine(Cys) {poly[LA-random-(Glc-Cys)]} was synthesized through ring-opening and copolymerization of L-lactide with cyclodepsipeptide cyclo{Glc-Cys(MBzl) and subsequent deprotection of methoxybenzyl groups. By changing the mol fraction of (Glc-Cys) unit, the solubility, thermal transition, degradation behavior of the modified poly(LA), and the water contact angle of its film could be varied. Moreover, to achieve high accumulation of thiol groups located on the surface of copolymer film, the synthesis of AB-type diblock copolymer of L-lactide (L-LA) and depsipeptide with pendant thiol groups were investigated. Cyclo[Gls-Cys(MBzl)] was polymerized in tetrahydrofran (THF) solution using potassium ethoxide as an initiator. The terminal hydroxyl group of the poly[Glc-Cys(MBzl)] obtained was converted to potassium alkoxide by K/naphthalene. L-LA was polymerized in THF using the polymer alkoxide as a macroinitiator to obtain poly[Glc-Cys(MBzl)]-block-polyLA showing two melting temperatures (Tms). Through subsequent deprotection of methoxybenzyl groups, the biodegradable amphiphilic AB-type block copolymer, poly(Glc-Cys)-block-polyLA, was obtained. The accumulation ability of thiol groups located on the surface of block copolymer film was evaluated to be higher than that of the random copolymer film.

改性聚(乳酸)[聚(LA)]的性能，并向聚(LA)引入侧硫醇基团，聚(LA)是L-LA、乙醇酸(Glc)和半胱氨酸(Cys)的无规三元共聚物{聚[LA L-丙交酯与环缩酚肽cyclo{Glc-Cys(MBzl)开环共聚合成-随机-(Glc-Cys)]}甲氧基苄基的脱保护。通过改变(Glc-Cys)单元的摩尔分数，可以改变改性聚(LA)的溶解度、热转变、降解行为及其薄膜的水接触角。此外，为了实现位于共聚物膜表面的硫醇基团的高度积累，研究了具有侧硫醇基团的L-丙交酯（L-LA）和缩酚肽的AB型二嵌段共聚物的合成。使用乙醇钾作为引发剂，在四氢呋喃（THF）溶液中聚合环[Gls-Cys（MBzl）]。所得聚[Glc-Cys(MBzl)]的末端羟基通过K/萘转化为醇钾。使用聚合物醇盐作为大分子引发剂在THF中聚合L-LA，得到具有两个熔融温度(Tms)的聚[Glc-Cys(MBzl)]-嵌段-聚LA。随后通过甲氧基苄基的脱保护，得到可生物降解的两亲性AB型嵌段共聚物，聚(Glc-Cys)-嵌段-聚LA。位于嵌段共聚物膜表面的硫醇基团的积累能力被评价为高于无规共聚物膜的硫醇基团的积累能力。