酶的添加与不同pH值对PLA-PCL无规共聚物水解行为的影响
|
摘要
对PLA-PCL无规共聚物在猪胰脂酶(PPL)水溶液及不同pH值水溶液中降解的失重率、组成、相对分子质量及其分布的变化进行研究,分别考察酶的添加及pH值的改变对材料水解性能的影响。实验结果显示:酶的加入促进了PLA-PCL无规共聚物的水解,使得共聚物质量损失更明显,酶对共聚物中CL链段的水解有促进作用;而化学水解过程中LA/CL组分比的变化说明PLA链段优先水解,酸性环境会加速PLA-PCL共聚物的水解。
The enzymatic degradation of PLA-PCL random copolymers was investigated in PBS(pH 7.4) containing 0. 02%lipase from porcine pancreas(PPL).Hydrolysis experiments of the PLA-PCL random copolymers were performed in water solutions with different pH values(1.0,7.4 and 9.0) at 37℃.The weight loss,changes in the composition, molecular weight and distribution were investigated.It was found that the degradation of copolymers was accelerated via PPL catalyzing the hydrolysis of ester bond.The H-NMR data showed that the CL content decreased in enzymatic degradation,LA content decreased during hydrolytic degradation,and PLA-PCL random copolymers degraded fastest in aqueous media at pH 1.0.
The enzymatic degradation of PLA-PCL random copolymers was investigated in PBS(pH 7.4) containing 0. 02%lipase from porcine pancreas(PPL).Hydrolysis experiments of the PLA-PCL random copolymers were performed in water solutions with different pH values(1.0,7.4 and 9.0) at 37℃.The weight loss,changes in the composition, molecular weight and distribution were investigated.It was found that the degradation of copolymers was accelerated via PPL catalyzing the hydrolysis of ester bond.The H-NMR data showed that the CL content decreased in enzymatic degradation,LA content decreased during hydrolytic degradation,and PLA-PCL random copolymers degraded fastest in aqueous media at pH 1.0.
引文
[1]郭圣荣.药用高分子材料[M].北京:人民卫生出版社,2009:26-28.
[2]蔡机敏.生物可降解高分子的合成及其应用研究进展[J].中国科技信息.2008(2):250-232.
[3]Lu X L,Cai W,Gao Z Y.Shape-memory behaviors of biodegradable poly(L-lactidc-co-e-caprolactone)copolymers[J].Journal of Applied Polymer Science,2008,108(2):1109-1115.
[4]Gaucher G,Dufresne M H,Sant V P,et al.Block copolymer micelles;Preparation,characterization and application in drug delivery[J].Journal of Controlled Release,2005,109(1-3):169-188.
[5]李孝红,袁明龙,熊成东.等.聚乳酸及其共聚物的合成和在生物医学上的应用[J].高分子通报.1999(1):24-32.
[6]Waknis V,Jonnalagadda S.Novel poly-DL-lactide-polycaprolactone copolymer based flexible drug delivery system for sustained release of ciprofloxacin[J].Drug Delivery,2011.18(4):236-245.
[7]Zhang Z,Zou S,Vancso G J,et al,Enzymatic surface erosion of poly(trimethylene carbonate)films studied by atomic force microscopy[J].Biomacromolecules.2005,6(6):3404-3409.
[8]Kulkarni A,Reiche J,Hartmann J,et al.Selective enzymatic degradation of poly(e-caprolactone)containing multiblock copolymers[J].European Journal of Pharmaceutics and Biopharmaceutics,2008,68(1):46-56.
[9]Liu F,Zhao Z,Yang J,et al.Enzyme-catalyzed degradation of poly(L-lactide)/poly(ε-caprolactone)diblock,triblock and four-armed copolymers[J].Polymer Degradation and Stability,2009,94(2):227-233.
[10]李凡,王莎,刘巍峰,等.聚乳酸(PLA)生物降解的研究进展[J].微生物学报,2008,48(2):262-268.
[11]马晓妍,石淑先,夏宇正,等.聚乳酸及其共聚物的制备和降解性能[J].北京化工大学学报.2004,31(1):51-56.
[12]Li S M.Hydrolytic degradation characteristics of aliphatic polyesters derived from lactic and glycolic acids[J].Journal of Biomedical Materials Research,1999,48(3):342-353.
[13]Yang J,Liu F,Yang L,et al.Hydrolytic and enzymatic degradation of poly(trimelhylene carbonate-co-D,L-lactide)random copolymers with shape memory behavior[J].European Polymer Journal,2010,46(4):783-791.
[14]Yavuz H,Baba?C,Tuzlako?lu K,el at.Preparation and degradation of L-lartide and e-caprolactone homo and copolymer films[J].Polymer Degradation and Stability,2002,75(3):431-437.
[2]蔡机敏.生物可降解高分子的合成及其应用研究进展[J].中国科技信息.2008(2):250-232.
[3]Lu X L,Cai W,Gao Z Y.Shape-memory behaviors of biodegradable poly(L-lactidc-co-e-caprolactone)copolymers[J].Journal of Applied Polymer Science,2008,108(2):1109-1115.
[4]Gaucher G,Dufresne M H,Sant V P,et al.Block copolymer micelles;Preparation,characterization and application in drug delivery[J].Journal of Controlled Release,2005,109(1-3):169-188.
[5]李孝红,袁明龙,熊成东.等.聚乳酸及其共聚物的合成和在生物医学上的应用[J].高分子通报.1999(1):24-32.
[6]Waknis V,Jonnalagadda S.Novel poly-DL-lactide-polycaprolactone copolymer based flexible drug delivery system for sustained release of ciprofloxacin[J].Drug Delivery,2011.18(4):236-245.
[7]Zhang Z,Zou S,Vancso G J,et al,Enzymatic surface erosion of poly(trimethylene carbonate)films studied by atomic force microscopy[J].Biomacromolecules.2005,6(6):3404-3409.
[8]Kulkarni A,Reiche J,Hartmann J,et al.Selective enzymatic degradation of poly(e-caprolactone)containing multiblock copolymers[J].European Journal of Pharmaceutics and Biopharmaceutics,2008,68(1):46-56.
[9]Liu F,Zhao Z,Yang J,et al.Enzyme-catalyzed degradation of poly(L-lactide)/poly(ε-caprolactone)diblock,triblock and four-armed copolymers[J].Polymer Degradation and Stability,2009,94(2):227-233.
[10]李凡,王莎,刘巍峰,等.聚乳酸(PLA)生物降解的研究进展[J].微生物学报,2008,48(2):262-268.
[11]马晓妍,石淑先,夏宇正,等.聚乳酸及其共聚物的制备和降解性能[J].北京化工大学学报.2004,31(1):51-56.
[12]Li S M.Hydrolytic degradation characteristics of aliphatic polyesters derived from lactic and glycolic acids[J].Journal of Biomedical Materials Research,1999,48(3):342-353.
[13]Yang J,Liu F,Yang L,et al.Hydrolytic and enzymatic degradation of poly(trimelhylene carbonate-co-D,L-lactide)random copolymers with shape memory behavior[J].European Polymer Journal,2010,46(4):783-791.
[14]Yavuz H,Baba?C,Tuzlako?lu K,el at.Preparation and degradation of L-lartide and e-caprolactone homo and copolymer films[J].Polymer Degradation and Stability,2002,75(3):431-437.