含PEG的聚氨基酸的制备及其细菌黏附性评价

Preparation of Poly(amino acid) Containing PEG and Evaluation of Bacterium Adhesion on Polymer Surface

【目的】采用嵌段共聚法将聚乙二醇(PEG)引入聚谷氨酸苄酯(PBLG)得到聚谷氨酸苄酯-聚乙二醇-聚谷氨酸苄酯两亲嵌段共聚物(PBLG-PEG-PBLG,缩写为GEG),研究引入PEG对GEG膜表面细菌黏附性的影响。【方法】以端氨基聚乙二醇引发谷氨酸苄酯N-羧酸酐开环聚合得到GEG,用凝胶渗透色谱、红外光谱、核磁共振谱和表面接触角对共聚物的结构和物理化学性质进行表征;将聚合物膜悬浮在金黄色葡萄球菌的菌悬液孵育24h,用扫描电镜观察细菌在聚合物表面黏附的情况。【结果】端氨基聚乙二醇能引发谷氨酸苄酯N-羧酸酐开环聚合形成嵌段共聚物;引入PEG不同程度地降低了材料表面的接触角,减少了细菌在共聚物表面的黏附;PEG嵌段在共聚物中的含量越高,材料表面接触角越小,黏附的细菌越少。【结论】将PEG引入PBLG能在某种程度上抑制细菌黏附。这种嵌段共聚物在组织工程和药学领域有潜在应用前景。

[Objective] Poly（ethylene glycol）（PEG） was introduced into poly（γ-benzyl L-glutamate）（PBLG） to obtain block copolymers （PBLG-PEG-PBLG, GEG） by block copolymerization, and the effect of introduction of PEG on bacteria adhering on GEG surfaces was assessed. [Methods] The block copolymers of poly（γ-benzyl L- glutamate） and poly（ethylene glycol） were prepared by ring-opening polymerization of γ-benzyl L-glutamate N- carboxyanhydride initiated by amine-terminated PEG （AT-PEG）. Their structures, physical and chemical properties were characterized by gel permeation chromatography （GPC）, infrared absorption spectroscopy （IR）, ^1 hydrogen-nuclear magnetic resonance spectrometer （^1 H-NMR） and surface contact angle with water. GEG membranes were incubated in the solution with Staphylococci aureus suspended for 24 hours, and then the adhesion of bacteria on their surfaces were observed under scanning electron microscope （SEM）. [ Results ] GEG could be obtained by AT-PEG initiating the ring-opening polymerization of γ-benzyl L-glutamate N- carboxyanhydride. T he introduction of PEG decreased the surface contact angle and the bacteria adhesion on polymer surfaces. With increasing the content of PEG in block copolymer, the surface contact angle and the adhered bacteria on surfaces of polymers decreased. [ Conclusion ] The introduction of PEG suppressed the adhesion of bacteria in some extent. The synthesized copolymers have potential use in the fields of pharmacy and tissue engineering.