谷胱甘肽端基修饰聚己内酯的合成及在水溶液中的聚集行为

SYNTHESIS OF GLUTATHIONE-TERMINATED POLY(ε-CAPROLACTONE)AND ITS SELF-ASSEMBLY IN AQUEOUS SOLUTION

用开环聚合法合成了端基分别为巯基和马来酰亚胺基团的聚己内酯,利用马来酰亚胺与巯基的迈克尔加成反应和巯基之间的偶联反应,合成了两种端基为谷胱甘肽的聚己内酯(GS-PCL和GSS-PCL),利用核磁共振氢谱和凝胶渗透色谱表征了两亲性聚己内酯的结构.研究了这两种聚己内酯在水中的聚集行为,发现这两种聚已内酯都可在一定pH值下聚集形成球形胶束,胶束的形态、大小等受pH影响;同时,由GSS-PCL形成的聚集体还表现出氧化还原敏感性.

Two kinds of end-functionalized poly（ε-caprolactone） s, maleimido-PCL and HS-PCL, were synthesized by the ring-opening polymerization of ε-caprolactone （ε-CL） with N-hydroxyl ethyl maleimide （HEME） and 2- mercaptoethanol （ME） as initiators, respectively. Polymerizations were catalyzed by tin （Ⅱ） trifluoromethane （Sn（OTf）2） in bulk under mild conditions. These polymers showed low polydispersities and have functional groups at both ends. Two glutathione-terminated poly（ε-caprolactone） （GS-PCL and GSS-PCL） were then synthesized by Michael addition reaction of the maleimido-PCL with glutathione, or the coupling reaction of HS-PCL with glutathione, respectively. The structures of the two amphiphilic polyesters were confirmed by ^1H-NMR and GPC measurements. Glutathione groups on the chain end increased the hydrophilicity of PCL, therefore, the polyesters can self-assemble in aqueous buffer solutions. Transmission electron microscopy （TEM） measurements confirmed the formation of spherical aggregates with the diameter range from 20 - 80 nm, and the size of the aggregates was found to increase with the decease of the pH of the buffer. In addition, aggregates from GSS-PCL showed redox-sensitive properties.