卟啉为核的聚(ε-己内酯)-嵌段-聚(甲基丙烯酸-2-(N-葡萄糖酰胺)乙酯)的合成及性能

Synthesis and Properties of Porphyrin-cored Poly-(ε-caprolactone)-block-poly(gluconamidoethyl methacrylate)

摘要:

通过开环聚合和原子转移自由基聚合制备了三个四臂星型卟啉为核的聚(ε-己内酯)-嵌段-聚甲基丙烯酸-2-(N-葡萄糖酰胺)乙酯（4sPCL-b-PGAMA）共聚物。产物的结构通过1HNMR、GPC、UV-vis得以确证。通过DSC发现，当共聚物中亲水聚甲基丙烯酸-2-(N-葡萄糖酰胺)乙酯（PGAMA）的质量分数由0%增至79%时，结晶度由73.9%降至0.9%，证明PGAMA能有效改善聚(ε-己内酯)（PCL）的结晶性。通过荧光探针法研究含等量潜在卟啉核的四(4-羟基苯基)卟啉（THPPH2）、4sPCL24和4sPCL24-PGAMA37在相同光照条件下的荧光淬灭程度（△I），发现△ITHPPH2>△I4sPCL24>△I4sPCL24-PGAMA37，证明大分子骨架能有效延缓卟啉核的自淬灭。4sPCL-b-PGAMA自组装胶束的形态随着PGAMA质量分数从79%降至21%，由70nm左右的球过度为蠕虫状，最终转变为200nm左右囊泡。此外，加入刀豆球蛋白（Con A）后的4sPCL-b-PGAMA胶束水溶液的紫外吸光度明显增大，说明两者在水中形成更大的交联聚集体，证明该共聚物对Con A具有特定的生物分子识别作用。

Abstract:

Three four-armed star-shaped poly(ɛ-caprolactone)-b-poly(gluconamidoethyl methacrylate)(4sPCL-b-PGAMA) copolymers with porphyrin core were synthesized via ring-opening polymerization and atom transfer radical polymerization.The structure of the result products was characterized by 1HNMR,GPC and UV-vis.DSC result shows that degree of crystallinity decreased from 73.9 to 0.9,with increasing the weight fraction of hydrophilic poly(gluconamidoethyl methacrylate)(PGAMA) within the copolymers from 0% to 79%,indicating that PGAMA can improve efficiently the crystallization of poly(-caprolactone)(PCL).The fluorescence quenching extent(△I) of tetrakis(4-hydroxylphenyl)-porphyrin(THPPH2),4sPCL24 and 4sPCL24-PGAMA37 with the equal number of potential porphyrin core was investigated by fluorescence probe method,exhibiting △ITHPPH2>△I4sPCL24>△I4sPCL24-PGAMA37,demonstrating that the polymeric skeleton can delay successfully the self-quenching of the porphyrin core.Morphology of 4sPCL-b-PGAMA self-assembled aggregates varied from spherical micelles at 70nm,to worm-like aggregates,finally to vesicles at 200nm, with decreasing the weight fraction of PGAMA from 79% to 21%.Moreover,the UV-vis absorbance increased greatly with adding concanavalin A(Con A) to the copolymer micelles solution,indicating the formation of the bigger cross-linked aggregates in aqueous.This demonstrates that 4sPCL-b-PGAMA has specific recognition with Con A