Mizutani Manabu, Arnold Steven C, Matsuda Takehisa
Department of Bioengineering, National Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565, Japan.
Biomacromolecules. 2002 Jul-Aug;3(4):668-75. doi: 10.1021/bm0101670.
Photoreactive phenylazide-end-capped liquid copolymers were prepared by ring-opening copolymerization of epsilon-caprolactone (CL) and trimethylene carbonate (TMC) at an equimolar monomer feed ratio in the presence of a polyol, namely, a low-molecular-weight alcohol (di-, tri-, and tetraol) or poly(ethylene glycol) (PEG) as an initiator and tin(II) 2-ethylhexanoate as a catalyst, followed subsequently by phenylazide derivatization at their hydroxyl terminus. These tri- and tetrabranched liquid copolymers (precursors) with a molecular weight from approximately 2500 to 7000 g/mol were cross-linked to yield insoluble solids by ultraviolet (UV) light irradiation. The photocuring rate increased with increasing functionality of phenylazide and UV intensity and decreasing thickness of the liquid film of precursors. The photo-cross-linkability of phenylazide-derivatized liquid copolymers was found to be higher than that of the corresponding coumarin-derivatized liquid copolymers. Poly(lactide) (PLA) films surface-layered with photocured copolymers were prepared by coating surfaces with phenylazide-derivatized copolymers and their subsequent photoirradiation. Endothelial cells adhered well on the nontreated PLA and low-molecular-weight alcohol-based copolymer-layered and photocured films. Little cell adhesion was observed on the hydrolytically surface-eroded PLA film and the PEG-based copolymer-layered film. When a phenylazide-derivatized hexapeptide with the cell-adhesion tripeptidyl sequence, Arg-Gly-Asp (RGD), common to cell adhesive proteins, was photoimmobilized on these surfaces, the surfaces became cell adhesive. Microarchitectured surfaces, which were prepared by sequential procedures of surface coating and photocuring using a photomask with lattice windows, produced regionally differentiated cell adhesiveness.
通过在多元醇（即低分子量醇（二醇、三醇和四醇）或聚乙二醇（PEG））作为引发剂以及2-乙基己酸亚锡作为催化剂的存在下，使ε-己内酯（CL）和碳酸三亚甲基酯（TMC）以等摩尔单体进料比进行开环共聚，制备了光反应性叠氮苯基封端的液体共聚物，随后在其羟基末端进行叠氮苯基衍生化。这些分子量约为2500至7000 g/mol的三分支和四分支液体共聚物（前体）通过紫外线（UV）照射交联以产生不溶性固体。光固化速率随着叠氮苯基官能度的增加、UV强度的增加以及前体液膜厚度的减小而增加。发现叠氮苯基衍生化的液体共聚物的光交联性高于相应的香豆素衍生化的液体共聚物。通过用叠氮苯基衍生化的共聚物涂覆表面并随后进行光辐照，制备了表面层有光固化共聚物的聚（丙交酯）（PLA）膜。内皮细胞在未处理的PLA以及低分子量醇基共聚物层和光固化膜上粘附良好。在水解表面侵蚀的PLA膜和PEG基共聚物层膜上观察到很少的细胞粘附。当具有细胞粘附蛋白共有的细胞粘附三肽基序列Arg-Gly-Asp（RGD）的叠氮苯基衍生化六肽光固定在这些表面上时，这些表面变得具有细胞粘附性。通过使用带有晶格窗的光掩模进行表面涂覆和光固化的顺序程序制备的微结构表面产生了区域分化的细胞粘附性。
