能够促进细胞黏附的生物活性表面的制备

PREPARATION OF BIOACTIVE SURFACES FOR PROMOTING CELL ADHESION

报道了一种能够促进细胞黏附的生物活性表面的制备方法.首先通过表面引发原子转移自由基聚合方法在硅表面接枝了聚(N-甲基丙烯酰氧基琥珀酰亚胺)(PNMASI)聚合物刷.随着反应时间的增加,接枝层厚度基本呈线性增长,表明聚合反应具有一定的可控性.蛋白质吸附测试表明PNMASI改性后的表面具有高密度固定生物分子的能力.同时,通过表面引发连续ATRP技术制备了聚甲基丙烯酸寡聚乙二醇酯(POEGMA)和PNMASI的嵌段共聚物刷,并固定了纤连蛋白.POEGMA的引入不仅可以阻碍非特异性蛋白质的吸附,同时有利于保持所固定的纤连蛋白的活性.蛋白质吸附测试以及细胞黏附实验的结果表明,该表面在阻碍非特异性蛋白质吸附的同时能够有效地促进细胞的黏附和铺展.

A simple and attractive method for preparing bioactive surfaces which can effectively promote cell adhesion was introduced.Poly（N-methacryloyloxysuccinimide）（PNMASI） brushes containing a large amount of N-hydroxysuccinimide（NHS） active esters were prepared via surface initiated atom transfer radical polymerization（ATRP） on initiator-immobilized silicon surfaces.It was found that as the polymerization time increased,the thickness of PNMASI graft layer increased linearly,suggesting the controllability of the reaction.Protein adsorption test indicated that the PNMASI modified surfaces owned the great binding capacity of immobilized bioactive molecules.Furthermore,poly（oligo（ethylene glycol） methacrylate）-block-poly（N-methacryloyloxysuccinimide）（POEGMA-b-PNMASI） copolymer modified surfaces were synthesized via surface initiate consecutive ATRP.Then fibronectin,a typical extracellular matrix protein,was used as a model bioactive molecule and immobilized on the POEGMA-b-PNMASI modified surfaces via formation of covalent amide bonds between NHS active esters and the primary amide groups on fibronectin.The underlying POEGMA layer will not only resist non-specific protein adsorption,but also provide a hydrophilic surrounding microenvironment,which is helpful to maintain the bioactivity of immobilized fibronectin.The results of protein adsorption and cell adhesion characterizations indicated that these bioactive surfaces could improve cell adhesion and spread effectively and maintain non-specific protein repellent property.