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.