Fabrication And Performance Optimization Of Antifouling And ?-folate Receptor Protein Specific Interaction Coatings

Biofouling is a key problem to the development of marine economy and biomedicine.The current solution is to coat biocompatible polymers on the material surface to resist biological fouling.Polyethylene glycol(PEG)and zwitterionic polymers are the most widely used materials,since both of polymers have high fouling resistance and are widely used in many kinds of material surface modification.On the other hand,fabrication of a specific interaction surface on antifouling coating is desirable to improve the selectivity of targeted drugs.The research was mainly concerned with the following aspects.(1)The copolymer(PMEN)of 2-methacryloyloxyethyl phosphorycholine-(MPC)and p-nitrophenyloxygenethyl methacrylate(NPCEMA)was synthesized by radical polymerization.A Surface Plasma Resonance(SPR)instrument was employed to investigate the coating fabrication and the antifouling performance.Polydopamine(PDA)film was firstly deposited on the surface of SPR sensor chip.PMEN and PEG-COOH were then immobilized on the PDA film by amidation coupling.By changing the reaction time and polymers,different polymer coatings with a series of thicknesses were prepared.Meanwhile,protein adsorption amount on the prepare coatings was also measured quantitatively.Thus the relationship between the coating thicknesses and the protein adsorption amounts was established.These detailed results could explain well about the controversies of which coating is more efficent.(2)In order to demonstrate the coating fabrication and its antifouling performance of the SPR coating could be duplicated on other substrates,glass,silicon wafer,stainless steel,polypropylene,and polytetrafluoroethylene were immersed in dopamine aqueous solution,subsequently immersed PMEN or PEG-COOH aqueous solution to immobilize the polymer coating by amidation coupling.The coating fabrication was demonstrated by static contact angle(SCA),X-ray photoelectron spectroscopy(XPS),atomic force microscopy(AFM)characterizations.Platelet attachment,bacteria adhesion and fluorescent protein adsorption results comfirmed the excellent antifouling properties.(3)PEG-COOH and PMEN10 combination coating(PDA/PEG-COOH/PMEN10)was fabricated and the ability of protein adsorption resistance was optimized.Furthermore,folic acid(FA)groups were tethered at the end carboxylic groups of PEG chains also by amidation coupling.The specific interaction between FA and FRa was measured and optimized by the SPR system The association constant was derived by utilizing Clamp99 software fitting.This substrate-independent fabrication and performance optimizable antifouling as well as specific interaction coatings may be helpful in developing highly selective drug delivery systems.