The Preparation Of PLLA-MPEG Microbrushes For Protein Resistance

In this paper, poly(L-lactic acid)-co-methoxyl poly(ethylene glycol)(PLLA-MPEG) microbrushe films with different morphology and hydrophilicity were prepared on PLLA film by Langmuir-Blogett(LB)technique, casting, and chemical grafting methods. The effect of prepared methods on the morphology, stability and protein resistance ability of films was studied by atomic force microscope (AFM) and contact angle.Firstly, PLLA casting/PLLA-MPEG casting films were prepared. The transport rate of BSA was studied. The PLLA-MPEG molecules were found to fall off from the film easily. Secondly, PLLA spin-coating/PLLA-MPEG LB microbrush films were prepared on PLLA spin-coating films. The effect of prepared parameters on morphology and property of LB microbrushes was also explored. PLLA spin-coating/PLLA-MPEG LB microbrushes could been grafted firmly after being treated in hot water. Then, PLLA-MPEG grafted microbrushes were prepared by UV-graft polymerization. A stable hydrophilic microbrush film of PLLA-MPEG could be obtained after irradiation for 10 minutes by UV. Finally, the property and the ability of FITC-BSA resistance of the three microbushes were compared.It was shown that by the three methods, hydrophilic protein resistance microbrush films could be prepared. PLLA-MPEG LB microbrush would grafted firmly by being treated with hot water, while PLLA-MPEG casting film had a good filming property but a poor stability. The microbrushes prepared by photocatalysis method could been grafted firmly on PLLA casting film, which is hoped to be applied in surface modification of medical devices or bioembedded material, effectively reducing and preventing protein contamination.