Preparation And Application Of Novel Amphiphilic Comb Block Copolymers

In the field of biomedicine, the applications of synthetic materials aremore and more popular. Non-biocompatible materials can cause thrombus,inhibition and infection in human body. It was proved that protein adsorptionon the material surface is the initial reason for all of the problems. Therefore,the modification of material surface and improvement of biocompatibilityfocuses on the inhibition of protein adsorption on the material surface.In this study, several PNIPAM-PEO and PNIPAM-PVP comb blockcopolymers were synthesized. ~1H-NMR, GPC and UV were used tocharacterize those new kind of amphiphilic copolymers. Their properties ofpreadsorption and protein resistance on monodisperse PS microsphere andsheet materials are investigated by dynamic light scattering, UV quantitativeanalysis and contact angle measurement. The central contents are asfollowed:(1) PNIPAM-PEO comb block copolymers with different EO/NIPAM rations and PNIPAM-PVP with different graft length and density weresynthesized, using RAFT controllable free radical polymerizationtechnique and PVP or PEO macromonomer.(2) It was proved the copolymers can pre-adsorb on PS microsphere surfaceand reduce protein adsorption obviously. Their effect of proteinresistance still works at temperature higher than the LCST of PNIPAM.(3) The copolymers can pre-adsorb on PS or glass sheet surface and provedto be useful for reducing protein adsorption.(4) More content of hydrophilic branches in the copolymer resulted in abetter protein resistance both at room temperature and temperaturehigher than the LCST of PNIPAM.(5) Flocculation test on heating and cooling of PS suspension in thepresence of protein provided a simple and effective method toqualitatively evaluate the protein resistance of the polymers used forpre-adsorption treatment.