Preparation And Application Of PVP-b-PMMA Based On RAFT Polymerization Amphiphilic Block Polymer

For the past few years, the research on the loading hydrophobic drugs of polymermicelles that use to improve the drugs solubility more and more. In this paper, we use potassium ethyl xanthate and 2-bromine propionic acid ethyl ester as raw materialsto get small molecule chain transfer agent S-（2-ethyl propionate）-O-ethyl xanthate （CTA） under the room temperature response. Then, methyl methacrylate （MMA） and N-vinyl pyrrolidoneas （NVP） as monomer, and azodiisobutyronitrile （AIBN） as the initiator after two reversible addition-breaking chain transfer polymerization （RAFT） polymerization method was synthesized with different contents of MMA parents block polymer PVP-b-PMMA.FT-IR analysis for the structure of the polymer;’H-NMR analysis for the structure of polymer and purity, compare the proportion of functional group peak corresponding to determine polymer polymerization degree and molecular weight according to the calculated;GPC test to get the number average molecular weight and molecular weight distribution of polymers.Fe₃O₄ surface physical adsorption and chemical amine molecules with a layer of oil, the oil amine molecules made of Fe₃O₄ becomes a hydrophobic surface, using TEM after verification by self-assembly Fe₃O₄ can very good to the interior of the micelle, and evenly dispersed in the lumen of micelle.Therefore, the study drug carrier has the premise.Chromatography with pyrene probe fluorescence of parents block polymer PVP-b-PMMA test get the critical micelle concentration of the polymer CMC （10-4 g/L）, and with the increase of content of MMA chain segment CMC values shows the tendency of decreasing.The polymer with indomethacin （IMC） after drug in PBS solution for self-assembly drug-polymer interactions （LC） and packet encapsulation efficiency （EE） test, the measured drug loadings was 29.5% and the envelopment rate was 59.0%.In vitro release studies have shown that hydrophobic MMA and IMC-hydrophobic interface between hydrophobic forces （hydrophobic hydrophobic interactions） and covalent bond （hydrogen bonding） makes the PVP-b-PMMA micelles for drug indomethacin sustained-release was more than 36h.TEM observation before and after the release of the drug release 4h for the morphology of micelles, it can be seen that the drug release before and after the release of micelle form almost without any change, so to analyze the stability of micelle morphology of IMC slow-release played a role.