Miniemulsion RAFT Copolymerization of MMA with Acrylic Acid and Methacrylic Acid and Bioconjugation with BSA

Abstract

Polymerization through reversible addition-fragmentation chain-transfer (RAFT) polymerization has been extensively employed for the production of polymers with controlled molar mass, complex architectures and copolymer composition distributions intended for biomedical and pharmaceutical applications. In the present work, RAFT miniemulsion copolymerizations of methyl methacrylate with acrylic acid and methacrylic acid were conducted to prepare hydrophilic polymer nanoparticles and compare cell uptake results after bioconjugation with bovine serum albumin (BSA), used as a model biomolecule. Obtained results indicate that the RAFT agent 2-cyano-propyl-dithiobenzoate allowed for successful free radical controlled methyl methacrylate copolymerizations and performed better when methacrylic acid was used as comonomer. Results also indicate that poly(methyl methacrylate-co-methacrylic acid) nanoparticles prepared by RAFT copolymerization and bioconjugated with BSA were exceptionally well accepted by cells, when compared to the other produced polymer nanoparticles because cellular uptake levels were much higher for particles prepared in presence of methacrylic acid, which can probably be associated to its high hydrophilicity.

Effects of Different Stabilizers on Miniemulsion Methyl Methacrylate Polymerizations

“…These concentrations were defined in accordance with previous MMA miniemulsion polymerization studies. [8,16,29,30] The initial miniemulsions were prepared with a sonifier (Branson 450, Marshall Scintific, Hampton, USA) at 160 W for 5 min or with an ultra-turrax (T10 basic, IKA, Staufen, Germany) for 5 min at 14,500 rpm, using an ice bath to control the temperature of the emulsified system and keep it close to room temperature. The polymerizations were conducted in a 100 mL glass reactor (EasyMax 102, Mettler Toledo, Ohio, USA) at 80 o C under the agitation of 500 rpm for 180 min.…”