A facile method for the controlled polymerization of biocompatible and thermoresponsive oligo(ethylene glycol) methyl ether methacrylate copolymers

Photochemically controlled ATRP-like polymerization is successfully used to prepare a thermoresponsive copolymer of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) and di(ethylene glycol) methyl ether methacrylate (MEO2MA). The photochemically controlled method described here provides good control over the polymer structure, architecture, and properties. This photopolymerization renders polymers with narrow molecular weight distributions (Mw/Mn = 1.3) and high monomer conversions (>90%) while using a very low iridium-based catalyst concentration (25 ppm). In addition, the reaction rate of this polymerization is fast, reaching 50% monomer conversion in less than 1 h of reaction. The lower critical solution temperature (LCST) of the prepared polymer was also adjusted to be in the range of physiological temperatures, undergoing a coil-to-globule transition at 43 °C. In addition, the resulting polymer showed no cytotoxicity on four mammalian cell lines at the highest concentration tested (0.4 mg/ml), which highlights its potential use in different biomedical applications.We thank the ERC Consolidator Grant program (ERC-2013- CoG-614715, NANOHEDONISM) for the financial support. CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011 financed by the Instituto de Salud Carlos III with the assistance of the European Regional Development Fund.Peer reviewe