Formation of novel thermo-responsive hybrid vesicles: influence of molar ratio of lipids and heating

Abstract

Thermo-responsive triblock copolymer, [poly(2-isopropyl-2-oxazoline)-b-poly(dimethylsiloxane)-b-poly(2-isopropyl-2-oxazoline] (IDI) was synthesized, for the first time, by ring opening polymerization and it can self-assemble in to polymersome in aqueous solution. We demonstrate a simple route to develop the novel hybrid vesicles, from the IDI and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), by systematically regulating the molar ratio of DMPC. Effect of heating on the hybrid vesicular solution has also been examined. Differential scanning calorimetry (DSC), dynamic light scattering and fluorescence spectroscopy were used to investigate the role of molar ratio of DMPC and heating time of the mixture on the formation of hybrid vesicles. From DSC measurements, we interestingly found that heating the mixture of IDI and DMPC enhanced the insertion of IDI into the membrane of liposomes. The present findings confirm the potential utility of hybrid vesicular systems for the design of functional hybrid materials and could be used for controlled drug delivery applications.