Preparation of Gel-Liposome Nanoparticles for Drug Delivery Applications*

Liposomes are amongst the most effective delivery vehicles developed to date. Despite many advantages including biocompatibility, biodegradability, and the ability to carry both hydrophilic and lipophilic compounds, liposomes suffer from low physical stability. This limitation can be effectively addressed by inclusion of a polymeric scaffold within the core of liposomes. Given the versatility of poly (ethylene glycol) (PEG) hydrogels, these polymers have a great potential for the use in liposomal core. As a step towards the development of a robust liposomal delivery platform, here we aim to develop a simple and reliable technique for the fabrication of liposomes with PEG gel cores. We assess the resultant nanoparticles using scanning electron microscopy and dynamic light scattering and demonstrate that the presented approach can successfully produce gel-liposome nanoparticles with spherical shape and 150-200 nm size. These nanoparticles are further evaluated for colloidal stability in physiological solution. Moreover, we demonstrate the versatility of this method by studying the effect of changing (A) the membrane composition in liposomes, and (B) the hydrogel concentration in liposomal core, on the formation of gel-liposome particles.