PREPARATION OF HYDROLYSABLE BIOCOMPATIBLE POLYMERSOMES FOR DRUG DELIVERY

The desire to understand molecular self-assembly and to explore potential applications motivates the study of self-assembly principles, theories, properties and structures of the assemblies. Block copolymer chains aggregate into various morphologies according to different contributions to the free energy of the system. The most common morphologies are spherical and cylindrical micelles, and polymeric vesicles, termed polymersomes. Polymersomes are hollow spheres with sizes ranging from tens of nanometres to tens of micrometres, typically having a hydrophobic wall and hydrophilic internal and external coronas. Polymersomes have been studied vastly in the last decade and new types of drug delivery systems based on their unique properties have been reported. Yet, only few studies dealt with biocompatible and biodegradable polymersomes. A better understanding of the formation mechanisms of polymersomes and of the relation between nanostructure and properties are still required. This research deals with the formation of polymersomes from two types of biocompatible and biodegradable block copolymers, poly(ethylene oxide)-b-poly(ε-caprolactone) (PEO-b-PCL) and poly(ethylene oxide)-b-poly(lactic acid) (PEO-b-PLA). The study of the relation between aggregates morphology and preparation techniques include variation of experimental parameters and evaluating their effect on the formed structures. The main tools that used in the research are size and structure characterization using light and X-ray scattering techniques and electron microscopy. Three types of block copolymer aggregates have been produced and and characterization of structure has been conducted. In order to allow a rational design of polymersomes, insights into the formation and properties of biocompatible polymersome systems are needed. Therefore, the overall goal of this research is to establish a better understanding of biocompatible block copolymer systems with an emphasis on systems that lead to formation of polymersomes