Synthesis and characterization of responsive polymer capsules

Abstract

The cell encapsulation by a polymeric membrane protects the cells from harsh environmental conditions, which allows the application of these cells in condition that they would not survive. This protection points towards applications as treatment of diseases and synthesis of organic compounds in harsh conditions, for example. However, theer is a lack of studies concerning the production or investigation of systems in which the polymer membrane can controll preferably the ingress or egress of products from interior of the capsules, in contrast to the current scenario of the synthesis of responsive polymers and smart materials. The incorporation of responsive polymers in the synthesis of materials for cell encapsulement is a promissing opportunity, which was not explored in the literature. The aim of this project is the synthesis and characterization of polymeric capsules based on tribloc copolymers composed of 2-ethyl-2-oxazoline (EtOx), 4-vinylpyridine (4VP)/4-benzoic acid (4VBA) and ethylspiropyran methacrylate (SPMA). The copolymers will be synthesized via Cationic Ring Opening Polymerization (CROP) of EtOx follwed by the polymeraztion of 4VP/4VBA and SPMA by Atom Transfer Radical Polymerization (ATRP). Besides presenting controlled architecture, these tribloc polymers will present side groups capable of cross-linking by exposure to UV light. The copolymers will be used as interfacial agent in the formation of a water in oil emulsion and then cross-linked, resulting in polymeric capsules. This system will be studied with respct to the pH-, thermo- and photo-responsive behavior, and the relation with its properties, e.g., permeability, since polymers based on EtOx, 4VP/4VBA and SPMA are responsive to variations on the temperature, pH and light, respectively. (AU)