Designing core-shell microparticles for programmed release through reaction-diffusion mediated photolithography

Abstract

Core-shell microparticle encapsulating multiple active substances in different compartment has im-portant applications for therapeutics and pharmaceuticals. However, traditional core-shell release system entails uncontrolled release behavior and only allows limited combinations of core and shell materials, which further limits combinations of actives loaded in core and shell. In this thesis, I report a simple lithographic approach to design new type of polymeric core-shell micro-particles which release multi-actives in controlled fashion. Reaction-Diffusion mediated Photolithography (RDP) which locally generates 3-dimensional microstructure is sequentially employed to generate core and shell. The resulting microparticle consists of three distinct compartment

core, shell and disk. Core and shell are programmed to release different kind of actives with distinctive kinetics whereas disk prevents direct ex-posure of core. Engineering release kinetics is achieved by tailoring mesh size of polymer composing each compartment. Microparticle size can be delicately controlled and combinations of core and shell materials are extensive. Using the same strategy, multi-layered microparticles loading multiple component is also pre-pared. We believe that this core-shell template can potentially serve as carriers for delivering synergistic com-binations of drugs, opening up new opportunities for pharmacotherapy.