Controlled Fabrication of Shape-encoded Macroporous Microparticles with Replica Molding via Phase Separation.
Abel, John H.
- Facile fabrication of non-spherical, shape-controlled microparticles with large pores is an important challenge toward the development of high capacity functional microplatforms, especially in biosensing. This thesis presents a method of fabricating shape-controlled macroporous microparticles through a replica molding-phase separation (RM-PS) strategy. RM is a robust soft-lithographic technique in... read morevolving the use of microscale molds and UV light-induced radical polymerization to create polymeric microparticles with reliable duplication of complex 2D shapes. Hildebrand solubility parameter (HSP) in conjunction with the group contribution method is used to predict phase separation while in-mold, and through selection of an inert porogen material, to control pore size. This strategy is employed in the fabrication of macroporous poly(ethylene glycol) (PEG) microparticles with phthalate porogen solvents. Results demonstrate reliable macroporous microparticle fabrication, while retaining structure and physical stability. The pore size is shown to increase as the monomer-porogen solubility decreases and phase separation becomes more rapid, as predicted by HSP calculations. Importantly, a change in solubility during polymerization is not required using this platform unlike current methods, suggesting the potential for a general method to design and fabricate macroporous microparticles with other polymeric units.read less