Shape and size specific: Fabrication, characterization, and application of highly tailored biocompatible hydrogel particles for use in materials and biomedical settings

This work details the method development of a bench top process designed to fabricate highly defined particles of uniform shape and size. In this method, perfluorinated elastomeric molds were patterned off of etched silicon wafers and other substrates. These molds were then filled with a pre-particle solution that was subsequently solidified by UV photoradical initiated polymerization. Particle harvesting by physical agitation and a variety of sacrificial adhesive layers was examined. Purification of particles was also explored using multiple techniques including: centrifugation, dialysis, and a variety of filtration techniques. Regioselective chemical and metallic surface functionalization was demonstrated. Direct particle analysis was performed using microscopic techniques and indirect analysis of particle loading and surface chemistry was performed using spectrophotometric, fluorescence, and mass spectrometry techniques.;Micron scale particles were fabricated with a variety of shapes, sizes, chemistries, and cargos for materials applications. It was determined that particle shape dictated how particles with an induced dipole moment aligned and crystallized in alternating electric fields. Control over chaining and alignment with respect to particle orientation was gained when particles were loaded with superparamagnetic cargo.;Nanometer scale particles with different form factors were also fabricated for in vivo imaging and biodstribution studies in small animals. The particles ranged in size from 80 nm to 2000 nm in length. Particles were surface modified with poly(ethylene glycol) for protection from the reticuloendothelial system. The particles contained or were surface modified with one or more contrast agent including near infrared fluorescent dye, iron oxide nanoparticles (for Magnetic Resonance Imaging), or Cu64 for Positron Emission Tomography. This research laid the groundwork for future experiments in targeted delivery of therapeutics to tumors using the template based particle fabrication technology.