Biomimetic materials for recognition of biomolecules: Recognitive networks for drug delivery and bionanotechnology
Abstract
Studies of protein binding domains reveal molecular architectures with specific chemical moieties that provide a framework for selective recognition of target biomolecules in aqueous environment. By matching functionality and positioning of chemical residues, biomimetic polymer networks have been prepared with tailored affinity and selectivity towards the biomolecule, D-glucose. This work addresses the preparation, behavior, and dynamics of the three-dimensional structure of biomimetic polymers for selective recognition via non-covalent complexation. Novel copolymer networks containing poly(ethylene glycol) (PEG) and functional monomers such as acrylamide, methacrylic acid, and acrylic acid were synthesized in dimethyl sulfoxide and water via UV-free radical polymerization. Polymers were characterized by single and competitive equilibrium and kinetic binding studies, fluorescent and confocal microscopy studies, dynamic and equilibrium solvent and template transport studies, DPC, and SEM. Results qualitatively and quantitatively demonstrate effective glucose-binding polymers in aqueous solvent with complex contributions from both diffusional transport as well as macromolecular chemomimesis. Due to the presence of template, the imprinting process created vacuoles of recognition cavities and resulted in more porous, less densely structured networks with more open and interconnected pores. Polymerization kinetic studies suggested that the template molecule had more than a dilution effect on the polymerization, and the effect of the template was related strongly to the rate of propagation as the crosslinking to functional monomer ratio decreased. In addition, biomimetic recognitive networks for D-glucose were micropatterned on silicon to fabricate microstructures. Utilizing photolithography techniques, sharp polymer micropatterns of a variety of shapes and dimensions, such as silicon microcantilever and quartz crystal microbalance (QCM) designs, have been created on silicon substrates via UV free-radical polymerizations with strict spatial control. Micropatterns were characterized using optical microscopy, SEM, and profilometry. QCM experiments confirmed selectivity and affinity for D-glucose and demonstrated the potential of biomimetic networks as biosensing elements. The processes and analytical techniques presented are applicable to other recognitive networks for biomolecules, in which hydrogen bonding, hydrophobic, or ionic contributions will direct recognition. Further developments are expected to have direct impact on applications such as biomolecule controlled and modulated drug and protein delivery, drug and biological elimination, tissue engineering, and micro- or nano- diagnostic devices and arrays.
Degree
Ph.D.
Advisors
Wankat, Purdue University.
Subject Area
Chemical engineering
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