Hydrogels for Biomacromolecule Immobilization and Sensing

The main focus of this thesis centers on the development of stimuli-responsive hydrogels that have utility for pH-responsive valves, biomacromolecule sensing, irreversible biomacromolecule immobilization, and reversible biomacromolecule immobilization. Each system discussed has its function derived from a novel fabrication protocol or through the development of new hybrid polymer biomaterials. Molecular sensing was accomplished by preparing crosslink-cleavable hydrogels with progressively more complex recognition elements. Initial work investigated the swelling kinetics of disulfide crosslinked hydrogels as a model system for protease responsive hydrogels. More complex peptide-containing hydrogels that have utility for biomacromolecule detection, were then prepared using a novel disulfide-exchange protocol for the preparation of methacrylamide containing peptides. Utilizing this protocol, methacrylamide containing peptides that were responsive to alpha-chymotrypsin (CKYC) and botulism neurotoxin (CSNKTRIDEANQRATK{Nle}LC) were successfully synthesized and copolymerized into polyacrylamide hydrogel networks. When exposed to buffered solutions that contain their sequence specific protease, the hydrogels were completely dissolved. Hydrogels capable of covalent and reversible biomacromolecule immobilization were also developed. Covalent attachment of proteins and lipids to a pH-responsive scaffold was accomplished through a mild oxidation of glycerol monomethacrylate- co-acrylic acid hydrogels, followed by chemoselective ligation of aminooxy, hydrazide, or amine functionalized molecules. Using this strategy, fluorescently labeled proteins as well as lipids that can maintain a chemical gradient between the inside and outside of the hydrogel were prepared. Finally, design elements for surface-immobilized temperature responsive hydrogels that have utility for reversible biomacromolecule immobilization were investigated. Atom transfer radical polymerization was used to grow poly(N-isopropylacrylamide) polymer films from surfaces with varying initiator densities and polymer molecular weights. The lower critical solution temperature behavior for these films were quantified. Finally, the appendix describes a silica colloid system that undergoes a charge reversal once exposed to UV light. Such systems should be useful for in situ modification of colloidal particles, a technique not currently available.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Plunkett, Kyle N.

Contributors dc:contributor

• Moore, Jeffrey S.

• Chemistry, Organic

Language dc:language

eng

Identifier

(MiAaPQ)AAI3199114

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84198