| Hydrogels have been extensively investigated in the field of biomaterials, due to their many advantageous properties. Hydrogels formed from multifunctional, degradable macromers that can be polymerized in situ and tailored to fit a wide range of degradation profiles are explored in this thesis. Specifically, poly(vinyl alcohol) (PVA) was modified with either non-degradable or degradable pendent groups that can be radically polymerized to form a variety of hydrogel networks. The reaction behavior of these systems, as well as the functional group conversion, was characterized as a function of the polymerization conditions and macromer chemistry. The volumetric swelling ratio and compressive modulus were also measured and used to understand factors influencing the network structure.; Degradable ester linkages were incorporated into the PVA macromers, and the degradation and erosion of the hydrogels were characterized as a function of time. Comparisons were made between systems with variations in either the chemistry or polymerization conditions. To better understand the complexities in the systems, especially the influence of the network structure on the degradation dependent properties, a statistical/kinetic model was developed. The model included kinetic information about the hydrolysis of the crosslinks and also structural information about the many different configurations present in the network. The model was validated through comparison of model mass loss predictions with experimentally measured results for several different PVA networks. In addition, the copolymerization of macromers was explored and characterized experimentally and theoretically.; Finally, two biomaterial applications were explored for these in situ forming, degradable PVA macromers. The first application was for tissue engineering cartilage. PVA and poly (ethylene glycol) macromers were used to photoencapsulate chondrocytes in copolymer networks, and the biochemical and histological results of the neocartilaginous tissue were analyzed. Secondly, the gels were reacted in vivo as a filler and adhesive to prevent seromas. Preliminary tests were done with a modified radical mastectomy rat model. These studies showed that the use of an in situ formed PVA polymer could significantly reduce the amount of serous fluid accumulation, as compared to the control. In addition, the release of solute molecules could be beneficial in the healing process, and therefore, the release was characterized for two different PVA networks. |
