Biodegradable hydrogels and cryogels for biomedical applications, in particular bone tissue engineering

This work consists of synthesis, characterization and evaluation of bisphosphonate, bisphosphonic acid or carboxylic acid functionalized polymers, macromers and their crosslinked network hydrogels and cryogels for various biomedical applications in particular bone tissue engineering. In the first project, poly(amido amine) (PAA) macromers functionalized using sodium alendronate, and their cryogels were synthesized and the effects of the macromer structure as well as bisphosphonic acid content on the cryogel properties such as swelling, degradation, mineralization, and mechanical properties were investigated. In the second project, novel PAA polymers and macromers functionalized using tetraethyl vinylidene bisphosphonate were synthesized. The polymers' rheological properties were investigated in the context of their interaction with cations such as Ca2+ and Fe3+. Subsequently, both bisphosphonate-functionalized and control macromers were copolymerized with HEMA to prepare hydrogels. The swelling, degradation, mechanical, biocompatibility, cell adhesion and biomineralization characteristics of these hydrogels were thoroughly examined to assess their suitability for potential applications in tissue engineering and the effect of bisphosphonate functionalization. The third section reports the synthesis of four novel highly water soluble, carboxylated diacrylate and diacrylamide macromeric crosslinkers based on meso-2,3-dimercaptosuccinic acid and their hydrogels with 2-hydroxyethyl methacrylate. The study is focused on examining how macromer structure and amounts enable control of the swelling, degradation, mechanical properties, and metal adsorption capabilities of the hydrogels. In the last part, phosphate functionalized double network hydrogels were prepared using dual curing method, an aza-Michael reaction of 1,4-butanediamine with poly(ethylene glycol) diacrylate or N,N'-methylene bisacrylamide followed by radical photopolymerization of 10-methacryloyloxydecyl dihydrogen phosphate, and their potential use for tissue engineering applications were investigated.