Development of biodegradable polyurethane based hard tissue support materials

Yagci, B.S., Development of Biodegradable Polyurethane Based Hard Tissue Support Materials, Hacettepe University Institute of Health Sciences Basic Pharmaceutical Sciences Program, Ankara, 2018. It is important to develop hard tissue support products and innovative biomaterials for bone injuries. In this thesis, it is aimed to develop biodegradable polyurethane based bone regenerative films as hard tissue supporting materials. For this purpose, bioactive polyurethane elastomer films were synthesized by two step condensation polymerization of polycaprolactone diol and hexamethylene diisocyanate monomers with bioactive chain regulators . Chain regulators, amino acid molecule L-glutamine, drug active agent metformin and inorganic compound β-glycerophosphate were integrated in to diisocyanate-terminated polyurethane prepolymer via their difunctional groups. The average molecular weights of polyurethane-based prepolymers, chemical, thermal, viscoelastic, mechanical, surface properties and biodegradation behaviors of chain extended polyurethane films were investigated. The macromolecular structures of bioactive chain regulator containing polyurethanes had shown chemical differences due to the presence of urethane, urea hydrogen bonds. Dynamic mechanical analyzes have shown that polyurethane films possess all the transitions of viscoelastic behavior. β-glycerophosphate caused decrease in glass transition temperature (Tg), elastic modulus, ultimate tensile strength and elongation at break point values of polyurethanes. On the other hand metformin increased Tg temperature and decreased the mechanical properties of polyurethanes. β-TCP (β-Tricalcium phosphate) containing polyurethane composites were prepared and their chemical, mechanical, surface properties and biodegradation behaviors were characterized. β-TCP containing polyurethane films had shown lower elastic modulus values compared to polyurethane elastomer films. In this thesis, significant and positive findings were obtained for the use of the developed biodegradable polyurethane elastomers as bone regenerative film. Keywords: Polyurethane, bioactive chain regulator, bone regenerative film, elastomer.