Novel Biodegradable Polyurethanes Reinforced With Green Nanofibers for Applications in Tissue Engineering
thesisposted on 22.05.2021, 09:32 by Hamza M. Nakhoda
New class of green biocomposites were designed and synthesized for tissue engineering applications. These newly introduced non-cytotoxic, biodegradable polyurethane composites had different compositions (i.e., ratio of hard to soft segments) of the linear, aliphatic hexamethylene diisocyanate and polycaprolactone diol. The porosity was introduced in the polyurethane matrix using a combination of salt leaching and thermally induced phase separation (TIPS). The resulting interconnected pore size was characterized using Scanning Electron Microscope (SEM) to be between 125-355 μm. Porosity was determined using liquid displacement and found to be between 70-75% for non-reinforced matrices, 64-70% for reinforcement with 5 wt% biocellulose nanofiber (BCNF), 59-69% for 10 wt% BCNF, and 57-69% for 15 wt% BCNF biocomposite samples. Dependent on the composition, compressive strength showed up to a little less than two-fold increase (85%) for green BCNF reinforcement of 5 wt% and more than two-fold increase (120%) for 10 wt%. The tensile strength also increased up to almost two-fold (114%) for reinforcement with 5 wt% BCNF and to more than two-fold (140%) for 10 wt% reinforcement. Higher degrees of reinforcement showed a detrimental effect on both properties. Properties demonstrate that this novel class of nanostructured biocomposite holds potential to be utilized as scaffolds for tissue regeneration.