Fabrication and characterization analysis on polyurethane electrospun nanofibers incorporated with chitosan/elastin for cardiovascular grafting

Abstract

Cardiovascular disease is the leading cause of death worldwide, where the damage of cardiac tissues is one of its major effects. Current synthetic graft scaffolds to repair and replace cardiac tissues have limitations to cover small blood vessels and have compliance mismatch which later contribute to scaffold failure. Therefore, the incorporation of natural polymers, such as elastin and chitosan, into a synthetic electrospun polymer of polyurethane (PU) is necessary to overcome these complications. Natural polymers such as chitosan and its derivatives are beneficial for wound healing while elastin has shown a successful approach in providing viscoelastic properties. Polyurethane is a synthetic polymer which is commonly used as a substitute of cardiovascular soft tissues due to its biocompatibility, elasticity and mechanical properties. In this study, PU was blended with chitosan nanoparticles and elastin at different elastin concentrations (1% and 1.5%) to be electrospun to form mat fiber scaffolds. The formation of chitosan nanoparticles was verified by using ultravioletvisible (UV-Vis) spectrophotometer at an absorption peak of 290 nm. The physicochemical properties of the electrospun PU incorporated with chitosan/elastin were investigated through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and contact angle measurement. The SEM images were also subjected to fiber diameter, pore size and porosity analyses. The PU incorporated with chitosan/elastin nanofibers were homogenously electrospun with less beads at the flow rate of 0.5 mL/h and 12 kV voltage using 21-G stainless steel needle. The incorporation of chitosan and 1% elastin have increased the fiber diameter by 73.03%, the pore size by 21.05% and the porosity by 14.54% compared to the pure PU. The functional groups of chitosan and elastin (N–H and C–N) were presented in the FTIR spectral peaks. While the wettability of PU nanofibers incorporated with chitosan/elastin was increased by 22.53% compared to the PU nanofibers. The polymer scaffold that was made from natural and synthetic biomaterials in this study, is projected to be used in a range of cardiovascular applications, specifically to address the limitation on small blood vessels and to overcome the physiological properties mismatch.