UC Irvine

PurposePolymeric heart valves (PHVs) offer the potential to combine the durability of mechanical valves with the favorable hemodynamics of bioprosthetic valves; however, establishing clear relationships between polymer properties and valve-level function remains a key challenge. This study evaluates polycarbonate-based polyurethanes as candidate scaffold materials for polymeric mitral valves through a multiscale structure–function approach.MethodsTwo aromatic polycarbonate-based thermoplastic polyurethanes, Carbothane AC-4095A (CB95-AC) and QuadraSil ARCS 90A (Qsil), were characterized using rheological, mechanical, and spectroscopic analyses. Trileaflet valve scaffolds were fabricated and evaluated using particle image velocimetry (PIV), pressure–flow measurements, and accelerated wear testing (AWT) up to 50 million cycles. Preliminary in vivo performance was assessed following implantation of a CB95-AC valve in an ovine model.ResultsQsil exhibited higher solution viscosity, lower storage modulus, and improved elastic recovery, indicating a more compliant response, whereas CB95-AC demonstrated greater stiffness and tear resistance. Both materials maintained stable valve function, with preserved projected orifice area and repeatable pressure waveforms after AWT. PIV analysis showed physiologic pulsatile inflow and intraventricular vortex formation for both valves, with Qsil producing slightly broader vorticity patterns and CB95-AC exhibiting more localized flow structures. Evaluation of the CB95-AC valve in vivo demonstrated preserved transmitral inflow with low pressure gradients and no evidence of obstruction.ConclusionPolycarbonate-based polyurethanes provide promising performance as polymeric mitral valve scaffolds, with material-dependent differences influencing leaflet mechanics and flow organization while maintaining structural integrity during comparative accelerated wear testing. These findings provide a multiscale framework for evaluating associations between polymer properties, mechanical behavior, and valve-level performance in next-generation polymeric and hybrid tissue-engineered heart valves.