Hemocompatibility and Hemodynamics of Novel Hyaluronan–Polyethylene Materials for Flexible Heart Valve Leaflets
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Polymeric heart valves (PHVs) hold the promise to be more durable than bioprosthetic heart valves and less thrombogenic than mechanical heart valves. We introduce a new framework to manufacture hemocompatible polymeric leaflets for HV (PHV) applications using a novel material comprised of interpenetrating networks (IPNs) of hyaluronan (HA) and linear low density polyethylene (LLDPE). We establish and characterize the feasibility of the material as a substitute leaflet material through basic hemodynamic measurements in a trileaflet configuration, in addition to demonstrating superior platelet response and clotting characteristics. Plain LLDPE sheets were swollen in a solution of silylated-HA, the silylated-HA was then crosslinked to itself before it was reverted back to native HA via hydrolysis. Leaflets were characterized with respect to (1) bending stiffness, (2) hydrophilicity, (3) whole blood clotting, and (4) cell (platelet and leukocyte) adhesion under static conditions using fresh human blood. In vitro hemodynamic testing of prototype HA/LLDPE IPN PHVs was used to assess feasibility as functional HVs. Bending stiffness was not significantly different from natural fresh leaflets. HA/LLDPE IPNs were more hydrophilic than LLDPE controls. HA/LLDPE IPNs caused less whole blood clotting and reduced cell adhesion compared to the plain LLDPE control. Prototype PHVs made with HA/LLDPE IPNs demonstrated an acceptable regurgitation fraction of 4.77 ± 0.42%, and effective orifice area in the range 2.34 ± 0.5 cm2. These results demonstrate strong potential for IPNs between HA and polymers as future hemocompatible HV leaflets. Further studies are necessary to assess durability and calcification resistance.
KeywordsInterpenetrating polymer network Hemocompatible Thrombus Blood-contacting materials Hemodynamics Platelet Bending stiffness
Research reported in this publication was supported by the Colorado Office of Economic Development and International Trade, Bioscience Discovery Evaluation Grant Program, and by the National Institutes of Health National Heart, Lung and Blood Institute under Award Number R01HL119824. The content is solely the responsibility of the authors and does not necessarily represent the official views of the State of Colorado or the National Institutes of Health.
Conflict of interest
Authors David A. Prawel, Harold (Casey) Dean, Marcio Forleo, Nicole Lewis, Justin Gangwish, Ketul C. Popat, Lakshmi Prasad Dasi, and Susan P. James declare that they have no conflict of interest.
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