Prawel David A, Dean Harold, Forleo Marcio, Lewis Nicole, Gangwish Justin, Popat Ketul C, Dasi Lakshmi Prasad, James Susan P
Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA ; School of Biomedical Engineering, Colorado State University, Fort Collins, CO, USA.
Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA.
Cardiovasc Eng Technol. 2014 Mar 1;5(1):70-81. doi: 10.1007/s13239-013-0171-5.
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 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. 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 cm. 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.
聚合物心脏瓣膜（PHV）有望比生物人工心脏瓣膜更耐用，且比机械心脏瓣膜的血栓形成倾向更低。我们引入了一种新框架，使用由透明质酸（HA）和线性低密度聚乙烯（LLDPE）的互穿网络（IPN）组成的新型材料，来制造用于心脏瓣膜（PHV）应用的血液相容性聚合物瓣叶。除了展示出卓越的血小板反应和凝血特性外，我们还通过三叶瓣配置下的基本血流动力学测量，确立并表征了该材料作为替代瓣叶材料的可行性。将普通LLDPE片材在硅烷化HA溶液中溶胀，然后使硅烷化HA自身交联，之后通过水解使其恢复为天然HA。使用新鲜人血，在静态条件下对瓣叶进行以下方面的表征：（1）弯曲刚度，（2）亲水性，（3）全血凝血，以及（4）细胞（血小板和白细胞）粘附。对原型HA/LLDPE IPN PHV进行血流动力学测试，以评估其作为功能性心脏瓣膜的可行性。弯曲刚度与天然新鲜瓣叶无显著差异。HA/LLDPE IPN比LLDPE对照更具亲水性。与普通LLDPE对照相比，HA/LLDPE IPN引起的全血凝血更少，细胞粘附减少。用HA/LLDPE IPN制成的原型PHV表现出可接受的反流分数为4.77±0.42%，有效瓣口面积在2.34±0.5平方厘米范围内。这些结果表明，HA与聚合物之间的IPN作为未来血液相容性心脏瓣膜瓣叶具有强大潜力。有必要进行进一步研究以评估其耐久性和抗钙化性。
