Surface Anticoagulation of Mechanical Heart Valves using Electrically Induced Biomimetic Glycocalyx: an In-vitro study to assess Hemocompatibility and Optimal Voltage

BackgroundMechanical heart valves (MHVs) remain the most durable option for valve replacement, but they are highly thrombogenic and therefore necessitate life-long anticoagulation. We designed a novel MHV assembly based on "Surface Anticoagulation by Electrically induced Biomimetic Glycocalyx" (SAEBG) that imposes a weak negative potential across the valves blood-contacting surfaces using an implantable pacemaker as an energy source. The concept is inspired by the native vascular endothelium, where the luminal glycocalyx carries a net negative surface charge that repels platelets and proteins. The present study aims to assess hemocompatibility and determine the optimal voltage to achieve thromboresistance in our electrically activated MHV. MethodsBileaflet MHV were immersed in human platelet-rich plasma or whole blood and connected to a programmable pulse generator. Control valves (0 V) were compared to those activated at 0.25, and 0.5 V. The control/activated valves were immersed in PRP/blood for 30 min under gentle agitation at 35 {+/-} 2 {degrees}C. Hemolysis and blood cell integrity in the supernatant fluid were quantified using standard hematology analyses. Valves immersed in PRP were assessed by scanning electron microscopy (SEM). ResultsThe cell/deposit free area as assessed by SEM was highest with 0.5 V ([~]96%), while the corresponding free areas for controls and 0.25 V were [~]86% and [~]58% respectively. The platelet counts, platelet and coagulation markers were close to the measurement uncertainty ranges for all the experiments. Hemolysis was <0.1 % for all conditions, and the leucocyte and red-cell counts changed by <2 %. ConclusionsImposing a mild electrical potential ([~]0.5 V) on an MHV reproduces the anti-thrombotic behaviour of vascular endothelium, while a lower potential (0.25 V) was insufficient. The electrical field did not injure blood cells or activate coagulation pathways, establishing a safe and effective voltage window for the SAEBG valve to enable further swine model experiments.