Expanded Poly(tetrafluoroethylene) Blood Vessel Grafts with Embedded Reactive Oxygen Species (ROS)-Responsive Antithrombogenic Drug for Elimination of Thrombosis

Abstract

Treatment of cardiovascular diseases suffers from the lack of transplantable small-diameter blood vessel (SDBV) grafts that can prohibit/eliminate thrombosis. Although expanded poly­(tetrafluoroethylene) (ePTFE) has the potential to be used for SDBV grafts, recurrence of thrombus remains the biggest challenge. In this study, a reactive oxygen species (ROS)-responsive antithrombogenic drug synthesis and a bulk coating process were employed to fabricate functional ePTFE grafts capable of prohibiting/eliminating blood clots. The synthesized drug that would release antiplatelet ethyl salicylate (ESA), in responding to ROS, was dissolved in a polycaprolactone (PCL) solution, followed by a bulk coating of the as-fabricated ePTFE grafts with the PCL/drug solution. Nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM) were employed to investigate and confirm the synthesis and presence of the ROS-responsive drug in the ePTFE grafts. The ESA release functions were demonstrated via the drug-release profile and dynamic anticoagulation tests. The biocompatibility of the ROS-responsive ePTFE grafts was demonstrated via lactate dehydrogenase (LDH) cytotoxicity assays, live and dead cell assays, cell morphology, and cell–graft interactions. The ROS-responsive, antithrombogenic ePTFE grafts provide a feasible way for maintaining long-term patency, potentially solving a critical challenge in SDBV applications.

Hydrogel-coating improves the in-vivo stability of electrochemical aptamer-based biosensors

“…7f . To test for the presence of thrombosis in intravenous placements, [38] we collected the vessels from the rats one week after tail-vein implantation. In neither case did we observe thrombosis for either gel-protected or unprotected implantations ( Fig.…”

“…Likewise, we did not detect any hematological changes in terms of white blood cells, red blood cells, hemoglobin, and platelets counts (Fig. 7f. To test for the presence of thrombosis in intravenous placements, [38] we collected the vessels from the rats one week after tail-vein implantation. In neither case did we observe thrombosis for either gel-protected or unprotected implantations (Fig.…”

Tissue Engineering for Mimics and Modulations of Immune Functions

“…First, heparin, a universal anticoagulant, was immobilized on graft surfaces to reinforce the antithrombotic properties. [ 30–41 ] Heparin interacted with antithrombin III and enhanced inhibition of blood coagulant factors including factor Xa and thrombin, thereby avoiding blood coagulation. [ 42 ] Heparin in multiple layers can be immobilized on ε ‐polycaprolactone (PCL) graft surfaces by combining EDC/NHS coupling and layer‐by‐layer assembly, preventing long‐term thrombus formation.…”

“…synthesized a drug that would release antiplatelet ethyl salicylate induced by ROS and coated it on a PTFE vascular graft together with PCL. [ 41 ] Peng et al. grafted the REDV peptide, which inhibits nonspecific adhesion of platelets, to decellularized amniotic membrane (AM) hydrogel through EDC/NHS coupling.…”

Viscosity characterization and flow simulation and visualization of polytetrafluoroethylene paste extrusion using a green and biofriendly lubricant

“…In addition, the porous structure of surface‐modified ePTFE can allow for endothelial tissue growth, as can additional biomolecules such as angiogenic growth factors and/or antithrombogenic drugs added to the graft. [ 14‐17 ] Thus, the fabrication of ePTFE vascular grafts is of significant interest.…”