New thermoplastic elastomers for safer, greener and customizable blood-contacting medical devices with antithrombotic profile

Introduction: Thermoplastic elastomers (TPEs) of the polyurethane (PU)-type have broad applications in medical and healthcare products. However, they are prepared from toxic isocyanates, and the hemocompatibility of TPEs used for manufacturing blood-contacting medical devices remains insufficient, leading to high rates of thrombotic complications, in addition to the risk of infection of implantable devices.

Method: In this paper, we report the facile, up-scalable preparation of a greener non-isocyanate polyurethane (NIPU)-based TPE. We characterized this NIPU in terms of mechanical properties, processability, in vitro hemocompatiblity (namely through the measurement of hemolysis, platelet adhesion, coagulation activation, and kallikrein-like activity), bacterial adhesion, in vitro biocompatibility (towards human fibroblasts and endothelial cells), and in vivo biocompatibility (through subcutaneous implantation in rabbits for up to one month).

Results: Our NIPU can be processed by multiple relevant manufacturing techniques, i.e. hot pressing, extrusion, injection-molding, electrospinning, and additive manufacturing. In vitro hemocompatibility tests with human blood demonstrate better performance than a conventional medical grade PU-based TPE. This NIPU triggers less contact phase activation of coagulation and significantly less platelet adhesion, and the adhesion of Staphylococcus epidermidis is also reduced compared to PU. This new TPE biomaterial is neither hemolytic nor cytotoxic upon indirect or direct contact with endothelial cells or fibroblasts. Additionally, subcutaneous implantation of this NIPU in rabbits for one and four weeks confirms in vivo biocompatibility and no material degradation.

Conclusion: Our NIPU is therefore a highly valuable potential isocyanate-free alternative to conventional PU-based TPEs for manufacturing customizable blood-contacting devices with improved hemocompatibility and durability.

Publikationsverlauf

Artikel online veröffentlicht:
13. Februar 2025