Biofunctional impact of textured coatings in the application of heart assist therapy

Abstract

Due to a lack of organs, cardiac support systems are being implanted in patients with severe congestive heart failure. One of the solutions to overcome complications such as inflow obstruction or pump thrombosis, which may occur in the case of ventricular assist devices, is to modify the surface of cannulas for the controlled blood clotting process. The results obtained up till now for developed surface coatings clearly show the influence of topographical and mechanical parameters of the coatings on cell viability and protein adsorption mechanism. The new coatings should enable the controlled growth of scar tissue, resulting in the limitation of thromboembolic events, and the reduction of cystic tissue growth into the flow lumen. The aim of this study is to evaluate the correlation between surface topography parameters on the susceptibility of cells to grow and adhere to the substrate as a solution with potential for use in MCS (mechanical circulatory support) devices. Research on surfaces used in MCS devices and on inflow cannulas has been carried out for many years, while the novelty of the present solution makes it a milestone within that type of application simultaneously allowing for appropriate selection of process parameters. Surface modification of titanium alloy Ti6Al7Nb was carried out using vacuum powder sintering of CP-Ti (commercially pure titanium) powder with two morphologies (regular spheres and irregular grains). The characterization of coatings obtained with the proposed method and the influence of measured topographic parameters (applying scanning electron microscopy, contact angle measurement and contact profilometry) on the cytotoxicity and susceptibility to protein adsorption were presented. Advanced albumin adsorption studies have fully confirmed the dependence of surface complexity on protein adsorption. The obtained results show a high potential of the produced coatings toward enabling permanent integration at the implant with the soft tissue.