In vitro haemocompatibility and cytocompatibility evaluation of silver thin film-deposited heart valve prosthesis material

Abstract

ABSTRACTOne of the most important requirements for a blood-interfacing implant like pyrolytic carbon (PyC)-based heart valve prosthesis is biocompatibility. The aim of this investigation was to evaluate the in vitro haemocompatibility and cytocompatibility of PyC surfaces coated with silver thin films by pulsed laser deposition (PLD) technique at various ablation pulses. The haemocompatibility of the coated PyC surfaces was assessed by the estimation of thrombin time (TT) and the percentage of haemolysis and analysis of platelet aggregation by scanning electron microscopy. The in vitro cytotoxicity of AgNP-coated PyCs at 7500 and 10,000 ablation pulses was tested against chick fibroblast and human peripheral blood mononuclear (PBM) cells by optical microscopy, methylthiazolyl diphenyl-tetrazoliumdiphenyl-tetrazolium bromide assay and epifluorescence microscopy. The results showed that the deposition of AgNPs on PyCs up to 10,000 ablation pulses had improved the haemocompatibility significantly when compared to uncoated controls which were evident from the increased TT, decreased haemolysis and little or no platelet aggregation. AgNP coating of PyCs prepared at both ablation pulses had significantly improved their cytocompatibility to fibroblast and PBM cells when compared to untreated controls. Deposition of AgNPs by PLD technique has converted the procoagulant nature of PyC material into anticoagulant one and also enhanced the cytocompatibility of the heart valve material.