Novel green surface modification of metallocene polyethylene by steam to enhance its hemocompatible properties

Abstract

Steam treatment is a green surface modification technique that was used to improve the surface characteristics and hemocompatibility of metallocene polyethylene (mPE). In this study, a sharp decrease in the mean contact angle of steam-exposed mPE compared to that of untreated mPE showed enhanced hydrophilicity. The increased surface roughness was demonstrated by atomic force microscopy, scanning electron microscopy, and Hirox three-dimensional microscopy. The average roughness of the control mPE (2.757 nm) was enhanced to 8.753 nm by steam treatment. Fourier transform infrared spectroscopy analysis illustrated no chemical changes, but the changes in the absorbance intensity ensured morphological changes. Blood compatibility studies were assessed by coagulation assays, hemolysis, and platelet adhesion tests. The mean number of platelets adhered to the steam-treated sample (11) was half of the number of platelets adhered to the untreated mPE surface (22). The clotting time on the steam exposed surface was delayed, hemolysis and platelet adhesion were significantly reduced. The green surface modification of mPE with steam enhanced its surface properties and hemocompatibility. The improved blood compatibility of mPE may help in the efficient designing of hemocompatible biomaterials such as cardiovascular implants.