Blood platelets change morphological shape upon activation. The platelets are rather spherical when not disturbed, like in the blood of a healthy person. When disturbed the shape changes from spherical to dendritic, spread dendritic and finally they assume a fully spread form which is a typical form suitable to prevent blooding. The morphological shapes therefore indicate the level of activation and this in turn indicates intensity of coagulation cascade. The morphological shapes were studied to detail and differences in activation mechanisms between untreated and plasma treated surfaces are elaborated in this paper.
COBISS.SI-ID: 27713575
A method for nanostructuring pyrolytic graphite (a material often used for synthetic heart valves) has been developed. Samples of smooth surface were exposed to highly reactive oxygen plasma. In a range of treatment parameters the etching was selective enough to cause formation of densely packed nanocones of typical lateral dimension at the base as well as height of a micro meter. The structures were incubated with platelet rich human blood and the activation of platelets was studied upon different incubation parameters. A dramatic difference in the concentration of platelets in the highly activated state between smooth and nano-structured surface of this material confirmed the original hypotheses of poor activation of blood platelets on the surface on nanostructured carbon materials.
COBISS.SI-ID: 27550759
Any surface finish of cardiovascular implants should allow for rapid endothelisation after implantation. In order to check this view of biocompatibility we performed in-vitro research on adhesion of blood proteins on the material used for commercial artificial blood vessels as well as proliferation of endothelial cells on materials treated according to our method. Not only we found improved adsorption of blood proteins but the endothelisation was obtained faster than in the case of untreated materials.
COBISS.SI-ID: 27161383
Materials suitable for coating cardiovascular implants should be antibacterial in order to be used in medical praxis. In order to achieve this effect we invented an multistep technique comprising of surface activation using oxygencontaining gaseous plasma and subsequent deposition of ultrathin films. Three monomers (allylamine, Nallylmethylamine and N,Ndimethylallylamine) were used for grafting onto plasma activated LDPE surface. Antibacterial agent triclosan was anchored on such substrates. Excellent results were obtained on lowdensity polyethylene substrates tested in vitro by inhibition zone method on agar plates for Staphylococcus aureus and Escherichia coli strains.
COBISS.SI-ID: 26378791
Improved biocompatibility of polyethylene was achieved by deposition of an antithrombogenic coating. Both pure chitosan thin film and chitosan/pectin multilayer was immobilized via polyacrylic acid (PAA) brushes grafted on the LDPE surface. The grafting was initiated by a lowtemperature plasma treatment of the LDPE surface.
COBISS.SI-ID: 26064423