Morphology Transformations of Platelets on Plasma Activated Surfaces

Abstract

Improved hemocompatibility from the perspective of platelets adhesion and activation on polyethylene terephthalate surfaces has been addressed. The activation stage of platelets has been determined from their size and morphology using scanning electron microscopy (SEM). The activation of platelets on untreated polymer materials was very intensive. Polymer materials were treated with weakly ionized oxygen plasma in order to repel platelet adhesion. Already short treatment times (3s) showed significant reduction of the total number and of highly activated forms of adhered platelets. Possible mechanisms of different behaviour of blood platelets on plasma treated polymer were discussed in terms of surface adhesion and changes in morphology.

Haemostatic Response of Polyethylene Terephthalate Treated by Oxygen and Nitrogen Plasma Afterglows

“…The polymers without any antithrombogenic surface finish therefore adhere blood platelets and cause their activation as observed in Figure 3. neutral oxygen atoms is therefore beneficial and results are similar to those obtained by treatment of this polymer in oxygen plasma [24,25]. The poor ability for adhesion of blood platelets on oxygen-functionalized materials has been explained by different conformation of blood proteins that adhere to the surface of PET polymer in a fraction of a second after incubating with fresh blood, so well before any platelet adheres and activates [26].…”

Hemocompatibility properties of a polymer surface treated in plasma containing sulfur

“…Results regarding hemocompatibility have been obtained by other researchers as well. Modic et al studied platelet adhesion on surfaces treated in pure oxygen plasma and found these surfaces to have excellent hemocompatibility properties . In contrast, Kolar et al and Primc et al studied the influence of nitrogen and ammonia plasma treatment on platelet adhesion and found worse hemocompatibility in comparison with that produced by oxygen plasma treatment .…”

“…Modic et al studied platelet adhesion on surfaces treated in pure oxygen plasma and found these surfaces to have excellent hemocompatibility properties. [6] In contrast, Kolar et al and Primc et al studied the influence of nitrogen and ammonia plasma treatment on platelet adhesion and found worse hemocompatibility in comparison with that produced by oxygen plasma treatment. [5,26] However, the hemocompatibility of surfaces treated in nitrogen and ammonia plasma still appears to be better than that produced by SO 2 or H 2 S plasma treatments.…”

“…In the case of improving hemocompatibility properties of vascular grafts, plasma is normally used only as an initial step to enable further surface grafting with specific molecules that have antithrombogenic properties . Nevertheless, it has also been shown that a remarkable decrease in platelet adhesion can be obtained by using solely an oxygen plasma treatment …”

“…[5] Nevertheless, it has also been shown that a remarkable decrease in platelet adhesion can be obtained by using solely an oxygen plasma treatment. [6] According to the literature, functional groups containing sulfur may be antithrombogenic as well due to negatively charged SO 3 groups. [7][8][9][10] Surfaces with these groups can be prepared by plasma treatment, [7,11,12] plasma polymerization, [13] chemical synthesis [8][9][10] , or by surface grafting with special substances (e.g., fucoidan, [14] sulfonated chitosan, [15] , and sulfated hyaluronic acid [16] ).…”