Abstract
An ultrastructural preservation of platelet plasma membrane glycocalyx (GC) which adhered on HEMA-St ABA type block copolymer (HSB) surfaces for 5 hours was analyzed by transmission electron microscopy (TEM). The platelet GC was stained with ruthenium red. Then, the ultrastructural changes observed by TEM of ultrathin vertical sections of the adhered platelets were evaluated quantitatively using a highspeed image processor-analyzer. PSt and HEMA-St random copolymer surfaces were used as controls. The platelets on the HSB surfaces adhered with supporting narrow spaces which formed scaffolding, keeping the GC the same as the intact platelet GC. On the other hand, the platelets on the control surfaces adhered without the narrow spaces for the GC, indicating strong adhesion. Their external GC seemed to be lacking in some places. The intracellular changes of platelets on the HSB surfaces were significantly inhibited compared to those on the control surfaces. The number of the platelet storage granules of the HSB surfaces showed no significant difference compared to intact platelets. These results suggest that remarkable inhibition of the platelet ultrastructural changes on the HSB surfaces is due to good preservation of ultrastructure of the platelet GC followed by the continued soft landings of the platelets for 5 hours.
