Abstract
Poly (2-hydroxyethyl methacry late) (PHEMA)/polyamine graft copolymers (HA) were prepared, and their interaction with rat platelets was examined by the use of column method. Significantly, platelet adhesion was minimized on the surface of HA copolymer with particular contents of polyamine (2-7 wt%) under the physiological conditions. Through the study using cytoskeleton-disrupted platelets, it was concluded that adhesion of platelets on HA surface was caused primarily by ionic interaction between platelets and microphase separated surface of HA. Thus, change in protonation degree of polyamine grafts with surrounding pH crucially affect the platelet retention. Actually, retention of platelets on HA was increased with increasing the protonation degree of amino groups in polyamine grafts. From the above results, it was suggested that concentration and domain-structured distribution of the protonated amino groups on HA were the determining factors for platelets adhesion on HA copolymer surfaces.
