Synthesis of 2-hydroxyethyl methacrylate舑dimethylsiloxane block copolymers and their ability to suppress blood platelet aggregation

Abstract

In order to elucidate the interaction between blood platelets and polymer surfaces of microdomain structure, block copolymers consisting of hydrophilic chains of 2-hydroxyethyl methacrylate (HEMA) and hydrophobic chains of dimethylsiloxane (DMS) were synthesized. Films of the HEMA舑DMS block copolymers exhibiting hydrophilic舑hydrophobic microphase-separated structures were found to enhance platelet adhesion more than homogeneous surfaces of poly(HEMA) or poly(DMS). Platelet adhesion to the block copolymer increased with morphological changes in microdomains so long as the HEMA composition of the block copolymer was 0.90 to 0.58. Platelet adhesion also varied with morphological change in the microdomains caused by changing the casting solvents, though an identical copolymer was employed. These results indicated that platelet adhesion to the HEMA舑DMS block copolymer was influenced by domain morphology rather than HEMA composition of the copolymers. In spite of the enhancement of platelet adhesion, the HEMA舑DMS block copolymers effectively suppressed shape change and aggregation of adhered platelets. The HEMA舑DMS block copolymers were considered to have good antithrombogenecity on the basis of inhibition of activation and aggregation of adhered platelets. © 1983 The Society of Polymer Science, Japan.