Abstract
Poly (2-hydroxyethyl methacrylate) (PHEMA)-Polystyrene (PSt)-PHEMA ABA-type block copolymer (HSB) surfaces with lamellar-shaped microdomain structure inhibited necrosis of lymphocytes. In contrast, PSt and PHEMA-PSt random copolymer (HSR) surfaces caused necrosis of lymphocytes. In order to clarify the inhibitory mechanism, sialic acid-removed lymphocytes adhered to and eluted on HSB surfaces were analyzed by scanning (SEM) and transmission electron microscopy (TEM). TEM images of eluted lymphocytes and the mitochondria were evaluated quantitatively by an image processor-analyzer. Neuraminidase was used to remove sialic acid from the glycoproteins of lymphocyte plasma membrane. PSt and PHEMA-PSt random copolymer (HSR) surfaces were used as controls. The interaction between the polymer surfaces and the lymphocytes was carried out by the microsphere column method. The adhered lymphocytes were all observed to be round in all cases. The eluted lymphocytes were all observed to be round keeping cytoplasm well, too. Computerized TEM image analysis did not indicate significant differences in all cases. The results of previous papers (Jpn J Artif Organs 27-2, 495, 1998/28-1, 230, 1999) as well as this study suggest that the microdomain structure surfaces of HSB inhibit the necrosis of the lymphocytes because the surfaces do not have an important effect on the sialic acid of the plasma membrane glycoproteins.
