Shear-Induced Hemolysis with Commercial and Glow Discharge Silicones

Abstract

The hemolytic characteristics of 14 different polydimethyl-siloxane materials were studied, using a rotating disk device to shear whole human blood for 6000 sec. Disk surfaces included commercial Silastic products with and without silica filler, coatings formed from hexa-methyl and tetra-methyl disiloxane monomer vapors by glow discharge, and heparinized silicones. Results are presented in the form of kinetic hemolysis curves (KHC)–plots of plasma hemoglobin vs. time–and analyzed in terms of the slopes of these curves in the 1500–6000 sec region where the KHC is nearly linear.

It was found that most silicone products are low-hemolysis materials, comparable to polyethylene (PE) but often about 20% less hemolytic; one product was superior by about 40%. The only consistent exceptions to this were the glow discharge surfaces from HEXA-methyl disiloxane (15–80% poorer than PE) and heparinized surfaces (70–280% more hemolytic than PE).