Blood compatible aspects of DNA-modified polysulfone membrane-protein adsorption and platelet adhesion

DNA was used as a biomaterial to modify the polysulfone (PSf) membrane by blending it with PSf. The blood compatibility of the membranes was then investigated. The water contact angle decreased, and the hydrophilicity increased when a single strand DNA was blended with PSf. Because of the hydrophilic surface, the DNA-blended PSf membranes had a lower protein adsorption than the PSf membrane, but it was not significantly decreased due to the interaction between the DNA and proteins. Circular dichroism (CD) spectroscopy was used to examine the changes in the secondary structure of the proteins after adsorption onto the polymer surface and desorption from the polymer surface into the SDS solution. The conformation of the proteins adsorbed onto the PSf membrane and desorbed from the PSf membrane significantly changed, but that of the proteins for the DNA-blended PSf membranes differed only slightly from the native one. The number of platelets that adhered on the surface of the DNA-blended PSf membranes was reduced compared to that on the PSf membrane. This suggested that DNA can be regarded as a biopolymer to modify PSf, and contributes to the hydrophilic and hemocompatible wipers on the surface of the hydrophobic PSf membranes.