The influence of antimicrobial treatments on the cytocompatibility of polyurethane biosensor membranes

The cytocompatibility of polyurethane membranes was tested following ultraviolet or gamma irradiation as well as treatment with hydrogen peroxide or glutaraldehyde containing solutions. Despite the fact that all of the methods had been recommended for antimicrobial treatment of glucose biosensors, the treatments investigated significantly influenced cytocompatibility characteristics. Cytotoxicity of membrane eluates was not observed following irradiation treatments. This was also the case when the membranes were repeatedly washed following chemical treatment. Cell growth upon the membranes was stimulated to a different extent after gamma and UV irradiation as well as following hydrogen peroxide treatments. Residues of an urea-based hydrogen peroxide inclusion compound caused a restriction in cell growth upon the membranes as was similarly observed with 2 and 4% glutaraldehyde solutions acting over 2 and 4 h, respectively. It is concluded that cytocompatibility in vitro reflecting the host response against a biomaterial in vivo does not only depend upon the material itself but also upon antimicrobial treatments which could have consequences for its bioperformance characteristics.