Preliminary evaluation of bare or polymer-coated colloidal monoclinic zirconia of nominal particle size 100 nm indicated that it is an effective adsorbent for pyrogenic lipopolysaccharides (LPS) as measured by chemical and Limulus amebocyte lysate (LAL) assays. Zirconia at 50 μm ml-1 adsorbed 99.95% of added E. coli O128 LPS. Residual LPS levels below 0.1 ng ml-1 were easily attained. Collidal zirconia was able to remove LPS from solution in the presence of bovine albumin (BSA). Some LPS contaminating BSA lacked affinity for zirconia. Preadsorption of phosphate onto bare zirconia blocked LPS adsorption. However, phosphated-oligomeric glycidyl (epoxy) pentaerythritol-coated colloidal zirconia could be derivatized with imidazole-containing ligands to produce an LPS-binding surface. Preliminary results of adsorption of LPS by the coated particles indicated a reduced level of LPS binding compared to bare zirconia, probably because the particles aggregated during the derivatization process, reducing the effective surface available for LPS adsorption.
- E. coli pyrogen removal
- Pyrogenic lipopolysaccharides
- colloidal zirconia