Albumin‐Coated Amberlite XAD‐7 Resin for Hemoperfusion in Acute Liver Failure: Part I: Adsorption Studies

Abstract

Platelets adhere to most foreign surfaces. As a result, polymers and albumin have been suggested as possible coatings to improve the blood compatibility of such surfaces. Amberlite XAD‐7 has a high affinity for human serum albumin (HSA) and several protein‐bound toxic metabolites. In the present study it is shown that HSA can be tightly bound to Amberlite XAD‐7 without. the use of chemical coupling agents. Optimal binding was achieved at pH 5.0 and the adsorption conforms to Langmuir's isotherm. Theoretical analysis of data and absence of a residual surface coating visible with scanning electron microscopy suggest a monolayer of albumin. The amount of HSA eluted from the resin under severe flow conditions was negligible (˜1%). Furthermore, in stirred batch studies with human plasma, the HSA coating did not decrease the adsorptive capacity of XAD‐7 for bile acids and bilirubin.