The aim of this study was to prepare a new adsorbent for bilirubin (BR); low generation (G, G 4) hexanediamine-containing polyamidoamine (PAMAM) dendrons were supported on chitosan (CS) microspheres (CS-Gn, n = 0,1,2,3,4). The adsorption properties of this novel adsorbent for BR in aqueous solution were examined. The adsorption percentages were over 70% at 0.5 h and over 90% at 1 h. The adsorption capacity was up to 43 mg/g and was not yet saturated. The BR adsorption increased with increasing temperature and increasing BR initial concentration and was the highest at pH 7.4; it decreased slightly with increasing ionic strength and occurred even in the presence of bovine serum albumin (BSA). We observed that the CS-Gn microspheres had satisfactory competitive abilities with BSA, although the adsorption percentage decreased a certain extent in the presence of BSA. In addition, the CS-Gn microspheres were easier to prepare than the usual PAMAM dendrimers. In summary, this adsorbent is a promising biomedical material for BR removal for artificial liver supported systems. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013