Selective adsorption of bilirubin against albumin to alkylamine functionalized PVA microspheres

AbstractAdsorbents are widely used in hemoperfusion for bilirubin removal. However, their performance is often compromised by the presence of plasma proteins. In this study, the bilirubin adsorption capacity of polyvinyl alcohol microspheres (PVAm) functionalized with different amino-alkane ligands has been investigated, with the aim of gaining binding selectivity over albumin. Octylamine-functionalized PVA microspheres (PVAm-8) exhibited an excellent adsorption capacity for bilirubin (75% and 3.95 mg/mL in PBS vs 72% and 3.84 mg/mL in albumin solution) when compared to the clinical adsorbent BPR (92% and 4.84 mg/mL in PBS vs 71%, and 3.80 mg/mL in albumin solution). The bilirubin adsorption capacities of PVAm-8 were largely unaffected by the presence of albumin. Adsorption of bilirubin to PVAm-8 occurs mainly through hydrophobic effects, with adsorption consistent with the monolayer model and the pseudo-first-order model operating in both PBS and albumin solution. The effects of PVAm-8 on hemolytic activ...