Enterovirus 71 adsorption on metal ion‐composite chitosan beads

In this study, we developed composite chitosan beads combining various metal ions, including Ni 2+ , Cu 2+ , Zn 2+ , and Fe 2+ , for direct adsorption of enterovirus 71 (EV71). The metal‐ion species had significant effects on the adsorption capacity of beads. Among these metal ion‐composite chitosan beads, Ni 2+ ‐chitosan beads exhibited the best adsorption capacity of EV71. Using a concentration of 0.01‐M Ni 2+ was found to best provide for bead formation and EV71 adsorption. The adsorption of EV71 for Ni 2+ ‐chitosan beads at neutral or alkaline pH was favored. Under a competitive condition with albumin proteins, Ni 2+ ‐chitosan beads exhibited significant capacity of EV71 adsorption in culture media. The adsorption of EV71 on the Ni 2+ ‐chitosan beads was attributed to the strong binding between Ni 2+ ions chelated to the surface amino acid of EV71 capsids and Ni 2+ ions chelated on the chitosan materials. Moreover, the adsorbed EV71 retained its antigenicity and infectivity after desorption. The Ni 2+ ‐chitosan beads exhibit a promising application to EV71 adsorption and removal. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012