Modifications in the nanoparticle-protein interactions for tuning the protein adsorption and controlling the stability of complexes

Kumar, S.*; Saha, D.*; 高田 慎一  ; Aswal, V. K.*; 瀬戸 秀紀

Kumar, S.*; Saha, D.*; Takata, Shinichi; Aswal, V. K.*; Seto, Hideki

We report the pathways to suppress or enhance the protein adsorption on nanoparticles and thereby control the stability of the nanoparticle-protein complexes with the help of selective additives. This has been achieved by tuning the electrostatic interaction between the nanoparticles and proteins, in the presence of surfactant and multivalent counterions. The preferential binding of the proteins with the surfactant and multivalent ions induced charge reversibility of nanoparticles can lead to adsorption of an otherwise non-adsorbing protein and vice versa. The findings are demonstrated for anionic silica nanoparticles and two globular proteins [lysozyme (cationic) and bovine serum albumin (BSA) (anionic)] as model systems, in the presence of two ionic surfactants [anionic sodium dodecyl sulfate (SDS) and cationic dodecyltrimethylammonium bromide (DTAB)], and ZrCl as multivalent salt.