Immobilization of HSA on polyamidoamine-dendronized magnetic microspheres for application in direct chiral separation of racemates

Abstract

Magnetic microspheres containing dendrimers and chiral selectivity show great performance for applications in pharmacology and biomedicine. In this study, a novel chiral magnetic nano-selector was prepared by immobilizing human serum albumin (HSA) on polyamidoamine dendrimer (PAMAM)-modified magnetic silica microspheres (PMSMs). The functionalized magnetic microspheres had a core–shell structure, with an average diameter of 600 nm. They exhibited strong magnetic response, with a high magnetization saturation of 46 emu g⁻¹. UV-vis spectrophotometry and confocal laser scanning microscopy indicated that the HSA binding capacity on PMSM increased with increasing PAMAM generation. An immunoaffinity assay indicated that HSA retained a high level of activity, after immobilization on PMSM. HSA-immobilized PMSM (HSA–PMSM) was applied in the direct chiral separation of three biological racemates. The separation results show that HSA–PMSM selectively interacted with the racemates, and exhibited different activity toward each enantiomer. The results obtained by CD and CE indicated that HSA immobilized on third-generation PMSM possessed excellent chiral separation capability and biocompatibility. The chiral recognition capability of HSA–PMSM increased with increasing PAMAM generation. The chiral magnetic nano-selector is effective for the enantiomeric separation of chiral drugs, and has potential application in pharmacological and biomedical research.