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

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.