Synthesis and characterization of Fe3O4@SiO2@poly-l-alanine, peptide brush–magnetic microspheres through NCA chemistry for drug delivery and enrichment of BSA

A novel Fe3O4@SiO2@poly-l-alanine peptide brush–magnetic microsphere (PBMMs) was synthesized from amine-functionalized Fe3O4 through the surface-initiated polymerization of N-carboxyanhydrides. Two materials with different peptide lengths were obtained from different amounts of N-carboxyanhydrides. These materials were characterized by Fourier transform infrared, transmission electron microscopy, large-angle powder X-ray diffraction, vibrating sample magnetometer and elemental analysis. Furthermore, the loading and release behavior of ibuprofen and the enrichment of bovine serum albumin on the two materials were investigated and it was shown that the PBMMs have a maximum uptake amount of ibuprofen of 40.3 mg g−1, and an enrichment of bovine serum albumin of 20.9 mg g−1. These materials are promising candidates for targeted drug delivery and protein enrichment.