Scheme 1. Synthesis Route of (a) R-BSA, (b) BSA@PSiNPs, R-BSA@PSiNPs Nanocomposites and Schematic Illustration of the Interactions between Macrophages and (c) BSA, (d) R-BSA, (e) BSA@PSiNPs, and (f) R-BSA@PSiNPs, and the Corresponding Signaling Pathways.