Fig. 1. Physicochemical characterization of Pt@BSA and Pt@BSA-RM nanoparticles. (A) ICP-OES spectrum showing the characteristic platinum (Pt) signal at 266 nm. (B) Standard calibration curve of the Pt concentration at 266 nm used for quantification. (C) Optimization of the blood volume for coincubation with nanoparticles. (D) Hydrodynamic diameter distributions of Pt@BSA and Pt@BSA-RM nanoparticles measured by DLS (n = 3). (E) Zeta potential values of Pt@BSA and Pt@BSA-RM nanoparticles (n = 3). (F) Transmission electron microscopy (TEM) image of Pt@BSA-RM nanoparticles showing the intact membrane coating (scale bar = 100 nm). (G) Stability assessment of Pt@BSA-RM nanoparticles in different media (PBS (pH 7.4), 10% FBS, SBF, and acidic PBS (pH 5.5)) over 72 h, monitored by DLS and zeta potential. (H) In vitro drug release profiles of Pt@BSA and Pt@BSA-RM nanoparticles under 1 mM H₂O₂ stimulation over 60 h. Data are presented as mean ± SD. *p < 0.05; ***p < 0.001; ns, no significance.