Figure 1. Stability of silicon particles in serum.

A. Discoidal porous silicon particles (1,000 ×400 nm) were incubated in FBS, pH 5.7. Aliquots of particle suspension were samples after 1, 3, and 10 days. Particle structure was analyzed using a scanning electron microscope. B. Particle size was measured with a Multisizer 4 instrument, and displayed based on diameter (upper panel) and volume (bottom panel). The dashed lines indicate the size of median volume (0.13, 0.125, 0.088 and 0.07 μm³ on days 0, 1, 3 and 10).