Figure 12.

Possible mechanism for targeted radiosensitization by PCSN probes. Internalized silica nanoparticles may disturb the permeability of the lysosomal membrane in the targeted cell (HER2 positive), and the resulting lysosomal destabilization leads to cell destruction and autophagy. The major effect of ionizing radiation on the cell is direct damage to the DNA, and possible additional effect can also damage lysosomal membrane permeabilization, thereby activating cell death. The combination of PCSN probes and radiation may thus cause cell growth inhibition and cell death through lysosomal membrane destabilization. Anti-HER2 antibody on PCSN probes can also inhibit the MAPK and PI3K pathways, leading to the suppression of cell growth and proliferation. Yellow arrow signals: ionized radiation; mAb: Anti-HER2 antibody; Orange star-like dots around silica nanoparticle: fluorophore; Blue dots in the cell: degraded silica nanoparticle.