(color online) Inhibition of tumor growth by (Si+Pc) NPs. (a) Representative photos of MGC-803 tumor bearing mice on different days during PDT treatment. (b) Quantitatively time-dependent distribution of tumor size. The solutions, including PBS, (Si+Pc) NP dispersion and free Pc, are injected on the 1st day and 7th day followed by 30 min NIR exposure each time after injection. Error bars are based on the SD of triplicated samples.