This article presents the development and characterization of SiO2 nannoparticles loaded with methylene blue (SiO2-MB), which are designed to administered for photodynamic therapy (PDT). Induced by light irradiation, the entrapped MB generated 1O2, and the produced 1O2 was measured with anthracene-9,10-dipropionic acid. In comparison to the unmodified MB, the MB
nanoparticles display lower singlet oxygen production but higher DNA photocleavage capability.
Furthermore, in vitro experiments illustrated that SiO2-MB was efficiently taken up by tumor cells, and that light irradiation of such impregnated cells resulted in significant cell death. Thus, these
properties of SiO2-MB could possibly make it especially promising foruse in clinical photodynamic therapy.