Changes of the intracellular NO levels as a function of the time after the PDT. The averaged fluorescence intensity of control cells (white triangle) was set as 100%. TiO2 (white square)- or N-TiO2 (black circle)-treated cells were incubated with 100 μg/ml under light-free conditions for 2 h before the irradiation.
Li et al. Nanoscale Research Letters 2013 8:96 doi:10.1186/1556-276X-8-96