UC Davis

The translation of photodynamic therapy (PDT) to the clinic has mostly been limited to superficial diseases where traditional light delivery is noninvasive. To overcome this limitation, a variety of mechanisms have been suggested to noninvasively deliver light to deep tissues. This work explores the minimum amount of light required by these methods to produce a meaningful PDT effect in the in vitro setting under representative low fluence and wavelength conditions. This threshold was found to be around 192 mJ/cm(2) using the clinically approved photosensitizer aminolevulinic acid and 12 mJ/cm(2) for the more efficient, second generation photosensitizer TPPS2a.