Effects of combined photochemical internalization and hyperthermia are sensitively dependent on radiant exposure

Publication Type:

Conference Paper


SPIE BiOSPhotonic Therapeutics and Diagnostics IX, SPIE, Volume 8565, San Francisco, California, USA, p.85655F - 85655F-8 (2013)


Combination therapies of photochemical internalization (PCI) and hyperthermia (HT) were investigated in an in vitro system consisting of human glioma spheroids. Spheroids (350-400 μm dia.) were irradiated with 670 nm laser light in an incubator at temperatures ranging from 37 to 50 °C. For each temperature investigated (45 min. heating time), spheroids were divided into 5 groups: control, dark control, bleomycin-only, photodynamic therapy (PDT), and PCI. PDT and PCI spheroids were exposed to radiant exposures ranging from 0.5-3.0 J cm-2 using an irradiance of 5 mW cm-2. Toxicity was evaluated from spheroid growth kinetics. The combination of PCI and HT resulted in growth delays over a very narrow range of radiant exposures (1.5 – 2.5 J cm-2) and temperatures (40 – 42 °C).