Combinatorial treatment of photothermal therapy using gold nanoshells with conventional photodynamic therapy to improve treatment efficacy: An in vitro study

Background and Objective Both photodynamic (PDT) and photothermal (PTT) therapy have proven to be effective treatment strategies for cancer, but the approach of combining them into a single treatment modality may offer better treatment efficacy. We compare the treatment efficacy of such combined treatment with the individual treatment. Study Design/Materials and Methods We perform the individual PDT, PTT and combined treatment under selected in vitro condition with our low light dose of 1.44 J/cm 2 and compare their cell viability using crystal fast violet assay. Results Compared to PDT and PTT alone which can reduce cell viability to 30.9% and 44.0% respectively, the combined treatment under a single irradiation can further reduce the cell viability to 17.5%. Conclusion A combined PDT and PTT treatment appears to be a more effective treatment strategy compared to conventional PDT or emerging PTT treatment. Lesers Surg. Med. 40:584–589, 2008. © 2008 Wiley‐Liss, Inc.