Resistance to Photodynamic Therapy in Cancer

This volume provides a comprehensive review of resistance induced by photodynamic therapy (PDT) in tumor cells. Understanding the underlying mechanisms in this process leads to the improvement of therapeutic modality, in combination with chemotherapy, immunotherapy, and radiotherapy. Photodynamic therapy is a minimally invasive therapeutic procedure that can exert a selective or preferential cytotoxic activity toward malignant cells. The procedure involves administration of an intrinsically non-toxic photosensitizing agent (PS) followed by irradiation at a wavelength corresponding to a visible absorption band of the sensitizer. In the presence of oxygen, a series of events lead to direct tumor cell death, damage to the microvasculature, and induction of a local inflammatory reaction. Studies reveal that PDT can be curative, particularly in early stage tumors and this volume explores the potential of PDT, but also reveals strategic approaches to overcome resistance in tumor cells.

Giulio Jori is Professor of Biophysics at the University of Padova, Italy. He has been a founding member and President of the European Society for Photobiology. His research interests are focused on basic mechanisms of photodynamic action at a cellular and tissue level, as well as investigations concerning the application of photodynamic therapy for the treatment of tumours and microbial infections. Dr. Jori is Editor-in-chief of Journal of Photochemistry and Photobiology and he was also chairman of the ownership board of the journal Photochemical and Photobiological Sciences. He has been the chief organizer of nine International Symposia on Photodynamic Therapy and Photodiagnosis in Clinical Practice. In addition, he has received an award for excellence in research from the European Society for Photobiology.

Valentina Rapozzi is a Researcher at the University of Udine, Italy. Dr. Rapozzi's research is focused on the antitumoral molecular pathways in photodynamic therapy. She is a member of the European Society for Photobiology, and a member of the Council of the Italian Society of Photobiology.