Oral Abstracts 137 Methods: The use of anti-angiogenic agents such as Avastin and Erbitux in combination with PDT was assessed in an in vivo pre- clinical model. VEGF pathway was targeted using Avastin and the epidermal growth factor receptor (EGFR) pathway was targeted using Erbitux. Results: PDT followed by Avastin inhibited VEGF expression and other important growth factors in bladder carcinoma xenografts. In a similar way, PDT and Erbitux suppressed growth factors related to the EGFR pathway. It was noticed that PDT induced tumor destruction can be maintained and significantly enhanced by the administration of Erbitux. VEGF and EGFR pathways play a major role in angiogenesis of bladder tumors. Combining angiogenic inhibitors with PDT protocol to block VEGF and EGFR pathways has proven to be effective in controlling tumor regrowth. Conclusion: The success achieved by combining angiogenic inhibitors with PDT can provide information for potential target mechanisms, which can be translated into clinical studies with bet- ter response rate, less local and systemic toxicity and improved overall survival in patients. doi:10.1016/j.pdpdt.2011.03.047 O035 Contributions of experiment designs in photodynamic therapy: Photosensitizer design, treatment analysis and optimization T. Bastogne 1 , L. Tirand 1 , J. Gravier 3 , D. Bechet 1 , V. Morosini 1 , M. Pernot 1 , C. Frochot 2 , A. Richard 1 , F. Guillemin 1 , M. Barberi- Heyob 1 1 CRAN, Nancy-UniversitÚ, CNRS UMR 7039, Centre Alexis Vautrin, France 2 LRGP, Nancy-UniversitÚ, CNRS UPR 3349, Nancy, France 3 CEA LETI, Grenoble, France Introduction: One of the difficulties in the development of the photodynamic therapy (PDT) is inherent to the multidisciplinary feature of this treatment gathering mainly clinicians, physicists, biologists, and chemists. Another issue is the great number of bio- physical and biochemical parameters involved in the design of new photosensitizers as well as in the in vivo application of this treat- ment. We present a global development approach based on the methodology and tools of experimental design. Three study cases are developed to assess to potential relevance of such an empirical model-based approach for the development of PDT. Methods and results: In a first study, an in vitro screening exper- imental design was carried out. The addressed question dealt with the determination of influent factors on the phototoxicity of a new photosensitizer based on quantum dots. Five factors were exam- ined: the nature of quantum dots, the excitation light wavelength, the incubation time with cells, the photoactivable compound con- centration and the fluence level. Relevance of each factor was finally estimated and compared to identify the significant parame- ters. In comparison with a typical factorial design, the total number of experiments (42 trials) was divided by 5. In a second study, an in vivo factorial experimental design was applied to detect potential synergic effects between four therapeu- tic factors: the phenotype of the cancer cell line, the food type, the nature of photosensitizer and the post-injection time, on the in vivo selectivity (cancer/normal tissue) of the tested photosensitiz- ers. Results particularly pointed out the presence of a statistically significant synergic effect between these four factors and provided the optimal modalities to maximize the response in term of tumor- to-normal tissue ratio. In a third study, a Doehlert experimental design associated with a response surface model was used to determine the in vivo PDT modalities (photosensitizer concentration, irradiance and fluence) to both minimize the post-treatment growth rate of the tumor and maximize its growth delay. Only 13 experimental conditions were tested and the relevance of the optimized condition was corrobo- rated by in vivo validation experiments. Conclusion: These studies have confirmed the applicability and attractive contributions of experimental design techniques in the development and determination of optimal modalities of new pho- tosensitizers in PDT. Their main advantages are to a priori organize experiments according to specific questions while minimizing the experimental cost and controlling as much as possible the experi- mental uncertainty. doi:10.1016/j.pdpdt.2011.03.048 O036 Therapeutic effects of systemic PDT in a leukemia animal model using A20 cell lines L.Y. Wen 1 , S. Bae 1 , W.S. Ahn 1,2 1 Cancer Research Institute, Republic of Korea 2 Department of Obstetrics and Gynecology, The Catholic University of Korea, Seoul, Republic of Korea Keywords: A20; Leukemia; Lymphoma; Photodynamic therapy; Sys- temic therapy Purpose: In our study, for the application of photodynamic therapy to systemic diseases such as leukemia, lymphoma, and metastatic cancer of which tumor formation area could not be clearly compartmentalized, a systemic PDT method was developed and its effect was examined in an animal model. Materials and methods: The effect of growth inhibition of A20 cell lines (H-2d, murine B-lymphoma/leukemia, Balb/c ori- gin) induced by PDT/Photodithazine was evaluated by the Ez-Cytox assay. After PDT, the change of cell morphology assessed by light microscope and the induction of apoptosis as well as the change of cell cycle assessed by FACS analysis were analyzed. A20 cells were injected to Balb/c mice through the tail vein, and phytodynamic therapy was performed. Photodithazine at diverse concentrations was injected intravenously, and after 1 hour, micro photofibers 200 m in diameter were inserted to the tail vein, and irradiated with laser at 50—1200 J. The changes caused by systemic PDT in the brain, heart, kidney, liver, spleen, and other major organs were assessed by H and E staining, and the effect of systemic PDT was assessed by the survival rate of experimental animals. Results: A20 cells were treated with phytodynamic therapy, and the effect of cell growth inhibition and marked morphologi- cal changes such as the formation of air bubbles in cell membrane, etc. were observed. In addition, by photodynamic therapy, apo- ptosis and G1 arrest were induced. In a leukemia animal model, it was observed that the survival rate of the systemic PDT group was increased by more than 25% (P < 0.05). Conclusion: This study is the first report performed systemic PDT in the systemic tumor model leukemia. In addition, by the study, experimental bases that photodynamic therapy that has been applied to local treatments only such as solid tumors could be effec- tively applied to the treatment of systemic tumors or tumors of which tumor formation area could not be determined clearly were provided. doi:10.1016/j.pdpdt.2011.03.049