Photodynamic therapy(PDT) is recently developed as an effective treatment for malignant disease. Carboplatin, a less nephrotoxic analog of cisplatin, has been widely used for the treatment of multiple malignancies. In this study, we investigated the cytotoxic and apoptotic effect of combined modality of photofrin mediated PDT with cisplatin and carboplatin on KB cell human oral cancer cell line in vitro. The a ttached KB cells were incu bated with c isplatin(0.04mg/ml) and carboplatin(0.02mg/ml) for 24h at 37℃ and followed by photosensitization with photofrin for 6h and laser irradiation with 630nm LED at an intensity of 2.0 J/cm2 for activating photofrin for 15min. Then MTT assay and SYTO 16 green & Propidium iodide (PI) double staining were used respectively to measure the cytotoxicity and nuclear morphology at 24h after PDT. This study demonstrates that the combined modality with carbopaltin resulted in enhanced apoptotic cell death as well as cytotoxic e ffect on KB c ells in vitro, which s uggests the feasibility of combined modality and the possibility o f reducing the effective dosage of photofrin and carboplatin and lowering the side effects on normal cells

Photodynamic therapy is a non-invasive cancer therapy that has recently attracted much attention in the field of cancer treatment. This study is an experiment to observe the effect of laser dose difference in photodynamic therapy. Murine breast cancer cells, EMT6 cells, were used to generate tumor bearing mouse models. The experimental group was divided into 5 groups as control group, laser 100 J/cm2, 200 J/cm2, 300 J/cm2 and 400 J/cm2 irradiation group. Photofrin was administered intraperitoneally and after 48 hours, laser irradiated on tumor with energy 0-400 J/cm2. the tumor volume was measured with a digital caliper on day 0, day 2, day 4, day 8 and day 12. The volume of tumor after photodynamic therapy was increased in the control group, laser 100 J/cm2 irradiation group and laser 200 J/cm2 irradiation group until day 12 after irradiation. Both the laser 300 J/cm2 irradiated group and the laser 400 J/cm2 irradiated group showed a decrease in the tumor volume from 2 to 12 days after irradiation. These results suggested that treatment effect will be obtained at a dose of 300 J/cm2 or more in the experiment using the tumor bearing mouse model and photoprin.