An in vitro and in vivo study of combination therapy with Photogem®-mediated photodynamic therapy and cisplatin on mouse cancer cells (CT-26).

Abstract Objective: This study was designed to evaluate the anticancer effect of cisplatin and photodynamic therapy (PDT) combined in vitro and in vivo. Background Data: PDT, these days, is a promising modality for the treatment of cancer and infections. In order to optimize the treatment, cisplatin is often combined with other chemotherapeutic agents. Methods: Colon cancer cells were incubated with cisplatin (0.1, 1, and 6 μg/ml), followed by photosensitization with Photogem® and irradiation with a 632 nm diode laser at an energy density of 3.2 J/cm2. An MTT assay was then used to measure cell viability. For in vivo studies, established tumors were treated with cisplatin (3 mg/kg) alone or with PDT (5 mg/kg of Photogem®, 600 J/cm2). The sizes of the tumors were continuously measured to note the effects. Results: The cell viability of the combined therapy group was 19.88 ± 0.41, corresponding to a 9% increase compared with that of the cisplatin- or PDT-only groups. In vivo, the tumors treated with PDT or ...