A needle-type immunotherapeutic system incorporating laser light and platonin in combination with ethanol injection in the treatment of cancer growing in deep organs.

Platonin is a potent cell-activating agent and a photosensitizing dye characterized by a typical absorption peak at 590 nm. It has been already clarified that macrophage activity is enhanced synergistically by platonin administration together with laser light irradiation. This method is considered to be useful in cancer immunotherapy. In this study, a needle-type therapeutic system incorporating this method was applied for the therapy of a homogeneous tumor grafted onto mice. The tumor was strongly cicatrized by collagen fibers at an early stage of the treatment. A high T/B cell ratio of lymphocytes was observed in the peripheral blood of the treated mice. In addition, a high survival ratio was seen, especially in the group of concomitant therapy with ethanol injection (PEI method). It was determined that the induction of high immunopotentiation of mice was triggered by ethanol injection at an early stage. These results demonstrated that the system is reliable for the treatment of cancer in deep organs such as a liver, requiring no major surgical intervention.