Ultrasound Activated Hematoporphyrin Killing Effect From The Body Melanoma (of Libr), Gastric Cancer Cells (7901)

A malignant tumor is a kind of disease directly threatening human'slife. At present many treatments have been invented in order to be antitumor. Thesemethods include an application of ultrasound including high intensity focusedultrasound (HIFU) surgery ultrasound thermal treatment and sonodynamic therapy(SDT). There are some deficiencies and difficulties to apply the first two to clinic, butthe third treatment has its advantages. It has coordination effect with using thephotosensitive drugs (such as hematoporphyrin) and can penetraing tissue deeply andbeing easier to focus, not need expensive equipment and avoiding thermal side-effect,so the application of sonodynamic treatment is a promising way on treatment oftumors in deep tissue. Many scholars at home and abroad, especially Japanesescholars S. Umemura and N. Yumita, have done many researches on this and obtainedsome primary results, but those studies are limited in material and means. So there is along way to go to apply SDT to clinic.In order to apply this method to clinic, and treat tumors in human's body witheffectively and conveniently activate photosensitive drugs, based on the internal andexternal studies, this paper has designed to solve the two significative problems. Oneis to define the optimum hematoporphyrin concentration, the optimum timing of theirradiation and the optimum ultrasonic intensity under firmed ultrasonic frequency,the other is to study whether or not SDT can cause cancer cells apoptosic phenomenaunder certain conditions.The author has used MTT, which has been proved to be a reliable way to studythe activity of cells, to do research on LiBr and 7901 in vitro under the certain focusultrasonic frequency (1100kHz), when the ultrasonic intensity was 0.06w/cm~2, theexperimental results show that the minimum survival rate of 7901 cells exposed toultrasound in combination with 0. 2mg/ml hematoporphyrin for 180 s was 13% of thecontrol, and the minimum survival rate of LiBr cells (1100kHz, 0.06w/cm~2,l80s)was 29%. After 8 hours, the apoptosis phenomena was observed in the LiBrcells (l100kHz, 0.06W/cm2, 60s to 90s). The studies above provide importantparameters for further research on in vitro and in vivo experiments and advance theprogram of the sonodynamic therapy (SDT).