Treatment of cancer by low intensity laser radiation therapy

Progress in Biophysics and Molecular Biology

4 years ago

Treatment of cancer by low intensity laser radiation therapy

Cancer treatment is one of the main challenges that face the scientific centers all over the world. The cancer incidence percentage increases year after year. The most used treatment for cancer is chemotherapy which is an application of systemic cytotoxic drug inside the patient. There are two main problems in chemotherapy that the cytotoxic drug is given systematically and cannot be localized in the tumor region in most cases that lead to killing the cancer cells as well as normal cells; and that cause the chemotherapy side effects like anemia, decrease in all blood cells count and platelets, nausea, vomiting, diarrhea, hair and nails loss and may cause a kind of blood toxicity. Photodynamic therapy (PDT) is a relatively new approach for the treatment of malignancies with only minimal side effects for the patient. It is based on the administration of a tumor-localizing dye (photosensitizer, PS) that becomes toxic to neoplastic cells when is activated by light (usually from a laser) at a specific wavelength in the presence of O2. In this work photodynamic therapy modality was used. Porphyrin derivative was used as a photo sensitizer drug and one source of energy were used; namely infrared laser with three frequency levels (1000, 2000, and 3000 Hz). Tumor-bearing animals were divided into the following groups each of 10 animals. The 1st group consists of two control groups: the 1st one was untreated group and the 2nd one was injected with photosensitizer alone. The 2nd group consists of 30 mice divided into 3 sub-groups and tumor site was irradiated with laser light as follows:1000 Hz,2000 Hz and 3000 Hz for 5 min.3rd group consists of 30 mice injected with HPD 12.5 mg/kg,then divided into 3 subgroup and tumor site was irradiated with laser light at the same conditions of 2ndgroup.The results show decrease in tumor size treated with drug (HPD) which is used as a photo sensitizer, laser, and combined treatment, both in the presence and absence of photosensitizer. Combined treatment is more effective on tumor cells than using of laser and drug alone. Also the presence of photosensitizer increases the effect of laser on tumor size. However, from histopathology of ehrlich tumor using 3000 Hz of laser irradiation in the presence of the photosensitizer drug approximately has the most effect than using the photosensitizer drug alone and exhibit totally necrotized tumor. It could be concluded that the use of the photosensitizer drug alone has no effect on the ehlrich tumor. However, the presence of the drug gave maximum effects with exposure to 3000 Hz infrared laser irradiation. The work needs to be extended to reach more and powerful effects using the photodynamic therapy with exposure to other different energies of infrared laser radiation.

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DOI: S0079610717301323