Photodynamic therapy is an effective modality for treating advanced melanoma. However, melanoma's inherent resistance to laser radiation hinders its widespread clinical application. The near-infrared laser radiation range of 1264-1270 nm offers unique properties: firstly, its ability to penetrate melanin-producing cells, and secondly, its capability to generate singlet oxygen without xenobiotics. We assess the impact of continuous wave 1265 nm laser radiation on an antioxidant defense system in melanoma B16-F10 and normal CHO-K1 cells. We observe a time-dependent increase in superoxide dismutase and glutathione-S-transferase activities, fluctuations in reduced glutathione levels, as well as a simultaneous increase in melanoma cell proliferation and cell death. We hypothesize that the differential activation of cellular antioxidant defense mechanisms contributes to melanoma cells' resilience to laser radiation.
The present work discusses effect of infrared (IR) femtosecond laser irradiation on neoplasm of white
mice with experimental cervical cancer- 5 (CC-5 on the 20th and 30th days after tumor transplantation). Tumor
tissue was irradiated by femtosecond erbium doped fiber laser: the wavelength is 1.55 μm, average and peak
powers are1,25 mW and 6kW, respectively, irradiation trials n=10. The average energy density (energy dose)
on a tissue for two groups of animals was 0,24 J/cm2 and 0,36 J/cm2 for a single trial. Irradiation was
followed by biochemical determination of LPO AOS parameters (“Lipid peroxidation-antioxidants” system):
malondialdehyde (MDA), activity of superoxide dismutase (SOD), catalase and glutathione-reductase (GR),
glutathione-S-transferase (GST). A subsequent morphological study of tumor tissue was performed.
Mathematical analysis of data demonstrates a weak dependence of the studied parameters on energy
dose. The latter implies the trigger effect of IR femtosecond laser irradiation on redox-dependent processes in
neoplasm at experimental cervical cancer.
The cytochemical analysis of the aerobic and anaerobic bactericidal, phagocytic activity, phagocytosis
completeness, as well as membrane topology and rigidity has been performed with the Scanning probe
microscopy (Solver Pro, NT-MDT, Russia) in neutrophils of the patients with cervical carcinoma treated
with the Erbium laser radiation at different intensity. The obtained data reveal a significant effect of the
femtosecond laser radiation on neutrophil morphofunctional state in patients with cervical cancer. The
efficiency of the femtosecond radiation depends on its intensity and clinical stage of the cervical cancer.
The effect of femtosecond laser radiation provided by the Erbium fiber laser with the pulse duration
of 10-13 s, peak and average power of 6,0±0,3 kW and 1,26±0,15 mW, respectively, wavelength λ of 1,55 μm
has been studied in the experiments on rat ascitic ovarian tumor cell in vitro. Irradiation has been performed
at the average intensity of 0,033±0.002 mW/cm2 at two expositions under femtosecond laser radiation of 600
and 900 s. The membrane topology and rigidity of the cancer cells have been estimated with the Scanning
probe microscopy (SolverPro, NT-MDT, Russia). Besides, the viability and apoptosis of the cancer cells have
been estimated. Free-radical processes and antioxidant enzyme activity have been studied in cancer cell
lysate. Femtosecond laser irradiation was established to increases the activity of the
"Lipoperoxidation - antioxidants" system in neoplasm, enhance the apoptosis, decrease the viability, and change cancer cell
membrane topology and rigidity in vitro depending on the energy density of the irradiation.
In the present work the effects of high-power femtosecond laser irradiation on a functional condition of red blood cells
and neutrophils in vitro have been investigated. The data on parameters of the lipid peroxidation - antioxidants system,
hemoglobin level and rigidity of red blood cell membranes testify destabilization of the membranes under the influence
of the given laser. The study of phagocytic activity, anaerobic and aerobic metabolism of neutrophils, and rigidity of
their membranes allows to suppose the dose-dependent effect to be stimulating.
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