RESUMO
Tm:YAP laser system at power levels up to 1.2 W at 1980 nm was established in both continuous-wave and modulated modes of operation. The fluence effect of the laser system for skin ablation was analyzed by histology analysis with Wistar rat skin tissues. Thermally altered length, thermally altered area, ablation area, and ablation depth parameters were measured on histology images of skin samples just after the laser operation and after four-day healing period. Continuous-wave mode of operation provided higher thermal effects on the skin samples. Lower fluence levels were found for efficient ablation effect.
Assuntos
Procedimentos Cirúrgicos Dermatológicos , Terapia a Laser/instrumentação , Terapia a Laser/métodos , Fenômenos Fisiológicos da Pele , Pele/patologia , Túlio , Animais , Desenho de Equipamento , Análise de Falha de Equipamento , Masculino , Ratos , Ratos WistarRESUMO
Photodynamic therapy (PDT), due to its positive outcomes in clinical applications, easiness of practice and few side effects, is a good candidate for an efficient treatment of cancer. Indocyanine green (ICG), a water-soluble, anionic tricarbocyanine and non-toxic molecule is a promising photosensitive agent for PDT applications on tumor cells. ICG exhibits strong maximum absorption at around 805 nm which will be an advantage for its use in PDT; light at that wavelength can be used to treat deeper tumors. In this study the inhibitory growth effects of ICG-PDT on MDA-MB231 human breast cancer cells were investigated in a time course experiment. Cells were irradiated with a continuous wave diode laser (lambda=809 nm, 60 mW, 24 J cm(-2)). Cell viability was measured by MTT assay 0, 3, 6, 9, 12, 24 and 48h after light irradiation. The results showed that ICG-PDT application exerted its photo-oxidative effect on MDA-MB231 breast cancer cells immediately. Relative cell viability was determined throughout the 48h time course, and a consistent decrease was observed after ICG-PDT applications. In conclusion, ICG when used in combination with near-infrared light showed a very fast (within 3h) and persistent (up to 48h) photo-toxic effect on MDA-MB231 human breast cancer cells.
