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Photosensitizers have been used for years to treat or diagnose several oncological diseases. In this research, we evaluate Rhodamine (Rh-640 perchlorate), a second-generation photosensitizer's mediated preliminary photodynamic effects. To investigate these preliminary dose–response effects on the Rhabdomyosarcoma cancer cell line, the UV absorption spectra, standard curve, and cytotoxic analysis of Rh-640 perchlorate are demonstrated. The absorption spectra suggest that longer wavelengths of light like yellow-red light are best used for light irradiation. Different concentrations are used to evaluate absorbance and cytotoxic response. The results suggest that Rh-640 perchlorate may be used for the selective destruction of cancer cells without imposing any toxicity on normal cells in the dark. This research finding also suggests that its efficiency may also be evaluated on other cancer cell lines. [ABSTRACT FROM AUTHOR]

The studies about therapeutic applications of gold (AuNPs) and silver (AgNPs) NanoParticles, in conventional and non-conventional cancer therapies are gaining increased attention. PhotoDynamic Therapy (PDT) consists in the use of photosensitizers (PSs), which upon accumulation in tumor cells cause the death of malignant cells after irradiation with light. PDT respect conventional chemotherapy has minimal systemic toxicity since PSs possess high selectivity to cancer cells. In PDT, AuNPs and AgNPs can be used to enhance singlet oxygen (1O2) production from PSs by exploiting surface plasmon resonance phenomenon based on the interaction of the conduction electrons of metal nanostructures with incoming light. AuNPs are highly stable and biocompatible; conversely, AgNPs could release Ag+ ions. To avoid this, we use glucose as capping agents. The maximum absorption peak of AgNPs and AuNPs is at 420 and 530 nm, respectively. These peaks coincide with light wavelengths used in our previous works to excite Rose Bengal (RB) in HeLa cells. Our results highlight the potentiality of such nanostructures in PDT: both NPs enter HeLa cells, colocalize with RB and induce toxic effects upon green light irradiation. In particular, the presence of AuNPs and AgNPs enhance the 1O2. Moreover, the antiproliferative effect of AgNPs alone corroborates the possibility to synergize the toxic effects of PDT treatment against cancer cells. [ABSTRACT FROM AUTHOR]

Cirrhosis is the consequence of chronic liver disease, which is common in people of Asian countries. In this experimental approach, HepG2 cells are treated as experimental model (appropriate biological sample), extracted from the hepatocellular site of tissue. The author tried to demonstrate the comparison of biological damaging effects of zinc oxide nonmaterial's (ZnO NMs) and carbon tetrachloride CCl4 labeled with HepG2 cells and normal liver tissue as experimental model. Laser scanning microscopy (confocal microscopy) as well as neutral red assay (NRA) has been applied for the assessment of cell toxicity which acts as milestone in the field of photodynamic therapy (PDT). In addition, photodynamic damage in HepG2 cell line was examined using a continuous wave (CW) He-Ne laser. Malignant cell lines are a good source for the optimization of different PDT parameters. We used HepG2 (liver carcinoma) as biological sample in first and last step of our conducted experiment. At the end, two different experiments were performed to analyze the photodynamic damage. For the first one, 1 ml of ALA (300 µg /ml) was added to cell suspension and incubated for 0–24 hours then irradiated with He-Ne lasers at wavelength 630 nm at different light doses 5, 10, 15, 20 mW (0–15 minutes suggested as optimal time of irradiation for each cell line) and obtained photodynamic damage of cell line was recorded by cell count. In the second experiment, 1 ml of ALA with different concentration 0–1000 µg/ml was added to cell suspension and incubated for 48 hours then irradiated with He-Ne Laser 630 nm at light dose 20 mw (15 minutes act as time of optimization for each cellular model) and complied photodynamic damage of relevant cell line was assessed by cell count. Loss in cell viability in labeled (HepG2 cells) is significantly higher for 630 nm He-Ne (CW). [ABSTRACT FROM PUBLISHER]