Study of the efficacy of 5-ALA mediated photodynamic therapy on human rhabdomyosarcoma cell line (RD)

Abstract

The aim of this study was to investigate the mechanism of cell death by photodynamic therapy (PDT) in the Rhabdomyosarcoma (RD) cell line. The present study evaluates the effects of photodynamic therapy (PDT) with 5-ALA as photosensitizer using human muscle cancer cells as experimental model. We study the photosensitizer uptake, cytotoxicity, phototoxicity, and cellular viability of the RD cells which was estimated by means of neutral-red spectrophotometric assay. The given experiment was consisted of two steps. For the first one, RD cells were exposed to 5-ALA at concentrations of 0 up to 1000 μg of ALA/ml in minimum essential medium (MEM). The optimal uptake of photosensitizer (5-ALA) in RD cells was investigated by means of spectrometric measurements. Cells viability was determined by means of neutral red assay (NRA). In the second step, 5-ALA exposed RD cells were irradiated with red light (a diode laser, λ = 635 nm) at total light dose of 80 J/cm 2 . The influence of different incubation times and concentrations of 5-ALA, different irradiation doses and various combinations of photosensitizer and light doses on the viability of RD cells were investigated. It was observed that sensitizer concentration or light doses have no significant effect on cells viability when studied independently. The maximal cellular uptake occurred after 47 hours in vitro incubation. The phototoxic assay showed that ALA-PDT induced killing of 76% of the cells at 250 μg/ml drug dose and 80 J/cm 2 light dose.

Analysis of the combined effect of lasers of different wavelengths for PDT outcome using 600, 630, and 660 nm

“…Higher absorption imply in higher production of singlet oxygen and therefore higher photodynamic action and better PDT outcome. This study is in agreement with earlier studies using a variety of photosensitizers in different chemical and biological environments [38][39][40][41][42].…”

Optical image analysis of fat cells for indocyanine green mediated near-infrared laser treatment

“…In addition to photochemical damaging, some enhanced thermal damaging is expected because of the more effective laser heating of selectively stained tissue sites. Apoptosis and other morphological modifications of cells are typically detected using histological analysis of samples [23][24][25][26][27][28][29][31][32][33]. In our work, we used machine vision based inspection of the morphological changes of adipocytes.…”

Sensitivity of A-549 human lung cancer cells to nanoporous zinc oxide conjugated with Photofrin

“…Its molecular structural formula has been reported previously [26]. Photofrin was dissolved in phosphate-buffered saline (PBS, pH 7.4) to obtain a stock solution (1,000 μg/ml) [18][19][20] which was stored in the dark at 4°C. ZnO NPs-coated tips were dipped five times into the prepared Photofrin solution.…”

“…Cells were maintained at 37°C in a moist environment as a subconfluent monolayer and were routinely subcultured twice or three times weekly. Cell cultures at 70-80% confluence were harvested using 0.25% trypsin [18][19][20][21][22]. After trypsinization, some cells were transferred to a regular Petri dish and incubated again for 24 h to allow attachment to the bottom of the Petri dish at 37°C in a CO 2 -enriched atmosphere.…”

“…The photosensitizer is administered either systemically or topically and is activated by visible light at a specific wavelength, commonly from a low-power laser, to produce cytotoxic free radicals, namely singlet oxygen, in the presence of molecular oxygen. Singlet oxygen damages cellular organelles which triggers a cascade of events resulting in cell death either by apoptosis or necrosis [10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”