EFFECTS OF ERYTHROSINE WITH/OUT NANO-TIO2 DIOXIDE-MEDIATED PHOTODYNAMIC THERAPY ON HGF-1 AND HOK CELLS BY PRESTOBLUE® VIABILITY ASSAY

Abstract

The photodynamic therapy (PDT) is an alternative treatment for localized target tissue (e.g. tumors, cancers, etc.) that mainly results in target cell death in oxidation mechanism in producing reactive oxygen species (ROS).  Erythrosine dye, not only is known as a standard disclosing agent in Dentistry, with its photosensitizer (PS) property, it also has been used as an antimicrobial PS. However, the cell viability of normal human oral cells of Erythrosine dye tested with Nano-titanium dioxide (Nano-TiO₂) which is widely utilized as a photo-catalyst in order to enhance a photodynamic reaction still has been unknown.

Objectives: To study the effects of Erythrosine with/out Nano-TiO₂ as a photosensitizer on viability and morphology of normal human gingival fibroblast cell line (ATCC^® CRL-2014, HGF-1) and Primary Human Oral Keratinocytes; HOK (ATCC^® PCS200­014™) primary cells.

Methods: Eleven test groups of each HGF-1 and HOK were tested by Erythrosine as a photosensitizer in different concentration namely, Erythrosine (Ery) at 0 µM, 55 µM, 110 µM, 220 µM, and 440 µM in the presence and/or absence of 1% w/w Nano-TiO₂ with blue light, Nano-TiO₂ alone, and control groups (positive control = DMEM, abd negative control = H₂O₂). With LED-dental curing light (BA Optima 10, 420-480 nm, 16-19 J/cm²) for 1 min, at 1, 6, or 24 hrs, cell viability assays using PrestoBlue^® (Invitrogen, Life Technologies GmbH, Darmstadt Germany) with Varioskan™ at excitation/emission wavelength 560/590 nm. Cell morphology was investigated by SEM (S3000N, Hitashi, Japan).

Results: The difference between HGF-1 and HOK cell viability in Erythrosine-Nano-titamium dioxide-mediated photodynamic therapy was not statistically significant (p-value < 0.05) among the groups at all-time point, except for Erythrosine 440 µM that significantly reduced cell viability observed at 24 hrs. by utilizing one-way ANOVA and post hoc test. Furthermore, some morphology changes were observed between test and control groups by SEM.

Conclusions: Erythrosine with Nano-TiO₂, a novel PDT photosensitizer in the range of the present study exerted no toxicity on HGF-1 and HOK cells.