Synthesis of amino acid-based carbon dots: Effect on oral cancer cells.

Purpose: To assess if amino acid-based carbon dots (CDs) eliminate in vitro cancer cells.

Methods: CDs were synthesized using cysteine as a precursor and metal and photosensitizer as modifiers. In vitro cell viability tests were performed using cancer and normal cells without and with H₂O₂ and laser irradiation. Methylene blue (MB) solution was used to evaluate the production of ROS by CDs via observing absorbance differences before and after treatments. Extracellular oxygen production was measured in real-time using a probe. The generation of singlet oxygen was spectroscopically evaluated using RNO-ID assay.

Results: Within the test conditions, CDs fn-Cei-Ce6 achieved significantly low in vitro cancer cell viability (near to 26% of initial cell count) at 20 ppm concentration, high absorbance difference (Δ) in all wavelengths, oxygen production approximately to 1.2 mg/L, and high absorbance decrease of RNO-ID assay solution all with 100 µM H₂O₂ and laser irradiation conditions.

Clinical significance: Amino acid-based carbon dots (CDs) eliminated cancer cells in vitro with near to 74% of initial cancer cells under 100 µM H₂O₂ and laser irradiation conditions. The results may be extended to the clinical potential of fn-Cei-Ce6 in treating tumors in the oral cavity.