Sulphur-doped carbon dots as a highly efficient nano-photodynamic agent against oral squamous cell carcinoma

Cell Prolif. 2020 Apr;53(4):e12786. doi: 10.1111/cpr.12786.

Abstract

Objectives: Photodynamic therapy (PDT) is a novel non-invasive therapeutic method, which has been widely applied for the treatment of human oral cancers. However, the problems of undesirable singlet oxygen (1 O2 ) quantum yields and long-term phototoxicity were inevitable during the application of traditional photosensitizers. Therefore, it is necessary to explore novel photosensitizers for the improvement of therapeutic effects. In our study, the sulphur-doped carbon dots (S-CDs) of high yield of singlet oxygen (1 O2 ) were synthesized as a nano-photosensitizer for OSCC to improve the PDT efficacy in clinical practice.

Materials and methods: After synthesis of the novel S-CDs, the size, morphologic characteristics, surface potential and yield of singlet oxygen (1 O2 ) were determined. In vitro study was performed to compare the therapeutic effect as well as the biocompatibility of the novel S-CDs to those of 5-ALA. Besides, possible mechanism of action was illustrated.

Results: After synthesis of the novel S-CDs, the size, morphologic characteristics, surface potential and yield of singlet oxygen (1 O2 ) were determined. In vitro study was performed to compare the therapeutic effect as well as the biocompatibility of the novel S-CDs to those of 5-ALA. Besides, possible mechanism of action was illustrated.

Conclusions: These data from the in vitro study demonstrated the promising safety profile of the low dose (nmol/L) S-CDs, which indicated the novel S-CDs could be used as a promising photodynamic agent for oral cancer therapy.

Keywords: apoptosis; nano-photodynamic agent; oral squamous cell carcinoma; sulphur-doped carbon dots.

MeSH terms

  • Apoptosis / drug effects
  • Carbon / chemistry
  • Carbon / pharmacology*
  • Carcinoma, Squamous Cell / drug therapy*
  • Carcinoma, Squamous Cell / pathology
  • Cell Line, Tumor
  • Humans
  • Models, Molecular
  • Mouth Neoplasms / drug therapy*
  • Mouth Neoplasms / pathology
  • Nanoparticles / chemistry
  • Nanoparticles / ultrastructure
  • Photochemotherapy
  • Photosensitizing Agents / chemistry
  • Photosensitizing Agents / pharmacology*
  • Sulfur / chemistry
  • Sulfur / pharmacology*

Substances

  • Photosensitizing Agents
  • Sulfur
  • Carbon