Title : Advanced multifunctional carbon dots/porphyrins for cancer diagnosis and photodynamic therapy
Abstract:
According to the findings of this study, a novel approach has been developed to address the constraints of employing porphyrins in photodynamic treatment, which include their low solubility and aggregation in biological contexts. The conjugation of porphyrins with graphene quantum dots (GQDs) was investigated as a means of improving the internalization of porphyrins by cancer cells. It was discovered that the GQDs could be linked to an aminoporphyrin using two different chemical methods: thionyl chloride (SOCl2) and 1-ethyl-3-(3′-dimethylaminopropyl) carbodiamide (EDAC). Detailed investigation using several characterization techniques, including TEM, AFM, FTIR, Raman, XPS, and UV-vis, confirm that the SOCl2 method resulted in enhanced porphyrin loading by GQDs when compared to the EDAC method.
Here we investigated the photoactivity of the resulting hybrids and the respective precursors under irradiation with white light, to explore their potential use as photodynamic therapeutic (PDT) agents against breast cancer cells (T-47D cell line). Aminoporphyrin, with an IC50 in the range of 10−100 nM, showed a significant photocytotoxic effect when compared to other reported modified porphyrins. The hybrids showed improved photocytotoxicity with an IC50 1 order of magnitude lower than aminoporphyrin. According to our studies, the synthesized aminoporphyrin-GQDs hybrids promoted efficient uptake by the T-47D cells when compared with the non-immobilized porphyrin. The higher photocytotoxic effects were observed for concentrations higher than 10 nM. These results can be understood as the synergistic effect of the conjugation of porphyrin with GQDs that promotes an efficient uptake of porphyrin by the cancer cells. However, it was noticed that the reduction singlet oxygen generation efficiency of conjugated porphyrin. This preliminary study points out that the new hybrids based on aminoporphyrin-GQDs hybrids present a high potential for being further investigated using patient-specific inducible pluripotent stem cells in 3D culture as predictive cell models for future in vivo PDT studies.
