The Photodynamic Anti-Tumor Effects of New PPa-CDs Conjugate with pH Sensitivity and Improved Biocompatibility

Abstract

Background: Photodynamic therapy has been increasingly used to cope with the alarming problem of cancer. Porphyrins and their derivatives are widely used as Potent Photosensitizers (PS) for PDT. However, the hydrophobicity of porphyrins poses a challenge for their use in clinics, while most of the carbon dots (CDs) are known for good biocompatibility, solubility, and pH sensitivity.

Objective: This study aimed to improve the properties/biocompatibility of the pyropheophorbide-α for PDT.

Methods: The PPa-CD conjugate was synthesized through covalent interaction using amide condensation. The structure of synthesized conjugate was confirmed by TEM, 1HNMR, and FTIR. The absorption and emission spectra were studied. In vitro, cytotoxicity of the conjugate was examined in human esophageal cancer cell line (Eca-109).

Results: The results showed that the fluorescence of the drug was increased compared to its precursor. CDbased conjugate could generate ROS as well as enhanced biocompatibility by decreasing cytotoxicity. The conjugated drug also showed pH sensitivity in different solutions.

Conclusion: The dark toxicity, as well as hemocompatibility, was improved.

Keywords: Photodynamic therapy; carbon dots; hemocompatibility; pH sensitivity; photosensitizer; tumor.