Design, Synthesis, and Biological Activity of Releasable m-THPC-PEGfolate Conjugate Using a Disulfide-containing Linker

The present study reported the preparation of a novel mutual prodrug containing meso-tetra (m-hydroxy phenyl) chlorin (m-THPC), PEG and folate. The folate receptor (FR) targeting compound is a water-soluble chemical incorporating a hydrophilic PEG spacer unit and a reducible selfimmolative disulfide-based linker system between the FR-targeting ligand and the chlorin. The m- THPC-s-s-PEG-Folate was proved to release the parent drug and exhibited significant targeting effects on HeLa cells. In addition, the redox-responsive folate targeting photosensitizer m-THPC-s-s-PEG-Folate showed slightly higher phototoxicity than m-THPC-PEG-Folate for HeLa cells.