Development of axially substituted silicon phthalocyanine conjugated with betulinic acid nanoparticles for imaging-guided photodynamic therapy in breast cancer treatment

Photodynamic Therapy (PDT) represents a crucial strategy in cancer treatment, exploiting the unique properties of photosensitizers. Silicon phthalocyanine, a second-generation photosensitizer, is known for its outstanding photophysical properties and biocompatibility, while betulinic acid is recognized for its potent anticancer activity. In this study, betulinic acid was conjugated at the axial position of silicon phthalocyanine to synthesize Betulinic Acid-Axially Substituted Silicon Phthalocyanine (Bai-SiPc). The compound was then encapsulated with TPA-mPEG (triphenylamine polyethylene glycol) to form TPA-mPEG@Bai-SiPc nanoparticles. Structural characterization of the synthesized complex was conducted using 1H NMR, FT-IR, and MALDI-TOF-MS. The photodynamic efficacy of TPA-mPEG@Bai-SiPc was assessed in vitro with the MCF-7 breast cancer cell line. Results indicate that TPA-mPEG@Bai-SiPc exhibits excellent biocompatibility and pronounced phototoxicity, positioning it as a highly effective photosensitizer with superior PDT performance against breast cancer.