Nanoporous Silica Nanoparticles Coated with Peptide P14 and Decorated with 5-Fluorouracil and Indocyanine Green for NIR-Triggered Photothermal/Photodynamic Therapy

Nowadays, many cancer treatment paradigms are being rewritten due to advances in materials science, nanotechnology, and biomedicine. With the aid of nanomaterials and nanotechnology, many positive and meaningful attempts and breakthroughs in drug delivery and multistrategy collaborative chemotherapy have been made during traditional cancer chemotherapy treatment. In this work, a nanoparticle 5-FU/ICG@NP has been synthesized, with 5-Fluorouracil (5-FU) and indocyanine green (ICG) co-loaded within the nanoporous silica nanoparticles (NSN) decorated with amphiphilic targeting polypeptide P14 (NSN-P14, NP). The nanoparticles 5-FU/ICG@NP have been proven to have outstanding dimensional stability, photothermal effect, reactive oxygen species (ROS) generation, and tumor cell targeting capacity. The in vitro anticancer activity of the nanoparticles was evaluated by cytotoxicity, apoptosis, live and dead staining, cell cycle, and cell ultrathin section analysis. The results showed that the nanoparticles could effectively exert the combined effects of 5-FU chemotherapy and ICG photothermal and photodynamic therapy and effectively inhibit the activity of MCF-7 cells. Finally, the therapeutic effects of nanoparticles on tumor-bearing mouse models were evaluated systematically through small animal imaging and HE and TUNEL staining. The results showed that fluorescence-labeled nanoparticles exhibited initial accumulation at the tumor site approximately 1 h after intravenous injection. The fluorescence intensity peaked at the tumor site within 6 h and remained relatively stable during continuous monitoring for 48 h. The nanoparticles effectively induced apoptosis of tumor cells in vivo through the combination of 5-FU chemotherapy with near-infrared-triggered ICG photothermal and photodynamic therapy. Therefore, the nanoparticles synthesized in this work are an efficient nanodrug delivery platform, which has potential clinical applications in combination with tumor chemotherapy/photothermal/photodynamic therapy in future.