A novel NIR-controlled NO release of sodium nitroprusside-doped Prussian blue nanoparticle for synergistic tumor treatment

Nitric oxide (NO) has shown positive effects in tumor treatment. However, controlling NO release in specific targets is still a crucial challenge for antitumor therapy. Considering that sodium nitroprusside (SNP) and potassium ferricyanide have similar chemical structures, a near infrared (NIR) laser-controlled NO release nanoplatform has been fabricated by allowing SNP to participate in mesoporous Prussian blue (m-PB) nanoparticle formation. The resulting SNP-doped m-PB (m-PB-NO) exhibited a good NIR-controlled NO release behavior, and the amount of NO released can be controlled by adjusting the laser intensity and irradiation time. Given that m-PB-NO still has strong absorption in NIR region, it exhibited an excellent photothermal effect in vitro and in vivo. After carrying antitumor drug, docetaxel (DTX)-loaded m-PB-NO (DTX@m-PB-NO) can simultaneously achieve NIR-controlled NO release, good photothermotherapy, and chemotherapy. The combination therapy of DTX@m-PB-NO showed a significant synergistic effect compared with each monotherapy and can significantly improve the therapeutic effect. Combination therapy also significantly inhibited the lung metastasis of 4T1 breast cancer cells in tumor-bearing mice by ablating primary tumors.