Mn(I)(CO)3-Prussian Blue Nanohybrids (MnI(CO)3@PBNPs) as Red light-activatable Platforms for synergic Photo-activated Chemotherapy and Photodynamic Therapy

Abstract

Prussian blue nanoparticles (PBNPs), an FDA-approved iron hexacyanoferrate framework, have emerged as multifunctional nanoplatforms for phototherapy owing to their biocompatibility, photostability, and strong red-to-NIR absorption. Building upon these advantages, we developed a red-light-activatable hybrid nanocomposite, MnI(CO)3@PBNPs, by functionalizing PBNPs with a photoresponsive Mn(I)-carbonyl complex. This nanoplatform integrates the photosensitizing nature of PBNPs with the photoinduced CO-releasing ability of MnI(CO)3, achieving synergistic dual-mode therapy through photodynamic (PDT) and photoactivated chemotherapy (PACT) mechanisms. Under red-light irradiation (600–720 nm, 30 W), MnI(CO)3@PBNPs simultaneously generated singlet oxygen (1O2) and cytotoxic CO (kCO = 3.0 × 10-4 s-1), leading to marked light-dependent cytotoxicity against MCF-7, MDA-MB-231, and Hep-G2 cells, with IC50 values of 76, 82, and 92 µg mL⁻¹, respectively, while showing negligible dark toxicity (IC50 > 200 µg mL-1). Flow cytometry confirmed apoptosis as the primary mode of cell death. This work represents the first PBNP–Mn(I) carbonyl hybrid achieving red-light-triggered PDT–PACT synergy, providing spatial and temporal therapeutic control. Owing to its biodegradability and tunable optical response, MnI(CO)3@PBNPs hold strong potential for next-generation Prussian blue-based phototherapeutic nanomedicines.