Photodynamically Active Zinc‐Phthalocyanine Loaded Mesoporous Bioactive Glass Nanoparticles for Biomedical Applications

Photodynamic therapy (PDT) is a promising approach for treating infections and cancer. However, the clinical translation of many photosensitizers is hindered by poor water solubility and tendency to aggregate. To overcome these limitations, zinc phthalocyanine (ZnPc), a highly effective photosensitizer, is loaded into mesoporous bioactive glass (MBG) nanoparticles(NPs) in this study. The resulting ZnPc@MBGNPs with diameters ranging from 100 to 160 nm are well‐dispersed, as confirmed both by scanning electron microscopy and transmission electron microscopy. ZnPc loading reduces the specific surface area and pore volume by ∼20%, confirming successful incorporation. Structural analysis (X‐ray diffraction, Fourier transform infrared, X‐ray photoelectron spectroscopy) reveals a heterogeneous nanocomposite system. Despite the reduced specific surface area, the nanoparticles retain their bioactivity after incubation in simulated body fluid. In vitro studies show no cytotoxicity without light, while red‐light activation (at 660 nm) induces a dose‐ and time‐dependent reduction in cell viability. In vivo testing using Galleria mellonella confirms biocompatibility at 50 µg/mL. After irradiation, ZnPc@MBGNPs exhibit strong antimicrobial activity against S. aureus , with a minimum inhibitory concentration equal to the minimum bactericidal concentration of 50 µg/mL. This study presents a multifunctional nanoplatform that combines photodynamic efficiency, bioactivity, and antibacterial performance, offering potential for clinical applications such as infection control and tissue regeneration.