Multifaced Antifungal Activity of Dialdehyde Chitosan Loaded with Zinc Metal-Organic Framework (Zn-MOF)

Controlling pathogenic fungi is challenging due to their ability to form biofilms, further protected by adhesin proteins and persister cells, leading to increased resistance to antifungal agents. Thus, there is a pressing need to develop potent antifungal agents that employ a multifaceted approach to inhibit fungal growth. This study aimed to create biofungicides by harnessing the antifungal properties of zinc-metal organic frameworks (Zn-MOF) and dialdehyde chitosan (Cs) derived from black soldier flies (BSF). Chitosan was oxidized using potassium periodate to produce dialdehyde chitosan (OCs), which was then loaded with Zn-MOF, resulting in Zn-MOF-OCs. Fourier Transform Infrared (FT-IR) spectroscopy and powder X-ray diffraction (XRD) confirmed the presence of carbonyl functional groups in the OCs and the sharp, intense peaks associated with zinc, indicating successful intercalation. Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX) revealed changes in surface morphology and the presence of zinc confirmed the successful loading of Zn-MOF onto the OCs. Thermogravimetric analysis (TGA) demonstrated a weight loss of approximately 33.89% OCs and 34.22% framework between 300 °C and 400 °C. The antifungal activities of OCs, Zn-MOF, and Zn-MOF-OCs against Aspergillus brasiliensis, and Candida albicans evaluated using the plate count method highlighted the significant impact of the Zn-MOF-OCs nanocomposite as a biofungicides.