Biogenic synthesis and characterization of antimicrobial, anti-inflammatory, antioxidant, and biocompatible iron oxide nanoparticles (FeONPs) using Arthrospira sp. Extract

Green nanotechnology offers a sustainable and eco-friendly pathway for large-scale nanoparticle synthesis, minimizing environmental hazards associated with conventional chemical methods. In this study, we report the phyco-synthesis of iron oxide nanoparticles (FeONPs) using Arthrospira sp., a cyanobacterium enriched with diverse bioactive compounds, as both a reducing and stabilizing agent. Despite extensive exploration of algal mediated nanoparticle synthesis, the biomedical potential of Arthrospira derived FeONPs remains largely underexplored. Here, FeONPs were synthesized via a two-step process involving the reaction of Arthrospira sp. aqueous extract with ferric chloride under optimized conditions, followed by calcination. The resultant FeONPs were comprehensively characterized through ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), dynamic surface analysis (DSA), and zeta potential measurements. Biomedical evaluation was performed through multiple in vitro assays, including assessments of antioxidant, antimicrobial, anti-inflammatory, anti-diabetic, and cytotoxic activities. The FeONPs exhibited pronounced antioxidant potential (IC₅₀: 81.91-453.04 µg/mL), and notable antifungal activity against Aspergillus flavus (IC₅₀: 22.51 µg/mL). Furthermore, they demonstrated dose-dependent α-amylase inhibition (IC₅₀: 591 µg/mL), low cytotoxicity (IC₅₀: 1324 µg/mL), and excellent biocompatibility. This study pioneers Arthrospira sp. as a scalable, cost-effective biofactory for the sustainable production of FeONPs, bridging the gap between green synthesis and biomedical applications. Future investigations will focus on in vivo validation, elucidation of antimicrobial mechanisms, and integration into drug delivery systems. With their multifunctional bioactivities, Arthrospira sp. mediated FeONPs hold significant promise for next-generation nanotherapeutics, leading towards a new paradigm in sustainable nanomedicine.