Evaluating the biological performance of green-synthesised cerium oxide nanoparticles through antioxidant, antibacterial, and cellular compatibility for diabetic wound healing applications

Bacterial infections and oxidative stress pose a significant challenge in diabetic wounds, contributing to the delayed healing that affects millions of individuals globally. Recent studies have investigated the therapeutic application of lanthanide metals in their treatment, notably cerium oxide (CeO 2 ), derived from cerium oxalate or hydroxide. This study explores the formulation and biocompatibility of cerium oxide nanoparticles (CeO 2 NPs) synthesised using Aloe arborescens plant extract. CeO 2 NPs were synthesised, functionalised with citric acid and characterised using DLS, FESEM, FTIR, and TEM to analyse their size, morphology, charge, and composition. Their antioxidant behaviour was assessed by H 2 O 2 radical scavenging, compared with Aloe-PE. The bacterial susceptibility was evaluated on Pseudomonas aeruginosa and Staphylococcus aureus . Cellular compatibility was evaluated with ATP-based viability assays, morphological analysis, and fluorescence microscopy. The CeO 2 NPs exhibited a UV-vis peak between 350-375 nm, with an optical band gap of 3.26 eV. They showed high stability, with a surface charge of -32.8 mV and an average hydrodynamic diameter of 228.8 nm. The FESEM analysis revealed a consistent morphology, with an elemental composition primarily cerium oxide, while the TEM analysis showed a core particle size range of 2 to 7 nm. The FTIR further validated the compositional results, indicating the presence of functional groups (–OH, C=O, –COO⁻) associated with the capping and stabilisation of the NPs, demonstrating the successful incorporation of plant-derived organic constituents. Furthermore, the CeO 2 NPs inhibited the growth of P. aeruginosa and S. aureus without exhibiting cytotoxicity in diabetic BJ-5ta fibroblastic cells. The study highlighted the green synthesis of CeO₂ NPs, which exhibited well-defined structures and antibacterial activity against wound-related pathogens, while maintaining cytocompatibility. These findings suggest the potential of CeO₂ nanoparticles as multifunctional therapeutic candidates for wound management.