Protein misfolding by manganese (III) oxide nanoparticles generated by pulsed laser ablation in liquids

•α-Mn2O3 nanocolloids are synthesized using laser ablation in liquids.•α-Mn2O3 nanocolloids are added to Human serum albumin (HSA) protein and fibrillation of the protein is investigated.•The protein misfolded on adding the nanocolloids.•In-vitro studies confirm an increase in the fibrillation of the HSA protein with nanocolloidal concentration. The high demand for metal oxide nanoparticles for applications in various fields has led to increased research and investigation. However, one tends to neglect the harmful effects of these synthesized nanoparticles on human health. Mn2O3 nanoparticles are a type of metal oxide nanoparticle that can have harmful effects if ingested or inhaled. In this study, Mn2O3 nanoparticles are synthesized using laser ablation at the manganese-water interface. The structural and optical properties of the nanoparticles are studied using HR-TEM, Micro-Raman, Ultraviolet–visible (UV–vis), and Photoluminescence spectroscopy. The cubic bixbyite α-Mn2O3 nanoparticles produced by laser ablation are used for studying their role in inhibiting or promoting protein fibrillation. Different concentrations of α-Mn2O3 nanoparticles are added to Human serum albumin (HSA) protein, where the fibrillation of the protein is investigated with the help of thioflavin T (ThT) dye using fluorescence spectroscopy. The protein misfolded on adding the nanoparticles that could be seen in the images obtained using fluorescence microscopic imaging, where the HSA forms a dense network of fibrils. In-vitro studies reveal that the increasing concentration of the nanoparticles increases the fibrillation of the HSA protein.