Ultrasound- and magnetic field-triggered destruction of insulin- and lysozyme-derived amyloid fibrils via biogenic magnetosomes.

Amyloid fibrils, highly ordered protein aggregates, are implicated in numerous diseases, including neurodegenerative and systemic amyloidoses. Proteins such as insulin and lysozyme, though not directly associated with neurodegeneration, form amyloid fibrils in metabolic and systemic contexts and serve as well-established models for studying amyloid formation and destruction. Fibrils formed by diverse proteins share common morphological traits and a conserved cross-β sheet structure, making these models broadly relevant. Their high stability presents a major therapeutic challenge, yet the same property underpins their use in biotechnology and materials science. In this work, we explore the potential of naturally occurring biogenic magnetosomes (MTS), Fe3O4 nanocrystals enveloped by a phospholipid membrane in chain-like assemblies, to promote the destruction of insulin and lysozyme amyloid fibrils. Using Thioflavin T fluorescence assays and atomic force microscopy, we evaluated fibril degradation under various conditions, including passive incubation with MTS and stimulation by ultrasound (US) and alternating magnetic fields (AMF). MTS alone induced concentration-dependent fibril disruption, while the combined application of US and AMF markedly enhanced destruction, even at low nanoparticle concentrations. The elongated shape and aligned magnetic structure of MTS leads to better responsiveness to two physical stimuli, which helps break down the cross‑β sheet network. These findings identify MTS as promising biocompatible nano-agents for non-pharmacological amyloid clearance and as a novel platform for amyloid-targeted therapies.