Radiofrequency-Induced Disassembly of Insulin Fibrillar Structures Using Functionalized Magnetic Nanoparticles

Amyloidosis is characterized by the deposition of misfolded proteins as highly stable, insoluble β-sheet-rich fibrils, posing a major therapeutic challenge due to their resistance to degradation. Insulin-derived amyloidosis at subcutaneous injection sites is a clinically significant complication in patients with diabetes, leading to impaired insulin absorption, unpredictable glycemic control, substantially increased insulin dose requirements, and localized masses (amyloidomas) that may require surgical excision when symptomatic. In this study, we evaluated sodium oleate-functionalized magnetic nanoparticles (MNs) with a hydrodynamic diameter of 50 nm with a magnetite (iron oxide—Fe3O4) core as a targeted physical intervention to disrupt preformed insulin amyloid fibrils. The strategy exploits localized nanoscale hyperthermia generated by MNs under a high-frequency radiofrequency (RF) field (1.65 MHz). Fibril integrity and disassembly kinetics were assessed using Thioflavin T (ThT) fluorescence assays and fluorescence microscopy. RF-activated MNs induced rapid, concentration-dependent fibril disruption; notably, at 2 mg/mL MNs, near-complete disassembly was achieved within 15 min—a timeframe compatible with clinical procedures. Neither RF nor MNs alone produced significant effects, confirming a synergistic magnetothermal mechanism. These results provide a proof of concept for a minimally invasive, externally triggered approach to clear localized insulin amyloid deposits, offering promising potential as a novel therapeutic strategy for managing injection-site amyloidosis in diabetic patients, where current options remain limited and often inadequate.