Interference of dextran- magnetite nanoparticles with insulin amyloid aggregation. Nanoparticles inhibited insulin fibrillization and depolymerized insulin amyloid fibrils. Size of nanoparticles significantly influences their anti-amyloid activities. The most effective inhibition of insulin amyloid fibrillization was detected for the smallest nanoparticles. Contrary, DC50 values decreased with increasing size of nanoparticles.