Amyloid fishing: β-Amyloid adsorption using tailor-made coated titania nanoparticles

Amyloidoses are a family of diseases characterized by abnormal protein folding that leads to fibril aggregates, amyloids. Extensive research efforts are devoted to developing inhibitors to amyloid aggregates. Here we set to explore functionalized titania (TiO2) nanoparticles (NPs) as potential amyloid inhibiting agents. TiO2 NPs were coated by a catechol derivative, dihydroxy-phenylalanine propanoic acid (DPA), and further conjugated to the amyloids' specific dye Congo-Red (CR). TiO2-DPA-CR NPs were found to target mature fibrils of β-amyloid (Aβ). Moreover, coated NPs incubated with Aβ proteins suppressed amyloid fibrillation. TiO2-DPA-CR were found to target amyloids in solution and induce their sedimentation upon centrifugation. This work demonstrates the potential utilization of TiO2-DPA NPs for labeling and facilely separating from solution mature amyloid fibrils.