Diverse antithetical effects of the bio-compatible Ag-NPs on the hen egg lysozyme amyloid aggregation: from an efficient inhibitor to obscure inducer

Formation and deposition of amyloid aggregates are pathological hallmark of several neurodegenerative diseases such as Alzheimer’s (AD), Parkinson (PD), and Huntington’s diseases. Thus, one therapeutic strategy is to eliminate/dismantle toxic aggregates by suppressing/breaking fibrils. The conventional treatment strategies often fail due to their poor solubility, lower bioavailability, and ineffective ability to cross the blood–brain barrier. Nanoparticles (NPs) exhibit promise at low sub-stoichiometric ratios, and, due to tunable size and surface properties, present an ideal platform for the design of effective aggregation suppressors. In the present study, we characterized the bio-compatible (silver nanoparticles) Ag-NPs and assessed those antithetical aggregation inhibitory/inductive capabilities at different NPs/protein ratios. It is proposed that negative (inhibitory) and positive (inductive) influences of NPs on the hen egg white lysozyme (HEWL) amyloid aggregation are achieved via different independent mechanisms. Based on obtained insights in this field, rationally design of effective NP-based therapeutics for neurodegenerative diseases may be a feasible perspective.