Stimuli-responsive nanomaterials for modulating amyloid aggregate structure

Abstract

Stimuli-responsive nanomaterials allow spatiotemporal treatment of lesions in the body regardless of dysfunctional physiological and metabolic functions. This dissertation describes the designs of different stimuli-responsive nanomaterials for modulating amyloid aggregate structure as the potential treatments of amyloidogenic diseases, particularly Alzheimer’s disease. Chapter 1 provides an overview of recent advances to modulate Alzheimer’s β-amyloid (Aβ) aggregates by introducing different tissue-penetrable external stimuli and stimuli-responsive materials with piezoelectric, magnetothermal, magnetoelectric, photoelectrochemical, photoacoustic, photothermal, and photodynamic properties. This chapter summarizes the rational approaches in nanoscopic and molecular levels to each treatment strategy. Chapter 2 elucidates the piezoelectric treatment strategy for disassembling Aβ aggregates by introducing ultrasound waves and the bismuth oxychloride nanosheet, which is capable of evoking wireless electrochemical reactions upon receiving repetitive mechanical stimuli. This chapter investigates the piezocatalytic efficacy on the Aβ aggregate’s protein secondary structure and the Aβ-associated neurotoxicity. Chapter 3 proposes the magnetoelectric treatment strategy for modulating Aβ aggregates by adopting low-frequency magnetic fields and magnetoelectric nanomaterials, which emit electric fields in response to applied external magnetic fields. This chapter highlights the enhanced magnetoelectric coupling effect of the bismuth ferrite-coated cobalt ferrite nanoparticles for cleaning Aβ aggregates by converting water and dissolved oxygen molecules into reactive oxygen species without induction heating effect of magnetic fields. Chapter 4 presents the phonon-associated photodynamic platform for disaggregating Aβ aggregates by employing near-infrared (NIR) light and ternary chalcogenide nanomaterials. The copper molybdenum sulfide nanocube exhibits NIR photocatalytic activity capable of producing singlet oxygen species based on its low band gap and electron–phonon coupling property. This chapter describes the NIR light-controlled oxidative modification of Aβ fibrils and plaques through the catalytic phonon fields of the copper molybdenum sulfide nanocube. Chapter 5 demonstrates the new aspect of minerals in the Earth’s crust for denaturing the structure of the β-sheet structured pore-forming Aβ oligomer, which is the most neurotoxic species among different Aβ aggregates. Linnaeite is a cobalt sulfide mineral with NIR light-responsive photocatalytic capacity generating hydroxyl radical and superoxide radical anion. This chapter proposes the medical potential of the linnaeite mineral based on the NIR light-triggered structural modification of βPFO.