Amino Acid-Functionalized Gold Nanochaperones Offer Strategic Roadmap for Alzheimer's Protein Misfolding Modulation

Alzheimer's disease (AD) is a devastating neurodegenerative disorder marked by the misfolding and aggregation of amyloid-β (Aβ) peptides and tau proteins, leading to profound synaptic dysfunction. Current treatments offer only limited disease modification, primarily due to the structural complexity of Aβ aggregates, poor blood-brain barrier (BBB) penetration, and insufficient targeting of toxic oligomeric intermediates. Nanotechnology, particularly gold nanoparticles (AuNPs), presents a promising avenue to overcome these challenges by offering tunable properties and multivalent binding capabilities to modulate pathological protein aggregation.

This comprehensive review synthesizes current advances in amino acid-engineered gold nanochaperones, analyzing their mechanisms of interaction with various Aβ species. The authors integrated mechanistic insights and design considerations to outline how these functionalized nanoparticles can be optimized for modulating amyloid-β aggregation. Furthermore, the review critically evaluates key translational challenges, including blood-brain barrier delivery, biodistribution, nanotoxicology, protein corona formation, and clinical development considerations, providing a strategic roadmap for future therapeutic development.

The review highlights that amino acid-functionalized gold nanoparticles modulate Aβ aggregation through multiple synergistic mechanisms. These include electrostatic interactions, hydrophobic effects, π-π stacking, hydrogen bonding, and metal-ligand coordination, enabling selective targeting of monomers, oligomers, and fibrillar aggregates. This multifaceted approach addresses the inherent structural heterogeneity of amyloid species, a major hurdle for conventional therapies. The review emphasizes that optimizing properties like size, shape, surface charge, and the specific amino acid type is crucial for enhancing binding affinity and effectively modulating aggregation pathways. Key translational hurdles identified include achieving efficient blood-brain barrier penetration, ensuring favorable biodistribution, mitigating potential nanotoxicology, and understanding the impact of protein corona formation on therapeutic efficacy. This integrated framework bridges molecular mechanisms with engineering design principles.

The strategic integration of specific amino acid functionalities onto gold nanoparticles allows for precise control over their interaction with Aβ, offering a versatile platform to address the structural heterogeneity of amyloid species.