Decomposition of amyloid fibrils by NIR-active upconversion nanoparticles

Area of Science:

• Biochemistry
• Materials Science
• Photochemistry

Background:

• Amyloid fibrils (AFs) are protein aggregates implicated in various neurodegenerative diseases.
• Current methods for AF degradation are limited in efficacy and specificity.
• Targeting AFs with localized reactive oxygen species presents a promising therapeutic strategy.

Purpose of the Study:

• To demonstrate the decomposition of amyloid fibrils (AFs) using near-infrared (NIR) light-activated upconversion nanoparticles (UCNPs).
• To investigate the mechanism of AF decomposition mediated by photogenerated singlet oxygen (1O2).

Main Methods:

• Complexation of NIR-active upconversion nanoparticles (UCNPs) with photosensitizers.
• Irradiation with NIR light to trigger UCNP upconversion and subsequent photosensitizer activation.
• Generation of singlet oxygen (1O2) in close proximity to amyloid superstructures.
• Assessment of AF decomposition using appropriate analytical techniques.

Main Results:

• NIR light successfully induced AF decomposition via UCNP-photosensitizer complexes.
• The process relies on the photochemical reaction cascade initiated by upconversion.
• Singlet oxygen (1O2) generation was confirmed as the key cytotoxic species responsible for AF degradation.
• Localized generation of 1O2 near AFs led to effective decomposition.

Conclusions:

• This study presents a novel, light-triggered approach for amyloid fibril (AF) decomposition.
• The use of NIR-active upconversion nanoparticles offers a non-invasive method for activating therapeutic agents.
• The localized generation of singlet oxygen provides a targeted strategy for degrading pathological amyloid structures.