Multifunctional Nitrogen-Doped Carbon Dots to Inhibit the Aggregation of Aβ Peptide and Depolymerize the Aβ Fibrils by Modulating Reactive Oxygen Species.

Multifunctional nitrogen-doped carbon dots (N-CDs) were synthesized, and the morphology, composition, and spectral properties of N-CDs were characterized by multiple characterization techniques. The inhibition of β-amyloid (Aβ) peptide aggregation and the destruction of the Aβ fibril structure by N-CDs were also studied. The conformational transition and morphology of Aβ in the presence of N-CDs were monitored by far-UV circular dichroism (CD) spectroscopy and transmission electron microscopy (TEM). The results demonstrated that the prepared N-CDs could effectively inhibit Aβ peptide aggregation and depolymerize Aβ fibrils. Furthermore, the inhibition and disaggregation mechanism of existing Aβ fibrils by N-CDs was studied by electron paramagnetic resonance spectroscopy (EPR). The results showed that the modulation of reactive oxygen species (ROS) by N-CDs and multiple interactions between N-CDs and Aβ fibrils played a crucial part in restraining and reducing the aggregation of Aβ. Our work demonstrates the therapeutic potential of N-CDs in suppressing Aβ peptide aggregation and destroying existing Aβ fibrils, which provides a new perspective strategy in the treatment of Alzheimer's disease (AD).