Multifunctional Carbon Quantum Dots Prevent Soluble-to-Toxic Transformation of Amyloid and Oxidative Stress

Abstract

Carbon quantum dots (CQDs), depending on their surface functionalization, have found utility across a number of biological applications. Here, we demonstrate that individual CQDs can serve multifunctional roles, which is a key requisite for the development of drugs for neurodegenerative disorders such as Parkinson’s disease (PD). Na-citrate-, phenylboronic acid-, and 4-aminophenylboronic acid-derived CQDs were evaluated for their ability to intervene in amyloid-forming trajectories and restore intracellular homeostasis under oxidative stress. While all three CQDs were able to prevent the soluble-monomer to mature-fibril conversion of hen-egg white lysozyme, Na-citrate- and 4-aminophenylboronic acid-derived CQDs were also able to scavenge reactive oxygen species when exposed to a broad spectrum of free radical generators. Furthermore, Na-citrate and 4-aminophenylboronic acid CQDs preincubated in a neuroblastoma-derived SHSY-5Y cell line were able to rescue it from rotenone (neurotoxicant)-induced cell death while demonstrating no difference in cytotoxicity up to 120 μg/mL (compared to untreated controls). The CQDs were also able to restitute cells from rotenone-elicited apoptosis and oxidative stress. Together, these results suggest that CQDs can serve as a one-pot solution for multifactorial diseases such as PD by serving as a neuroprotectant. Importantly, the use of CQDs as multifactorial interventional agents represents a sustainable mechanism by which to advance biomedicine.