Title : Development of novel polyphenolic carbon quantum dots to intervene in neurodegeneration induced by emerging contaminants
Abstract:
The progression of neurodegenerative diseases, including Parkinson’s disease (PD), Alzheimer’s disease (AD), and amyotrophic lateral sclerosis (ALS), has been strongly associated with prolonged exposure to environmental neurotoxicants such as herbicides, weedicides, and pesticides. Among these, paraquat—a widely used herbicide—has been implicated in dopaminergic neuronal damage, particularly in the substantia nigra region of the midbrain, contributing to the onset of PD. Despite extensive research, there remains a critical need for therapeutic agents capable of penetrating the blood-brain barrier (BBB) to prevent or mitigate neurodegeneration caused by such toxicants.
Carbon quantum dots (CQDs) are emerging as promising nanomaterials for biomedical applications due to their biocompatibility, tunable physicochemical properties, and potential for BBB permeability. In this study, CQDs were synthesized using a green chemistry-based hydrothermal method and subsequently characterized through multiple spectroscopic techniques. Pulse-chase fluorescence studies revealed that CQDs effectively inhibit the soluble-to-toxic transition of amyloid-forming proteins, such as Hen Egg White Lysozyme (HEWL), a model amyloid protein. Furthermore, Thioflavin-T (ThT) fibril binding assays confirmed the presence of sp²-rich centers within CQDs, which function as free radical scavengers, thereby contributing to their neuroprotective properties.
The in vitro neuroprotective efficacy of CQDs derived from caffeic acid, quinic acid, and chlorogenic acid was assessed using the SH-SY5Y human neuroblastoma cell line, while in vivo studies were conducted using Caenorhabditis elegans as a model organism for PD. Notably, these CQDs demonstrated the ability to protect paraquat-induced dopaminergic neuronal damage in C. elegans, indicating their potential as therapeutic agents against environmentally induced neurodegenerative disorders. Our findings suggest that these biocompatible, engineered CQDs, synthesized via sustainable green chemistry approaches, represent promising candidates for mitigating the adverse neurological effects associated with chronic exposure to environmental neurotoxicants.
