Advanced Neuronal Modulation with Semiconducting Graphitic Carbon Nitride: Insights from In Vitro, In Vivo, and In Silico Studies

Impaired neuronal functions and cell death within ailments such as neurodegenerative Parkinson's disease pose significant challenges due to their complex pathophysiology and limited treatment options. In this landscape, innovative materials with unique physicochemical properties that ameliorate the debilitated neuronal functions are critically required. Neuronal functions rely on the conduction of nerve impulses, a process that can be effectively targeted using advanced materials that exhibit conducive properties essential for modulating neural activity. For their semiconductor characteristics, combined with well-suited biocompatibility, graphitic carbon nitride (g-C3N4) nanosheets provide promising avenues for such neurotherapeutic applications. Our multidisciplinary study investigates the potential of g-C3N4 nanosheets in promoting neuronal differentiation and network formation across in vitro and in vivo systems. SH-SY5Y cells exposed to g-C3N4 demonstrated enhanced neuronal differentiation and neuritic outgrowth over a chronic 21-days period, accompanied by an increased intracellular Ca2+ influx, pivotal for dopamine biosynthesis, as evidenced by the upregulated expression of vesicular monoamine transporter 2 (VMAT2), aromatic l-amino acid decarboxylase (AADC), and tyrosine hydroxylase (TH) genes. Utilizing transgenic Caenorhabditis elegans model expressing human alpha-synuclein, we observed the neuroprotective potential of g-C3N4, as evidenced by reduced protein aggregation and improved dopaminergic functions. In the pursuit of exploring the mechanism of g-C3N4-induced neuronal stimulation, the semiconducting nature of g-C3N4 came forth, which was further validated using theoretical (in silico) models. These models demonstrated an increase in the chemical potential of the material upon the application of electrical biases. Studying Ca2+ channel inhibition, we also observed that phenotypic and molecular effects were the outcomes of the stimulation caused due to the presence of g-C3N4 nanosheets. Our findings, supported by experimental and in silico studies, suggest that g-C3N4 nanosheets can effectively modulate neuronal behavior through their semiconducting properties, offering promising avenues for therapeutic interventions in neurodegenerative diseases.