(Invited) Tuning Chirality of Graphene Quantum Dots to Empower Medical Imaging and Theranostic Applications

Abstract

Chiral nanostructures from metals and semiconductor, including graphene-based materials, are increasingly recognized for their potential in polarization-sensitive optoelectronics. Particularly, graphene quantum dots (GQDs) modified with L/D amino acids exhibit unique chiral properties due to edge-specific interactions, offering new possibilities in biomedicine. Our study delves into the interaction of these chiral nanomaterials with biological systems, revealing significant implications for their application in biology and medicine. We discovered that attaching L/D amino acid moieties to GQDs induces nanoscale chirality by helical buckling, influenced by the chiral interactions at the graphene edges. The chirality of GQDs affects their interaction at the nanoscale with cells and tissues. Molecular dynamics simulations show that D-GQDs are more likely to accumulate within cellular membranes compared to L-GQDs. Additionally, experiments on chiral GQD permeation through lipid membranes of extracellular vesicles demonstrated that optimizing chirality via ligand tuning and GQD size can significantly enhance their permeation efficiency into lipid bilayers, exceeding 80%. Leveraging this enhanced transmembrane transport, chiral GQDs have been applied in imaging and efficient drug loading for therapeutic extracellular vesicles. Furthermore, we explored how GQD chirality affects transport in tumor-like cellular spheroids. The results indicate that L-GQDs exhibit a 1.7 times higher apparent diffusion coefficient than D-GQDs, enhancing their transport into these spheroids. In summary, our research underscores the importance of controlling and engineering GQD chirality. This approach not only enhances the transport of drug carriers through biological barriers but also opens new avenues for advanced imaging and theranostic applications.