Graphene Quantum Dot-PEI-Cyclodextrin Nanocarrier for Simultaneous miR21a Delivery and Cell Imaging in Cancer Therapy

Over-expression of miR21 plays an important role in several cancers by promoting cancer cell proliferation, migration, invasion, and metastasis. Here, we attempted to prepare a beta cyclodextrin-polyethyleneimine-graphene quantum dot (beta CD-PEI-GQD) nanocarrier for cellular delivery of miR21a. For this purpose, tosylated-beta CD and GQD were conjugated to branched PEI. The product was characterized by FTIR, H-1-NMR, and fluorescence spectroscopy. The morphology, particle size distribution, and zeta-potential of miR21a were examined by TEM and DLS following overnight incubation with beta CD-PEI-GQD in aqueous media. The miR21 silencing was measured by stem-loop RT-PCR in HepG2 human hepatoma cell line. Cellular uptake and cell toxicity assays were determined by fluorescence microscopy and Trypan blue staining method, respectively. The formation of miR21a/CD-PEI-GQD Nanoplex with a decreased average size of 114 nm and a zeta-potential (+36.1 mV) lower than CD-PEI-GQD nanocarrier by adding miR21a was confirmed at optimum C/P ratio =8.7. RT-PCR revealed that miR21a/beta CD-PEI-GQD Nanoplex significantly downregulated miR21 expression levels effectively. Overall, miR21a delivery using CD-PEI-GQD is presented as a novel trackable nanocarrier for cancer therapy.