3D Nanostructures for Tissue Engineering, Cancer Therapy, and Gene Delivery

Figure 15

Nanotechnology focused on graphene used to identify miRNAs. (a) The dye-labeled PNA becomes fluorescent when nonconjugated; however, fluorescence becomes quenched after contact with GO. (b) Nanoparticle graphene oxide technique for intracellular miRNA identification has been used as a fluorescence quencher for the identification and tracking of dye-labeled nucleic acid probes in living cells by miRNA multiplex in vitro. Dye-labeled PNA fluorescence is quenched when interacting with GO, and further hybridization of the PNA with the target miRNA has helped activate the GO surface PNA sample and recovery of fluorescence. The ability of the PNA-GO probe to enter cells and the minimization of nonspecific fluorescence signal allows sensitive monitoring of multiple miRNA targets even in living cells with low basal fluorescence. (c) GO-sample fluorescent microscopy of MCF-7 cancer cells for quantitative miR-21 detection. MCF-7 cells had substantial fluorescence due to the strong expression of miR-21. GO: graphene oxide; PNA: peptide nucleic acid [118].