Synthesis of cell-permeable peptide nucleic acids and characterization of their hybridization and uptake properties

Rapid fluorescence imaging of miRNAs in human cells using templated Staudinger reaction

“…15 Additionally, modification of the peptoid backbone with guanidine residues (GPNA) confers cell permeability to oligomers. 16 These features had led us to explore PNA-GPNA hybrids as a platform in templated reactions and we had shown that probes as short as 6 mer provided sufficient duplex stability to promote a Staudinger reaction. 4,13 Our previous design used a rhodamine dye quenched by a single azide which provided a greater than 30 fold enhancement of fluorescence upon Staudinger reduction.…”

“…Two additional reactions for RNU44 and RNU48 were performed for each cell line, as housekeeping controls. The RT reactions were performed at the following conditions: 16 C for 30 min, 42 C for 30 min and 85 C for 5 min. The cDNA products were then 1 : 5 diluted and 2ml of the cDNA were used as template for TaqMan reaction along with the corresponding TaqMan 20Â assay of each TaqMan miRNA Assay.…”

Insights on chiral, backbone modified peptide nucleic acids: Properties and biological activity

“…However, introducing a D-arginine containing moiety in every other position of an a-GPNAs, produced constructs with increased DNA's affinity. 90 This result was explained considering that the electrostatic attraction between the guanidinium group and the phosphate overcame the steric repulsion in the latter cases. 90 PNA containing arginine residues (GPNA) were more easily taken up by mammalian cell and resulted in being less toxic compared to PNA and PNA conjugated with polyarginine.…”

“…90 This result was explained considering that the electrostatic attraction between the guanidinium group and the phosphate overcame the steric repulsion in the latter cases. 90 PNA containing arginine residues (GPNA) were more easily taken up by mammalian cell and resulted in being less toxic compared to PNA and PNA conjugated with polyarginine. 91 GPNAs were successfully used to target the transcriptional start site of E-cadherin gene producing a sequence-specific antisense effect.…”

Peptide Nucleic Acids (PNA) in Chemical Biology and Drug Discovery

“…In most cases, a slight decrease in PNA -DNA duplex stability is observed, but in a few cases (in particular, for the lysine derivative), improved DNA and RNA binding (specifically using the d-form) is seen [10]), and this is especially pronounced when homo-chiral d-lysPNA cassettes are introduced [11]. Likewise, arginine-derived PNAs [6] [12] [13] (argPNA; Fig. 1) may be of interest, as the cationic guanidinium group facilitates (endosomal) cellular uptake of the PNA (vide infra).…”