title: Comparative characterization and cytotoxicity study of TAT-peptide as potential vectors for siRNA and Dicer-substrate siRNA.
abstract: Recently, a newly discovered Dicer-substrate siRNA (DsiRNA) demonstrates higher potency in gene silencing than siRNA but both suffer from rapid degradation, poor cellular uptake and chemical instability. Therefore, Tat-peptide was exploited to protect and facilitate their delivery into cells. In this study, Tat-peptide was complexed with siRNA or DsiRNA through simple complexation. The physicochemical properties (particle size, surface charge and morphology) of the complexes formed were then characterized. The ability of Tat-peptide to carry and protect siRNA or DsiRNA was determined by UV-Vis spectrophotometry and serum protection assay, respectively. Cytotoxicity effect of these complexes was assessed in V79 cell line. siRNA-Tat complexes had particle size ranged from 186 ± 17.8 to 375 ± 8.3 nm with surface charge ranged from -9.3 ± 1.0 to +13.5 ± 1.0 mV, depending on the Tat-to-siRNA concentration ratio. As for DsiRNA-Tat complexes, the particle size was smaller than the ones complexed with siRNA, ranging from 176 ± 8.6 to 458 ± 14.7 nm. Their surface charge was in the range of +27.1 ± 3.6 to +38.1 ± 0.9 mV. Both oligonucleotide (ON) species bound strongly to Tat-peptide, forming stable complexes with loading efficiency of more than 86%. These complexes were relatively non cytotoxic as the cell viability of ∼90% was achieved. In conclusion, Tat-peptide has a great potential as siRNA and DsiRNA vector due to the formation of stable complexes with desirable physical characteristics, low toxicity and able to carry high amount of siRNA or DsiRNA.
authors: Centre for Drug Delivery Research, Faculty of Pharmacy, Universiti Kebangsaan Malaysia , Jalan Raja Muda Abdul Aziz, Kuala Lumpur , Malaysia.
authors: Haliza
authors: H
authors: Katas
authors: Maria
authors: M
authors: Abdul Ghafoor Raja
authors: Lee Choy
authors: LC
authors: Ee
mesh_terms: D002470:Cell Survival; D057846:Cell-Penetrating Peptides; D016503:Drug Delivery Systems; D020868:Gene Silencing; D015756:Genes, tat; D009841:Oligonucleotides / Q000737:chemistry*; D010316:Particle Size; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D014162:Transfection / Q000379:methods*
chemical_list: D057846:Cell-Penetrating Peptides; D009841:Oligonucleotides; D034741:RNA, Small Interfering
keywords: Cell penetrating peptides; DsiRNA; Tat-peptide; siRNA; simple complexation