Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.108 (TAT)
 2,389 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lack of capacity to cross the nucleus membrane seems to be one of the main reasons for the lower transfection efficiency of gene vectors observed in vivo study than in vitro. To solve this problem, a new non-viral gene vector was designed. First, a degradable polyethylenimine (PEI) derivate was synthesized by crosslinking low-molecular-weight (LMW) PEI with N-octyl-N-quaternary chitosan (OTMCS), and then adopting a designed trifunctional peptide (RGDC-TAT-NLS) with good tumor targeting, cell uptake and nucleus transport capabilities to modify OTMCS-PEI. The new gene vector was termed as OTMCS-PEI-R18 and characterized in terms of its chemical structure and biophysical parameters. Gene transfection efficiency and nucleus transport mechanism of this vector were also evaluated. The polymer showed controlled degradation and remarkable buffer capabilities with the particle size around 100-300 nm and the zeta potential ranged from 5 mV to 40 mV. Agraose gel electrophoresis showed that OTMCS-PEI-R18 could effectively condensed plasmid DNA at a ratio of 1.0. Besides, the polymer was stable in the presence of sodium heparin and could resist digestion by DNase I at a concentration of 63U DNase I/DNA. OTMCS-PEI-R18 also showed much lower cytotoxicity and better transfection rates compared to polymers OTMCS-PEI-R13, OTMCS-PEI and PEI 25 KDa in vitro and in vivo. Furthermore, OTMCS-PEI-R18/DNA complexes could accumulate in the nucleus well soon and not rely on mitosis absolutely due to the newly incorporated ligand peptide NLS with the specific nuclear delivery pathway indicating that the gene delivery system OTMCS-PEI-R18 could reinforce gene transfection efficiency in vivo.
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PMID:A Biodegradable Polyethylenimine-Based Vector Modified by Trifunctional Peptide R18 for Enhancing Gene Transfection Efficiency In Vivo. 2793 84

The key for better antitumor efficacy is to improve the specificity of antitumor drugs for tumor cells and diminish their cytotoxicity to normal tissues. Targeted nanoparticles as antitumor drug delivery system can resolve this problem. In this study, we prepared folate and TAT (arginine-rich cell-penetrating peptide) modified N-PEG-N'-octyl-chitosan to form the folate/TAT-PEG-OC micelles. Then, the molecular structure, morphology, size distribution and bio-safety of the micelles were characterized. In order to investigate the drug-loading capacity of folate/TAT-PEG-OC micelles, doxorubicin (DOX) was used as model drug to prepare DOX-loaded chitosan micelles. Here, the confocal microscopy was used to evaluate the cellular uptake of DOX/folate/TAT-PEG-OC micelles, while the self-built NIR imaging system was used to evaluate the dynamic behavior of ICG-Der-01/folate/TAT-PEG-OC micelles in vivo. Our results demonstrate that the dual-modified PEG-OC micelles not only have good morphology, uniform size distribution and excellent drug loading capacity, but also show a strong capability for the efficient intracellular uptake and enhanced targeting behaviors in a folate receptor positive tumor model (Bel-7402 human hepatocellular cells). All these results suggest the potential application of folate/TAT-PEG-OC micelles in the targeted diagnosis and therapy to different kinds of folate receptor positive tumors.
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PMID:Conjugates of TAT and folate with DOX-loaded chitosan micelles offer effective intracellular delivery ability. 2968 20