Filtered By:
Specialty: Chemistry

This page shows you your search results in order of relevance.

Order by Relevance | Date

Total 1197 results found since Jan 2013.

Utility of the 2-Nitrobenzenesulfonamide Group as a Chemical Linker for Enhanced Extracellular Stability and Cytosolic Cleavage in siRNA-Conjugated Polymer Systems.
Abstract Herein we report the 2-nitrobenzenesulfonamide group as a new chemical linker that responds to the difference in redox potential across the cellular membrane, toward the construction of siRNA-polymer conjugates. PEG-conjugated to siRNA via the 2-nitrobenzenesulfonamide group (PEG-sul-siRNA) exhibited highly selective siRNA release under intracellular conditions due to the exclusive presence of GSH/GST ratios in the cell. In addition, siRNA release from PEG-sul-siRNA under extracellular reductive conditions was dramatically suppressed relative to PEG-siRNA conjugates containing a conventional redox-sensiti...
Source: ChemMedChem - November 9, 2016 Category: Chemistry Authors: Huang CH, Takemoto H, Nomoto T, Tomoda K, Matsui M, Nishiyama N Tags: ChemMedChem Source Type: research

Molecules, Vol. 23, Pages 1586: The Mechanism for siRNA Transmembrane Assisted by PMAL
nnan Lu The capacity of silencing genes makes small interfering RNA (siRNA) appealing for curing fatal diseases. However, the naked siRNA is vulnerable to and degraded by endogenous enzymes and is too large and too negatively charged to cross cellular membranes. An effective siRNA carrier, PMAL (poly(maleic anhydride-alt-1-decene) substituted with 3-(dimethylamino) propylamine), has been demonstrated to be able to assist siRNA transmembrane by both experiments and molecular simulation. In the present work, the mechanism of siRNA transmembrane assisted by PMAL was studied using steered molecular dynamics simulations bas...
Source: Molecules - June 29, 2018 Category: Chemistry Authors: Yanfei Lu Jipeng Li Nan Su Diannan Lu Tags: Article Source Type: research

The 2'-caged-tethered-siRNA shows light-dependent temporal controlled RNAi activity for GFP gene into HEK293T cells.
This report describes the syntheses of bulkier siRNA from 2'-caged-tethered-siRNAs, containing bulkier photolabile protecting group (o-nitrobenzyl) at 2'-position of ribose nucleoside. Importantly, these 2'-caged-siRNAs exhibit the light-dependent RNA interference (RNAi) activity into HEK293T cells for the GFP gene expression. The 2'-caged-siRNAs are synthesized by caging the sense and antisense strand of siRNA. The biochemical evaluations of these caged-siRNAs show that antisense-strand caged-siRNAs decrease RNAi activity temporarily in dark while enhancing RNAi activity, almost like control, after exposure withUV- light....
Source: Bioorganic and Medicinal Chemistry - December 9, 2020 Category: Chemistry Authors: Bollu A, Hassan MK, Dixit M, Sharma NK Tags: Bioorg Med Chem Source Type: research

Molecules, Vol. 28, Pages 2191: Potential of siRNA-Bearing Subtilosomes in the Treatment of Diethylnitrosamine-Induced Hepatocellular Carcinoma
grawal Mohammad Owais Therapeutics, based on small interfering RNA (siRNA), have demonstrated tremendous potential for treating cancer. However, issues such as non-specific targeting, premature degradation, and the intrinsic toxicity of the siRNA, have to be solved before they are ready for use in translational medicines. To address these challenges, nanotechnology-based tools might help to shield siRNA and ensure its specific delivery to the target site. Besides playing a crucial role in prostaglandin synthesis, the cyclo-oxygenase-2 (COX-2) enzyme has been reported to mediate carcinogenesis in various types of canc...
Source: Molecules - February 27, 2023 Category: Chemistry Authors: Fauzia Jamal Ghufran Ahmed Mohammad Farazuddin Ishrat Altaf Saba Farheen Qamar Zia Asim Azhar Hira Ahmad Aijaz Ahmed Khan Satyanarayana Somavarapu Anshu Agrawal Mohammad Owais Tags: Article Source Type: research

Gene silencing by 2'-O-methyldithiomethyl-modified siRNA, a prodrug-type siRNA responsive to reducing environment.
Abstract RNAs bearing various 2'-modifications have been synthesized in an effort to improve nuclease resistance. However, the gene silencing activity of small interfering RNAs (siRNAs) has been decreased or sometimes completely suppressed by the chemical modifications. We previously developed a post-synthetic approach for the synthesis of 2'-O-methyldithiomethyl-modified RNA, which can be converted into unmodified RNA under reducing conditions, and named it Reducing-Environment-Dependent Uncatalyzed Chemical Transforming RNA (REDUCT RNA). Here, the gene silencing activity of REDUCT siRNA bearing 2'-O-methyldithio...
Source: Bioorganic and Medicinal Chemistry Letters - December 22, 2015 Category: Chemistry Authors: Ochi Y, Imai M, Nakagawa O, Hayashi J, Wada SI, Urata H Tags: Bioorg Med Chem Lett Source Type: research

Anti-tumor effects of combined doxorubicin and siRNA for pulmonary delivery
In this study, combined doxorubicin (DOX) and Bcl2 siRNA was employed for cancer therapy using polyethylenimine (PEI) as the carrier of Bcl2 siRNA. Most of the DOX and siRNA possessed high cellular uptake efficiency in B16F10 cells, which was proved by FCM and CLSM analysis. Real-time PCR showed that PEI/Bcl2 siRNA exhibited high gene silencing efficiency with 70% Bcl2 mRNA being knocked down. The combination of DOX and siRNA could enhance the cell proliferation inhibition and the cell apoptosis against B16F10 cells compared to free DOX or PEI/Bcl2 siRNA. Furthermore, the biodistribution of DOX and siRNA via pulmonary admi...
Source: Chinese Chemical Letters - December 15, 2016 Category: Chemistry Source Type: research

Evaluation of siRNA and Cationic Liposomes Complexes as a Model for in vitro siRNA Delivery to Cancer Cells
This study aims to investigate the effect of different molar charge ratios (R+/-) between positive charges from microfluidics-produced cationic liposomes (CL) (egg phosphatidylcholine, 1,2-dioleoyl-3-trimethylammonium-propane and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine) and negative charges from siRNA and on physico-chemical and morphological properties of the lipoplexes (CL/siRNA) as well as their in vitro luciferase silencing effect in HeLa cells. R+/- 3.27 was found to be the optimum point for complexation. This finding was confirmed by gel retardation and siRNA accessibility assays. According to Cryo-TEM analysis...
Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects - July 6, 2018 Category: Chemistry Source Type: research

Molecules, Vol. 24, Pages 2211: Current Aspects of siRNA Bioconjugate for In Vitro and In Vivo Delivery
i Studies on siRNA delivery have seen intense growth in the past decades since siRNA has emerged as a new class of gene therapeutics for the treatment of various diseases. siRNA bioconjugate, as one of the major delivery strategies, offers the potential to enhance and broaden pharmacological properties of siRNA, while minimizing the heterogeneity and stability-correlated toxicology. This review summarizes the recent developments of siRNA bioconjugate, including the conjugation with antibody, peptide, aptamer, small chemical, lipidoid, cell-penetrating peptide polymer, and nanoparticle. These siRNA bioconjugate, either ...
Source: Molecules - June 12, 2019 Category: Chemistry Authors: Wanyi Tai Tags: Review Source Type: research

A cathepsin B/GSH dual-responsive fluorinated peptide for effective siRNA delivery to cancer cells
Bioorg Chem. 2023 Mar 20;135:106485. doi: 10.1016/j.bioorg.2023.106485. Online ahead of print.ABSTRACTSmall interfering RNA (siRNA) can be exploited to silence specific genes associated with cancer development, and successful siRNA therapy is highly dependent on the efficiency of the siRNA delivery vector. Herein, a well-designed novel redox- and enzyme-responsive fluorinated polyarginine (PFC-PR) was developed to be used as an anti-cancer siRNA carrier. The multiple guanidine groups could provide positive charges and bind with siRNA efficiently, and further fluorination modification enhanced the interaction with siRNA, re...
Source: Bioorganic Chemistry - March 24, 2023 Category: Chemistry Authors: Zhen Shi Yuhan Yang Ziyang Guo Shun Feng Yu Wan Source Type: research

Attachment of Cell-Binding Ligands to Arginine-Rich Cell-Penetrating Peptides Enables Cytosolic Translocation of Complexed siRNA.
Abstract Cell-penetrating peptides (CPPs), such as nona-arginine (9R), poorly translocate siRNA into cells. Our studies demonstrate that attaching 9R to ligands that bind cell surface receptors quantitatively increases siRNA uptake and importantly, allows functional delivery of complexed siRNA. The mechanism involved accumulation of ligand-9R:siRNA microparticles on the cell membrane, which induced transient membrane inversion at the site of ligand-9R binding and rapid siRNA translocation into the cytoplasm. siRNA release also occurred late after endocytosis when the ligand was attached to the L isoform of 9R, but...
Source: Chemistry and Biology - December 23, 2014 Category: Chemistry Authors: Zeller S, Choi CS, Uchil PD, Ban H, Siefert A, Fahmy TM, Mothes W, Lee S, Kumar P Tags: Chem Biol Source Type: research

Molecules, Vol. 21, Pages 1279: Development of an Innovative Intradermal siRNA Delivery System Using a Combination of a Functional Stearylated Cytoplasm-Responsive Peptide and a Tight Junction-Opening Peptide
In this study, we examined intradermal siRNA permeability in the tape-stripped (20 times) back skin of mice or AD-like skin of auricles treated with 6-carboxyfluorescein-aminohexyl phosphoramidite (F AM)-labeled siRNA, the tight junction modulator AT1002, and the functional cytoplasm-responsive stearylated peptide STR-CH2R4H2C by using confocal laser microscopy. We found that strong fluorescence was observed deep and wide in the epidermis and dermis of back skin and AD-like ears after siRNA with STR-CH2R4H2C and AT1002 treatment. After 10 h from administration, brightness of FAM-siRNA was significantly higher for STR-CH2R4...
Source: Molecules - September 23, 2016 Category: Chemistry Authors: Hisako Ibaraki Takanori Kanazawa Yuuki Takashima Hiroaki Okada Yasuo Seta Tags: Article Source Type: research

Molecules, Vol. 21, Pages 1334: Targeted Delivery of siRNA to Transferrin Receptor Overexpressing Tumor Cells via Peptide Modified Polyethylenimine
In conclusion, the HAI peptide may be useful to target TfR overexpressing tumors in targeted gene and siRNA delivery approaches.
Source: Molecules - October 9, 2016 Category: Chemistry Authors: Yuran Xie Bryan Killinger Anna Moszczynska Olivia Merkel Tags: Article Source Type: research

Molecules, Vol. 22, Pages 231: Construction and Biological Evaluation of a Novel Integrin ανβ3-Specific Carrier for Targeted siRNA Delivery In Vitro
Conclusion: The chimeric peptide of c(RGD)2-9R can be developed as an effective siRNA delivery carrier and shows potential as a new strategy for RNAi-based gene therapy.
Source: Molecules - February 3, 2017 Category: Chemistry Authors: Xueqi Chen Meng Liu Rongfu Wang Ping Yan Chunli Zhang Chao Ma Lei Yin Tags: Article Source Type: research