scholarly journals Pharmacodynamic and Pharmacokinetic Properties of Full Phosphorothioate Small Interfering RNAs for Gene Silencing In Vivo

Author(s):  
Christian Berk ◽  
Gianluca Civenni ◽  
Yuluan Wang ◽  
Christian Steuer ◽  
Carlo V. Catapano ◽  
...  
Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2692 ◽  
Author(s):  
Francesco Mainini ◽  
Michael R. Eccles

RNA interference (RNAi) uses small interfering RNAs (siRNAs) to mediate gene-silencing in cells and represents an emerging strategy for cancer therapy. Successful RNAi-mediated gene silencing requires overcoming multiple physiological barriers to achieve efficient delivery of siRNAs into cells in vivo, including into tumor and/or host cells in the tumor micro-environment (TME). Consequently, lipid and polymer-based nanoparticle siRNA delivery systems have been developed to surmount these physiological barriers. In this article, we review the strategies that have been developed to facilitate siRNA survival in the circulatory system, siRNA movement from the blood into tissues and the TME, targeted siRNA delivery to the tumor or specific cell types, cellular uptake, and escape from endosomal degradation. We also discuss the use of various types of lipid and polymer-based carriers for cancer therapy, including a section on anti-tumor nanovaccines enhanced by siRNAs. Finally, we review current and recent clinical trials using NPs loaded with siRNAs for cancer therapy. The siRNA cancer therapeutics field is rapidly evolving, and it is conceivable that precision cancer therapy could, in the relatively near future, benefit from the combined use of cancer therapies, for example immune checkpoint blockade together with gene-targeting siRNAs, personalized for enhancing and fine-tuning a patient’s therapeutic response.


2010 ◽  
Vol 107 (5) ◽  
pp. 1864-1869 ◽  
Author(s):  
Kevin T. Love ◽  
Kerry P. Mahon ◽  
Christopher G. Levins ◽  
Kathryn A. Whitehead ◽  
William Querbes ◽  
...  

Significant effort has been applied to discover and develop vehicles which can guide small interfering RNAs (siRNA) through the many barriers guarding the interior of target cells. While studies have demonstrated the potential of gene silencing in vivo, improvements in delivery efficacy are required to fulfill the broadest potential of RNA interference therapeutics. Through the combinatorial synthesis and screening of a different class of materials, a formulation has been identified that enables siRNA-directed liver gene silencing in mice at doses below 0.01 mg/kg. This formulation was also shown to specifically inhibit expression of five hepatic genes simultaneously, after a single injection. The potential of this formulation was further validated in nonhuman primates, where high levels of knockdown of the clinically relevant gene transthyretin was observed at doses as low as 0.03 mg/kg. To our knowledge, this formulation facilitates gene silencing at orders-of-magnitude lower doses than required by any previously described siRNA liver delivery system.


2008 ◽  
Vol 8 (5) ◽  
pp. 2187-2204 ◽  
Author(s):  
J. N. Moreira ◽  
A. Santos ◽  
V. Moura ◽  
M. C. Pedroso de Lima ◽  
S. Simões

New molecular biology techniques have uncovered the hidden role of genes in cancer. Identification of activated oncogenes, as fundamental genetic differences relative to normal cells, has made it possible to consider such genes as targets for antitumor therapy, namely by applying gene silencing strategies. In this regard, antisense oligonucleotides or small interfering RNAs, constitute promising therapeutic tools. The widespread clinical application of such molecules as modulators of gene expression, is still dependent on several aspects that limit their bioavailability, including: enhanced biological stability, favourable pharmacokinetics, enhanced tumor cell uptake and, consequently, efficient targeted delivery. One of the most promising strategies to overcome the barriers faced by gene silencing molecules, upon systemic administration, involves the use of lipid-based nanoparticles. The first part of this review aims at providing the reader with the molecular mechanism of action of the most important gene silencing molecules used in anticancer therapy. The primary obstacle for translating gene silencing technology from an effective research tool into a feasible therapeutic strategy remains its efficient delivery to the targeted cell type in vivo. Therefore, an overview of different lipid-based strategies for nucleic acid delivery will be presented on the second part. As we learn more about the pharmacokinetics and pharmacodynamics of the carrier and/or of the gene silencing molecules, it will be possible to further improve the delivery strategy that likely in the future will lead to the ideal non-viral particle for targeted cancer systemic gene silencing.


2006 ◽  
Vol 0 (0) ◽  
pp. 060801084750001
Author(s):  
Marius Grzelinski ◽  
Beata Urban-Klein ◽  
Tobias Martens ◽  
Katrin Lamszus ◽  
Udo Bakowsky ◽  
...  

2021 ◽  
Vol 49 (18) ◽  
pp. 10250-10264
Author(s):  
Hartmut Jahns ◽  
Rohan Degaonkar ◽  
Peter Podbevsek ◽  
Swati Gupta ◽  
Anna Bisbe ◽  
...  

Abstract In order to achieve efficient therapeutic post-transcriptional gene-silencing mediated by the RNA interference (RNAi) pathway, small interfering RNAs (siRNAs) must be chemically modified. Several supra-RNA structures, with the potential to stabilize siRNAs metabolically have been evaluated for their ability to induce gene silencing, but all have limitations or have not been explored in therapeutically relevant contexts. Covalently closed circular RNA transcripts are prevalent in eukaryotes and have potential as biomarkers and disease targets, and circular RNA mimics are being explored for use as therapies. Here we report the synthesis and evaluation of small circular interfering RNAs (sciRNAs). To synthesize sciRNAs, a sense strand functionalized with the trivalent N-acetylgalactosamine (GalNAc) ligand and cyclized using ‘click’ chemistry was annealed to an antisense strand. This strategy was used for synthesis of small circles, but could also be used for synthesis of larger circular RNA mimics. We evaluated various sciRNA designs in vitro and in vivo. We observed improved metabolic stability of the sense strand upon circularization and off-target effects were eliminated. The 5′-(E)-vinylphosphonate modification of the antisense strand resulted in GalNAc-sciRNAs that are potent in vivo at therapeutically relevant doses. Physicochemical studies and NMR-based structural analysis, together with molecular modeling studies, shed light on the interactions of this novel class of siRNAs, which have a partial duplex character, with the RNAi machinery.


2017 ◽  
Vol 114 (32) ◽  
pp. E6490-E6497 ◽  
Author(s):  
Samantha M. Sarett ◽  
Thomas A. Werfel ◽  
Linus Lee ◽  
Meredith A. Jackson ◽  
Kameron V. Kilchrist ◽  
...  

Clinical translation of therapies based on small interfering RNA (siRNA) is hampered by siRNA's comprehensively poor pharmacokinetic properties, which necessitate molecule modifications and complex delivery strategies. We sought an alternative approach to commonly used nanoparticle carriers by leveraging the long-lived endogenous serum protein albumin as an siRNA carrier. We synthesized siRNA conjugated to a diacyl lipid moiety (siRNA-L2), which rapidly binds albumin in situ. siRNA-L2, in comparison with unmodified siRNA, exhibited a 5.7-fold increase in circulation half-life, an 8.6-fold increase in bioavailability, and reduced renal accumulation. Benchmarked against leading commercial siRNA nanocarrier in vivo jetPEI, siRNA-L2 achieved 19-fold greater tumor accumulation and 46-fold increase in per-tumor-cell uptake in a mouse orthotopic model of human triple-negative breast cancer. siRNA-L2 penetrated tumor tissue rapidly and homogeneously; 30 min after i.v. injection, siRNA-L2 achieved uptake in 99% of tumor cells, compared with 60% for jetPEI. Remarkably, siRNA-L2 achieved a tumor:liver accumulation ratio >40:1 vs. <3:1 for jetPEI. The improved pharmacokinetic properties of siRNA-L2 facilitated significant tumor gene silencing for 7 d after two i.v. doses. Proof-of-concept was extended to a patient-derived xenograft model, in which jetPEI tumor accumulation was reduced fourfold relative to the same formulation in the orthotopic model. The siRNA-L2 tumor accumulation diminished only twofold, suggesting that the superior tumor distribution of the conjugate over nanoparticles will be accentuated in clinical situations. These data reveal the immense promise of in situ albumin targeting for development of translational, carrier-free RNAi-based cancer therapies.


2018 ◽  
Vol 24 (23) ◽  
pp. 2692-2700 ◽  
Author(s):  
H. Susana Marinho ◽  
Paulo Marcelino ◽  
Helena Soares ◽  
Maria Luísa Corvo

Background: Ischaemia-reperfusion injury (IRI), a major complication occurring during organ transplantation, involves an initial ischemia insult, due to loss of blood supply, followed by an inflammation-mediated reperfusion injury. A variety of molecular targets and pathways involved in liver IRI have been identified. Gene silencing through RNA interference (RNAi) by means of small interference RNA (siRNA) targeting mediators of IRI is a promising therapeutic approach. Objective: This study aims at reviewing the use of siRNAs as therapeutic agents to prevent IRI during liver transplantation. Method: We review the crucial choice of siRNA targets and the advantages and problems of the use of siRNAs. Results: We propose possible targets for siRNA therapy during liver IRI. Moreover, we discuss how drug delivery systems, namely liposomes, may improve siRNA therapy by increasing siRNA stability in vivo and avoiding siRNA off-target effects. Conclusion: siRNA therapeutic potential to preclude liver IRI can be improved by a better knowledge of what molecules to target and by using more efficient delivery strategies.


2019 ◽  
Vol 15 ◽  
Author(s):  
Xingzhou Li ◽  
Tianhong Zhang ◽  
Wu Zhong

Background: The pharmacokinetic properties of T705 are not optimal for the development of new drugs. Objective: To improve the pharmacokinetic properties of T-705, structure modification of T-705 was conducted using a prodrug strategy. Method: The acidic amide H atom (N4-H) of T705 was attempted to be replaced with acyloxyalkyl groups following the prodrugs development strategy for carboxylic acids, and the resulting compounds were investigated whether could work as prodrugs and contribute to improving the pharmacokinetic properties of the parent compound T705 in vivo. Results: 4-acyloxyalkyl-T705 (4a–e), did act as prodrugs in vivo. 4-iso-butyryloxymethyl-T705 (4a) and 4-acetoxymethyl-T705 (4b) could significantly improve the plasma concentration and systemic exposure for T705, compound 4a displayed non inferior anti-influenza activities, compared with its parent drug T705. Conclusion: Our prodrugs development strategy for T705 is feasible, which may serves as a reference to prodrugs development of similar heterocyclic amides compounds.


2021 ◽  
Vol 14 (7) ◽  
pp. 622
Author(s):  
Arne Krüger ◽  
Ana Paula de Jesus Santos ◽  
Vanessa de Sá ◽  
Henning Ulrich ◽  
Carsten Wrenger

Aptamers are single-stranded DNA or RNA molecules which are submitted to a process denominated SELEX. SELEX uses reiterative screening of a random oligonucleotide library to identify high-affinity binders to a chosen target, which may be a peptide, protein, or entire cells or viral particles. Aptamers can rival antibodies in target recognition, and benefit from their non-proteic nature, ease of modification, increased stability, and pharmacokinetic properties. This turns them into ideal candidates for diagnostic as well as therapeutic applications. Here, we review the recent accomplishments in the development of aptamers targeting emerging viral diseases, with emphasis on recent findings of aptamers binding to coronaviruses. We focus on aptamer development for diagnosis, including biosensors, in addition to aptamer modifications for stabilization in body fluids and tissue penetration. Such aptamers are aimed at in vivo diagnosis and treatment, such as quantification of viral load and blocking host cell invasion, virus assembly, or replication, respectively. Although there are currently no in vivo applications of aptamers in combating viral diseases, such strategies are promising for therapy development in the future.


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