scholarly journals Vehicles for Small Interfering RNA transfection: Exosomes versus Synthetic Nanocarriers

2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Markus Duechler

AbstractTherapies based on RNA interference (RNAi) hold a great potential for targeted interference of the expression of specific genes. Small-interfering RNAs (siRNA) and micro-RNAs interrupt protein synthesis by inducing the degradation of messenger RNAs or by blocking their translation. RNAibased therapies can modulate the expression of otherwise undruggable target proteins. Full exploitation of RNAi for medical purposes depends on efficient and safe methods for delivery of small RNAs to the target cells. Tremendous effort has gone into the development of synthetic carriers to meet all requirements for efficient delivery of nucleic acids into particular tissues. Recently, exosomes unveiled their function as a natural communication system which can be utilized for the transport of small RNAs into target cells. In this review, the capabilities of exosomes as delivery vehicles for small RNAs are compared to synthetic carrier systems. The step by step requirements for efficient transfection are considered: production of the vehicle, RNA loading, protection against degradation, lack of immunogenicity, targeting possibilities, cellular uptake, cytotoxicity, RNA release into the cytoplasm and gene silencing efficiency. An exosomebased siRNA delivery system shows many advantages over conventional transfection agents, however, some crucial issues need further optimization before broad clinical application can be realized.

2018 ◽  
Author(s):  
Maire F. Osborn ◽  
Andrew H. Coles ◽  
Annabelle Biscans ◽  
Reka A. Haraszti ◽  
Loic Roux ◽  
...  

AbstractEfficient delivery of therapeutic RNA is the fundamental obstacle preventing its clinical utility. Lipid conjugation improves plasma half-life, tissue accumulation, and cellular uptake of small interfering RNAs (siRNAs). However, the impact of conjugate structure and hydrophobicity on siRNA pharmacokinetics is unclear, impeding the design of clinically relevant lipid-siRNAs. Using a panel of biologically-occurring lipids, we show that lipid conjugation modulates siRNA hydrophobicity and governs spontaneous partitioning into distinct plasma lipoprotein classes in vivo. Lipoprotein binding influences siRNA distribution by delaying renal excretion and promoting uptake into lipoprotein receptor-enriched tissues. Lipid-siRNAs elicit mRNA silencing without causing toxicity in a tissue-specific manner. Lipid-siRNA internalization occurs independently of lipoprotein endocytosis, and is mediated by siRNA phosphorothioate modifications. Although biomimetic lipoprotein nanoparticles have been considered for the enhancement of siRNA delivery, our findings suggest that hydrophobic modifications can be leveraged to incorporate therapeutic siRNA into endogenous lipid transport pathways without the requirement for synthetic formulation.


2018 ◽  
Vol 115 (12) ◽  
pp. E2696-E2705 ◽  
Author(s):  
Jiahe Li ◽  
Connie Wu ◽  
Wade Wang ◽  
Yanpu He ◽  
Elad Elkayam ◽  
...  

Small interfering RNA (siRNA) represents a promising class of inhibitors in both fundamental research and the clinic. Numerous delivery vehicles have been developed to facilitate siRNA delivery. Nevertheless, achieving highly potent RNA interference (RNAi) toward clinical translation requires efficient formation of RNA-induced gene-silencing complex (RISC) in the cytoplasm. Here we coencapsulate siRNA and the central RNAi effector protein Argonaute 2 (Ago2) via different delivery carriers as a platform to augment RNAi. The physical clustering between siRNA and Ago2 is found to be indispensable for enhanced RNAi. Moreover, by utilizing polyamines bearing the same backbone but distinct cationic side-group arrangements of ethylene diamine repeats as the delivery vehicles, we find that the molecular structure of these polyamines modulates the degree of siRNA/Ago2-mediated improvement of RNAi. We apply this strategy to silence the oncogene STAT3 and significantly prolong survival in mice challenged with melanoma. Our findings suggest a paradigm for RNAi via the synergistic coassembly of RNA with helper proteins.


2020 ◽  
Vol 16 (7) ◽  
pp. 1169-1181
Author(s):  
Dhananjay Suresh ◽  
Brian Jenkins ◽  
Ajit Zambre ◽  
Anandhi Upendran ◽  
Raghuraman Kannan

Developing a delivery vehicle to protect siRNA from degradation is a significant challenge. To solve this challenge, researchers attempted to use protein-based nanoparticles to deliver siRNA with limited to moderate success. However, a systematic investigation of comparing the ability of different protein-based nanoparticles as vehicles to deliver siRNA stably within cells is still unavailable. Therefore, in this study we synthesized a library of both non-targeted (proteinsiRNA) nanoparticles (NPs) and targeted (antibody conjugated protein-siRNA) NPs and evaluated ability to stably deliver siRNA in to cells to silence the gene of interest. We investigated nanoparticles of casein, bovine serum albumin, and gelatin for the delivery of siRNA. We synthesized and characterized a total of 12 nanoconjugates; in these conjugates, we either encapsulated, electrostatically attached, or covalently conjugated siRNA. We evaluated the efficiency of attaching siRNA to nanoconjugates, stability, and cellular delivery. The ability of siRNA to silence the protein of interest in cancer cells was also investigated. Among non-targeted conjugates, BSA matrix imparted relatively high stability to siRNA when encapsulated. Among targeted nanoconjugates, gelatin nanoparticles rendered high stability to siRNA upon covalent conjugation to the surface. On comparing with both targeted and non-targeted NPs for release of siRNA within cells, antibody-gelatin-siRNA conjugate exhibited high release and functional activity (down-regulation of target protein levels) within the cells as confirmed by both fluorescence imaging and Western blotting. In summary, our investigations show that targeted gelatin nanoparticles and non-targeted BSA nanoparticles possess high stability and excellent gene suppression capabilities and warrants further studies. We can extend the results from this study to develop stable siRNA delivery vehicles to specifically silence the protein of interest.


Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3413 ◽  
Author(s):  
Ehexige Ehexige ◽  
Tsogzolmaa Ganbold ◽  
Xiang Yu ◽  
Shuqin Han ◽  
Huricha Baigude

Lipid nanoparticles (LNP) are the most potent carriers for the delivery of nucleic acid-based therapeutics. The first FDA approved a short interfering RNA (siRNA) drug that uses a cationic LNP system for the delivery of siRNA against human transthyretin (hTTR). However, preparation of such LNP involves tedious multi-step synthesis with relatively low yields. In the present study, we synthesized cationic peptidomimetic functionalized cholesterol (denote Chorn) in straightforward chemical approaches with high yield. When formulated with helper lipids, Chorn LNPs complexed with siRNA to form nanoparticles with an average diameter of 150 nm to 200 nm. Chorn LNP mediated transfection of a green fluorescence protein (GFP) expressing plasmid resulted in 60% GFP positive cells. Moreover, Chorn LNP delivered siRNA against polo-like kinase 1 (Plk1), a disease related gene in cancer cells and efficiently suppressed the expression of the gene, resulting in significant morphological changes in the cell nuclei. Our data suggested that cholesterol based cationic LNP, prepared through a robust chemical strategy, may provide a promising siRNA delivery system.


2020 ◽  
Vol 6 (6) ◽  
pp. 278-289
Author(s):  
Chi Ma ◽  
Dandan Zhu ◽  
Yu Chen ◽  
Yiwen Dong ◽  
Wenyi Lin ◽  
...  

AbstractSmall interfering RNA (siRNA)-based RNA interference has emerged as a promising therapeutic strategy for the treatment of a wide range of incurable diseases. However, the safe and effective delivery of siRNA therapeutics into the interior of target cells remains challenging. Here, we disclosed novel amphiphilic peptide dendrimers (AmPDs) that composed of hydrophobic two lipid-like alkyl chains and hydrophilic poly(lysine) dendrons with different generations (2C18-KK2 and 2C18-KK2K4) as nanovehicles for siRNA delivery. These AmPDs are able to self-assemble into supramolecular nanoassemblies that are capable of entrapping siRNA molecules into nanoparticles to protect siRNA from enzymatic degradation and promote efficient intracellular uptake without evident toxicity. Interestingly, by virtue of the optimal balance of hydrophobic lipid-like entity and hydrophilic poly(lysine) dendron generations, AmPD 2C18-KK2K4 bearing bigger hydrophilic dendron can package siRNA to form stable, but more ready to disassemble complexes, thereby resulting in more efficient siRNA releasing and better gene silencing effect in comparison with AmPD 2C18-KK2 bearing smaller dendron. Additional studies confirmed that 2C18-KK2K4 can capitalize on the advantages of lipid and peptide dendrimer vectors for effective siRNA delivery. Collectively, our AmPD-based nanocarriers indeed represent a safe and effective siRNA delivery system. Our findings also provide a new perspective on the modulation of self-assembly amphiphilic peptide dendrimers for the functional and adaptive delivery of siRNA therapeutics.


Acta Naturae ◽  
2013 ◽  
Vol 5 (3) ◽  
pp. 35-53 ◽  
Author(s):  
N. A. Nikitenko ◽  
V. S. Prassolov

RNA interference (RNAi) is a powerful method used for gene expression regulation. The increasing knowledge about the molecular mechanism of this phenomenon creates new avenues for the application of the RNAi technology in the treatment of various human diseases. However, delivery of RNA interference mediators, small interfering RNAs (siRNAs), to target cells is a major hurdle. Effective and safe pharmacological use of siRNAs requires carriers that can deliver siRNA to its target site and the development of methods for protection of these fragile molecules from in vivo degradation. This review summarizes various strategies for siRNA delivery, including chemical modification and non-viral approaches, such as the polymer-based, peptide-based, lipid-based techniques, and inorganic nanosystems. The advantages, disadvantages, and prospects for the therapeutic application of these methods are also examined in this paper.


2021 ◽  
Vol 2 (2) ◽  
pp. 16-19
Author(s):  
Shazia Choudhary ◽  
Sheeba Murad ◽  
Sana Gul ◽  
Hayat Khan ◽  
Samra Khalid ◽  
...  

RNA interference (RNAi) refers to the inhibition of gene expression by small double-stranded RNA molecules. This technology can prove to be a breakthrough biological discovery of the decade as it has the potential to revolutionize the field of therapeutics. RNA interference (RNAi) through small interfering RNA (siRNA) is currently being evaluated for its efficacy to be used in therapeutics as well as prophylactic strategies. Many studies are being conducted across the globe to optimize the siRNA delivery systems (in terms of safe, stable and efficient delivery) in various disorders. There are a number of diseases such as autoimmune diseases, cancer associated pathological changes, bacterial and viral induced disorders, where RNAi pathway can be explored and RNAi technology can be used as a tool to intervene such abnormalities. This review is an effort to review latest advancements in the field of siRNA based therapy development and the pits and falls generally encountered in the use of this technology.


2021 ◽  
Author(s):  
Mehran Vaezi ◽  
Ahmad Movahedpour ◽  
Mortaza Taheri-Anganeh ◽  
Mehrdad Ameri

Abstract We investigated the encapsulation of small interfering RNA (siRNA) in carbon nanotube (CNT) using molecular dynamics simulation. siRNAs can be used to silence specific genes effectively if they remain intact while they are delivered to their target cells. Along with the various drug delivery systems designed for this purpose, CNTs are a promising one. Based on their shape, siRNA can encapsulate inside CNTs and protect them from degradation. However, several factors can affect siRNA encapsulation inside CNTs including temperature and CNT diameter. Herein, we conducted a simulation study to evaluate the impact of these factors in the placement of siRNA. Our results can be considered in designing further experimental siRNA delivery systems using carbon nanotubes.


2019 ◽  
Vol 69 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Londiwe Simphiwe Mbatha ◽  
Fiona Chepkoech Maiyo ◽  
Moganavelli Singh

Abstract Use of exogenous small interfering RNA (siRNA) has shown potential in gene silencing. The need for target-specific siRNA delivery vehicles is crucial to successful gene silencing. This study is aimed at developing and evaluating the safety and efficiency of siRNA delivery using unmodified and folic acid (FA) modified poly(amidoamine) generation 5 (PAMAM G5D) functionalized gold nanoparticles (Au:G5D/Au:G5D:FA) in vitro. All formulations were physico--chemically characterized and nanocomplexes were evaluated using the band shift, dye displacement, nuclease protection, MTT cell viability, and luciferase reporter gene assays. Nanocomplexes bound and protected siRNA against degrading RNases, and were well tolerated by the cells. The Au:G5D:FA nanocomplexes elicited excellent gene silencing in folate receptor expressing HeLa-Tat-Luc cells, decreasing significantly in the presence of excess FA ligand, indicating nanocomplex uptake by the mechanism of receptor mediation. These results highlight the synergistic role played by Au and the dendrimer in enhancement of transgene silencing.


2019 ◽  
Author(s):  
Matthias Zytnicki ◽  
Ignacio González

AbstractSmall RNAs (sRNAs) encompass a great variety of different molecules of different kinds, such as micro RNAs, small interfering RNAs, Piwi-associated RNA, among other. These sRNA have a wide range of activities, which include gene regulation, protection against virus, transposable element silencing, and have been identified as a key actor to study and understand the development of the cell. Small RNA sequencing is thus routinely used to assess the expression of the diversity of sRNAs, usually in the context of differentially expression, where two conditions are compared. Many tools have been presented to detect differentially expressed micro RNAs, because they are well documented, and the associated genes are well defined. However, tools are lacking to detect other types of sRNAs, which are less studied, and have an imprecise “gene” structure. We present here a new method, called srnadiff, to find all kinds of differentially expressed sRNAs. To the extent of our knowledge, srnadiff is the first tool that detects differentially expressed sRNAs without the use of external information, such as genomic annotation or reference sequence of sRNAs.Author summaryWe present here a new method for the ab initio discovery of differentially expressed small RNAs. The standard method, sometimes named annotate-then-identify, first finds possible genes, and tests for differential expression. In contrast, our method skips the first step and scans the genome for potential differentially expressed regions (the identify-then-annotate strategy). Since our method is the first one to use the identify-then-annotate strategy on sRNAs, we compared our method against a similar method, developed for long RNAs (derfinder), and to the annotate-then-identify strategy, where the sRNAs have been identified beforehand using a segmentation tool, on three published datasets, and a simulated one. Results show that srnadiff gives much better results than derfinder, and is also better than the annotate-then-identify strategy on many aspects. srnadiff is available as a Bioconductor package, together with a detailed manual: https://bioconductor.org/packages/release/bioc/html/srnadiff.html


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