On the cellular processing of non-viral nanomedicines for nucleic acid delivery: Mechanisms and methods (original) (raw)

Delivery Systems for Nucleic Acids and Proteins: Barriers, Cell Capture Pathways and Nanocarriers

Pharmaceutics

Gene therapy has been used as a potential approach to address the diagnosis and treatment of genetic diseases and inherited disorders. In this line, non-viral systems have been exploited as promising alternatives for delivering therapeutic transgenes and proteins. In this review, we explored how biological barriers are effectively overcome by non-viral systems, usually nanoparticles, to reach an efficient delivery of cargoes. Furthermore, this review contributes to the understanding of several mechanisms of cellular internalization taken by nanoparticles. Because a critical factor for nanoparticles to do this relies on the ability to escape endosomes, researchers have dedicated much effort to address this issue using different nanocarriers. Here, we present an overview of the diversity of nanovehicles explored to reach an efficient and effective delivery of both nucleic acids and proteins. Finally, we introduced recent advances in the development of successful strategies to deliver ...

Directing the Way—Receptor and Chemical Targeting Strategies for Nucleic Acid Delivery

Pharmaceutical Research

Nucleic acid therapeutics have shown great potential for the treatment of numerous diseases, such as genetic disorders, cancer and infections. Moreover, they have been successfully used as vaccines during the COVID-19 pandemic. In order to unfold full therapeutical potential, these nano agents have to overcome several barriers. Therefore, directed transport to specific tissues and cell types remains a central challenge to receive carrier systems with enhanced efficiency and desired biodistribution profiles. Active targeting strategies include receptor-targeting, mediating cellular uptake based on ligand-receptor interactions, and chemical targeting, enabling cell-specific delivery as a consequence of chemically and structurally modified carriers. With a focus on synthetic delivery systems including polyplexes, lipid-based systems such as lipoplexes and lipid nanoparticles, and direct conjugates optimized for various types of nucleic acids (DNA, mRNA, siRNA, miRNA, oligonucleotides),...

Responsive Nanocarriers as an emerging platform for cascaded delivery of nucleic acids to cancer

Advanced drug delivery reviews, 2017

Cascades of systemic and intracellular obstacles, including low stability in blood, little tumor accumulation, weak tumor penetration, poor cellular uptake, inefficient endosomal escape and deficient disassembly in the cytoplasm, must be overcome in order to deliver nucleic acid drugs for cancer therapy. Nanocarriers that are sensitive to a variety of physiological stimuli, such as pH, redox status, and cell enzymes, are substantially changing the landscape of nucleic acid drug delivery by helping to overcome cascaded systemic and intracellular barriers. This review discusses nucleic acid-based therapeutics, systemic and intracellular barriers to efficient nucleic acid delivery, and nanocarriers responsive to extracellular and intracellular biological stimuli to overcome individual barriers. In particular, responsive nanocarriers for the cascaded delivery of nucleic acids in vivo are highlighted. Developing novel cascaded nanocarriers that transform their physicochemical properties ...

Hitching a Ride: Enhancing Nucleic Acid Delivery into Target Cells Through Nanoparticles

2020

Nucleic acids have gained significant interest in medicine for their therapeutic and prophylactic application. However, if delivered alone, nucleic acids are susceptible to nuclease degradation. Hence, delivering them with a suitable delivery system which can protect them could be beneficial. There is an increasing demand for novel delivery systems for nucleic acids to use them as vaccines and for gene therapy. Out of many types of delivery systems, nanoparticles are gaining importance because of their suitable properties. Hence, this chapter mainly focuses on discussing various types of nanoparticles for the delivery of nucleic acids. Recent applications of various types of nanoparticle-based viral and non-viral vectors and their advantages and disadvantages will be discussed in detail. The potential improvements which can be made to each existing nanoparticle systems are expressed. Overall this chapter is to provide an overview of importance of nanoparticles for nucleic acid deliv...

Intracellular trafficking of nucleic acids

Expert Opinion on Drug Delivery, 2004

Until recently, the attention of most researchers has focused on the first and last steps of gene transfer, namely delivery to the cell and transcription, in order to optimise transfection and gene therapy. However, over the past few years, researchers have realised that the intracellular trafficking of plasmids is more than just a 'black box' and is actually one of the major barriers to effective gene delivery. After entering the cytoplasm, following direct delivery or endocytosis, plasmids or other vectors must travel relatively long distances through the mesh of cytoskeletal networks before reaching the nuclear envelope. Once at the nuclear envelope, the DNA must either wait until cell division, or be specifically transported through the nuclear pore complex, in order to reach the nucleoplasm where it can be transcribed. This review focuses on recent developments in the understanding of these intracellular trafficking events as they relate to gene delivery. Hopefully, by continuing to unravel the mechanisms by which plasmids and other gene delivery vectors move throughout the cell, and by understanding the cell biology of gene transfer, superior methods of transfection and gene therapy can be developed.

Cationic lipid saturation influences intracellular delivery of encapsulated nucleic acids

Journal of Controlled Release, 2005

An analogous series of cationic lipids (1,2-distearyloxy-N,N-dimethyl-3-aminopropane (DSDMA), 1,2-dioleyloxy-N,Ndimethyl-3-aminopropane (DODMA), 1,2-dilinoleyloxy-N,N-dimethyl-3-aminopropane (DLinDMA) and 1,2-dilinolenyloxy-N,N-dimethyl-3-aminopropane (DLenDMA)) possessing 0, 1, 2 or 3 double bonds per alkyl chain respectively, was synthesized to determine the correlation between lipid saturation, fusogenicity and efficiency of intracellular nucleic acid delivery. 31 P-NMR analysis suggests that as saturation increases, from 2 to 0 double bonds, lamellar (L a) to reversed hexagonal (H II) phase transition temperature increases, indicating decreasing fusogenicity. This trend is largely reflected by the efficiency of gene silencing observed in vitro when the lipids are formulated as Stable Nucleic Acid Lipid Particles (SNALPs) encapsulating small inhibitory RNA (siRNA). Uptake experiments suggest that despite their lower gene silencing efficiency, the less fusogenic particles are more readily internalized by cells. Microscopic visualization of fluorescently labelled siRNA uptake was supported by quantitative data acquired using radiolabelled preparations. Since electrostatic binding is a precursor to uptake, the pKa of each cationic lipid was determined. The results support a transfection model in which endosomal release, mediated by fusion with the endosomal membrane, results in cytoplasmic translocation of the nucleic acid payload.

Engineered nonviral nanocarriers for intracellular gene delivery applications

Biomedical materials (Bristol, England), 2012

The efficient delivery of nucleic acids into mammalian cells is a central aspect of cell biology and of medical applications, including cancer therapy and tissue engineering. Non-viral chemical methods have been received with great interest for transfecting cells. However, further development of nanocarriers that are biocompatible, efficient and suitable for clinical applications is still required. In this paper, the different material platforms for gene delivery are comparatively addressed, and the mechanisms of interaction with biological systems are discussed carefully.

How cationic lipids transfer nucleic acids into cells and across cellular membranes: Recent advances

Journal of Controlled Release, 2013

Cationic lipid-and polymer-based nanodevices are considered appropriate alternatives for virus-based particles for delivery of nucleic acids, including genes and siRNA, into eukaryotic cells. Because of colloidal stability concerns and toxicity issues the potential in vivo application of these so-called non-viral systems, in particular cationic lipids, was met with considerable skepticism. However, in recent years, the development of novel ionizable cationic lipid formulations in conjunction with sophisticated procedures to carefully control the size of the nanoparticles has rapidly advanced options for a successful therapeutic application. Thus it would appear that cationic lipids have taken a prominent step ahead in their potential use as nanocarriers for siRNA delivery in gene silencing of target genes in a variety of diseases. Verification and improvement of delivery efficiency as well as screening of targeting ligands justify further work in revealing underlying mechanisms that are instrumental in efficient crossing of cellular barriers by cationic lipid-based nanocarriers. In this regard, triggering entry into specific pathways or modulating trafficking along such pathways, either by targeting of nanoparticles or by affecting specific cellular signaling pathways, may represent promising tools. Such options may involve, for example, facilitating nanoparticle transport across endothelial cells by transcytotic mechanisms, or improving delivery efficiency by affecting nanoparticle trafficking that avoids lysosomal delivery. Here, recent progress in the field of lipid-based nanocarriers is discussed, with a focus on mechanisms underlying their interactions with cells in vitro. Where appropriate, we will include mechanisms for polymer-based systems in our discussion.

Endocytosis Pathways for Nucleic Acid Therapeutics

Nano LIFE, 2012

The development of nanoscale delivery vehicles for siRNAs is a current topic of considerable importance. However, little is understood about the exact trafficking mechanisms for siRNA-vehicle complexes across the plasma membrane and into the cytoplasm. While some information can be gleaned from studies on delivery of plasmid DNA, the different delivery requirements for these two vehicles makes drawing specific conclusions a challenge. However, using chemical inhibitors of different endocytosis pathways, studies on which endocytotic pathways are advantageous and deleterious for the delivery of nucleic acid drugs are emerging. Using this information as a guide, it is expected that the future development of effective siRNA delivery vehicles and therapeutics will be greatly improved.

Exploring the role of polymer structure on intracellular nucleic acid delivery via polymeric nanoparticles

Intracellular nucleic acid delivery has the potential to treat many genetically-based diseases, however, gene delivery safety and efficacy remains a challenging obstacle. One promising approach is the use of polymers to form polymeric nanoparticles with nucleic acids that have led to exciting advances in non-viral gene delivery. Understanding the successes and failures of gene delivery polymers and structures is the key to engineering optimal polymers for gene delivery in the future. This article discusses the polymer structural features that enable effective intracellular delivery of DNA and RNA, including protection of nucleic acid cargo, cellular uptake, endosomal escape, vector unpacking, and delivery to the intracellular site of activity. The chemical properties that aid in each step of intracellular nucleic acid delivery are described and specific structures of note are highlighted. Understanding the chemical design parameters of polymeric nucleic acid delivery nanoparticles is important to achieving the goal of safe and effective non-viral genetic nanomedicine.