Microfluidic fabrication of lipid nanoparticles for the delivery of nucleic acids (original) (raw)

Lipid Nanoparticles for Cell-Specific in Vivo Targeted Delivery of Nucleic Acids

Biological and Pharmaceutical Bulletin, 2020

The last few years have witnessed a great advance in the development of nonviral systems for in vivo targeted delivery of nucleic acids. Lipid nanoparticles (LNPs) are the most promising carriers for producing clinically approved products in the future. Compared with other systems used for nonviral gene delivery, LNPs provide several advantages including higher stability, low toxicity, and greater efficiency. Additionally, systems based on LNPs can be modified with ligands and devices for controlled biodistribution and inter-nalization into specific cells. Efforts are ongoing to improve the efficiency of lipid-based gene vectors. These efforts depend on the appropriate design of nanocarriers as well as the development of new lipids with improved gene delivery ability. Several ionizable lipids have recently been developed and have shown dramatically improved efficiency. However, enhancing the ability of nanocarriers to target specific cells in the body remains the most difficult challenge. Systemically administered LNPs can access organs in which the capil-laries are characterized by the presence of fenestrations, such as the liver and spleen. The liver has received the most attention to date, although targeted delivery to the spleen has recently emerged as a promising tool for modulating the immune system. In this review, we discuss recent advances in the use of LNPs for cell-specific targeted delivery of nucleic acids. We focus mainly on targeting liver hepatocytes and spleen immune cells as excellent targets for gene therapy. We also discuss the potential of endothelial cells as an alternate approach for targeting organs with a continuous endothelium.

Lipid-Based Nanoparticles as Nonviral Gene Delivery Vectors

Methods in Molecular Biology, 2013

Efficient delivery of nucleic acids into cells is a promising technique to modulate cellular gene expression for therapeutic and research applications. Cationic lipid-based liposomes represent one of the most intensively studied and employed nonviral vectors. They are positively charged at physiological pH and spontaneously self-assemble with polyanionic nucleic acids forming nanoscaled complexes named lipoplexes. Here, we draft a simple protocol for the development, characterization, optimization, and screening of liposomal formulations for in vitro gene delivery. In particular, we report as a practical example a quick method to formulate and extrude nanometer-sized unilamellar cationic vesicles composed of DOTAP as cationic lipid and DOPE as zwitterionic helper lipid at 1:1 molar ratio. The physico-chemical characterization of liposomes and lipoplexes involves the measurement of mean diameter and overall surface charge using Dynamic Light Scattering (DLS) and Laser Doppler Microelectrophoresis. The outlined transfection procedure takes into account several experimental parameters affecting the in vitro performance of gene delivery systems, paying special attention to the charge ratio (CR). Gene delivery effectiveness is evaluated both in terms of transfection efficiency and cytotoxicity of the vector to find the optimal transfection conditions. Importantly, the proposed protocol can be easily shifted to different types of nonviral vectors.

Role of Lipid-Based and Polymer-Based Non-Viral Vectors in Nucleic Acid Delivery for Next-Generation Gene Therapy

Molecules

The field of gene therapy has experienced an insurgence of attention for its widespread ability to regulate gene expression by targeting genomic DNA, messenger RNA, microRNA, and short-interfering RNA for treating malignant and non-malignant disorders. Numerous nucleic acid analogs have been developed to target coding or non-coding sequences of the human genome for gene regulation. However, broader clinical applications of nucleic acid analogs have been limited due to their poor cell or organ-specific delivery. To resolve these issues, non-viral vectors based on nanoparticles, liposomes, and polyplexes have been developed to date. This review is centered on non-viral vectors mainly comprising of cationic lipids and polymers for nucleic acid-based delivery for numerous gene therapy-based applications.

Genospheres: self-assembling nucleic acid-lipid nanoparticles suitable for targeted gene delivery

Gene Therapy, 2006

We describe the assembly of a cationic lipid-nucleic acid nanoparticle from a liquid monophase containing water and a water miscible organic solvent where both lipid and DNA components are separately soluble prior to their combination. Upon removal of the organic solvent, stable and homogenously sized (70-100 nm) lipid-nucleic acid nanoparticles (Genospherest) were formed. The low accessibility (o15%) of the nanoparticle-encapsulated DNA to a DNA intercalating dye indicated well-protected nucleic acids and high DNA incorporation efficiencies. It was demonstrated that Genospheres could be stably stored under a variety of conditions including a lyophilized state where no appreciable increase in particle size or DNA accessibility was observed following reconstitution.

Nano-Encapsulation and Conjugation Applied in the Development of Lipid Nanoparticles Delivering Nucleic Acid Materials to Enable Gene Therapies

2024

Nano-encapsulation and conjugation are the main strategies employed for drug delivery. Nanoparticles help improve encapsulation and targeting efficiency, thus optimizing therapeutic efficacy. Through nanoparticle technology, replacement of a defective gene or delivery of a new gene into a patient’s genome has become possible. Lipid nanoparticles (LNPs) loaded with genetic materials are designed to be delivered to specific target sites to enable gene therapy. The lipid shells protect the fragile genetic materials from degradation, then successfully release the payload inside of the cells, where it can integrate into the patient’s genome and subsequently express the protein of interest. This review focuses on the development of LNPs and nano-pharmaceutical techniques for improving the potency of gene therapies, reducing toxicities, targeting specific cells, and releasing genetic materials to achieve therapeutic effects. In addition, we discuss preparation techniques, encapsulation efficiency, and the effects of conjugation on the efficacy of LNPs in delivering nucleic acid materials.

Cholesterol-rich lipid-mediated nanoparticles boost of transfection efficiency, utilized for gene editing by CRISPR-Cas9

International Journal of Nanomedicine, 2019

Purpose: Gene therapy has become a promising remedy to treat disease by modifying the person's genes. The therapeutic potential of related tools such as CRISPR-Cas9 depends on the efficiency of delivery to the targeted cells. Numerous transfection reagents have been designed and lots of efforts have been devoted to develop carriers for this purpose. Therefore, the aim of the present study was to develop novel cholesterol-rich lipid-based nanoparticles to enhance transfection efficiency and serum stability. Materials and methods: We constructed two-, three-and four-component cationic liposomes (CLs) to evaluate the combined effect of cholesterol domain and DOPE (dioleoyl phosphatidylethanolamine), a fusogenic lipid, and the PEG (polyethylene glycol) moiety location inside or outside of the cholesterol domain on transfection efficiency and other properties of the particle. Lipoplex formation and pDNA (plasmid DNA) entrapment were assessed by gel retardation assay at different N/P ratios (3, 5, 7). Physicochemical characteristics, cytotoxicity, serum stability and endosomal escape capability of the lipoplexes were studied and transfection potential was measured by firefly luciferase assay. Next, HEK293 cell line stably expressing GFP was utilized to demonstrate the editing of a reporter through Cas9 and sgRNA plasmids delivery by the selected CL formula, which showed the highest transfection efficiency. Results: Among the designed CLs, the four-component formula [DOTAP (1,2-dioleoyl-3-trimethylammoniumpropane)/DOPE/cholesterol/Chol-PEG (cholesterol-polyethylene glycol)] showed the highest rate of transfection at N/P 3. Finally, transfection of Cas9/sgRNA by this formulation at N/P 3 resulted in 39% gene-editing efficiency to knockout GFP reporter. The results also show that this CL with no cytotoxicity effect can totally protect the plasmids from enzymatic degradation in serum. Conclusion: The novel PEGylated cholesterol domain lipoplex providing serum stability, higher transfection efficiency and endosomal release can be used for in vivo Cas9/sgRNA delivery and other future gene-therapy applications.

Recent advances in gene delivery using nanostructures and future prospects

Gene therapy has attracted much attention as an encouraging solution to treat a wide range of diseases rather than rare hereditary and single-gene disorders. For this purpose, nucleic acids must be delivered to human target cells. This article reviews the history, key issues, recent advances, and future of gene therapy using nanostructures. Some intracellular and extracellular barriers need to be removed. Today, a wide range of nano-vectors vectors have been developed. Several vectors based on nanostructures have been developed and used for the successful treatment of some inherited diseases, immunodeficiency, ocular and cancer. Viral vectors are suitable for gene therapy for diseases that require long-term gene expression. Although non-viral vectors are less effective than viruses, they are more specific, have less immunogenicity, and are capable of transmitting longer genes. Overall, recent advances in various gene therapy strategies have been able to meet some of the expectations of gene therapy for years, and have raised many hopes for further success. Gene therapy seems to be the ultimate solution of the present century to treat many human diseases.

Lipid Nanoparticles for Delivery of Therapeutic RNA Oligonucleotides

Molecular Pharmaceutics, 2019

Gene therapy is an exciting field that has the potential to address emerging scientific and therapeutic tasks. RNA-based gene therapy has made remarkable progress in recent decades. Nevertheless, efficient targeted delivery of RNA therapeutics is still a prerequisite for entering the clinics. In this review, we introduce current delivery methods for RNA gene therapeutics based on lipid nanoparticles (LNP). We focus on the clinical appeal of recent RNA NPs and discuss existing challenges of fabrication and screening LNP candidates for effective translation into drugs of human metabolic diseases and cancer.

A general strategy to achieve ultra-high gene transfection efficiency using lipid-nanoparticle composites

Biomaterials, 2014

Gene therapy provides a new hope for previously "incurable" diseases. Low gene transfection efficiency, however, is the bottle-neck to the success of gene therapy. It is very challenging to develop non-viral nanocarriers to achieve ultra-high gene transfection efficiencies. Herein, we report a novel design of "tight binding-but-detachable" lipid-nanoparticle composite to achieve ultrahigh gene transfection efficiencies of 60~82%, approaching the best value (~90%) obtained using viral vectors. We show that Fe@CNPs nanoparticles coated with LP-2000 lipid molecules can be used as gene carriers to achieve ultra-high (60e80%) gene transfection efficiencies in HeLa, U-87MG, and TRAMP-C1 cells. In contrast, Fe@CNPs having surface-covalently bound N,N,N-trimethyl-N-2-methacryloxyethyl ammonium chloride (TMAEA) oligomers can only achieve low (23e28%) gene transfection efficiencies. Similarly ultrahigh gene transfection/expression was also observed in zebrafish model using lipid-coated Fe@CNPs as gene carriers. Evidences for tight binding and detachability of DNA from lipid-nanoparticle nanocarriers will be presented.

Impact of Formulation Conditions on Lipid Nanoparticle Characteristics and Functional Delivery of CRISPR RNP for Gene Knock-Out and Correction

Pharmaceutics, 2022

The CRISPR-Cas9 system is an emerging therapeutic tool with the potential to correct diverse genetic disorders. However, for gene therapy applications, an efficient delivery vehicle is required, capable of delivering the CRISPR-Cas9 components into the cytosol of the intended target cell population. In this study, we optimized the formulation conditions of lipid nanoparticles (LNP) for delivery of ready-made CRISPR-Cas9 ribonucleic protein (RNP). The buffer composition during complexation and relative DOTAP concentrations were varied for LNP encapsulating in-house produced Cas9 RNP alone or Cas9 RNP with additional template DNA for gene correction. The LNP were characterized for size, surface charge, and plasma interaction through asymmetric flow field flow fractionation (AF4). Particles were functionally screened on fluorescent reporter cell lines for gene knock-out and gene correction. This revealed incompatibility of RNP with citrate buffer and PBS. We demonstrated that LNP for g...