A tale of nucleic acid-ionizable lipid nanoparticles: Design and manufacturing technology and advancement

Dual centrifugation as fast and novel screening approach for optimal RNA loaded lipid-based nanoparticles

The last decade has shown increased benefits for non-viral gene delivery. To overcome the challenges of nucleic acid administration, appropriate drug delivery systems (DDS) are required. The recently approved RNA formulations have demonstrated that lipid nanoparticles (LNPs) are suitable DDS for delivering RNAs. LNPs are commonly composed of cationic and/or ionizable lipids, helper lipids and PEGylated lipids. Conventional manufacturing procedures for LNPs are mixing systems, such as microfluidics, with drawbacks in terms of time and resource consumption. The LNPs produced also pose problems with storage stability. Based on a microRNA (miRNA) model, we present dual centrifugation (DC) as a novel and reproducible way for preparing RNA loaded LNP formulations via in-vial homogenization. Our formulations show promising results in size characteristics, as well as in their cell performance. Depending on the lipid composition of the LNPs, a remarkable knockdown efficiency is achieved. With a net formulation time of 7 min, an enormously fast approach can be presented. DC offers the capability for fast LNP screenings, with a loading capacity of up to 40 vials per run. The simplicity of the method could take advantage of bedside preparation, overcoming the hurdles of storage stability for LNP formulations.

Enhancing non-viral DNA delivery systems: Recent advances in improving efficiency and target specificity

DNA-based therapies are often limited by challenges such as stability, long-term integration, low transfection efficiency, and insufficient targeted DNA delivery. This review focuses on recent progress in the design of non-viral delivery systems for enhancing targeted DNA delivery and modulation of therapeutic efficiency. Cellular uptake and intracellular trafficking mechanisms play a crucial role in optimizing gene delivery efficiency. There are two main strategies employed to improve the efficiency of gene delivery vectors: (i) explore different administration routes (e.g., mucosal, intravenous, intramuscular, subcutaneous, intradermal, intratumoural, and intraocular) that best facilitates optimal uptake into the targeted cells and organs and (ii) modify the delivery vectors with cell-specific ligands (e.g., natural ligands, antibodies, peptides, carbohydrates, or aptamers) that enable targeted uptake to specific cells with higher specificity and improved biodistribution. We describe how recent progress in employing these DNA delivery strategies is advancing the field and increasing the clinical translation and ultimate clinical application of DNA therapies.

Developing a Ready-to-Use Lipid Nanoparticle Technology for Nucleic Acid Delivery Based on Deep Eutectic Solvents

Microfluidic technology has emerged as a prevalent tool to produce lipid nanoparticles (LNPs) for nucleic acid delivery. However, its wide-ranging application is hindered by specialized, costly equipment and consumables. Herein, a ready-to-use lipid nanoparticle (RULNP) technology employing deep eutectic solvents (DESs) was developed. The DES, consisting of fructose and glycerol ([Fru][Gly]), was able to dissolve lipids and nucleic acids, facilitating the formation of RULNPs by simple physical mixing and hydrating. This innovative approach circumvents the high costs and organic solvents associated with microfluidic methods and offers flexibility in preparation techniques, accommodating various application scenarios. RULNPs exhibited physicochemical properties and plasmid DNA (pDNA) or RNA delivery efficacy comparable to those of LNPs. Mechanistic studies revealed that RULNPs achieved superior cellular uptake compared with LNPs despite exhibiting limited endosomal escape capabilities. Collectively, the DES-based RULNP system presents a rapid and straightforward method for LNP production, potentially revolutionizing nucleic acid delivery.

Nanomaterials-assisted gene editing and synthetic biology for optimizing the treatment of pulmonary diseases

The use of nanomaterials in gene editing and synthetic biology has emerged as a pivotal strategy in the pursuit of refined treatment methodologies for pulmonary disorders. This review discusses the utilization of nanomaterial-assisted gene editing tools and synthetic biology techniques to promote the development of more precise and efficient treatments for pulmonary diseases. First, we briefly outline the characterization of the respiratory system and succinctly describe the principal applications of diverse nanomaterials in lung ailment treatment. Second, we elaborate on gene-editing tools, their configurations, and assorted delivery methods, while delving into the present state of nanomaterial-facilitated gene-editing interventions for a spectrum of pulmonary diseases. Subsequently, we briefly expound on synthetic biology and its deployment in biomedicine, focusing on research advances in the diagnosis and treatment of pulmonary conditions against the backdrop of the coronavirus disease 2019 pandemic. Finally, we summarize the extant lacunae in current research and delineate prospects for advancement in this domain. This holistic approach augments the development of pioneering solutions in lung disease treatment, thereby endowing patients with more efficacious and personalized therapeutic alternatives.

RP-HPLC-CAD method for the rapid analysis of lipids used in lipid nanoparticles derived from dual centrifugation

The use of lipids as suitable excipients for drug carrier systems has been established for years. Liposomes or lipid nanoparticles (LNPs) in general have been shown capable of delivering both hydrophilic and hydrophobic drugs. The Covid-19 pandemic and the resulting vaccines have significantly increased interest in the potential for these lipid-based systems, which can carry different types of therapeutic RNAs. LNPs used for the transfection of RNA are usually a multi-component mixture of phospholipids and other lipids. Essential components are positively charged or ionizable lipids such as DOTAP or SM-102, but also uncharged helper lipids such as cholesterol, DOPE, DSPC, DMG-PEG2000 or DSPE-PEG2000. Due to the differences in charge, simultaneous detection is a challenge. Here, we present a reversed-phase high-performance liquid chromatography charged-aerosol-detector method (RP-HPLC-CAD method) using a C-18 column for the simultaneous determination of charged and uncharged lipids. Our method has been validated according to the ICH-Q2 (R2) guideline for accuracy, precision, specificity and working range, including the limit of detection (LOD) and quantification (LOQ), as well as the calibration range. We were able to show satisfactory results in both precision and accuracy. The working range also shows great potential with a calibration range from 9.375 to 1000 μg/ml, LODs <1.85 μg/ml and LOQs <6.16 μg/ml. This method represents a fast and reproducible procedure for quantifying the lipids mentioned. In combination with the novel approach for the production of LNPs using dual centrifugation (DC), it offers the possibility of extremely rapid production of RNA-loaded LNPs, and the immediate analysis for their lipid components.

Lipid Nanoparticle-Based Delivery System-A Competing Place for mRNA Vaccines

mRNA, as one of the foci of biomedical research in the past decade, has become a candidate vaccine solution for various infectious diseases and tumors and for regenerative medicine and immunotherapy due to its high efficiency, safety, and effectiveness. A stable and effective delivery system is needed to protect mRNAs from nuclease degradation while also enhancing immunogenicity. The success of mRNA lipid nanoparticles in treating COVID-19, to a certain extent, marks a milestone for mRNA vaccines and also promotes further research on mRNA delivery systems. Here, we explore mRNA vaccine delivery systems, especially lipid nanoparticles (LNPs), considering the current research status, prospects, and challenges of lipid nanoparticles, and explore other mRNA delivery systems.

Building a Better Silver Bullet: Current Status and Perspectives of Non-Viral Vectors for mRNA Vaccines

In recent years, messenger RNA (mRNA) vaccines have exhibited great potential to replace conventional vaccines owing to their low risk of insertional mutagenesis, safety and efficacy, rapid and scalable production, and low-cost manufacturing. With the great achievements of chemical modification and sequence optimization methods of mRNA, the key to the success of mRNA vaccines is strictly dependent on safe and efficient gene vectors. Among various delivery platforms, non-viral mRNA vectors could represent perfect choices for future clinical translation regarding their safety, sufficient packaging capability, low immunogenicity, and versatility. In this review, the recent progress in the development of non-viral mRNA vectors is focused on. Various organic vectors including lipid nanoparticles (LNPs), polymers, peptides, and exosomes for efficient mRNA delivery are presented and summarized. Furthermore, the latest advances in clinical trials of mRNA vaccines are described. Finally, the current challenges and future possibilities for the clinical translation of these promising mRNA vectors are also discussed.

Why mRNA-ionizable LNPs formulations are so short-lived: causes and way-out

INTRODUCTION

Messenger ribonucleic acid (mRNA) and small interfering RNA (siRNA) are biological molecules that can be heated, frozen, lyophilized, precipitated, or re-suspended without degradation. Currently, ionizable lipid nanoparticles (LNPs) are a promising approach for mRNA therapy. However, the long-term shelf-life stability of mRNA-ionizable LNPs is one of the open questions about their use and safety. At an acidic pH, ionizable lipids shield anionic mRNA. However, the stability of mRNA under storage conditions remains a mystery. Moreover, ionizable LNPs excipients also cause instability during long-term storage.

AREA COVERED

This paper aims to illustrate why mRNA-ionizable LNPs have such a limited storage half-life. For the first time, we compile the tentative reasons for the short half-life and ultra-cold storage of mRNA-LNPs in the context of formulation excipients. The article also provided possible ways of prolonging the lifespan of mRNA-ionizable LNPs during long storage.

EXPERT OPINION

mRNA-ionizable LNPs are the future of genetic medicine. Current limitations of the formulation can be overcome by an advanced drying process or a whole new hybrid formulation strategy to extend the shelf life of mRNA-ionizable LNPs. A breakthrough technology may open up new research directions for producing thermostable and safe mRNA-ionizable LNPs at room temperature.