A fluorinated ionizable lipid improves the mRNA delivery efficiency of lipid nanoparticles

Oligonucleotide-Linked Lipid Nanoparticles as a Versatile mRNA Nanovaccine Platform

An effective delivery platform is crucial for the development of mRNA vaccines and therapeutics. Here, a versatile platform utilizing cholesterol-modified oligonucleotides (L-oligo) that bind to the mRNA within lipid nanoparticles (LNP), and enables the effective delivery of the mRNA into target cells is introduced. mRNA incorporated into LNPs via linkage with L-oligo, termed oligonucleotide-linked LNP (lnLNP), is superior in cellular uptake and transfection efficiency in target cells in vitro and in vivo, compared to the conventional LNP formulations. It is further applied lnLNP as an mRNA vaccine platform for SARS-CoV-2, demonstrating robust induction of neutralizing activity as well as polyfunctional SARS-CoV-2-specific T-cell response in vivo. The current strategy can be versatilely applied to different LNP platforms, for vaccine and therapeutic applications against various diseases, such as infections and cancers.

Beyond Lipids: Exploring Advances in Polymeric Gene Delivery in the Lipid Nanoparticles Era

The recent success of gene therapy during the COVID-19 pandemic has underscored the importance of effective and safe delivery systems. Complementing lipid-based delivery systems, polymers present a promising alternative for gene delivery. Significant advances have been made in the recent past, with multiple clinical trials progressing beyond phase I and several companies actively working on polymeric delivery systems which provides assurance that polymeric carriers can soon achieve clinical translation. The massive advantage of structural tunability and vast chemical space of polymers is being actively leveraged to mitigate shortcomings of traditional polycationic polymers and improve the translatability of delivery systems. Tailored polymeric approaches for diverse nucleic acids and for specific subcellular targets are now being designed to improve therapeutic efficacy. This review describes the recent advances in polymer design for improved gene delivery by polyplexes and covalent polymer-nucleic acid conjugates. The review also offers a brief note on novel computational techniques for improved polymer design. The review concludes with an overview of the current state of polymeric gene therapies in the clinic as well as future directions on their translation to the clinic.

Optimized lipid nanoparticles (LNPs) for organ-selective nucleic acids delivery in vivo

Nucleic acid therapeutics offer tremendous promise for addressing a wide range of common public health conditions. However, the in vivo nucleic acids delivery faces significant biological challenges. Lipid nanoparticles (LNPs) possess several advantages, such as simple preparation, high stability, efficient cellular uptake, endosome escape capabilities, etc., making them suitable for delivery vectors. However, the extensive hepatic accumulation of LNPs poses a challenge for successful development of LNPs-based nucleic acid therapeutics for extrahepatic diseases. To overcome this hurdle, researchers have been focusing on modifying the surface properties of LNPs to achieve precise delivery. The review aims to provide current insights into strategies for LNPs-based organ-selective nucleic acid delivery. In addition, it delves into the general design principles, targeting mechanisms, and clinical development of organ-selective LNPs. In conclusion, this review provides a comprehensive overview to provide guidance and valuable insights for further research and development of organ-selective nucleic acid delivery systems.

Multicomponent Synthesis of Imidazole-Based Ionizable Lipids for Highly Efficient and Spleen-Selective Messenger RNA Delivery

The spleen emerges as a pivotal target for mRNA delivery, prompting a continual quest for specialized and efficient lipid nanoparticles (LNPs) designed to enhance spleen-selective transfection efficiency. Here we report imidazole-containing ionizable lipids (IMILs) that demonstrate a pronounced preference for mRNA delivery into the spleen with exceptional transfection efficiency. We optimized IMIL structures by constructing and screening a multidimensional IMIL library containing multiple heads, tails, and linkers to perform a structure-activity correlation analysis. Following high-throughput in vivo screening, we identified A3B7C2 as a top-performing IMIL in spleen-specific mRNA delivery via the formulated LNPs, achieving a remarkable 98% proportion of splenic transfection. Moreover, A3B7C2-based LNPs are particularly potent in splenic dendritic cell transfection. Comparative analyses revealed that A3B7C2-based LNPs achieved a notable 2.8-fold and 12.9-fold increase in splenic mRNA transfection compared to SM102 and DLin-MC3-DMA lipid formulations, respectively. Additionally, our approach yielded an 18.3-fold enhancement in splenic mRNA expression compared to the SORT method without introducing additional anionic lipids. Collectively, these IMILs highlight promising avenues for further research in spleen-selective mRNA delivery. This work offers valuable insights for the swift discovery and rational design of ionizable lipid candidates tailored for spleen-selective transfection, thereby facilitating the application of mRNA therapeutics in spleen-related interventions.

Lipid Nanoparticle (LNP) Delivery Carrier-Assisted Targeted Controlled Release mRNA Vaccines in Tumor Immunity

In recent years, lipid nanoparticles (LNPs) have attracted extensive attention in tumor immunotherapy. Targeting immune cells in cancer therapy has become a strategy of great research interest. mRNA vaccines are a potential choice for tumor immunotherapy, due to their ability to directly encode antigen proteins and stimulate a strong immune response. However, the mode of delivery and lack of stability of mRNA are key issues limiting its application. LNPs are an excellent mRNA delivery carrier, and their structural stability and biocompatibility make them an effective means for delivering mRNA to specific targets. This study summarizes the research progress in LNP delivery carrier-assisted targeted controlled release mRNA vaccines in tumor immunity. The role of LNPs in improving mRNA stability, immunogenicity, and targeting is discussed. This review aims to systematically summarize the latest research progress in LNP delivery carrier-assisted targeted controlled release mRNA vaccines in tumor immunity to provide new ideas and strategies for tumor immunotherapy, as well as to provide more effective treatment plans for patients.

Messenger RNA Therapy for Female Reproductive Health

Female reproductive health has traditionally been an underrepresented area of research in the drug delivery sciences. This disparity is also seen in the emerging field of mRNA therapeutics, a class of medicines that promises to treat and prevent disease by upregulating protein expression in the body. Here, we review advances in mRNA therapies through the lens of improving female reproductive health. Specifically, we begin our review by discussing the fundamental structure and biochemical modifications associated with mRNA-based drugs. Then, we discuss various packaging technologies, including lipid nanoparticles, that can be utilized to protect and transport mRNA drugs to target cells in the body. Last, we conclude our review by discussing the usage of mRNA therapy for addressing pregnancy-related health and vaccination against sexually transmitted diseases in women. Of note, we also highlight relevant clinical trials using mRNA for female reproductive health while also providing their corresponding National Clinical Trial identifiers. In undertaking this review, our aim is to provide a fundamental background understanding of mRNA therapy and its usage to specifically address female health issues with an overarching goal of providing information toward addressing gender disparity in certain aspects of health research.

Liver-Specific Ionizable Lipid Nanoparticles Mediated Efficient RNA Interference to Clear "Bad Cholesterol"

Background

High-level low-density lipoprotein cholesterol (LDL-C) plays a vital role in the development of atherosclerotic cardiovascular disease. Low-density lipoprotein receptors (LDLRs) are scavengers that bind to LDL-C in the liver. LDLR proteins are regulated by proprotein convertase subtilisin/kexin type 9 (PCSK9), which mediates the degradation of LDLR and adjusts the level of the plasma LDL-C. The low expression of PCSK9 leads to the up-regulation of liver LDLRs and the reduction of plasma LDL-C. Hepatocytes are attractive targets for small interfering RNA (siRNA) delivery to silence Pcsk9 gene, due to their significant role in LDL-C regulation.

Methods

Here, a type of liver-specific ionizable lipid nanoparticles is developed for efficient siRNA delivery. This type of nanoparticles shows high stability, enabling efficient cargo delivery specifically to hepatocytes, and a membrane-active polymer that reversibly masks activity until an acidic environment is reached.

Results

Significantly, the siPcsk9 (siRNA targeting to Pcsk9)-loaded nanoparticles (GLP) could silence 90% of the Pcsk9 mRNA in vitro. In vivo study showed that the improved accumulation of GLP in the liver increased LDLR level by 3.35-fold and decreased plasma LDL-C by 35%.

Conclusion

GLP has shown a powerful effect on reducing LDL-C, thus providing a potential therapy for atherosclerotic cardiovascular disease.

Nano-bio interactions in mRNA nanomedicine: Challenges and opportunities for targeted mRNA delivery

Upon entering the biological milieu, nanomedicines swiftly interact with the surrounding tissue fluid, subsequently being enveloped by a dynamic interplay of biomacromolecules, such as carbohydrates, nucleic acids, and cellular metabolites, but with predominant serum proteins within the biological corona. A notable consequence of the protein corona phenomenon is the unintentional loss of targeting ligands initially designed to direct nanomedicines toward particular cells or organs within the in vivo environment. mRNA nanomedicine displays high demand for specific cell and tissue-targeted delivery to effectively transport mRNA molecules into target cells, where they can exert their therapeutic effects with utmost efficacy. In this review, focusing on the delivery systems and tissue-specific applications, we aim to update the nanomedicine population with the prevailing and still enigmatic paradigm of nano-bio interactions, a formidable hurdle in the pursuit of targeted mRNA delivery. We also elucidate the current impediments faced in mRNA therapeutics and, by contemplating prospective avenues-either to modulate the corona or to adopt an 'ally from adversary' approach-aim to chart a course for advancing mRNA nanomedicine.

Cellular Trafficking of Nanotechnology-Mediated mRNA Delivery

Messenger RNA (mRNA)-based therapy has emerged as a powerful, safe, and rapidly scalable therapeutic approach that involves technologies for both mRNA itself and the delivery vehicle. Although there are some unique challenges for different applications of mRNA therapy, a common challenge for all mRNA therapeutics is the transport of mRNA into the target cell cytoplasm for sufficient protein expression. This review is focused on the behaviors at the cellular level of nanotechnology-mediated mRNA delivery systems, which have not been comprehensively reviewed yet. First, the four main therapeutic applications of mRNA are introduced, including immunotherapy, protein replacement therapy, genome editing, and cellular reprogramming. Second, common types of mRNA cargos and mRNA delivery systems are summarized. Third, strategies to enhance mRNA delivery efficiency during the cellular trafficking process are highlighted, including accumulation to the cell, internalization into the cell, endosomal escape, release of mRNA from the nanocarrier, and translation of mRNA into protein. Finally, the challenges and opportunities for the development of nanotechnology-mediated mRNA delivery systems are presented. This review can provide new insights into the future fabrication of mRNA nanocarriers with desirable cellular trafficking performance.

Design and fabrication of intracellular therapeutic cargo delivery systems based on nanomaterials: current status and future perspectives

Intracellular cargo delivery, the introduction of small molecules, proteins, and nucleic acids into a specific targeted site in a biological system, is an important strategy for deciphering cell function, directing cell fate, and reprogramming cell behavior. With the advancement of nanotechnology, many researchers use nanoparticles (NPs) to break through biological barriers to achieving efficient targeted delivery in biological systems, bringing a new way to realize efficient targeted drug delivery in biological systems. With a similar size to many biomolecules, NPs possess excellent physical and chemical properties and a certain targeting ability after functional modification on the surface of NPs. Currently, intracellular cargo delivery based on NPs has emerged as an important strategy for genome editing regimens and cell therapy. Although researchers can successfully deliver NPs into biological systems, many of them are delivered very inefficiently and are not specifically targeted. Hence, the development of efficient, target-capable, and safe nanoscale drug delivery systems to deliver therapeutic substances to cells or organs is a major challenge today. In this review, on the basis of describing the research overview and classification of NPs, we focused on the current research status of intracellular cargo delivery based on NPs in biological systems, and discuss the current problems and challenges in the delivery process of NPs in biological systems.