Cellular Trafficking of Nanotechnology‐Mediated mRNA Delivery

Zong Y., Lin Y., Wei T., Cheng Q.

AbstractMessenger RNA (mRNA) has received great attention in the prevention and treatment of various diseases due to the success of COVID‐19 mRNA vaccines (Comirnaty and Spikevax). To meet the therapeutic purpose, it is required that mRNA must enter the target cells and express sufficient proteins. Therefore, the development of effective delivery systems is necessary and crucial. Lipid nanoparticle (LNP) represents a remarkable vehicle that has indeed accelerated mRNA applications in humans, as several mRNA‐based therapies have already been approved or are in clinical trials. In this review, we focus on mRNA‐LNP mediated anticancer therapy. We summarize the main development strategies of mRNA‐LNP formulations, discuss representative therapeutic approaches in cancer, and point out current challenges and possible future directions of this research field. We hope these delivered messages could help further improve the application of mRNA‐LNP technology in cancer therapy.This article is protected by copyright. All rights reserved

Zhang R., Shao S., Piao Y., Xiang J., Wei X., Zhang Z., Zhou Z., Tang J., Qiu N., Xu X., Liu Y., Shen Y.

AbstractIonizable cationic lipids are recognized as an essential component of lipid nanoparticles (LNPs) for messenger RNA (mRNA) delivery but can be confounded by low lipoplex stability with mRNA during storage and in vivo delivery. Herein, the rational design and combinatorial synthesis of esterase‐triggered decationizable quaternium lipid‐like molecules (lipidoids) is reported to develop new LNPs with high delivery efficiency and improved storage stability. This top lipidoid carries positive charges at the physiological condition but promptly acquires negative charges in the presence of esterase, thus permitting stable mRNA encapsulation during storage and in vivo delivery while balancing efficient mRNA release in the cytosol. An optimal LNP formulation is then identified through orthogonal optimization, which enables efficacious mRNA transfection selectively in spleen following intravenous administration. LNP‐mediated delivery of ovalbumin (OVA)‐encoding mRNA induces efficient antigen expression in antigen‐presenting cells (APCs) and elicits robust antigen‐specific immune responses against OVA‐transduced tumors. The work demonstrates potential of decationizable quaternium lipidoids for spleen‐selective mRNA transfection and cancer immunotherapy.This article is protected by copyright. All rights reserved

Liu X., Huang P., Yang R., Deng H.

Zhang W., Jiang Y., He Y., Boucetta H., Wu J., Chen Z., He W.

Messenger RNA (mRNA) is the template for protein biosynthesis and is emerging as an essential active molecule to combat various diseases, including viral infection and cancer. Especially, mRNA-based vaccines, as a new type of vaccine, have played a leading role in fighting against the current global pandemic of COVID-19. However, the inherent drawbacks, including large size, negative charge, and instability, hinder its use as a therapeutic agent. Lipid carriers are distinguishable and promising vehicles for mRNA delivery, owning the capacity to encapsulate and deliver negatively charged drugs to the targeted tissues and release cargoes at the desired time. Here, we first summarized the structure and properties of different lipid carriers, such as liposomes, liposome-like nanoparticles, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles, nanoemulsions, exosomes and lipoprotein particles, and their applications in delivering mRNA. Then, the development of lipid-based formulations as vaccine delivery systems was discussed and highlighted. Recent advancements in the mRNA vaccine of COVID-19 were emphasized. Finally, we described our future vision and perspectives in this field.

Sun B., Wu W., Narasipura E.A., Ma Y., Yu C., Fenton O.S., Song H.

The concept of using mRNA to produce its own medicine in situ in the body makes it an ideal drug candidate, holding great potential to revolutionize the way we approach medicine. The unique characteristics of mRNA, as well as its customizable biomedical functions, call for the rational design of delivery systems to protect and transport mRNA molecules. In this review, a nanoparticle toolkit is presented for the development of mRNA-based therapeutics from a drug delivery perspective. Nano-delivery systems derived from either natural systems or chemical synthesis, in the nature of organic or inorganic materials, are summarised. Delivery strategies in controlling the tissue targeting and mRNA release, as well as the role of nanoparticles in building and boosting the activity of mRNA drugs, will also be introduced. Finally, our insights into the clinical and translational development of mRNA nano-drugs are presented.

Chen S., Huang X., Xue Y., Álvarez-Benedicto E., Shi Y., Chen W., Koo S., Siegwart D.J., Dong Y., Tao W.

mRNA vaccines have emerged as a revolutionary tool to generate rapid and precise immune responses against infectious diseases and cancers. Compared with conventional vaccines such as inactivated viruses, viral vectors, protein subunits or DNA-based vaccines, mRNA vaccines stand out owing to multiple advantages, including simplicity of design, fast production, enhanced safety and high efficacy. Nevertheless, efficient and targeted delivery of mRNA molecules remains a significant challenge owing to their inherent instability and susceptibility to degradation. Nanotechnology offers innovative solutions to surmount these obstacles and amplify the potency of mRNA vaccines. This Primer aims to outline a modular approach to developing biomaterials and nanotechnology for mRNA vaccines, with a focus on particle design, formulation evaluation and therapeutic applications. We delve into the underlying mechanisms of nanoparticle-facilitated mRNA protection, cellular uptake, endosomal escape and immune stimulation. We underscore the critical parameters that impact the manufacturing and clinical implementation of nanomaterial-based mRNA vaccines. Finally, we present the current limitations and future perspectives in the advancement of nanotechnology-enhanced mRNA vaccines for broad applications in prophylactic and therapeutic interventions. mRNA vaccines produce rapid and precise immune responses against infectious diseases and cancers. Chen et al. discuss the development of biomaterials and nanotechnology for mRNA vaccines, how these are designed and evaluated and the underlying mechanisms of cellular uptake and immune stimulation.

Kon E., Ad-El N., Hazan-Halevy I., Stotsky-Oterin L., Peer D.

Harnessing mRNA–lipid nanoparticles (LNPs) to treat patients with cancer has been an ongoing research area that started before these versatile nanoparticles were successfully used as COVID-19 vaccines. Currently, efforts are underway to harness this platform for oncology therapeutics, mainly focusing on cancer vaccines targeting multiple neoantigens or direct intratumoural injections of mRNA–LNPs encoding pro-inflammatory cytokines. In this Review, we describe the opportunities of using mRNA–LNPs in oncology applications and discuss the challenges for successfully translating the findings of preclinical studies of these nanoparticles into the clinic. We critically appraise the potential of various mRNA–LNP targeting and delivery strategies, considering physiological, technological and manufacturing challenges. We explore these approaches in the context of the potential clinical applications best suited to each approach and highlight the obstacles that currently need to be addressed to achieve these applications. Finally, we provide insights from preclinical and clinical studies that are leading to this powerful platform being considered the next frontier in oncology treatment. In oncology, mRNA–lipid nanoparticles (LNPs) have been used either to achieve intratumoural expression of immune-stimulating cytokine combinations or as cancer vaccines, and new strategies are in development to enable the selective delivery of payloads into cancer cells previously considered unreachable. The authors of this Review present various approaches for delivering mRNA–LNPs to tumours and discuss improvements that will improve the selective targeting of cancer cells with mRNA–LNPs.

Kong B., Kim Y., Hye Kim E., Soo Suk J., Yang Y.

Messenger RNA (mRNA) is now in the limelight as a powerful tool for treating various human diseases, especially malignant tumors, thanks to the remarkable clinical outcomes of mRNA vaccines using lipid nanoparticle technology during the COVID-19 pandemic. Recent promising preclinical and clinical results that epitomize the advancement in mRNA and nanoformulation-based delivery technologies have highlighted the tremendous potential of mRNA in cancer immunotherapy. mRNAs can be harnessed for cancer immunotherapy in forms of various therapeutic modalities, including cancer vaccines, adoptive T-cell therapies, therapeutic antibodies, and immunomodulatory proteins. This review provides a comprehensive overview of the current state and prospects of mRNA-based therapeutics, including numerous delivery and therapeutic strategies.

Han G., Noh D., Lee H., Lee S., Kim S., Yoon H.Y., Lee S.H.

RNA vaccines have demonstrated their ability to solve the issues posed by the COVID-19 pandemic. This success has led to the renaissance of research into mRNA and their nanoformulations as potential therapeutic modalities for various diseases. The potential of mRNA as a template for synthesizing proteins and protein fragments for cancer immunotherapy is now being explored. Despite the promise, the use of mRNA in cancer immunotherapy is limited by challenges, such as low stability against extracellular RNases, poor delivery efficiency to the target organs and cells, short circulatory half-life, variable expression levels and duration. This review highlights recent advances in chemical modification and advanced delivery systems that are helping to address these challenges and unlock the biological and pharmacological potential of mRNA therapeutics in cancer immunotherapy. The review concludes by discussing future perspectives for mRNA-based cancer immunotherapy, which holds great promise as a next-generation therapeutic modality.

Kang D.D., Li H., Dong Y.

The accelerated progress and approval of two mRNA-based vaccines to address the SARS-CoV-2 virus were unprecedented. This record-setting feat was made possible through the solid foundation of research on in vitro transcribed mRNA (IVT mRNA) which could be utilized as a therapeutic modality. Through decades of thorough research to overcome barriers to implementation, mRNA-based vaccines or therapeutics offer many advantages to rapidly address a broad range of applications including infectious diseases, cancers, and gene editing. Here, we describe the advances that have supported the adoption of IVT mRNA in the clinics, including optimization of the IVT mRNA structural components, synthesis, and lastly concluding with different classes of IVT RNA. Continuing interest in driving IVT mRNA technology will enable a safer and more efficacious therapeutic modality to address emerging and existing diseases.

Kaltbeitzel J., Wich P.R.

AbstractProteins and enzymes are versatile biomaterials for a wide range of medical applications due to their high specificity for receptors and substrates, high degradability, low toxicity, and overall good biocompatibility. Protein nanoparticles are formed by the arrangement of several native or modified proteins into nanometer‐sized assemblies. In this review, we will focus on artificial nanoparticle systems, where proteins are the main structural element and not just an encapsulated payload. While under natural conditions, only certain proteins form defined aggregates and nanoparticles, chemical modifications or a change in the physical environment can further extend the pool of available building blocks. This allows the assembly of many globular proteins and even enzymes. These advances in preparation methods led to the emergence of new generations of nanosystems that extend beyond transport vehicles to diverse applications, from multifunctional drug delivery to imaging, nanocatalysis and protein therapy.

Lv Z., Huang M., Yang J., Li P., Chang L., Tang Q., Chen X., Wang S., Yao C., Liu P., Yang D.

AbstractMessenger RNA (mRNA) transfection is the prerequisite for the application of mRNA‐based therapeutics. In hard‐to‐transfect cells, such as macrophages, the effective transfection of mRNA remains a long‐standing challenge. Herein, a smart DNA‐based nanosystem is reported containing ribosome biogenesis‐promoting siRNA, realizing efficient mRNA transfection in macrophages. Four monomers are copolymerized to form a nanoframework (NF), including N‐isopropylacrylamide (NIPAM) as the skeleton and acrydite‐DNA as the initiator to trigger the cascade assembly of DNA hairpins (H1‐polyT and H2‐siRNA). By virtue of the phase transition characteristic of polymeric NIPAM, below the lower critical solution temperature (LCST, ≈34 °C), the NF swells to expose polyT sequences to hybridize with the polyA tail of mRNA. Above the LCST, the NF deswells to encapsulate mRNA. The disulfide bond in the NF responds to glutathione, triggering the disassembly of the nanosystem; the siRNA and mRNA are released in response to triphosadenine and RNase H. The siRNA down‐regulates the expression of heat shock protein 27, which up‐regulates the expression of phosphorylated ribosomal protein S6. The nanosystem shows satisfactory mRNA transfection and translation efficiency in a mouse model. It is envisioned that the DNA‐based nanosystem will provide a promising carrier to deliver mRNA in hard‐to‐transfect cells and promote the development of mRNA‐based therapeutics.

Han X., Alameh M., Butowska K., Knox J.J., Lundgreen K., Ghattas M., Gong N., Xue L., Xu Y., Lavertu M., Bates P., Xu J., Nie G., Zhong Y., Weissman D., et. al.

Lipid nanoparticle (LNP)-formulated messenger RNA (mRNA) vaccineare a promising platform to prevent infectious diseases as demonstrated by the recent success of SARS-CoV-2 mRNA vaccines. To avoid immune recognition and uncontrolled inflammation, nucleoside-modified mRNA is used. However, such modification largely abrogates the innate immune responses that are critical to orchestrating robust adaptive immunity. Here we develop an LNP component—an adjuvant lipidoid—that can enhance the adjuvanticity of mRNA-LNP vaccines. Our results show that partial substitution of ionizable lipidoid with adjuvant lipidoid not only enhanced mRNA delivery, but also endowed LNPs with Toll-like receptor 7/8-agonistic activity, which significantly increased the innate immunity of the SARS-CoV-2 mRNA-LNP vaccine with good tolerability in mice. Our optimized vaccine elicits potent neutralizing antibodies against multiple SARS-CoV-2 pseudovirus variants, strong Th1-biased cellular immunity, and robust B cell and long-lived plasma cell responses. Importantly, this adjuvant lipidoid substitution strategy works successfully in a clinically relevant mRNA-LNP vaccine, demonstrating its translational potential. A lipid nanoparticle (LNP) component—an adjuvant lipidoid—is developed to enhance the adjuvanticity of LNPs, which significantly increases the innate and adaptive responses of the COVID-19 mRNA vaccines with good tolerability in mice.

Zheng L., Bandara S.R., Tan Z., Leal C.

RNA therapeutics have the potential to resolve a myriad of genetic diseases. Lipid nanoparticles (LNPs) are among the most successful RNA delivery systems. Expanding their use for the treatment of more genetic diseases hinges on our ability to continuously evolve the design of LNPs with high potency, cellular-specific targeting, and low side effects. Overcoming the difficulty of releasing cargo from endocytosed LNPs remains a significant hurdle. Here, we investigate the fundamental properties of nonviral RNA nanoparticles pertaining to the activation of topological transformations of endosomal membranes and RNA translocation into the cytosol. We show that, beyond composition, LNP fusogenicity can be prescribed by designing LNP nanostructures that lower the energetic cost of fusion and fusion–pore formation with a target membrane. The inclusion of structurally active lipids leads to enhanced LNP endosomal fusion, fast evasion of endosomal entrapment, and efficacious RNA delivery. For example, conserving the lipid make-up, RNA–LNPs having cuboplex nanostructures are significantly more efficacious at endosomal escape than traditional lipoplex constructs.

Huang P., Wang C., Deng H., Zhou Y., Chen X.

Mao X., Lan Y., Lou F., Zhang Z., Jin Q., Jia Y., Li Y.

Gao M., Zhong J., Liu X., Zhao Y., Zhu D., Shi X., Xu X., Zhou Q., Xuan W., Zhang Y., Zhou Y., Cheng J.

Ji J., Li L., Guo W., Zhang J., Yao Y., Chen H., Liao F., Jin Z., Liu L., Ouyang J., Liang X.

Haghighi E., Abolmaali S.S., Dehshahri A., Mousavi Shaegh S.A., Azarpira N., Tamaddon A.M.

RNA therapeutics, such as mRNA, siRNA, and CRISPR–Cas9, present exciting avenues for treating diverse diseases. However, their potential is commonly hindered by vulnerability to degradation and poor cellular uptake, requiring effective delivery systems. Lipid nanoparticles (LNPs) have emerged as a leading choice for in vivo RNA delivery, offering protection against degradation, enhanced cellular uptake, and facilitation of endosomal escape. However, LNPs encounter numerous challenges for targeted RNA delivery in vivo, demanding advanced particle engineering, surface functionalization with targeting ligands, and a profound comprehension of the biological milieu in which they function. This review explores the structural and physicochemical characteristics of LNPs, in-vivo fate, and customization for RNA therapeutics. We highlight the quality-by-design (QbD) approach for targeted delivery beyond the liver, focusing on biodistribution, immunogenicity, and toxicity. In addition, we explored the current challenges and strategies associated with LNPs for in-vivo RNA delivery, such as ensuring repeated-dose efficacy, safety, and tissue-specific gene delivery. Furthermore, we provide insights into the current clinical applications in various classes of diseases and finally prospects of LNPs in RNA therapeutics.

Shi Y., Shi M., Wang Y., You J.

AbstractIn the last decade, messenger ribonucleic acid (mRNA)-based drugs have gained great interest in both immunotherapy and non-immunogenic applications. This surge in interest can be largely attributed to the demonstration of distinct advantages offered by various mRNA molecules, alongside the rapid advancements in nucleic acid delivery systems. It is noteworthy that the immunogenicity of mRNA drugs presents a double-edged sword. In the context of immunotherapy, extra supplementation of adjuvant is generally required for induction of robust immune responses. Conversely, in non-immunotherapeutic scenarios, immune activation is unwanted considering the host tolerability and high expression demand for mRNA-encoded functional proteins. Herein, mainly focused on the linear non-replicating mRNA, we overview the preclinical and clinical progress and prospects of mRNA medicines encompassing vaccines and other therapeutics. We also highlight the importance of focusing on the host-specific variations, including age, gender, pathological condition, and concurrent medication of individual patient, for maximized efficacy and safety upon mRNA administration. Furthermore, we deliberate on the potential challenges that mRNA drugs may encounter in the realm of disease treatment, the current endeavors of improvement, as well as the application prospects for future advancements. Overall, this review aims to present a comprehensive understanding of mRNA-based therapies while illuminating the prospective development and clinical application of mRNA drugs.

Jiao X., He X., Qin S., Yin X., Song T., Duan X., Shi H., Jiang S., Zhang Y., Song X.

AbstractmRNA‐based therapeutics increasingly demonstrate significant potential in treating various diseases, including infectious diseases, cancers, and genetic disorders. Effective delivery systems are crucial for advancing mRNA therapeutics. Lipid nanoparticles (LNPs) serve as an excellent carrier, widely validated for their safety and tolerability in commercially available mRNA vaccines. Standard LNPs typically consist of four components: ionizable lipids (ILs), helper lipids, cholesterol, and polyethylene glycol‐lipids (PEG‐lipids), with the structural design of ILs gradually becoming a focal point of research interest. The chemical structures and formulations of the other components also significantly affect the delivery efficiency, targeting specificity, and stability of LNPs. The complex formulations of LNPs may hinder the clinical transformation of mRNA therapeutics and have raised widespread concerns about their safety. This review aims to summarize the progress of LNPs‐based mRNA therapeutics in clinical trials, focusing on adverse effects that occurred during these trials. It also discusses representative innovations in LNP components, highlighting challenges and potential ways in this research field. We firmly believe this review will promote further improvements and designs of LNP compositions to optimize mRNA therapeutics.This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Biology‐Inspired Nanomaterials > Lipid‐Based Structures

Yan D., Wang W., Xie Z.

AbstractBaicalein (BAI) extracted from Chinese herb has been proved to increase the sensitivity of tumor cells to gemcitabine (GEM) and effectively solve the problem of drug resistance of tumor cells. Nevertheless, intravenous administration often leads to intolerance of patients and side effects. In this paper, we introduced egg‐based porous microparticles for controllable drug delivery and oncotherapy, which avoided frequent intravenous administration. The interconnected porous structure endowed the microparticles with the capacity of loading sufficient drugs and releasing in a controllable way by adjusting the concentration and proportion of egg white and yolk. We have demonstrated that the cell viability of drug delivery system group was less than 50%, while the single drug group was more than 70%, which indicated that the co‐delivery of GEM and BAI could significantly reduce the proliferation of cells. These features indicated that the egg porous microparticles are ideal for controllable drug delivery and oncotherapy.

Fedorovskiy A.G., Antropov D.N., Dome A.S., Puchkov P.A., Makarova D.M., Konopleva M.V., Matveeva A.M., Panova E.A., Shmendel E.V., Maslov M.A., Dmitriev S.E., Stepanov G.A., Markov O.V.

Over the past decade, mRNA-based therapy has displayed significant promise in a wide range of clinical applications. The most striking example of the leap in the development of mRNA technologies was the mass vaccination against COVID-19 during the pandemic. The emergence of large-scale technology and positive experience of mRNA immunization sparked the development of antiviral and anti-cancer mRNA vaccines as well as therapeutic mRNA agents for genetic and other diseases. To facilitate mRNA delivery, lipid nanoparticles (LNPs) have been successfully employed. However, the diverse use of mRNA therapeutic approaches requires the development of adaptable LNP delivery systems that can control the kinetics of mRNA uptake and expression in target cells. Here, we report effective mRNA delivery into cultured mammalian cells (HEK293T, HeLa, DC2.4) and living mouse muscle tissues by liposomes containing either 1,26-bis(cholest-5-en-3β-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride (2X3) or the newly applied 1,30-bis(cholest-5-en-3β-yloxycarbonylamino)-9,13,18,22-tetraaza-3,6,25,28-tetraoxatriacontane tetrahydrochloride (2X7) cationic lipids. Using end-point and real-time monitoring of Fluc mRNA expression, we showed that these LNPs exhibited an unusually delayed (of over 10 h in the case of the 2X7-based system) but had highly efficient and prolonged reporter activity in cells. Accordingly, both LNP formulations decorated with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE-PEG2000) provided efficient luciferase production in mice, peaking on day 3 after intramuscular injection. Notably, the bioluminescence was observed only at the site of injection in caudal thigh muscles, thereby demonstrating local expression of the model gene of interest. The developed mRNA delivery systems hold promise for prophylactic applications, where sustained synthesis of defensive proteins is required, and open doors to new possibilities in mRNA-based therapies.

Zhao H., Ma S., Qi Y., Gao Y., Zhang Y., Li M., Chen J., Song W., Chen X.

A novel polyamino acid-based phosphatidyl polymer library, which combines the advantages of phospholipids in cellular uptake and polymers in stabilization, can effectively deliver mRNA to the spleen following systemic administration.

Di J., Huang P., Chen X.