Emerging mRNA technologies: delivery strategies and biomedical applications

Development of a Flow Through-Based Limited Digestion Approach for High-Throughput and High-Sequence Coverage Mapping of Therapeutic mRNAs

Messenger RNAs (mRNAs) have rapidly emerged as a pivotal class of biotherapeutics with great promise in the prevention and treatment of various diseases. As with other biotherapeutics, the sequence accuracy and integrity of mRNAs are critical quality attributes (CQAs), influencing the translation efficiency and protein expression fidelity of mRNAs. Due to the generation of short and repetitive oligonucleotides, traditional sequence mapping methods, which utilize in-solution RNase T1 digestion followed by LC-MS/MS analysis, face challenges in achieving high sequence coverage. In this study, we developed a novel flow through (FT)-based strategy to achieve the limited RNase T1 digestion of therapeutic mRNAs, leading to improved mRNA sequence mapping by LC-MS/MS analysis. Compared with the traditional in-solution digestion methods, the FT-based digestion method could consistently generate an increased number of unique oligonucleotides with miscleavages, which significantly boosted the overall sequence coverage (over 93%) of therapeutic mRNAs of varying sizes. Moreover, the automated digestion workflow using the AssayMAP platform offers significant advantages in method reproducibility and throughput. The high throughput and high sequence coverage features of this method could facilitate its wide application in the development of mRNA-based therapeutics.

The Recent Research Progress of the Tumor mRNA Vaccine

Tumors have long posed a significant threat to human life and health, and the messenger ribonucleic acid (mRNA) vaccine is seen as an attractive approach for cancer immunotherapy due to its developmental simplicity, rapid manufacture, and increased immune safety and efficiency. In this review, we have summarized details of the developmental history of mRNA vaccines, discussed the basic molecular structure and the effect on the stable and translation level of mRNA, analyzed the underlying immune efficiency and mechanisms on tumors, and assessed the current status of clinical research. We explored the treatment and application prospects of mRNA vaccines, aiming to provide perspectives on the future of mRNA tumor vaccines for ongoing clinical research.

Delivery of mRNA Using Biomimetic Vectors: Progress and Challenges

Messenger RNA (mRNA) is an emerging class of therapeutic agents for treating a wide range of diseases. However, due to the instability and low cell transfection rate of naked mRNA, the expression of delivered mRNA in target cells or tissues in vivo requires delivery strategies. Biomimetic vectors hold advantages such as high biocompatibility, tissue specific targeting ability and efficient delivery mechanisms, potentially overcoming challenges faced by other delivery vectors. In this review, biomimetic vector-based mRNA delivery systems are summarized and discuss the possible challenges and prospects of such delivery systems, which may contribute to the progress and application of mRNA-based therapy in the biomedical field.

Fast and facile synthesis of amidine-incorporated degradable lipids for versatile mRNA delivery in vivo

Lipid nanoparticles (LNPs) are widely used for mRNA delivery, with cationic lipids greatly affecting biodistribution, cellular uptake, endosomal escape and transfection efficiency. However, the laborious synthesis of cationic lipids limits the discovery of efficacious candidates and slows down scale-up manufacturing. Here we develop a one-pot, tandem multi-component reaction based on the rationally designed amine-thiol-acrylate conjugation, which enables fast (1 h) and facile room-temperature synthesis of amidine-incorporated degradable (AID) lipids. Structure-activity relationship analysis of a combinatorial library of 100 chemically diverse AID-lipids leads to the identification of a tail-like amine-ring-alkyl aniline that generally affords efficacious lipids. Experimental and theoretical studies show that the embedded bulky benzene ring can enhance endosomal escape and mRNA delivery by enabling the lipid to adopt a more conical shape. The lead AID-lipid can not only mediate local delivery of mRNA vaccines and systemic delivery of mRNA therapeutics, but can also alter the tropism of liver-tropic LNPs to selectively deliver gene editors to the lung and mRNA vaccines to the spleen.

Local mRNA Delivery from Nanocomposites Made of Gelatin and Hydroxyapatite Nanoparticles

Local delivery of messenger ribonucleic acid (mRNA) is increasingly being advocated as a promising new strategy to enhance the performance of biomaterials. While extensive research has been dedicated to the complexation of these oligonucleotides into nanoparticles to facilitate systemic delivery, research on developing suitable biomaterial carriers for the local delivery of mRNA is still scarce. So far, mRNA-nanoparticles (mRNA-NPs) are mainly loaded into traditional polymeric hydrogels. Here, we show that calcium phosphate nanoparticles can be used for both reinforcement of nanoparticle-based hydrogels and the complexation of mRNA. mRNA was incorporated into lipid-coated calcium phosphate nanoparticles (LCPs) formulated with a fusogenic ionizable lipid in the outer layer of the lipid coat. Nanocomposites of gelatin and hydroxyapatite nanoparticles were prepared at various ratios. Higher hydroxyapatite nanoparticle content increased the viscoelastic properties of the nanocomposite but did not affect its self-healing ability. Combination of these nanocomposites with peptide, lipid, and the LCP mRNA formulations achieved local mRNA release as demonstrated by protein expression in cells in contact with the biomaterials. The LCP-based formulation was superior to the other formulations by showing less sensitivity to hydroxyapatite and the highest cytocompatibility.

Synergistic integration of mRNA-LNP with CAR-engineered immune cells: Pioneering progress in immunotherapy

Chimeric antigen receptor T cell (CAR-T) therapy has emerged as a revolutionary approach in the treatment of malignancies. Despite its remarkable successes, this field continues to grapple with challenges such as scalability, safety concerns, limited therapeutic effect, in vivo persistence, and the need for precise control over CAR expression. In the post-pandemic era of COVID-19 vaccine immunization, the application of messenger RNA (mRNA) encapsulated within lipid nanoparticles (LNPs) has recently garnered significant attention as a potential solution to address these challenges. This review delves into the dynamic landscape of mRNA-LNP technology and its potential implications for CAR-engineered immune cell-based immunotherapy.

Utilization of chitosan nanocomposites loaded with quantum dots enables efficient and traceable DNA delivery

Chitosan is widely employed in gene carriers due to its excellent gene loading capacity, ease of modification, and exceptional biodegradability. However, low gene delivery efficiency, high cytotoxicity, and lack of tracer biomimetic properties limit its clinical use. To address these issues, a novel biomimetic tracking gene delivery carrier, RBCm-C50kQT, was constructed by using the design scheme of cell membrane coated carbon quantum dots/chitosan. This carrier improves stability and tracking performance while embedding the cell membrane enhances biosafety. RBCm-C50kQT effectively carries and protects DNA, improving uptake and transfection efficiency with reduced cytotoxicity. It maintains strong fluorescence tracking and shows high uptake efficiencies of 83.62 % and 77.45 % in 293 T and HeLa cells, respectively, with maximum transfection efficiencies of 68.80 % and 45.47 %. This advancement supports gene therapy improvements and paves the way for future clinical applications.

Strategies for Organ-Targeted mRNA Delivery by Lipid Nanoparticles

Messenger RNA (mRNA) technology has rapidly evolved, significantly impacting various therapeutic applications, including vaccines, protein replacement, and gene editing. Lipid nanoparticles (LNPs) have emerged as a pivotal nonviral vector for mRNA delivery, crucial for organ-targeted therapies. Despite their success, most LNP formulations predominantly target the liver, limiting their use in nonliver diseases. This review explores strategies to achieve organ-specific mRNA delivery using LNPs, including the discovery of new lipid structures, modification of targeting ligands, incorporation of additional components, and optimization of LNP formulations. These advancements aim to enhance the precision and efficacy of mRNA therapeutics across a broader range of diseases.

Insights into the formulation of lipid nanoparticles for the optimization of mRNA therapeutics

mRNA-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.

Emerging mRNA Technology for Liver Disease Therapy

Liver diseases have consistently posed substantial challenges to global health. It is crucial to find innovative methods to effectively prevent and treat these diseases. In recent times, there has been an increasing interest in the use of mRNA formulations that accumulate in liver tissue for the treatment of hepatic diseases. In this review, we start by providing a detailed introduction to the mRNA technology. Afterward, we highlight types of liver diseases, discussing their causes, risks, and common therapeutic strategies. Additionally, we summarize the latest advancements in mRNA technology for the treatment of liver diseases. This includes systems based on hepatocyte growth factor, hepatitis B virus antibody, left-right determination factor 1, human hepatocyte nuclear factor α, interleukin-12, methylmalonyl-coenzyme A mutase, etc. Lastly, we provide an outlook on the potential of mRNA technology for the treatment of liver diseases, while also highlighting the various technical challenges that need to be addressed. Despite these difficulties, mRNA-based therapeutic strategies may change traditional treatment methods, bringing hope to patients with liver diseases.

Constructing a Ready-to-Use mRNA Vaccine Delivery System for the Prevention of Influenza A virus, Utilizing FDA-Approved Raw Materials

Messenger ribonucleic acid (mRNA) vaccines, serving as a rapid and easily scalable emergency preventive measure, have played a pivotal role in preventing infectious diseases. The effectiveness of mRNA vaccines heavily relies on the delivery carrier, but the current market options are predominantly lipid nanoparticles. Their intricate preparation process and high transportation costs pose challenges for widespread use in remote areas. In this study, we harnessed FDA-approved polymer PLGA and lipid components widely employed in clinical experiments to craft a ready-to-use mRNA vaccine delivery system known as lipid-polymer hybrid nanoparticles (LPP). Following formulation optimization, the PDCD nanoparticles emerged as the most effective, showcasing exceptional mRNA delivery capabilities both in vitro and in vivo. Loading PDCD nanoparticles with mRNA encoding the H1N1 influenza virus HA antigen-fused M2e peptide enabled the successful induction of M2e-specific antibodies and T cell immune responses in immunized mice. After three rounds of vaccine immunization, the mice demonstrated weight recovery to normal levels and maintained a survival rate exceeding 80% following an encounter with the H1N1 influenza virus. The innovative mRNA delivery system that we designed demonstrates outstanding effectiveness in preventing infectious diseases, with the potential to play an even more significant role in future clinical applications.

Isoprenoid CARTs: In Vitro and In Vivo mRNA Delivery by Charge-Altering Releasable Transporters Functionalized with Archaea-inspired Branched Lipids

The delivery of oligonucleotides across biological barriers is a challenge of unsurpassed significance at the interface of materials science and medicine, with emerging clinical utility in prophylactic and therapeutic vaccinations, immunotherapies, genome editing, and cell rejuvenation. Here, we address the role of readily available branched lipids in the design, synthesis, and evaluation of isoprenoid charge-altering releasable transporters (CARTs), a pH-responsive oligomeric nanoparticle delivery system for RNA. Systematic variation of the lipid block reveals an emergent relationship between the lipid block and the neutralization kinetics of the polycationic block. Unexpectedly, iA21A11, a CART with the smallest lipid side chain, isoamyl-, was identified as the lead isoprenoid CART for the in vitro transfection of immortalized lymphoblastic cell lines. When administered intramuscularly in a murine model, iA21A11-mRNA complexes induce higher protein expression levels than our previous lead CART, ONA. Isoprenoid CARTs represent a new delivery platform for RNA vaccines and other polyanion-based therapeutics.

Reformulating lipid nanoparticles for organ-targeted mRNA accumulation and translation

Fully targeted mRNA therapeutics necessitate simultaneous organ-specific accumulation and effective translation. Despite some progress, delivery systems are still unable to fully achieve this. Here, we reformulate lipid nanoparticles (LNPs) through adjustments in lipid material structures and compositions to systematically achieve the pulmonary and hepatic (respectively) targeted mRNA distribution and expression. A combinatorial library of degradable-core based ionizable cationic lipids is designed, following by optimisation of LNP compositions. Contrary to current LNP paradigms, our findings demonstrate that cholesterol and phospholipid are dispensable for LNP functionality. Specifically, cholesterol-removal addresses the persistent challenge of preventing nanoparticle accumulation in hepatic tissues. By modulating and simplifying intrinsic LNP components, concurrent mRNA accumulation and translation is achieved in the lung and liver, respectively. This targeting strategy is applicable to existing LNP systems with potential to expand the progress of precise mRNA therapy for diverse diseases.

An Overview of Nanoparticle-Based Delivery Platforms for mRNA Vaccines for Treating Cancer

With its unique properties and potential applications, nanoparticle-based delivery platforms for messenger RNA (mRNA) vaccines have gained significant attention in recent years. Nanoparticles have the advantages of enhancing immunogenicity, targeting delivery, and improving stability, providing a new solution for drug and vaccine delivery. In some clinical studies, a variety of nanoparticle delivery platforms have been gradually applied to a wide range of vaccine applications. Current research priorities are exploring various types of nanoparticles as vaccine delivery systems to enhance vaccine stability and immunogenicity. Lipid nanoparticles (LNPs) have shown promising potential in preclinical and clinical studies on the efficient delivery of antigens to immune cells. Moreover, lipid nanoparticles and other nanoparticles for nucleic acids, especially for mRNA delivery systems, have shown vast potential for vaccine development. In this review, we present various vaccine platforms with an emphasis on nanoparticles as mRNA vaccine delivery vehicles. We describe several novel nanoparticle delivery platforms for mRNA vaccines, such as lipid-, polymer-, and protein-based nanoparticles. In addition, we provide an overview of the anti-tumor immunity of nanovaccines against different tumors in cancer immunotherapy. Finally, we outline future perspectives and remaining challenges for this promising technology of nanoparticle-based delivery platforms for vaccines.

One-Component Cationic Lipids for Systemic mRNA Delivery to Splenic T Cells

Unlocking the full potential of mRNA immunotherapy necessitates targeted delivery to specific cell subsets in the spleen. Four-component lipid nanoparticles (LNPs) utilized in numerous clinical trials are primarily limited in hepatocyte and muscular targeting, highlighting the imperative demand for targeted and simplified non-liver mRNA delivery systems. Herein, we report the rational design of one-component ionizable cationic lipids to selectively deliver mRNA to the spleen and T cells with high efficacy. Unlike the tertiary amine-based ionizable lipids involved in LNPs, the proposed cationic lipids rich in secondary amines can efficiently deliver mRNA both in vitro and in vivo as the standalone carriers. Furthermore, these vectors facilitate efficacious mRNA delivery to the T cell subsets following intravenous administration, demonstrating substantial potential for advancing immunotherapy applications. This straightforward strategy extends the utility of lipid family for extrahepatic mRNA delivery, offering new insights into vector development beyond LNPs to further the field of precise mRNA therapy.

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.

Tripartite motif 8 promotes the progression of hepatocellular carcinoma via mediating ubiquitination of HNF1α

Tripartite motif 8 (TRIM8) is an E3 ligase that plays dual roles in various tumor types. The biological effects and underlying mechanism of TRIM8 in hepatocellular carcinoma (HCC) remain unknown. Hepatocyte nuclear factor 1α (HNF1α) is a key transcriptional factor that plays a significant role in regulating hepatocyte differentiation and liver function. The reduced expression of HNF1α is a critical event in the development of HCC, but the underlying mechanism for its degradation remains elusive. In this study, we discovered that the expression of TRIM8 was upregulated in HCC tissues, and was positively correlated with aggressive tumor behavior of HCC and shorter survival of HCC patients. Overexpression of TRIM8 promoted the proliferation, colony formation, invasion, and migration of HCC cells, while TRIM8 knockdown or knockout exerted the opposite effects. RNA sequencing revealed that TRIM8 knockout suppresses several cancer-related pathways, including Wnt/β-catenin and TGF-β signaling in HepG2 cells. TRIM8 directly interacts with HNF1α, promoting its degradation by catalyzing polyubiquitination on lysine 197 in HCC cells. Moreover, the cancer-promoting effects of TRIM8 in HCC were abolished by the HNF1α-K197R mutant in vitro and in vivo. These data demonstrated that TRIM8 plays an oncogenic role in HCC progression through mediating the ubiquitination of HNF1α and promoting its protein degradation, and suggests targeting TRIM8-HNF1α may provide a promising therapeutic strategy of HCC.

Liposome-lentivirus for miRNA therapy with molecular mechanism study

BACKGROUND

Cancer stem cells (CSCs) play a vital role in the occurrence, maintenance, and recurrence of solid tumors. Although, miR-145-5p can inhibit CSCs survival, poor understanding of the underlying mechanisms hamperes further therapeutic optimization for patients. Lentivirus with remarkable transduction efficiency is the most commonly used RNA carrier in research, but has shown limited tumor-targeting capability.

METHODS

We have applied liposome to decorate lentivirus surface thereby yielding liposome-lentivirus hybrid-based carriers, termed miR-145-5p-lentivirus nanoliposome (MRL145), and systematically analyzed their potential therapeutic effects on liver CSCs (LCSCs).

RESULTS

MRL145 exhibited high delivery efficiency and potent anti-tumor efficacy under in vitro and in vivo. Mechanistically, the overexpressed miR-145-5p can significantly suppress the self-renewal, migration, and invasion abilities of LCSCs by targeting Collagen Type IV Alpha 3 Chain (COL4A3). Importantly, COL4A3 can promote phosphorylating GSK-3β at ser 9 (p-GSK-3β S9) to inactivate GSK3β, and facilitate translocation of β-catenin into the nucleus to activate the Wnt/β-catenin pathway, thereby promoting self-renewal, migration, and invasion of LCSCs. Interestingly, COL4A3 could attenuate the cellular autophagy through modulating GSK3β/Gli3/VMP1 axis to promote self-renewal, migration, and invasion of LCSCs.

CONCLUSIONS

These findings provide new insights in mode of action of miR-145-5p in LCSCs therapy and indicates that liposome-virus hybrid carriers hold great promise in miRNA delivery.

Diagnosis of Nonalcoholic Fatty Liver Disease via a H2S-Responsive Bioluminescent Probe Combined with Firefly Luciferase mRNA Delivery

The early detection of nonalcoholic fatty liver disease (NAFLD) through bioluminescent probes is of great significance. However, there remains a challenge to apply them in nontransgenic natural animals due to the lack of exogenous luciferase. To address this issue, we herein report a new strategy for in situ monitoring of endogenous hydrogen sulfide (H2S) in the liver of NAFLD mice by leveraging a H2S-responsive bioluminescent probe (H-Luc) combined with firefly luciferase (fLuc) mRNA delivery. The probe H-Luc was created by installing a H2S recognition moiety, 2,4-dinitrophenol, onto the luciferase substrate (d-luciferin), which is allowed to release cage-free d-luciferin in the presence of H2S via a nucleophilic aromatic substitution reaction. In the meantime, the intracellular luciferase was introduced by lipid nanoparticle (LNP)-mediated fLuc mRNA delivery, rendering it suitable for bioluminescence (BL) imaging in vitro and in vivo. Based on this luciferase-luciferin system, the endogenous H2S could be sensitively and selectively detected in living cells, showing a low limit of detection (LOD) value of 0.72 μM. More importantly, after systematic administration of fLuc mRNA-loaded LNPs in vivo, H-Luc was able to successfully monitor the endogenous H2S levels in the NAFLD mouse model for the first time, displaying a 28-fold higher bioluminescence intensity than that in the liver of normal mice. We believe that this strategy may shed new light on the diagnosis of inflammatory liver disease, further elucidating the roles of H2S.

Leveraging high-throughput screening technologies in targeted mRNA delivery

Messenger ribonucleic acid (mRNA) has emerged as a promising molecular preventive and therapeutic approach that opens new avenues for healthcare. Although the use of delivery systems, especially lipid nanoparticles (LNPs), greatly improves the efficiency and stability of mRNA, mRNA tends to accumulate in the liver and hardly penetrates physiological barriers to reach the target site after intravenous injection. Hence, the rational design of targeting strategies aimed at directing mRNA to specific tissues and cells remains an enormous challenge in mRNA therapy. High-throughput screening (HTS) is a cutting-edge targeted technique capable of synthesizing chemical compound libraries for the large-scale experiments to validate the efficiency of mRNA delivery system. In this review, we firstly provide an overview of conventional low-throughput targeting strategies. Then the latest advancements in HTS techniques for mRNA targeted delivery, encompassing optimizing structures of large-scale delivery vehicles and developing large-scale surface ligands, as well as the applications of HTS techniques in extrahepatic systemic diseases are comprehensively summarized. Moreover, we illustrate the selection of administration routes for targeted mRNA delivery. Finally, challenges in the field and potential solutions to tackle them are proposed, offering insights for future development toward mRNA targeted therapy.

Ocular RNA nanomedicine: engineered delivery nanoplatforms in treating eye diseases

Ocular disorders remain a major global health challenge with unmet medical needs. RNA nanomedicine has shown significant therapeutic benefits and safety profiles in patients with complex eye disorders, already benefiting numerous patients with gene-related eye disorders. The effective delivery of RNA to the unique structure of the eye is challenging owing to RNA instability, off-target effects, and ocular physiological barriers. Specifically tailored RNA medication, coupled with sophisticated engineered delivery platforms, is crucial to guide and advance developments in treatments for oculopathy. Herein we review recent advances in RNA-based nanomedicine, innovative delivery strategies, and current clinical progress and present challenges in ocular disease therapy.

Combination therapy with oncolytic virus and T cells or mRNA vaccine amplifies antitumor effects

Antitumor therapies based on adoptively transferred T cells or oncolytic viruses have made significant progress in recent years, but the limited efficiency of their infiltration into solid tumors makes it difficult to achieve desired antitumor effects when used alone. In this study, an oncolytic virus (rVSV-LCMVG) that is not prone to induce virus-neutralizing antibodies was designed and combined with adoptively transferred T cells. By transforming the immunosuppressive tumor microenvironment into an immunosensitive one, in B16 tumor-bearing mice, combination therapy showed superior antitumor effects than monotherapy. This occurred whether the OV was administered intratumorally or intravenously. Combination therapy significantly increased cytokine and chemokine levels within tumors and recruited CD8+ T cells to the TME to trigger antitumor immune responses. Pretreatment with adoptively transferred T cells and subsequent oncolytic virotherapy sensitizes refractory tumors by boosting T-cell recruitment, down-regulating the expression of PD-1, and restoring effector T-cell function. To offer a combination therapy with greater translational value, mRNA vaccines were introduced to induce tumor-specific T cells instead of adoptively transferred T cells. The combination of OVs and mRNA vaccine also displays a significant reduction in tumor burden and prolonged survival. This study proposed a rational combination therapy of OVs with adoptive T-cell transfer or mRNA vaccines encoding tumor-associated antigens, in terms of synergistic efficacy and mechanism.

Regulatory insights into nanomedicine and gene vaccine innovation: Safety assessment, challenges, and regulatory perspectives

This analysis explores the principal regulatory concerns linked to nanomedicines and gene vaccines, including the complexities involved and the perspectives on how to navigate them. In the realm of nanomedicines, ensuring the safety of nanomaterials is paramount due to their unique characteristics and potential interactions with biological systems. Regulatory bodies are actively formulating guidelines and standards to assess the safety and risks associated with nanomedicine products, emphasizing the need for standardized characterization techniques to accurately gauge their safety and effectiveness. Regarding gene vaccines, regulatory frameworks must be tailored to address the distinct challenges posed by genetic interventions, necessitating special considerations in safety and efficacy evaluations, particularly concerning vector design, target specificity, and long-term patient monitoring. Ethical concerns such as patient autonomy, informed consent, and privacy also demand careful attention, alongside the intricate matter of intellectual property rights, which must be balanced against the imperative of ensuring widespread access to these life-saving treatments. Collaborative efforts among regulatory bodies, researchers, patent offices, and the private sector are essential to tackle these challenges effectively, with international cooperation being especially crucial given the global scope of nanomedicine and genetic vaccine development. Striking the right balance between safeguarding intellectual properties and promoting public health is vital for fostering innovation and ensuring equitable access to these ground-breaking technologies, underscoring the significance of addressing these regulatory hurdles to fully harness the potential benefits of nanomedicine and gene vaccines for enhancing healthcare outcomes on a global scale. STATEMENT OF SIGNIFICANCE: Several biomaterials are being proposed for the development of nanovaccines, from polymeric micelles, PLGA-/PEI-/PLL-nanoparticles, solid lipid nananoparticles, cationic lipoplexes, liposomes, hybrid materials, dendrimers, carbon nanotubes, hydrogels, to quantum dots. Lipid nanoparticles (LNPs) have gained tremendous attention since the US Food and Drug Administration (FDA) approval of Pfizer and Moderna's COVID-19 vaccines, raising public awareness to the regulatory challenges associated with nanomedicines and genetic vaccines. This review provides insights into the current perspectives and potential strategies for addressing these issues, including clinical trials. By navigating these regulatory landscapes effectively, we can unlock the full potential of nanomedicine and genetic vaccines using a range of promising biomaterials towards improving healthcare outcomes worldwide.

mRNA therapies: Pioneering a new era in rare genetic disease treatment

Rare genetic diseases, often referred to as orphan diseases due to their low prevalence and limited treatment options, have long posed significant challenges to our medical system. In recent years, Messenger RNA (mRNA) therapy has emerged as a highly promising treatment approach for various diseases caused by genetic mutations. Chemically modified mRNA is introduced into cells using carriers like lipid-based nanoparticles (LNPs), producing functional proteins that compensate for genetic deficiencies. Given the advantages of precise dosing, biocompatibility, transient expression, and minimal risk of genomic integration, mRNA therapies can safely and effectively correct genetic defects in rare diseases and improve symptoms. Currently, dozens of mRNA drugs targeting rare diseases are undergoing clinical trials. This comprehensive review summarizes the progress of mRNA therapy in treating rare genetic diseases. It introduces the development, molecular design, and delivery systems of mRNA therapy, highlighting their research progress in rare genetic diseases based on protein replacement and gene editing. The review also summarizes research progress in various rare disease models and clinical trials. Additionally, it discusses the challenges and future prospects of mRNA therapy. Researchers are encouraged to join this field and collaborate to advance the clinical translation of mRNA therapy, bringing hope to patients with rare genetic diseases.

Physiological Barriers and Strategies of Lipid-Based Nanoparticles for Nucleic Acid Drug Delivery

Lipid-based nanoparticles (LBNPs) are currently the most promising vehicles for nucleic acid drug (NAD) delivery. Although their clinical applications have achieved success, the NAD delivery efficiency and safety are still unsatisfactory, which are, to a large extent, due to the existence of multi-level physiological barriers in vivo. It is important to elucidate the interactions between these barriers and LBNPs, which will guide more rational design of efficient NAD vehicles with low adverse effects and facilitate broader applications of nucleic acid therapeutics. This review describes the obstacles and challenges of biological barriers to NAD delivery at systemic, organ, sub-organ, cellular, and subcellular levels. The strategies to overcome these barriers are comprehensively reviewed, mainly including physically/chemically engineering LBNPs and directly modifying physiological barriers by auxiliary treatments. Then the potentials and challenges for successful translation of these preclinical studies into the clinic are discussed. In the end, a forward look at the strategies on manipulating protein corona (PC) is addressed, which may pull off the trick of overcoming those physiological barriers and significantly improve the efficacy and safety of LBNP-based NADs delivery.

Unlocking the potential of nanocarrier-mediated mRNA delivery across diverse biomedical frontiers: A comprehensive review

Messenger RNA (mRNA) has gained marvelous attention for managing and preventing various conditions like cancer, Alzheimer's, infectious diseases, etc. Due to the quick development and success of the COVID-19 mRNA-based vaccines, mRNA has recently grown in prominence. A lot of products are in clinical trials and some are already FDA-approved. However, still improvements in line of optimizing stability and delivery, reducing immunogenicity, increasing efficiency, expanding therapeutic applications, scalability and manufacturing, and long-term safety monitoring are needed. The delivery of mRNA via a nanocarrier system gives a synergistic outcome for managing chronic and complicated conditions. The modified nanocarrier-loaded mRNA has excellent potential as a therapeutic strategy. This emerging platform covers a wide range of diseases, recently, several clinical studies are ongoing and numerous publications are coming out every year. Still, many unexplained physical, biological, and technical problems of mRNA for safer human consumption. These complications were addressed with various nanocarrier formulations. This review systematically summarizes the solved problems and applications of nanocarrier-based mRNA delivery. The modified nanocarrier mRNA meaningfully improved mRNA stability and abridged its immunogenicity issues. Furthermore, several strategies were discussed that can be an effective solution in the future for managing complicated diseases.

Peripheral extracellular vesicles in neurodegeneration: pathogenic influencers and therapeutic vehicles

Neurodegenerative diseases (NDDs) such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis epitomize a class of insidious and relentless neurological conditions that are difficult to cure. Conventional therapeutic regimens often fail due to the late onset of symptoms, which occurs well after irreversible neurodegeneration has begun. The integrity of the blood-brain barrier (BBB) further impedes efficacious drug delivery to the central nervous system, presenting a formidable challenge in the pharmacological treatment of NDDs. Recent scientific inquiries have shifted focus toward the peripheral biological systems, investigating their influence on central neuropathology through the lens of extracellular vesicles (EVs). These vesicles, distinguished by their ability to breach the BBB, are emerging as dual operatives in the context of NDDs, both as conveyors of pathogenic entities and as prospective vectors for therapeutic agents. This review critically summarizes the burgeoning evidence on the role of extracerebral EVs, particularly those originating from bone, adipose tissue, and gut microbiota, in modulating brain pathophysiology. It underscores the duplicity potential of peripheral EVs as modulators of disease progression and suggests their potential as novel vehicles for targeted therapeutic delivery, positing a transformative impact on the future landscape of NDD treatment strategies. Search strategy A comprehensive literature search was conducted using PubMed, Web of Science, and Scopus from January 2000 to December 2023. The search combined the following terms using Boolean operators: "neurodegenerative disease" OR "Alzheimer's disease" OR "Parkinson's disease" OR "Amyotrophic lateral sclerosis" AND "extracellular vesicles" OR "exosomes" OR "outer membrane vesicles" AND "drug delivery systems" AND "blood-brain barrier". MeSH terms were employed when searching PubMed to refine the results. Studies were included if they were published in English, involved human subjects, and focused on the peripheral origins of EVs, specifically from bone, adipose tissue, and gut microbiota, and their association with related diseases such as osteoporosis, metabolic syndrome, and gut dysbiosis. Articles were excluded if they did not address the role of EVs in the context of NDDs or did not discuss therapeutic applications. The titles and abstracts of retrieved articles were screened using a dual-review process to ensure relevance and accuracy. The reference lists of selected articles were also examined to identify additional relevant studies.

Engineered mRNA Delivery Systems for Biomedical Applications

Messenger RNA (mRNA)-based therapeutic strategies have shown remarkable promise in preventing and treating a staggering range of diseases. Optimizing the structure and delivery system of engineered mRNA has greatly improved its stability, immunogenicity, and protein expression levels, which has led to a wider range of uses for mRNA therapeutics. Herein, a thorough analysis of the optimization strategies used in the structure of mRNA is first provided and delivery systems are described in great detail. Furthermore, the latest advancements in biomedical engineering for mRNA technology, including its applications in combatting infectious diseases, treating cancer, providing protein replacement therapy, conducting gene editing, and more, are summarized. Lastly, a perspective on forthcoming challenges and prospects concerning the advancement of mRNA therapeutics is offered. Despite these challenges, mRNA-based therapeutics remain promising, with the potential to revolutionize disease treatment and contribute to significant advancements in the biomedical field.

From structural design to delivery: mRNA therapeutics for cancer immunotherapy

mRNA therapeutics have emerged as powerful tools for cancer immunotherapy in accordance with their superiority in expressing all sequence-known proteins in vivo. In particular, with a small dosage of delivered mRNA, antigen-presenting cells (APCs) can synthesize mutant neo-antigens and multi-antigens and present epitopes to T lymphocytes to elicit antitumor effects. In addition, expressing receptors like chimeric antigen receptor (CAR), T-cell receptor (TCR), CD134, and immune-modulating factors including cytokines, interferons, and antibodies in specific cells can enhance immunological response against tumors. With the maturation of in vitro transcription (IVT) technology, large-scale and pure mRNA encoding specific proteins can be synthesized quickly. However, the clinical translation of mRNA-based anticancer strategies is restricted by delivering mRNA into target organs or cells and the inadequate endosomal escape efficiency of mRNA. Recently, there have been some advances in mRNA-based cancer immunotherapy, which can be roughly classified as modifications of the mRNA structure and the development of delivery systems, especially the lipid nanoparticle platforms. In this review, the latest strategies for overcoming the limitations of mRNA-based cancer immunotherapies and the recent advances in delivering mRNA into specific organs and cells are summarized. Challenges and opportunities for clinical applications of mRNA-based cancer immunotherapy are also discussed.

Fluorinated Lipid Nanoparticles for Enhancing mRNA Delivery Efficiency

Lipid nanoparticles (LNPs), a nonviral nucleic acid delivery system, have shown vast potential for vaccine development and disease treatment. LNPs assist mRNA to cross physiological barriers such as cell membranes and endosomes/lysosomes, promoting the intracellular presentation of mRNA. However, the endosome escape efficiency and biosafety of currently commercialized LNPs are still unsatisfactory, resulting in underutilization of mRNA. Herein, we report that fluorinated modification of the 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-2000 (PEG-DSPE), termed as FPD, in the LNPs can improve the delivery efficiency of mRNA. FPD accounts for only 1.5% of lipids in LNPs but could mediate a 5-fold and nearly 2-fold enhancement of mRNA expression efficiency in B16F10 tumor cells and primary dendritic cells, respectively. Mechanism studies reveal that FPD promotes the cellular internalization of LNPs as well as endosome escape. In vivo studies substantiate that FPD can augment overall mRNA expression at least 3-fold, either by intravenous or intraperitoneal injection, compared to LNPs prepared with nonfluorinated PEG-lipids at a relatively low mRNA dose. Besides, with the introduction of FPD, mRNA expression in the spleen augmented compared to that of the DMG-PEG commercial formulations. Benefiting from a prudent dosage of fluorine, the fluorinated LNPs display favorable biosafety profiles at cellular and zoological levels.

Extracellular Vesicles: A New Star for Gene Drug Delivery

Recently, gene therapy has become a subject of considerable research and has been widely evaluated in various disease models. Though it is considered as a stand-alone agent for COVID-19 vaccination, gene therapy is still suffering from the following drawbacks during its translation from the bench to the bedside: the high sensitivity of exogenous nucleic acids to enzymatic degradation; the severe side effects induced either by exogenous nucleic acids or components in the formulation; and the difficulty to cross the barriers before reaching the therapeutic target. Therefore, for the successful application of gene therapy, a safe and reliable transport vector is urgently needed. Extracellular vesicles (EVs) are the ideal candidate for the delivery of gene drugs owing to their low immunogenicity, good biocompatibility and low toxicity. To better understand the properties of EVs and their advantages as gene drug delivery vehicles, this review covers from the origin of EVs to the methods of EVs generation, as well as the common methods of isolation and purification in research, with their pros and cons discussed. Meanwhile, the engineering of EVs for gene drugs is also highlighted. In addition, this paper also presents the progress in the EVs-mediated delivery of microRNAs, small interfering RNAs, messenger RNAs, plasmids, and antisense oligonucleotides. We believe this review will provide a theoretical basis for the development of gene drugs.

Supramolecular Lipid Nanoparticles Based on Host-Guest Recognition: A New Generation Delivery System of mRNA Vaccines For Cancer Immunotherapy

Dendritic cell (DC) maturation is a crucial process for antigen presentation and the initiation of T cell-mediated immune responses. Toll-like receptors play pivotal roles in stimulating DC maturation and promoting antigen presentation. Here, a novel message RNA (mRNA) cancer vaccine is reported that boosts antitumor efficacy by codelivering an mRNA encoding tumor antigen and a TLR7/8 agonist (R848) to DC using supramolecular lipid nanoparticles (SMLNP) as a delivery platform, in which a new ionizable lipid (N2-3L) remarkably enhances the translation efficiency of mRNA and a β-cyclodextrin (β-CD)-modified ionizable lipid (Lip-CD) encapsulates R848. The incorporation of R848 adjuvant into the mRNA vaccine through noncovalent host-guest complexation significantly promotes DC maturation and antigen presentation after vaccination, thus resulting in superior antitumor efficacy in vivo. Moreover, the antitumor efficacy is further boosted synergized with immune checkpoint blockade by potentiating the anticancer capability of cytotoxic T lymphocytes infiltrated in tumor sites. This work indicates that SMLNP shows brilliant potential as next-generation delivery system in the development of mRNA vaccines with high efficacy.

COVID-19 cooling: Nanostrategies targeting cytokine storm for controlling severe and critical symptoms

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to wreak havoc worldwide, the "Cytokine Storm" (CS, also known as the inflammatory storm) or Cytokine Release Syndrome has reemerged in the public consciousness. CS is a significant contributor to the deterioration of infected individuals. Therefore, CS control is of great significance for the treatment of critically ill patients and the reduction of mortality rates. With the occurrence of variants, concerns regarding the efficacy of vaccines and antiviral drugs with a broad spectrum have grown. We should make an effort to modernize treatment strategies to address the challenges posed by mutations. Thus, in addition to the requirement for additional clinical data to monitor the long-term effects of vaccines and broad-spectrum antiviral drugs, we can use CS as an entry point and therapeutic target to alleviate the severity of the disease in patients. To effectively combat the mutation, new technologies for neutralizing or controlling CS must be developed. In recent years, nanotechnology has been widely applied in the biomedical field, opening up a plethora of opportunities for CS. Here, we put forward the view of cytokine storm as a therapeutic target can be used to treat critically ill patients by expounding the relationship between coronavirus disease 2019 (COVID-19) and CS and the mechanisms associated with CS. We pay special attention to the representative strategies of nanomaterials in current neutral and CS research, as well as their potential chemical design and principles. We hope that the nanostrategies described in this review provide attractive treatment options for severe and critical COVID-19 caused by CS.

Engineered Silica Nanoparticles for Nucleic Acid Delivery

The development of nucleic acid-based drugs holds great promise for therapeutic applications, but their effective delivery into cells is hindered by poor cellular membrane permeability and inherent instability. To overcome these challenges, delivery vehicles are required to protect and deliver nucleic acids efficiently. Silica nanoparticles (SiNPs) have emerged as promising nanovectors and recently bioregulators for gene delivery due to their unique advantages. In this review, a summary of recent advancements in the design of SiNPs for nucleic acid delivery and their applications is provided, mainly according to the specific type of nucleic acids. First, the structural characteristics and working mechanisms of various types of nucleic acids are introduced and classified according to their functions. Subsequently, for each nucleic acid type, the use of SiNPs for enhancing delivery performance and their biomedical applications are summarized. The tailored design of SiNPs for selected type of nucleic acid delivery will be highlighted considering the characteristics of nucleic acids. Lastly, the limitations in current research and personal perspectives on future directions in this field are presented. It is expected this opportune review will provide insights into a burgeoning research area for the development of next-generation SiNP-based nucleic acid delivery systems.

Chemically Modified Platforms for Better RNA Therapeutics

RNA-based therapies have catalyzed a revolutionary transformation in the biomedical landscape, offering unprecedented potential in disease prevention and treatment. However, despite their remarkable achievements, these therapies encounter substantial challenges including low stability, susceptibility to degradation by nucleases, and a prominent negative charge, thereby hindering further development. Chemically modified platforms have emerged as a strategic innovation, focusing on precise alterations either on the RNA moieties or their associated delivery vectors. This comprehensive review delves into these platforms, underscoring their significance in augmenting the performance and translational prospects of RNA-based therapeutics. It encompasses an in-depth analysis of various chemically modified delivery platforms that have been instrumental in propelling RNA therapeutics toward clinical utility. Moreover, the review scrutinizes the rationale behind diverse chemical modification techniques aiming at optimizing the therapeutic efficacy of RNA molecules, thereby facilitating robust disease management. Recent empirical studies corroborating the efficacy enhancement of RNA therapeutics through chemical modifications are highlighted. Conclusively, we offer profound insights into the transformative impact of chemical modifications on RNA drugs and delineates prospective trajectories for their future development and clinical integration.

The landscape of nanoparticle-based siRNA delivery and therapeutic development

Five small interfering RNA (siRNA)-based therapeutics have been approved by the Food and Drug Administration (FDA), namely patisiran, givosiran, lumasiran, inclisiran, and vutrisiran. Besides, siRNA delivery to the target site without toxicity is a big challenge for researchers, and naked-siRNA delivery possesses several challenges, including membrane impermeability, enzymatic degradation, mononuclear phagocyte system (MPS) entrapment, fast renal excretion, endosomal escape, and off-target effects. The siRNA therapeutics can silence any disease-specific gene, but their intracellular and extracellular barriers limit their clinical applications. For this purpose, several modifications have been employed to siRNA for better transfection efficiency. Still, there is a quest for better delivery systems for siRNA delivery to the target site. In recent years, nanoparticles have shown promising results in siRNA delivery with minimum toxicity and off-target effects. Patisiran is a lipid nanoparticle (LNP)-based siRNA formulation for treating hereditary transthyretin-mediated amyloidosis that ultimately warrants the use of nanoparticles from different classes, especially lipid-based nanoparticles. These nanoparticles may belong to different categories, including lipid-based, polymer-based, and inorganic nanoparticles. This review briefly discusses the lipid, polymer, and inorganic nanoparticles and their sub-types for siRNA delivery. Finally, several clinical trials related to siRNA therapeutics are addressed, followed by the future prospects and conclusions.

DNA-Based Nonviral Gene Therapy─Challenging but Promising

Over the past decades, significant progress has been made in utilizing nucleic acids, including DNA and RNA molecules, for therapeutic purposes. For DNA molecules, although various DNA delivery systems have been established, viral vector systems are the go-to choice for large-scale commercial applications. However, viral systems have certain disadvantages such as immune response, limited payload capacity, insertional mutagenesis and pre-existing immunity. In contrast, nonviral systems are less immunogenic, not size limited, safer, and easier for manufacturing compared with viral systems. What's more, nonviral DNA vectors have demonstrated their capacity to mediate specific protein expression in vivo for diverse therapeutic objectives containing a wide range of diseases such as cancer, rare diseases, neurodegenerative diseases, and infectious diseases, yielding promising therapeutic outcomes. However, exogenous plasmid DNA is prone to degrade and has poor immunogenicity in vivo. Thus, various strategies have been developed: (i) designing novel plasmids with special structures, (ii) optimizing plasmid sequences for higher expression, and (iii) developing more efficient nonviral DNA delivery systems. Based on these strategies, many interesting clinical results have been reported. This Review discusses the development of DNA-based nonviral gene therapy, including novel plasmids, nonviral delivery systems, clinical advances, and prospects. These developments hold great potential for enhancing the efficacy and safety of nonviral gene therapy and expanding its applications in the treatment of various diseases.

Chimeric antigen receptor therapy meets mRNA technology

Genetically engineered immune cells expressing chimeric antigen receptors (CARs) have emerged as a new game changer in cancer immunotherapy. The utility of CAR T cell therapy against hematological malignancies has been validated in clinical practice. Other CAR immune cells are currently under investigation to improve the potency of CAR therapy in solid tumors. As a new class of therapeutic modalities, mRNA-based therapeutics hold enormous potential beyond COVID-19 mRNA vaccines. Arming immune cells with mRNA-encoded CARs represents a new frontier in cancer and beyond, enabling in vivo generation of CAR cells without causing transgene integration. In this review, we summarize recent advances in mRNA-based CAR immunotherapies and highlight their opportunities and challenges for the development of a new generation of living drugs.

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.

Unlocking Delivery Strategies for mRNA Therapeutics

mRNA emerged as an attractive therapy modality with the development of mRNA structure engineering techniques and delivery platforms. mRNA therapeutics, applied for vaccine therapy, protein replacement therapy, and chimeric antigen receptor (CAR) T cell-based therapy, has shown huge potential in treating a wide range of diseases, such as cancer and rare genetic diseases, with successful and exciting preclinical and clinical progress. In mRNA therapeutics, a potent delivery system is key to the success of its application for disease treatment. Herein, different types of mRNA delivery strategies, including nanoparticles produced from lipid or polymer materials, virus-based platforms, and exosome-based platforms, are mainly focused.

The potential of mRNA vaccines in cancer nanomedicine and immunotherapy

Owing to their outstanding performance against COVID-19, mRNA vaccines have brought great hope for combating various incurable diseases, including cancer. Differences in the encoded proteins result in different molecular and cellular mechanisms of mRNA vaccines. With the rapid development of nanotechnology and molecular medicine, personalized antigen-encoding mRNA vaccines that enhance antigen presentation can trigger effective immune responses and prevent off-target toxicities. Herein, we review new insights into the influence of encoded antigens, cytokines, and other functional proteins on the mechanisms of mRNA vaccines. We also highlight the importance of delivery systems and chemical modifications for mRNA translation efficiency, stability, and targeting, and we discuss the potential problems and application prospects of mRNA vaccines as versatile tools for combating cancer.

Sniping Cancer Stem Cells with Nanomaterials

Cancer stem cells (CSCs) drive tumor initiation, progression, and therapeutic resistance due to their self-renewal and differentiation capabilities. Despite encouraging progress in cancer treatment, conventional approaches often fail to eliminate CSCs, necessitating the development of precise targeted strategies. Recent advances in materials science and nanotechnology have enabled promising CSC-targeted approaches, harnessing the power of tailoring nanomaterials in diverse therapeutic applications. This review provides an update on the current landscape of nanobased precision targeting approaches against CSCs. We elucidate the nuanced application of organic, inorganic, and bioinspired nanomaterials across a spectrum of therapeutic paradigms, encompassing targeted therapy, immunotherapy, and multimodal synergistic therapies. By examining the accomplishments and challenges in this potential field, we aim to inform future efforts to advance nanomaterial-based therapies toward more effective "sniping" of CSCs and tumor clearance.

Hybrid mRNA Nano Vaccine Potentiates Antigenic Peptide Presentation and Dendritic Cell Maturation for Effective Cancer Vaccine Therapy and Enhances Response to Immune Checkpoint Blockade

Cancer vaccines combined with immune checkpoint blockades (ICB) represent great potential application, yet the insufficient tumor antigen presentation and immature dendritic cells hinder improved efficacy. Here, a hybrid nano vaccine composed by hyper branched poly(beta-amino ester), modified iron oxide nano adjuvant and messenger RNA (mRNA) encoded with model antigen ovalbumin (OVA) is presented. The nano vaccine outperforms three commercialized reagents loaded with the same mRNA, including Lipofectamine MessengerMax, jetPRIME, and in vivo-jetRNA in promoting dendritic cells' transfection, maturation, and peptide presentation. In an OVA-expressing murine model, intratumoral administration of the nano vaccine significantly induced macrophages and dendritic cells' presenting peptides and expressing co-stimulatory CD86. The nano vaccine also elicited strong antigen-specific splenocyte response and promoted CD8+ T cell infiltration. In combination with ICB, the nano vaccine aroused robust tumor suppression in murine models with large tumor burdens (initial volume >300 mm3 ). The hybrid mRNA vaccine represents a versatile and readily transformable platform and augments response to ICB.

Intranasal mRNA Delivery via Customized RNA-Polyplex Nanoparticles Enhancing Gene Expression through Photochemical Mechanisms

Achieving effective mRNA expression in vivo requires careful selection of an appropriate delivery vehicle and route of administration. Among the various routes of administration, intranasal administration has received considerable attention due to its ability to induce potent immune responses. In this context, we designed a specialized cationic polymer tailored for delivery of mRNA into the nasal cavity. These polymers are designed with varying degrees of substitution in different amine groups to allow for identification of the most suitable amine moiety for effective mRNA delivery. We also incorporated a photosensitizer within the polymer structure that can trigger the generation of reactive oxygen species when exposed to light. The synthesized cationic polymer is complexed with anionic mRNA to form a polyplex. Illuminating these polyplexes with laser light enhances their escape from intracellular endosomes, stimulating mRNA translocation into the cytoplasm, followed by increased mRNA expression at the cellular level. Through intranasal administration to C57BL/6 mice, it was confirmed that these photoactive polyplexes effectively induce mRNA expression and activate immune responses in vivo using photochemical effects. This innovative design of a photoactivated cationic polymer presents a promising and reliable strategy to achieve efficient intranasal mRNA delivery. This approach has potential applications in the development of mRNA-based vaccines for both prophylactic and therapeutic purposes.

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.

Protein-based delivery systems for RNA delivery

RNA-based therapeutics have emerged as promising approaches to modulate gene expression and generate therapeutic proteins or antigens capable of inducing immune responses to treat a variety of diseases, such as infectious diseases, cancers, immunologic disorders, and genetic disorders. However, the efficient delivery of RNA molecules into cells poses significant challenges due to their large molecular weight, negative charge, and susceptibility to degradation by RNase enzymes. To overcome these obstacles, viral and non-viral vectors have been developed, including lipid nanoparticles, viral vectors, proteins, dendritic macromolecules, among others. Among these carriers, protein-based delivery systems have garnered considerable attention due to their potential to address specific issues associated with nanoparticle-based systems, such as liver accumulation and immunogenicity. This review provides an overview of currently marketed RNA drugs, underscores the significance of RNA delivery vector development, delineates the essential characteristics of an ideal RNA delivery vector, and introduces existing protein carriers for RNA delivery. By offering valuable insights, this review aims to serve as a reference for the future development of protein-based delivery vectors for RNA therapeutics.

DNA Nanoflower Eye Drops with Antibiotic-Resistant Gene Regulation Ability for MRSA Keratitis Target Treatment

Methicillin-resistant Staphylococcus aureus (MRSA) biofilm-associated bacterial keratitis is highly intractable, with strong resistance to β-lactam antibiotics. Inhibiting the MRSA resistance gene mecR1 to downregulate penicillin-binding protein PBP2a has been implicated in the sensitization of β-lactam antibiotics to MRSA. However, oligonucleotide gene regulators struggle to penetrate dense biofilms, let alone achieve efficient gene regulation inside bacteria cells. Herein, an eye-drop system capable of penetrating biofilms and targeting bacteria for chemo-gene therapy in MRSA-caused bacterial keratitis is developed. This system employed rolling circle amplification to prepare DNA nanoflowers (DNFs) encoding MRSA-specific aptamers and mecR1 deoxyribozymes (DNAzymes). Subsequently, β-lactam antibiotic ampicillin (Amp) and zinc oxide (ZnO) nanoparticles are sequentially loaded into the DNFs (ZnO/Amp@DNFs). Upon application, ZnO on the surface of the nanosystem disrupts the dense structure of biofilm and fully exposes free bacteria. Later, bearing encoded aptamer, the nanoflower system is intensively endocytosed by bacteria, and releases DNAzyme under acidic conditions to cleave the mecR1 gene for PBP2a down-regulation, and ampicillin for efficient MRSA elimination. In vivo tests showed that the system effectively cleared bacterial and biofilm in the cornea, suppressed proinflammatory cytokines interleukin 1β （IL-1β） and tumor neocrosis factor-alpha （TNF-α）, and is safe for corneal epithelial cells. Overall, this design offers a promising approach for treating MRSA-induced keratitis.

Inhaled mRNA nanoparticles dual-targeting cancer cells and macrophages in the lung for effective transfection

Messenger RNA (mRNA)-based therapeutics are transforming the landscapes of medicine, yet targeted delivery of mRNA to specific cell types while minimizing off-target accumulation remains challenging for mRNA-mediated therapy. In this study, we report an innovative design of a cationic lipid- and hyaluronic acid-based, dual-targeted mRNA nanoformulation that can display the desirable stability and efficiently transfect the targeted proteins into lung tissues. More importantly, the optimized dual-targeted mRNA nanoparticles (NPs) can not only accumulate primarily in lung tumor cells and inflammatory macrophages after inhalation delivery but also efficiently express any desirable proteins (e.g., p53 tumor suppressor for therapy, as well as luciferase and green fluorescence protein for imaging as examples in this study) and achieve efficacious lung tissue transfection in vivo. Overall, our findings provide proof-of-principle evidence for the design and use of dual-targeted mRNA NPs in homing to specific cell types to up-regulate target proteins in lung tissues, which may hold great potential for the future development of mRNA-based inhaled medicines or vaccines in treating various lung-related diseases.

mRNA Cancer Vaccines: Construction and Boosting Strategies

In late 2020, the U.S. Food and Drug Administration (FDA) approved a lipid-based mRNA vaccine for the prevention of COVID-19, which has pushed this field to be more closely studied and motivated researchers to delve deeper into mRNA therapeutics. To date, the research on mRNA cancer vaccines has been developed rapidly, and substantial hopeful therapeutic results have been achieved against various solid tumors in clinical trials. In this review, we first introduce three main components of mRNA cancer vaccines, including mRNA antigens, adjuvants, and delivery vectors. Engineering these components can optimize the therapeutic effects of mRNA cancer vaccines. For instance, appropriate modification of mRNA structure can alleviate the poor stability and innate immunogenicity of mRNA, and the use of mRNA delivery vectors can address the issues of low delivery efficiency in vivo. Second, we emphatically discuss some strategies to further improve the efficacy of mRNA cancer vaccines, namely modulating the immunosuppressive tumor environment, optimizing administration routes, achieving targeting delivery to intended tissues or organs, and employing combination therapy. These strategies can strengthen the tumor inhibitory ability of mRNA cancer vaccines and increase the possibility of tumor elimination. Finally, we point out some challenges in the clinical practice of mRNA cancer vaccines and offer our perspectives on future developments in this rapidly evolving field. It is anticipated that mRNA cancer vaccines will be rapidly developed for clinical cancer therapy in the near future.

Mechanisms and research advances in mRNA antibody drug-mediated passive immunotherapy

Antibody technology is widely used in the fields of biomedical and clinical therapies. Nonetheless, the complex in vitro expression of recombinant proteins, long production cycles, and harsh storage conditions have limited their applications in medicine, especially in clinical therapies. Recently, this dilemma has been overcome to a certain extent by the development of mRNA delivery systems, in which antibody-encoding mRNAs are enclosed in nanomaterials and delivered to the body. On entering the cytoplasm, the mRNAs immediately bind to ribosomes and undergo translation and post-translational modifications. This process produces monoclonal or bispecific antibodies that act directly on the patient. Additionally, it eliminates the cumbersome process of in vitro protein expression and extends the half-life of short-lived proteins, which significantly reduces the cost and duration of antibody production. This review focuses on the benefits and drawbacks of mRNA antibodies compared with the traditional in vitro expressed antibodies. In addition, it elucidates the progress of mRNA antibodies in the prevention of infectious diseases and oncology therapy.