Opportunities and Challenges in the Delivery of mRNA-based Vaccines

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.

Exploring the theranostic potentials of miRNA and epigenetic networks in autoimmune diseases: A comprehensive review

BACKGROUND

Autoimmune diseases (AD) are severe pathophysiological ailments that are stimulated by an exaggerated immunogenic response towards self-antigens, which can cause systemic or site-specific organ damage. An array of complex genetic and epigenetic facets majorly contributes to the progression of AD, thus providing significant insight into the regulatory mechanism of microRNA (miRNA). miRNAs are short, non-coding RNAs that have been identified as essential contributors to the post-transcriptional regulation of host genome expression and as crucial regulators of a myriad of biological processes such as immune homeostasis, T helper cell differentiation, central and peripheral tolerance, and immune cell development.

AIMS

This article tends to deliberate and conceptualize the brief pathogenesis and pertinent epigenetic regulatory mechanism as well as miRNA networks majorly affecting five different ADs namely rheumatoid arthritis (RA), type 1 diabetes, multiple sclerosis (MS), systemic lupus erythematosus (SLE) and inflammatory bowel disorder (IBD) thereby providing novel miRNA-based theranostic interventions.

RESULTS & DISCUSSION

Pertaining to the differential expression of miRNA attributed in target tissues and cellular bodies of innate and adaptive immunity, a paradigm of scientific expeditions suggests an optimistic correlation between immunogenic dysfunction and miRNA alterations.

CONCLUSION

Therefore, it is not astonishing that dysregulations in miRNA expression patterns are now recognized in a wide spectrum of disorders, establishing themselves as potential biomarkers and therapeutic targets. Owing to its theranostic potencies, miRNA targets have been widely utilized in the development of biosensors and other therapeutic molecules originating from the same.

Harnessing synthetic biology for advancing RNA therapeutics and vaccine design

Recent global events have drawn into focus the diversity of options for combatting disease across a spectrum of prophylactic and therapeutic approaches. The recent success of the mRNA-based COVID-19 vaccines has paved the way for RNA-based treatments to revolutionize the pharmaceutical industry. However, historical treatment options are continuously updated and reimagined in the context of novel technical developments, such as those facilitated through the application of synthetic biology. When it comes to the development of genetic forms of therapies and vaccines, synthetic biology offers diverse tools and approaches to influence the content, dosage, and breadth of treatment with the prospect of economic advantage provided in time and cost benefits. This can be achieved by utilizing the broad tools within this discipline to enhance the functionality and efficacy of pharmaceutical agent sequences. This review will describe how synthetic biology principles can augment RNA-based treatments through optimizing not only the vaccine antigen, therapeutic construct, therapeutic activity, and delivery vector. The enhancement of RNA vaccine technology through implementing synthetic biology has the potential to shape the next generation of vaccines and therapeutics.

Intradermal Delivery of Naked mRNA Vaccines via Iontophoresis

Messenger RNA (mRNA) vaccines against infectious diseases and for anticancer immunotherapy have garnered considerable attention. Currently, mRNA vaccines encapsulated in lipid nanoparticles are administrated via intramuscular injection using a needle. However, such administration is associated with pain, needle phobia, and lack of patient compliance. Furthermore, side effects such as fever and anaphylaxis associated with the lipid nanoparticle components are also serious problems. Therefore, noninvasive, painless administration of mRNA vaccines that do not contain other problematic components is highly desirable. Antigen-presenting cells reside in the epidermis and dermis, making the skin an attractive vaccination site. Iontophoresis (ItP) uses weak electric current applied to the skin surface and offers a noninvasive permeation technology that enables intradermal delivery of hydrophilic and ionic substances. ItP-mediated intradermal delivery of biological macromolecules has also been studied. Herein, we review the literature on the use of ItP technology for intradermal delivery of naked mRNA vaccines which is expected to overcome the challenges associated with mRNA vaccination. In addition to the physical mechanism, we discuss novel biological mechanisms of iontophoresis, particularly ItP-mediated opening of the skin barriers and the intracellular uptake pathway, and how the combined mechanisms can allow for effective intradermal delivery of mRNA vaccines.

RNA Combined with Nanoformulation to Advance Therapeutic Technologies

Nucleic acid-based therapies have the potential to address numerous diseases that pose significant challenges to more traditional methods. RNA-based therapies have emerged as a promising avenue, utilizing nanoformulation treatments to target a range of pathologies. Nanoformulation offers several advantages compared to other treatment modalities, including targeted delivery, low toxicity, and bioactivity suitable for drug loading. At present, various types of nanoformulations are available, such as liposomes, polymeric nanoparticles (NPs), magnetic NPs, nanoshells, and solid lipid nanoparticles (SLNs). RNA-based therapy utilizes intracellular gene nanoparticles with messenger RNA (mRNA) emerging prominently in cancer therapy and immunotechnology against infectious diseases. The approval of mRNA-based technology opens doors for future technological advancements, particularly self-amplifying replicon RNA (repRNA). RepRNA is a novel platform in gene therapy, comprising viral RNA with a unique molecular property that enables the amplification of all encoded genetic information countless times. As a result, repRNA-based therapies have achieved significant levels of gene expression. In this context, the primary objective of this study is to furnish a comprehensive review of repRNA and its applications in nanoformulation treatments, with a specific focus on encapsulated nanoparticles. The overarching goal is to provide an extensive overview of the use of repRNA in conjunction with nanoformulations across a range of treatments and therapies.

Advancing personalized medicine in brain cancer: exploring the role of mRNA vaccines

Advancing personalized medicine in brain cancer relies on innovative strategies, with mRNA vaccines emerging as a promising avenue. While the initial use of mRNA vaccines was in oncology, their stunning success in COVID-19 resulted in widespread attention, both positive and negative. Regardless of politically biased opinions, which relate more to the antigenic source than form of delivery, we feel it is important to objectively review this modality as relates to brain cancer. This class of vaccines trigger robust immune responses through MHC-I and MHC-II pathways, in both prophylactic and therapeutic settings. The mRNA platform offers advantages of rapid development, high potency, cost-effectiveness, and safety. This review provides an overview of mRNA vaccine delivery technologies, tumor antigen identification, combination therapies, and recent therapeutic outcomes, with a particular focus on brain cancer. Combinatorial approaches are vital to maximizing mRNA cancer vaccine efficacy, with ongoing clinical trials exploring combinations with adjuvants and checkpoint inhibitors and even adoptive cell therapy. Efficient delivery, neoantigen identification, preclinical studies, and clinical trial results are highlighted, underscoring mRNA vaccines' potential in advancing personalized medicine for brain cancer. Synergistic combinatorial therapies play a crucial role, emphasizing the need for continued research and collaboration in this area.

Delivery of gene editing therapeutics

For the past decades, gene editing demonstrated the potential to attenuate each of the root causes of genetic, infectious, immune, cancerous, and degenerative disorders. More recently, Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR-associated protein 9 (CRISPR-Cas9) editing proved effective for editing genomic, cancerous, or microbial DNA to limit disease onset or spread. However, the strategies to deliver CRISPR-Cas9 cargos and elicit protective immune responses requires safe delivery to disease targeted cells and tissues. While viral vector-based systems and viral particles demonstrate high efficiency and stable transgene expression, each are limited in their packaging capacities and secondary untoward immune responses. In contrast, the nonviral vector lipid nanoparticles were successfully used for as vaccine and therapeutic deliverables. Herein, we highlight each available gene delivery systems for treating and preventing a broad range of infectious, inflammatory, genetic, and degenerative diseases. STATEMENT OF SIGNIFICANCE: CRISPR-Cas9 gene editing for disease treatment and prevention is an emerging field that can change the outcome of many chronic debilitating disorders.

Extracellular vesicles as a potential delivery platform for CRISPR-Cas based therapy in epithelial ovarian cancer

Ovarian Cancer (OC) is the most common gynecological malignancy and the eighth most diagnosed cancer in females worldwide. Presently, it ranks as the fifth leading cause of cancer-related mortality among patients globally. Major factors contributing to the lethality of OC worldwide include delayed diagnosis, chemotherapy resistance, high metastatic rates, and the heterogeneity of subtypes. Despite continuous efforts to develop novel targeted therapies and chemotherapeutic agents, challenges persist in the form of OC resistance and recurrence. In the last decade, CRISPR-Cas-based genome editing has emerged as a powerful tool for modifying genetic and epigenetic mechanisms, holding potential for treating numerous diseases. However, a significant challenge for therapeutic applications of CRISPR-Cas technology is the absence of an optimal vehicle for delivering CRISPR molecular machinery into targeted cells or tissues. Recently, extracellular vesicles (EVs) have gained traction as potential delivery vehicles for various therapeutic agents. These heterogeneous, membrane-derived vesicles are released by nearly all cells into extracellular spaces. They carry a molecular cargo of proteins and nucleic acids within their intraluminal space, encased by a cholesterol-rich phospholipid bilayer membrane. EVs actively engage in cell-to-cell communication by delivering cargo to both neighboring and distant cells. Their inherent ability to shield molecular cargo from degradation and cross biological barriers positions them ideally for delivering CRISPR-Cas ribonucleoproteins (RNP) to target cells. Furthermore, they exhibit higher biocompatibility, lower immunogenicity, and reduced toxicity compared to classical delivery platforms such as adeno-associated virus, lentiviruses, and synthetic nanoparticles. This review explores the potential of employing different CRISPR-Cas systems to target specific genes in OC, while also discussing various methods for engineering EVs to load CRISPR components and enhance their targeting capabilities.

Comparison of Post-Vaccination Response between mRNA and Vector Vaccines against SARS-CoV-2 in Terms of Humoral Response after Six Months of Observation

BACKGROUND

The emergence of the SARS-CoV-2 (COVID-19) pandemic has accelerated work on the creation of effective vaccines, both in terms of previously known vector vaccines and new-generation (mRNA) vaccines. The scientific research on vaccination against COVID-19 infection is limited; therefore, understanding how the immune system responds to vaccines is critical. In our study, we conducted a long-term analysis of the presence and persistence of the immune response via chemiluminescence, analyzing the level of IgG antibodies and neutralizing antibodies in subjects vaccinated with two types of mRNA (Comirnaty) and vector (Vaxzevria) vaccines.

MATERIALS AND METHODS

Healthcare workers and a group of teachers were recruited for this study according to the 2021 government-launched vaccination calendar. They received two doses of the Comirnaty or Vaxzevria vaccine. SRBD (spike-receptor binding domain) IgG antibody levels were measured monthly for 6 consecutive months with a chemiluminescent assay (CLIA) and neutralizing antibodies for two periods-1 and 5 months from the completion of the vaccination course.

RESULTS

168 people were recruited for this study: 135 people for the mRNA vaccine group and 33 people for the vector vaccine group. Comparing the serum IgG levels between the two types of vaccines, a significant difference in median values can be noted at all time points. In consecutive months, the mRNA-vaccinated group exhibited significantly higher SRBD levels compared to the vector group, with peak concentrations at one month after the complete vaccination cycle (745 AU/mL vs. 15.44 AU/mL; p < 0.001). Peak antibody concentration for the vector vaccine was observed one month later, at the third follow-up visit; however, the median IgG concentration was almost 7.7 times higher for the Comirnaty group. Both products were effective in stimulating neutralizing antibody production after vaccination. Higher median values were observed for the mRNA vaccines in both evaluations. At first evaluation, the median value for NA concentration in the Comirnaty group was 6 times higher than in the Vaxzevria group (median value 12.23 [IQR 27.3] vs. 1.7 [IQR 3.3]; p < 0.001.

CONCLUSIONS

People vaccinated with the mRNA vaccine (Comirnaty) showed a stronger immune response to the vaccination than the group of people administered the vector vaccine (Vaxzevria). The Comirnaty group showed higher levels of IgG, including neutralizing antibodies, at all time points during the follow-up period, and this was independent of having had a SARS-CoV-2 infection. A natural decrease in antibody levels was seen within 6 months. A booster vaccination may be required. No serious side effects were observed in either group.

Customizing cancer treatment at the nanoscale: a focus on anaplastic thyroid cancer therapy

Anaplastic thyroid cancer (ATC) is a rare but highly aggressive kind of thyroid cancer. Various therapeutic methods have been considered for the treatment of ATC, but its prognosis remains poor. With the advent of the nanomedicine era, the use of nanotechnology has been introduced in the treatment of various cancers and has shown great potential and broad prospects in ATC treatment. The current review meticulously describes and summarizes the research progress of various nanomedicine-based therapeutic methods of ATC, including chemotherapy, differentiation therapy, radioiodine therapy, gene therapy, targeted therapy, photothermal therapy, and combination therapy. Furthermore, potential future challenges and opportunities for the currently developed nanomedicines for ATC treatment are discussed. As far as we know, there are few reviews focusing on the nanomedicine of ATC therapy, and it is believed that this review will generate widespread interest from researchers in a variety of fields to further expedite preclinical research and clinical translation of ATC nanomedicines.

Contemporaneous SARS-CoV-2-Neutralizing Antibodies Mediated by N-glycan Shields

Mutations and the glycosylation of epitopes can convert immunogenic epitopes into non-immunogenic ones via natural selection or evolutionary pressure, thereby decreasing their sensitivity to neutralizing antibodies. Based on Thomas Francis's theory, memory B and T cells induced during primary infections or vaccination will freeze the new mutated epitopes specific to naïve B and T cells from the repertoire. On this basis, some researchers argue that the current vaccines derived from the previous strains of the SARS-CoV-2 virus do not increase immunity and may also prevent the immune response against new epitopes. However, evidence shows that even if the binding affinity is reduced, the previous antibodies or T cell receptors (TCRs) can still bind to this new epitope of the Beta, Gamma, and Delta variant if their concentration is high enough (from a booster injection) and neutralize the virus. This paper presents some convincing immunological reasons that may challenge this theory and argue for the continuation of universal vaccination to prevent further mutations of the SARS-CoV-2 virus. Simultaneously, the information presented can be used to develop vaccines that target novel epitopes or create new recombinant drugs that do not lose their effectiveness when the virus mutates.

STING agonist-boosted mRNA immunization via intelligent design of nanovaccines for enhancing cancer immunotherapy

Messenger RNA (mRNA) vaccine is revolutionizing the methodology of immunization in cancer. However, mRNA immunization is drastically limited by multistage biological barriers including poor lymphatic transport, rapid clearance, catalytic hydrolysis, insufficient cellular entry and endosome entrapment. Herein, we design a mRNA nanovaccine based on intelligent design to overcome these obstacles. Highly efficient nanovaccines are carried out with machine learning techniques from datasets of various nanocarriers, ensuring successful delivery of mRNA antigen and cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) to targets. It activates stimulator of interferon genes (STING), promotes mRNA-encoded antigen presentation and boosts antitumour immunity in vivo, thus inhibiting tumour growth and ensuring long-term survival of tumour-bearing mice. This work provides a feasible and safe strategy to facilitate STING agonist-synergized mRNA immunization, with great translational potential for enhancing cancer immunotherapy.

The impact of BNT162b2 mRNA vaccine on adaptive and innate immune responses

The mRNA-based BNT162b2 protects against severe disease and mortality caused by SARS-CoV-2 via induction of specific antibody and T-cell responses. Much less is known about its broad effects on immune responses against other pathogens. Here, we investigated the adaptive immune responses induced by BNT162b2 vaccination against various SARS-CoV-2 variants and its effects on the responsiveness of immune cells upon stimulation with heterologous stimuli. BNT162b2 vaccination induced effective humoral and cellular immunity against SARS-CoV-2 that started to wane after six months. We also observed long-term transcriptional changes in immune cells after vaccination. Additionally, vaccination with BNT162b2 modulated innate immune responses as measured by inflammatory cytokine production after stimulation - higher IL-1/IL-6 release and decreased IFN-α production. Altogether, these data expand our knowledge regarding the overall immunological effects of this new class of vaccines and underline the need for additional studies to elucidate their effects on both innate and adaptive immune responses.

mRNA vaccines in disease prevention and treatment

mRNA vaccines have emerged as highly effective strategies in the prophylaxis and treatment of diseases, thanks largely although not totally to their extraordinary performance in recent years against the worldwide plague COVID-19. The huge superiority of mRNA vaccines regarding their efficacy, safety, and large-scale manufacture encourages pharmaceutical industries and biotechnology companies to expand their application to a diverse array of diseases, despite the nonnegligible problems in design, fabrication, and mode of administration. This review delves into the technical underpinnings of mRNA vaccines, covering mRNA design, synthesis, delivery, and adjuvant technologies. Moreover, this review presents a systematic retrospective analysis in a logical and well-organized manner, shedding light on representative mRNA vaccines employed in various diseases. The scope extends across infectious diseases, cancers, immunological diseases, tissue damages, and rare diseases, showcasing the versatility and potential of mRNA vaccines in diverse therapeutic areas. Furthermore, this review engages in a prospective discussion regarding the current challenge and potential direction for the advancement and utilization of mRNA vaccines. Overall, this comprehensive review serves as a valuable resource for researchers, clinicians, and industry professionals, providing a comprehensive understanding of the technical aspects, historical context, and future prospects of mRNA vaccines in the fight against various diseases.

Sending a Message: Use of mRNA Vaccines to Target the Tumor Immune Microenvironment

While cancer immunotherapies have become central to treatment, challenges associated with the ability of tumors to evade the immune system remain significant obstacles. At the heart of this issue is the tumor immune microenvironment, the complex interplay of the tumor microenvironment and the immune response. Recent advances in mRNA cancer vaccines represent major progress towards overcoming some of the challenges posed by deleterious components of the tumor immune microenvironment. Indeed, major breakthroughs in mRNA vaccine technology, such as the use of replacement nucleotides and lipid nanoparticle delivery, led to the vital success of mRNA vaccine technology in fighting COVID-19. This has in turn generated massive additional interest and investment in the platform. In this review, we detail recent research in the nature of the tumor immune microenvironment and in mRNA cancer vaccines and discuss applications by which mRNA cancer vaccines, often in combination with various adjuvants, represent major areas of potential in overcoming tumor immune microenvironment-imposed obstacles. To this end, we also review current mRNA cancer vaccine clinical trials.

Complex Coacervates as a Promising Vehicle for mRNA Delivery: A Comprehensive Review of Recent Advances and Challenges

Messenger RNA (mRNA)-based therapies have gained significant attention, following the successful deployment of mRNA-based COVID-19 vaccines. Compared with traditional methods of genetic modification, mRNA-based therapies offer several advantages, including a lower risk of genetic mutations, temporary and controlled therapeutic gene expression, and a shorter production time, which facilitates rapid responses to emerging health challenges. Moreover, mRNA-based therapies have shown immense potential in treating a wide range of diseases including cancers, immune diseases, and neurological disorders. However, the current limitations of non-viral vectors for efficient and safe delivery of mRNA therapies, such as low encapsulation efficiency, potential toxicity, and limited stability, necessitate the exploration of novel strategies to overcome these challenges and fully realize the potential of mRNA-based therapeutics. Coacervate-based delivery systems have recently emerged as promising strategies for enhancing mRNA delivery. Coacervates, which are formed by the aggregation of two or more macromolecules, have shown great potential in delivering a wide range of therapeutics due to their ability to form a separated macromolecular-rich fluid phase in an aqueous environment. This phase separation enables the entrapment and protection of therapeutic agents from degradation as well as efficient cellular uptake and controlled release. Additionally, the natural affinity of coacervates for mRNA molecules presents an excellent opportunity for enhancing mRNA delivery to targeted cells and tissues, making coacervate-based delivery systems an attractive option for mRNA-based therapies. This review highlights the limitations of current strategies for mRNA delivery and the advantages of coacervate-based delivery systems to enable mRNA therapeutics. Coacervates protect mRNA from enzymatic degradation and enhance cellular uptake, leading to sustained and controlled gene expression. Despite their promising properties, the specific use of coacervates as mRNA delivery vehicles remains underexplored. This review aims to provide a comprehensive overview of coacervate-mediated delivery of mRNA, exploring the properties and applications of different coacervating agents as well as the challenges and optimization strategies involved in mRNA encapsulation, release, stability, and translation via coacervate-mediated delivery. Through a comprehensive analysis of recent advancements and recommended future directions, our review sheds light on the promising role of coacervate-mediated delivery for RNA therapeutics, highlighting its potential to enable groundbreaking applications in drug delivery and gene therapy.

mRNA-Based Nanomedicine: A New Strategy for Treating Infectious Diseases and Beyond

Messenger RNA (mRNA) has emerged as a new therapeutic agent for the prevention and treatment of a wide range of diseases. The recent achievement of the two lipid nanoparticle-mRNA vaccines developed by Moderna and Pfizer-BioNTech against coronavirus 2019 (COVID-19) disease in record time highlights the huge potential of mRNA technology and reshaping the landscape of vaccine development and the future of gene therapies. Challenges related to translational efficacy, mRNA stability, immunogenicity, and ensuring the quality of final products have been significantly improved by recent advancements in mRNA engineering and delivery. Thus, the present review aims to provide the latest innovations that incrementally overcome these issues and future directions in the context of ongoing clinical trials against infectious diseases and beyond.

Design and in silico analysis of mRNA vaccine construct against Salmonella

Salmonella infections are continuously growing. Causative serovars have gained enhanced drug resistance and virulence. Current vaccines have fallen short of providing sufficient protection. mRNA vaccines have come up with huge success against SARS-CoV-2; Pfizer-BioNTech and Moderna vaccines have resulted in >90% efficacy with efficient translocation, expression, and presentation of antigen to the host immune system. Herein, based on the same approach a mRNA vaccine construct has been designed and analyzed against Salmonella by joining regions of genes of outer membrane proteins C and F of S. Typhi through a flexible linker. Construct was flanked by regulatory regions that have previously shown better expression and translocation of encoded protein. GC content of the construct was improved to attain structural and thermodynamic stability and smooth translation. Sites of strong binding miRNAs were removed through codon optimization. Protein encoded by this construct is structurally plausible, highly antigenic, non-allergen to humans, and does not cross-react to the human proteome. It is enriched in potent, highly antigenic, and conserved linear and conformational epitopes. Most conserved conformational epitopes of core protein lie on extended beta hairpins exposed to the cellular exterior. Stability and thermodynamic attributes of the final construct were found highly comparable to the Pfizer-BioNTech vaccine construct. Both contain a stable stem-loop structure downstream of the start codon and do not offer destabilizing secondary structures upstream of the start codon. Given structural and thermodynamic stability, effective immune response, and epitope composition the construct is expected to provide broad-spectrum protection against clinically important Salmonella serovars.Communicated by Ramaswamy H. Sarma.

Lipid nanoparticles (LNPs) for in vivo RNA delivery and their breakthrough technology for future applications

RNA therapeutics show a significant breakthrough for the treatment of otherwise incurable diseases and genetic disorders by regulating disease-related gene expression. The successful development of COVID-19 mRNA vaccines further emphasizes the potential of RNA therapeutics in the prevention of infectious diseases as well as in the treatment of chronic diseases. However, the efficient delivery of RNA into cells remains a challenge, and nanoparticle delivery systems such as lipid nanoparticles (LNPs) are necessary to fully realize the potential of RNA therapeutics. While LNPs provide a highly efficient platform for the in vivo delivery of RNA by overcoming various biological barriers, several challenges remain to be resolved for further development and regulatory approval. These include a lack of targeted delivery to extrahepatic organs and a gradual loss of therapeutic potency with repeated doses. In this review, we highlight the fundamental aspects of LNPs and their uses in the development of novel RNA therapeutics. Recent advances in LNP-based therapeutics and preclinical/clinical studies are overviewed. Lastly, we discuss the current limitations of LNPs and introduce breakthrough technologies that might overcome these challenges in future applications.

Antisense Therapy for Infectious Diseases

Infectious diseases, particularly Tuberculosis (TB) caused by Mycobacterium tuberculosis, pose a significant global health challenge, with 1.6 million reported deaths in 2021, making it the most fatal disease caused by a single infectious agent. The rise of drug-resistant infectious diseases adds to the urgency of finding effective and safe intervention therapies. Antisense therapy uses antisense oligonucleotides (ASOs) that are short, chemically modified, single-stranded deoxyribonucleotide molecules complementary to their mRNA target. Due to their designed target specificity and inhibition of a disease-causing gene at the mRNA level, antisense therapy has gained interest as a potential therapeutic approach. This type of therapy is currently utilized in numerous diseases, such as cancer and genetic disorders. Currently, there are limited but steadily increasing studies available that report on the use of ASOs as treatment for infectious diseases. This review explores the sustainability of FDA-approved and preclinically tested ASOs as a treatment for infectious diseases and the adaptability of ASOs for chemical modifications resulting in reduced side effects with improved drug delivery; thus, highlighting the potential therapeutic uses of ASOs for treating infectious diseases.

Future prospects in mRNA vaccine development

The recent advancements in messenger ribonucleic acid (mRNA) vaccine development have vastly enhanced their use as alternatives to conventional vaccines in the prevention of various infectious diseases and treatment of several types of cancers. This is mainly due to their remarkable ability to stimulate specific immune responses with minimal clinical side effects. This review gives a detailed overview of mRNA vaccines currently in use or at various stages of development, the recent advancements in mRNA vaccine development, and the challenges encountered in their development. Future perspectives on this technology are also discussed.

RNA Vaccines: Yeast as a Novel Antigen Vehicle

In the last decades, technological advances for RNA manipulation enabled and expanded its application in vaccine development. This approach comprises synthetic single-stranded mRNA molecules that direct the translation of the antigen responsible for activating the desired immune response. The success of RNA vaccines depends on the delivery vehicle. Among the systems, yeasts emerge as a new approach, already employed to deliver protein antigens, with efficacy demonstrated through preclinical and clinical trials. β-glucans and mannans in their walls are responsible for the adjuvant property of this system. Yeast β-glucan capsules, microparticles, and nanoparticles can modulate immune responses and have a high capacity to carry nucleic acids, with bioavailability upon oral immunization and targeting to receptors present in antigen-presenting cells (APCs). In addition, yeasts are suitable vehicles for the protection and specific delivery of therapeutic vaccines based on RNAi. Compared to protein antigens, the use of yeast for DNA or RNA vaccine delivery is less established and has fewer studies, most of them in the preclinical phase. Here, we present an overview of the attributes of yeast or its derivatives for the delivery of RNA-based vaccines, discussing the current challenges and prospects of this promising strategy.

A microfluidic electrophoretic dual dynamic staining method for the identification and relative quantitation of dsRNA contaminants in mRNA vaccines

mRNA vaccines (i.e., COVID-19 vaccine) offer various advantages over traditional vaccines in preventing and reducing disease and shortening the time between pathogen discovery and vaccine creation. Production of mRNA vaccines results in several nucleic acid and enzymatic by-products, most of which can be detected and removed; however, double-stranded RNA (dsRNA) contaminants pose a particular challenge. Current purification and detection platforms for dsRNA vary in effectiveness, with problems in scalability for mass mRNA vaccine production. Effectively detecting dsRNA is crucial in ensuring the safety and efficacy of the vaccines, as these strands can cause autoimmune reactions with length-symptom dependency and enhance mRNA degradation. We present a new microfluidics method to rapidly identify and quantify dsRNA fragments in mRNA samples. Our innovation exploits the differences in the dynamic staining behavior between mRNA and dsRNA molecules to detect dsRNA contaminants in a high throughput approach. The limit of detection of the system for dsRNA was estimated to be between 17.7-76.6 pg μL-1 with a maximum loading capacity of mRNA of 12.99 ng μL-1. Based on these estimated values, our method allows for the detection of dsRNA contaminants present in percentages as low as 0.14-0.59% compared to the total mRNA concentration. Here, we discuss the molecular mechanism of the dynamic staining behavior of dsRNA and mRNA for two different stains. We believe our method will accelerate the mRNA vaccine development from initial development to quality control workflows.

New trends in brain tumor immunity with the opportunities of lymph nodes targeted drug delivery

Lymph nodes targeted drug delivery is an attractive approach to improve cancer immunotherapy outcomes. Currently, the depth of understanding of afferent and efferent arms in brain immunity reveals the potential clinical applications of lymph node targeted drug delivery in brain tumors, e.g., glioblastoma. In this work, we systematically reviewed the microenvironment of glioblastoma and its structure as a basis for potential immunotherapy, including the glial-lymphatic pathway for substance exchange, the lymphatic drainage pathway from meningeal lymphatic vessels to deep cervical lymph nodes that communicate intra- and extracranial immunity, and the interaction between the blood-brain barrier and effector T cells. Furthermore, the carriers designed for lymph nodes targeted drug delivery were comprehensively summarized. The challenges and opportunities in developing a lymph nodes targeted delivery strategy for glioblastoma using nanotechnology are included at the end.

Recent Advances in Messenger Ribonucleic Acid (mRNA) Vaccines and Their Delivery Systems: A Review

Messenger ribonucleic acid (mRNA) was found as the intermediary that transfers genetic information from DNA to ribosomes for protein synthesis in 1961. The emergency use authorization of the two covid-19 mRNA vaccines, BNT162b2 and mRNA-1273, is a significant achievement in the history of vaccine development. Because they are generated in a cell-free environment using the in vitro transcription (IVT) process, mRNA vaccines are risk-free. Moreover, chemical modifications to the mRNA molecule, such as cap structures and changed nucleosides, have proved critical in overcoming immunogenicity concerns, achieving sustained stability, and achieving effective, accurate protein production in vivo. Several vaccine delivery strategies (including protamine, lipid nanoparticles (LNPs), polymers, nanoemulsions, and cell-based administration) were also optimized to load and transport RNA into the cytosol. LNPs, which are composed of a cationic or a pH-dependent ionizable lipid layer, a polyethylene glycol (PEG) component, phospholipids, and cholesterol, are the most advanced systems for delivering mRNA vaccines. Moreover, modifications of the four components that make up the LNPs showed to increase vaccine effectiveness and reduce side effects. Furthermore, the introduction of biodegradable lipids improved LNP biocompatibility. Furthermore, mRNA-based therapies are expected to be effective treatments for a variety of refractory conditions, including infectious diseases, metabolic genetic diseases, cancer, cardiovascular and cerebrovascular diseases. Therefore, the present review aims to provide the scientific community with up-to-date information on mRNA vaccines and their delivery systems.

Advances in mRNA therapeutics for cancer immunotherapy: From modification to delivery

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.

Development of nucleic acid medicines based on chemical technology

Oligonucleotide-based therapeutics have attracted attention as an emerging modality that includes the modulation of genes and their binding proteins related to diseases, allowing us to take action on previously undruggable targets. Since the late 2010s, the number of oligonucleotide medicines approved for clinical uses has dramatically increased. Various chemistry-based technologies have been developed to improve the therapeutic properties of oligonucleotides, such as chemical modification, conjugation, and nanoparticle formation, which can increase nuclease resistance, enhance affinity and selectivity to target sites, suppress off-target effects, and improve pharmacokinetic properties. Similar strategies employing modified nucleobases and lipid nanoparticles have been used for developing coronavirus disease 2019 mRNA vaccines. In this review, we provide an overview of the development of chemistry-based technologies aimed at using nucleic acids for developing therapeutics over the past several decades, with a specific emphasis on the structural design and functionality of chemical modification strategies.

Terminal hairpins improve protein expression in IRES-initiated mRNA in the absence of a cap and polyadenylated tail

Synthesizing mRNA in vitro is a standard and simple procedure. Adding the 5' cap and 3' polyadenylated (poly(A)) tail to make this mRNA functional for use as a vaccine or therapy increases the time and cost of production and usually decreases the yield, however. We designed mRNA that lacked a cap and poly(A) tail but included an internal ribosomal entry site (IRES) to initiate protein translation. To protect the 5' and 3' ends of mRNA from exonucleases, we added stable terminal hairpins. When compared against typical mRNA (i.e., mRNA that contained a cap and poly(A) tail but lacked hairpins), expression of the delivered reporter protein in HEK293 cells was similar. Using a triple instead of a single hairpin at each end increased protein expression even more. This method has the potential to simplify the production and reduce the cost of synthesizing exogenous mRNA for use as biologics or vaccines.

Recent Advancement in mRNA Vaccine Development and Applications

Messenger RNA (mRNA) vaccine development for preventive and therapeutic applications has evolved rapidly over the last decade. The mRVNA vaccine has proven therapeutic efficacy in various applications, including infectious disease, immunotherapy, genetic disorders, regenerative medicine, and cancer. Many mRNA vaccines have made it to clinical trials, and a couple have obtained FDA approval. This emerging therapeutic approach has several advantages over conventional methods: safety; efficacy; adaptability; bulk production; and cost-effectiveness. However, it is worth mentioning that the delivery to the target site and in vivo degradation and thermal stability are boundaries that can alter their efficacy and outcomes. In this review, we shed light on different types of mRNA vaccines, their mode of action, and the process to optimize their development and overcome their limitations. We also have explored various delivery systems focusing on the nanoparticle-mediated delivery of the mRNA vaccine. Generally, the delivery system plays a vital role in enhancing mRNA vaccine stability, biocompatibility, and homing to the desired cells and tissues. In addition to their function as a delivery vehicle, they serve as a compartment that shields and protects the mRNA molecules against physical, chemical, and biological activities that can alter their efficiency. Finally, we focused on the future considerations that should be attained for safer and more efficient mRNA application underlining the advantages and disadvantages of the current mRNA vaccines.

Pesticide pestilence: Global scenario and recent advances in detection and degradation methods

Increased anthropogenic activities are confronted as the main cause for rising environmental and health concerns globally, presenting an indisputable threat to both environment and human well-being. Modern-day industrialization has given rise to a cascade of concurrent environmental and health challenges. The global human population is growing at an alarming rate, posing tremendous pressure on future food security, and healthy and environmentally sustainable diets for all. To feed all, the global food production needs to increase by 50% by 2050, but this increase has to occur from the limited arable land, and under the present-day climate variabilities. Pesticides have become an integral component of contemporary agricultural system, safeguarding crops from pests and diseases and their use must be reduce to fulfill the SDG (Sustainable Development Goals) agenda . However, their indiscriminate use, lengthy half-lives, and high persistence in soil and aquatic ecosystems have impacted global sustainability, overshot the planetary boundaries and damaged the pure sources of life with severe and negative impacts on environmental and human health. Here in this review, we have provided an overview of the background of pesticide use and pollution status and action strategies of top pesticide-using nations. Additionally, we have summarized biosensor-based methodologies for the rapid detection of pesticide residue. Finally, omics-based approaches and their role in pesticide mitigation and sustainable development have been discussed qualitatively. The main aim of this review is to provide the scientific facts for pesticide management and application and to provide a clean, green, and sustainable environment for future generations.

Functions of Circular RNA in Human Diseases and Illnesses

Circular RNAs (circRNAs) represent single-stranded RNA species that contain covalently closed 3' and 5' ends that provide them more stability than linear RNA, which has free ends. Emerging evidence indicates that circRNAs perform essential functions in many DNA viruses, including coronaviruses, Epstein-Barr viruses, cytomegalovirus, and Kaposi sarcoma viruses. Recent studies have confirmed that circRNAs are present in viruses, including DNA and RNA viruses, and play various important functions such as evading host immune response, disease pathogenesis, protein translation, miRNA sponges, regulating cell proliferation, and virus replication. Studies have confirmed that circRNAs can be biological signatures or pathological markers for autoimmune diseases, neurological diseases, and cancers. However, our understanding of circRNAs in DNA and RNA viruses is still limited, and functional evaluation of viral and host circRNAs is essential to completely understand their biological functions. In the present review, we describe the metabolism and cellular roles of circRNA, including its roles in various diseases and viral and cellular circRNA functions. Circular RNAs are found to interact with RNA, proteins, and DNA, and thus can modulate cellular processes, including translation, transcription, splicing, and other functions. Circular RNAs interfere with various signaling pathways and take part in vital functions in various biological, physiological, cellular, and pathophysiological processes. We also summarize recent evidence demonstrating cellular and viral circRNA's roles in DNA and RNA viruses in this growing field of research.

Viral vectors engineered for gene therapy

Gene therapy has seen major progress in recent years. Viral vectors have made a significant contribution through efficient engineering for improved delivery and safety. A large variety of indications such as cancer, cardiovascular, metabolic, hematological, neurological, muscular, ophthalmological, infectious diseases, and immunodeficiency have been targeted. Viral vectors based on adenoviruses, adeno-associated viruses, herpes simplex viruses, retroviruses including lentiviruses, alphaviruses, flaviviruses, measles viruses, rhabdoviruses, Newcastle disease virus, poxviruses, picornaviruses, reoviruses, and polyomaviruses have been used. Proof-of-concept has been demonstrated for different indications in animal models. Therapeutic efficacy has also been achieved in clinical trials. Several viral vector-based drugs have been approved for the treatment of cancer, and hematological, metabolic, and neurological diseases. Moreover, viral vector-based vaccines have been approved against COVID-19 and Ebola virus disease.

Barriers in Heart Failure Gene Therapy and Approaches to Overcome Them

With the growing prevalence and incidence of heart failure worldwide, investigation and development of new therapies to address disease burden are of great urgency. Gene therapy is one promising approach for the management of heart failure, but several barriers currently exclude safe and efficient gene delivery to the human heart. These barriers include the anatomical and biological difficulty of specifically targeting cardiomyocytes, the vascular endothelium, and immunogenicity against administered vectors and the transgene. We review approaches taken to overcome these barriers with a focus on vector modification, evasion of immune responses, and heart-targeted delivery techniques. While various modifications proposed to date show promise in managing some barriers, continued investigation into improvements to existing therapies is required to address transduction efficiency, duration of transgene expression, and immune response.

Alphaviruses in cancer immunotherapy

Alphaviruses have frequently been engineered for cancer therapy, cancer immunotherapy, and cancer vaccine development. As members of self-replicating RNA viruses, alphaviruses provide high levels of transgene expression through efficient self-amplifying of their RNA genome in host cells. Alphavirus vectors can be used as recombinant viral particles or oncolytic viruses. Alternatively, either naked or nanoparticle-encapsulated RNA and DNA replicons can be utilized. In the context of cancer prevention and treatment, antitumor, cytotoxic and suicide genes have been expressed from alphavirus vectors to provide tumor regression and tumor eradication. Moreover, immunostimulatory genes such as cytokines and chemokines have been used for cancer immunotherapy approaches. Expression of tumor antigens has been applied for cancer vaccine development. Alphavirus vectors has demonstrated tumor regression and even cure in various preclinical animal models. Immunization has elicited strong immune responses and showed protection against challenges with tumor cells in animal models. Several clinical trials have confirmed good safety and tolerability of alphaviruses in cancer patients although therapeutic efficacy will still require optimization.

Effective mRNA Delivery by Condensation with Cationic Nanogels Incorporated into Liposomes

The challenge in effective delivery of mRNA has been a major hurdle in their development as therapeutics. Herein, we present that the incorporation of cationic nanogels as the condensing material for mRNA into liposomes enables stable and enhanced mRNA delivery to cells in vitro. We prepared dextran-based nanogel particles, which were surface functionalized with oligoarginine peptide (DNPR9) and complexed with mRNA for incorporation into liposomes (LipoDNPR9). The use of DNPR9 with the liposomes resulted in enhanced internalization, as well as a 4-fold increase in transfection of luciferase mRNA when treated with A549 cells in vitro, compared to control liposomes. The enhancement in transfection efficiency was also observed in various cell lines while causing low cytotoxicity. The versatility of the strategy was also investigated by applying DNPR9 for mRNA condensation to ionizable lipid particles, which resulted in an ∼55% increase in transfection. The current development based on nanogel-incorporated liposomes introduces an effective platform for mRNA delivery, while the condensation strategy using DNPR9 can be widely applied for various lipid-based formulations to enhance their efficacy.

Optimization of formulation and atomization of lipid nanoparticles for the inhalation of mRNA

Lipid nanoparticles (LNPs) have demonstrated efficacy and safety for mRNA vaccine administration by intramuscular injection; however, the pulmonary delivery of mRNA encapsulated LNPs remains challenging. The atomization process of LNPs will cause shear stress due to dispersed air, air jets, ultrasonication, vibrating mesh etc., leading to the agglomeration or leakage of LNPs, which can be detrimental to transcellular transport and endosomal escape. In this study, the LNP formulation, atomization methods and buffer system were optimized to maintain the LNP stability and mRNA efficiency during the atomization process. Firstly, a suitable LNP formulation for atomization was optimized based on the in vitro results, and the optimized LNP formulation was AX4, DSPC, cholesterol and DMG-PEG_2K at a 35/16/46.5/2.5 (%) molar ratio. Subsequently, different atomization methods were compared to find the most suitable method to deliver mRNA-LNP solution. Soft mist inhaler (SMI) was found to be the best for pulmonary delivery of mRNA encapsulated LNPs. The physico-chemical properties such as size and entrapment efficiency (EE) of the LNPs were further improved by adjusting the buffer system with trehalose. Lastly, the in vivo fluorescence imaging of mice demonstrated that SMI with proper LNPs design and buffer system hold promise for inhaled mRNA-LNP therapies.

Quantification of SARS-CoV-2 spike protein expression from mRNA vaccines using isotope dilution mass spectrometry

The advent of mRNA vaccine technology has been vital in rapidly creating and manufacturing COVID-19 vaccines at an industrial scale. To continue to accelerate this leading vaccine technology, an accurate method is needed to quantify antigens produced by the transfection of cells with a mRNA vaccine product. This will allow monitoring of protein expression during mRNA vaccine development and provide information on how changes to vaccine components affects the expression of the desired antigen. Developing novel approaches that allow for high-throughput screening of vaccines to detect changes in antigen production in cell culture prior to in vivo studies could aid vaccine development. We have developed and optimized an isotope dilution mass spectrometry method to detect and quantify the spike protein expressed after transfection of baby hamster kidney cells with expired COVID-19 mRNA vaccines. Five peptides of the spike protein are simultaneously quantified and provide assurance that protein digestion in the region of the target peptides is complete since results between the five peptides had a relative standard deviation of less than 15 %. In addition, two housekeeping proteins, actin and GAPDH, are quantified in the same analytical run to account for any variation in cell growth within the experiment. IDMS allows a precise and accurate means to quantify protein expression by mammalian cells transfected with an mRNA vaccine.

Nanomaterials for mRNA-based therapeutics: Challenges and opportunities

Messenger RNA (mRNA) holds great potential in developing immunotherapy, protein replacement, and genome editing. In general, mRNA does not have the risk of being incorporated into the host genome and does not need to enter the nucleus for transfection, and it can be expressed even in nondividing cells. Therefore, mRNA-based therapeutics provide a promising strategy for clinical treatment. However, the efficient and safe delivery of mRNA remains a crucial constraint for the clinical application of mRNA therapeutics. Although the stability and tolerability of mRNA can be enhanced by directly retouching the mRNA structure, there is still an urgent need to improve the delivery of mRNA. Recently, significant progress has been made in nanobiotechnology, providing tools for developing mRNA nanocarriers. Nano-drug delivery system is directly used for loading, protecting, and releasing mRNA in the biological microenvironment and can be used to stimulate the translation of mRNA to develop effective intervention strategies. In the present review, we summarized the concept of emerging nanomaterials for mRNA delivery and the latest progress in enhancing the function of mRNA, primarily focusing on the role of exosomes in mRNA delivery. Moreover, we outlined its clinical applications so far. Finally, the key obstacles of mRNA nanocarriers are emphasized, and promising strategies to overcome these obstacles are proposed. Collectively, nano-design materials exert functions for specific mRNA applications, provide new perception for next-generation nanomaterials, and thus revolution of mRNA technology.

Targeted DNA Demethylation: Vectors, Effectors and Perspectives

Aberrant DNA hypermethylation at regulatory cis-elements of particular genes is seen in a plethora of pathological conditions including cardiovascular, neurological, immunological, gastrointestinal and renal diseases, as well as in cancer, diabetes and others. Thus, approaches for experimental and therapeutic DNA demethylation have a great potential to demonstrate mechanistic importance, and even causality of epigenetic alterations, and may open novel avenues to epigenetic cures. However, existing methods based on DNA methyltransferase inhibitors that elicit genome-wide demethylation are not suitable for treatment of diseases with specific epimutations and provide a limited experimental value. Therefore, gene-specific epigenetic editing is a critical approach for epigenetic re-activation of silenced genes. Site-specific demethylation can be achieved by utilizing sequence-dependent DNA-binding molecules such as zinc finger protein array (ZFA), transcription activator-like effector (TALE) and clustered regularly interspaced short palindromic repeat-associated dead Cas9 (CRISPR/dCas9). Synthetic proteins, where these DNA-binding domains are fused with the DNA demethylases such as ten-eleven translocation (Tet) and thymine DNA glycosylase (TDG) enzymes, successfully induced or enhanced transcriptional responsiveness at targeted loci. However, a number of challenges, including the dependence on transgenesis for delivery of the fusion constructs, remain issues to be solved. In this review, we detail current and potential approaches to gene-specific DNA demethylation as a novel epigenetic editing-based therapeutic strategy.

Bioinspired Lipid Nanocarriers for RNA Delivery

RNA therapy is a disruptive technology comprising a rapidly expanding category of drugs. Further translation of RNA therapies to the clinic will improve the treatment of many diseases and help enable personalized medicine. However, in vivo delivery of RNA remains challenging due to the lack of appropriate delivery tools. Current state-of-the-art carriers such as ionizable lipid nanoparticles still face significant challenges, including frequent localization to clearance-associated organs and limited (1-2%) endosomal escape. Thus, delivery vehicles must be improved to further unlock the full potential of RNA therapeutics. An emerging strategy is to modify existing or new lipid nanocarriers by incorporating bioinspired design principles. This method generally aims to improve tissue targeting, cellular uptake, and endosomal escape, addressing some of the critical issues facing the field. In this review, we introduce the different strategies for creating bioinspired lipid-based RNA carriers and discuss the potential implications of each strategy based on reported findings. These strategies include incorporating naturally derived lipids into existing nanocarriers and mimicking bioderived molecules, viruses, and exosomes. We evaluate each strategy based on the critical factors required for delivery vehicles to succeed. Finally, we point to areas of research that should be furthered to enable the more successful rational design of lipid nanocarriers for RNA delivery.

Lipid Nanoparticles as Promising Carriers for mRNA Vaccines for Viral Lung Infections

In recent years, there has been an increase in deaths due to infectious diseases, most notably in the context of viral respiratory pathogens. Consequently, the focus has shifted in the search for new therapies, with attention being drawn to the use of nanoparticles in mRNA vaccines for targeted delivery to improve the efficacy of these vaccines. Notably, mRNA vaccine technologies denote as a new era in vaccination due to their rapid, potentially inexpensive, and scalable development. Although they do not pose a risk of integration into the genome and are not produced from infectious elements, they do pose challenges, including exposing naked mRNAs to extracellular endonucleases. Therefore, with the development of nanotechnology, we can further improve their efficacy. Nanoparticles, with their nanometer dimensions, move more freely in the body and, due to their small size, have unique physical and chemical properties. The best candidates for vaccine mRNA transfer are lipid nanoparticles (LNPs), which are stable and biocompatible and contain four components: cationic lipids, ionizable lipids, polyethylene glycols (PEGs), and cholesterol, which are used to facilitate cytoplasmic mRNA delivery. In this article, the components and delivery system of mRNA-LNP vaccines against viral lung infections such as influenza, coronavirus, and respiratory syncytial virus are reviewed. Moreover, we provide a succinct overview of current challenges and potential future directions in the field.

An insight overview on COVID-19 mRNA vaccines: Advantageous, pharmacology, mechanism of action, and prospective considerations

The worldwide spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has urged scientists to present some novel vaccine platforms during this pandemic to provide a rather prolonged immunity against this respiratory viral infection. In spite of many campaigns formed against the administration of mRNA-based vaccines, those platforms were the most novel types, which helped us meet the global demand by developing protection against COVID-19 and reducing the development of severe forms of this respiratory viral infection. Some societies are worry about the COVID-19 mRNA vaccine administration and the potential risk of genetic integration of inoculated mRNA into the human genome. Although the efficacy and long-term safety of mRNA vaccines have not yet been fully clarified, obviously their application has switched the mortality and morbidity of the COVID-19 pandemic. This study describes the structural features and technologies used in producing of COVID-19 mRNA-based vaccines as the most influential factor in controlling this pandemic and a successful pattern for planning to produce other kind of genetic vaccines against infections or cancers.

Nucleic acid-based vaccine platforms against the coronavirus disease 19 (COVID-19)

The coronavirus disease 2019 (COVID-19) pandemic has infected 673,010,496 patients and caused the death of 6,854,959 cases globally until today. Enormous efforts have been made to develop fundamentally different COVID-19 vaccine platforms. Nucleic acid-based vaccines consisting of mRNA and DNA vaccines (third-generation vaccines) have been promising in terms of rapid and convenient production and efficient provocation of immune responses against the COVID-19. Several DNA-based (ZyCoV-D, INO-4800, AG0302-COVID19, and GX-19N) and mRNA-based (BNT162b2, mRNA-1273, and ARCoV) approved vaccine platforms have been utilized for the COVID-19 prevention. mRNA vaccines are at the forefront of all platforms for COVID-19 prevention. However, these vaccines have lower stability, while DNA vaccines are needed with higher doses to stimulate the immune responses. Intracellular delivery of nucleic acid-based vaccines and their adverse events needs further research. Considering re-emergence of the COVID-19 variants of concern, vaccine reassessment and the development of polyvalent vaccines, or pan-coronavirus strategies, is essential for effective infection prevention.

The mRNA Vaccine Technology Era and the Future Control of Parasitic Infections

Despite intensive long-term efforts, with very few exceptions, the development of effective vaccines against parasitic infections has presented considerable challenges, given the complexity of parasite life cycles, the interplay between parasites and their hosts, and their capacity to escape the host immune system and to regulate host immune responses. For many parasitic diseases, conventional vaccine platforms have generally proven ill suited, considering the complex manufacturing processes involved and the costs they incur, the inability to posttranslationally modify cloned target antigens, and the absence of long-lasting protective immunity induced by these antigens. An effective antiparasite vaccine platform is required to assess the effectiveness of novel vaccine candidates at high throughput. By exploiting the approach that has recently been used successfully to produce highly protective COVID mRNA vaccines, we anticipate a new wave of research to advance the use of mRNA vaccines to prevent parasitic infections in the near future. This article considers the characteristics that are required to develop a potent antiparasite vaccine and provides a conceptual foundation to promote the development of parasite mRNA-based vaccines. We review the recent advances and challenges encountered in developing antiparasite vaccines and evaluate the potential of developing mRNA vaccines against parasites, including those causing diseases such as malaria and schistosomiasis, against which vaccines are currently suboptimal or not yet available.

Current Status and Patent Prospective of Lipid Nanoparticle for mRNA Delivery

INTRODUCTION

mRNA-LNP delivery is currently a research hotspot in pharmaceutics. Lipid nanoparticle has emerged in pharmaceutical industry as popular and effective vehicles for mRNA delivery. It is therefore significant to understand current landscape and recent development of lipid nanoparticle for mRNA delivery.

AREAS COVERED

This article provides patent landscape and recent development for mRNA-LNP delivery by US-granted patent analysis. The US-granted patents from January 2003 to December 2022 were retrieved and analyzed by using patsnap.

EXPERT OPINION

Globally, the present article was the first one which showed that mRNA-LNP delivery system demonstrated three therapeutic applications including vaccines, anticancer, and diseases associated with protein or enzyme deficiencies. Modernatx is most powerful company, and leads almost all technologies in mRNA-LNP field. In addition, the technologies related to lipid nanoparticle for mRNA delivery are virtually controlled by top three assignees. mRNA-LNP delivery in therapy of diseases associated with enzyme deficiencies may be a future trend. The article provides recent advances in lipid nanoparticle for mRNA delivery.

A New Strategy for Nucleic Acid Delivery and Protein Expression Using Biocompatible Nanohydrogels of Predefined Sizes

We have developed new formulations of nanohydrogels (NHGs) complexed with DNA devoid of cell toxicity, which, together with their tuned sizes, makes them of great interest for delivering DNA/RNA for foreign protein expression. Transfection results demonstrate that, unlike classical lipo/polyplexes, the new NHGs can be incubated indefinitely with cells without apparent cellular toxicity, resulting in the high expression of foreign proteins for long periods of time. Although protein expression starts with a delay as compared to classical systems, it is sustained for a long period of time, even after passing cells without observation of toxicity. A fluorescently labelled NHG used for gene delivery was detected inside cells very early after incubation, but the protein expression was delayed by many days, demonstrating that there is a time-dependent release of genes from the NHGs. We suggest that this delay is due to the slow but continuous release of DNA from the particles concomitantly with slow but continuous protein expression. Additionally, results obtained after the in vivo administration of m-Cherry/NHG complexes indicated a delayed but prolonged expression of the marker gene in the tissue of administration. Overall, we have demonstrated gene delivery and foreign protein expression using GFP and m-Cherry marker genes complexed with biocompatible nanohydrogels.

COVID-19-Induced Myocarditis: Pathophysiological Roles of ACE2 and Toll-like Receptors

The clinical manifestations of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection responsible for coronavirus disease 2019 (COVID-19) commonly include dyspnoea and fatigue, and they primarily involve the lungs. However, extra-pulmonary organ dysfunctions, particularly affecting the cardiovascular system, have also been observed following COVID-19 infection. In this context, several cardiac complications have been reported, including hypertension, thromboembolism, arrythmia and heart failure, with myocardial injury and myocarditis being the most frequent. These secondary myocardial inflammatory responses appear to be associated with a poorer disease course and increased mortality in patients with severe COVID-19. In addition, numerous episodes of myocarditis have been reported as a complication of COVID-19 mRNA vaccinations, especially in young adult males. Changes in the cell surface expression of angiotensin-converting enzyme 2 (ACE2) and direct injury to cardiomyocytes resulting from exaggerated immune responses to COVID-19 are just some of the mechanisms that may explain the pathogenesis of COVID-19-induced myocarditis. Here, we review the pathophysiological mechanisms underlying myocarditis associated with COVID-19 infection, with a particular focus on the involvement of ACE2 and Toll-like receptors (TLRs).

Optimal delivery strategies for nanoparticle-mediated mRNA delivery

Messenger RNA (mRNA) has emerged as a new and efficient agent for the treatment of various diseases. The success of lipid nanoparticle-mRNA against the novel coronavirus (SARS-CoV-2) pneumonia epidemic has proved the clinical potential of nanoparticle-mRNA formulations. However, the deficiency in the effective biological distribution, high transfection efficiency and good biosafety are still the major challenges in clinical translation of nanomedicine for mRNA delivery. To date, a variety of promising nanoparticles have been constructed and then gradually optimized to facilitate the effective biodistribution of carriers and efficient mRNA delivery. In this review, we describe the design of nanoparticles with an emphasis on lipid nanoparticles, and discuss the manipulation strategies for nanoparticle-biology (nano-bio) interactions for mRNA delivery to overcome the biological barriers and improve the delivery efficiency, because the specific nano-bio interaction of nanoparticles usually remoulds the biomedical and physiological properties of the nanoparticles especially the biodistribution, mechanism of cellular internalization and immune response. Finally, we give a perspective for the future applications of this promising technology. We believe that the regulation of nano-bio interactions would be a significant breakthrough to improve the mRNA delivery efficiency and cross biological barriers. This review may provide a new direction for the design of nanoparticle-mediated mRNA delivery systems.

High-efficiency editing in hematopoietic stem cells and the HUDEP-2 cell line based on in vitro mRNA synthesis

Introduction: Genome editing tools, such as CRISPR/Cas, TALE nucleases and, more recently, double-strand-break-independent editors, have been successfully used for gene therapy and reverse genetics. Among various challenges in the field, tolerable and efficient delivery of editors to target cells and sites, as well as independence from commercially available tools for flexibility and fast adoption of new editing technology are the most pressing. For many hematopoietic research applications, primary CD34+ cells and the human umbilical cord-derived progenitor erythroid 2 (HUDEP-2) cell line are highly informative substrates and readily accessible for in vitro manipulation. Moreover, ex vivo editing of CD34+ cells has immediate therapeutic relevance. Both cell types are sensitive to standard transfection procedures and reagents, such as lipofection with plasmid DNA, calling for more suitable methodology in order to achieve high efficiency and tolerability of editing with editors of choice. These challenges can be addressed by RNA delivery, either as a mixture of guide RNA and mRNA for CRISRP/Cas-based systems or as a mixture of mRNAs for TALENs. Compared to ribonucleoproteins or proteins, RNA as vector creates flexibility by removing dependence on commercial availability or laborious in-house preparations of novel editor proteins. Compared to DNA, RNA is less toxic and by obviating nuclear transcription and export of mRNA offers faster kinetics and higher editing efficiencies. Methods: Here, we detail an in vitro transcription protocol based on plasmid DNA templates with the addition of Anti-Reverse Cap Analog (ARCA) using T7 RNA polymerase, and poly (A) tailing using poly (A) polymerase, combined with nucleofection of HUDEP-2 and patient-derived CD34+ cells. Our protocol for RNA-based delivery employs widely available reagents and equipment and can easily be adopted for universal in vitro delivery of genome editing tools. Results and Discussion: Drawing on a common use case, we employ the protocol to target a β-globin mutation and to reactivate γ-globin expression as two potential therapies for β-hemoglobinopathies, followed by erythroid differentiation and functional analyses. Our protocol allows high editing efficiencies and unimpaired cell viability and differentiation, with scalability, suitability for functional assessment of editing outcomes and high flexibility in the application to different editors.

Lipid nanomaterials-based RNA therapy and cancer treatment

We summarize the most important advances in RNA delivery and nanomedicine. We describe lipid nanoparticle-based RNA therapeutics and the impacts on the development of novel drugs. The fundamental properties of the key RNA members are described. We introduced recent advances in the nanoparticles to deliver RNA to defined targets, with a focus on lipid nanoparticles (LNPs). We review recent advances in biomedical therapy based on RNA drug delivery and state-of-the-art RNA application platforms, including the treatment of different types of cancer. This review presents an overview of current LNPs based RNA therapies in cancer treatment and provides deep insight into the development of future nanomedicines sophisticatedly combining the unparalleled functions of RNA therapeutics and nanotechnology.