Opportunities and Challenges in the Delivery of mRNA-based Vaccines

RNA vaccines: The dawn of a new age for tuberculosis?

Since 2019, there has been a growing focus on mRNA vaccines for infectious disease prevention, particularly following the emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). mRNA vaccines offer advantages such as rapid production and the ability to induce robust cellular and antibody responses, which are essential for combating infections that require cell-mediated immunity, including Tuberculosis (TB). This review explores recent progress in TB mRNA vaccines and addresses several key areas: (1) the urgent need for new TB vaccines; (2) current advancements in TB vaccine development, and the advantages and challenges of mRNA technology; (3) the design and characteristics of TB mRNA vaccines; (4) the immunological mechanisms of TB mRNA vaccines; (5) manufacturing processes for TB mRNA vaccines; and (6) safety and regulatory considerations. This interdisciplinary review aims to provide insights for researchers working to address critical questions in TB mRNA vaccine development.

Lipid nanoparticle (LNP) mediated mRNA delivery in neurodegenerative diseases

Neurodegenerative diseases (NDD) are characterized by the progressive loss of neurons and the impairment of cellular functions. Messenger RNA (mRNA) has emerged as a promising therapy for treating NDD, as it can encode missing or dysfunctional proteins and anti-inflammatory cytokines or neuroprotective proteins to halt the progression of these diseases. However, effective mRNA delivery to the central nervous system (CNS) remains a significant challenge due to the limited penetration of the blood-brain barrier (BBB). Lipid nanoparticles (LNPs) offer an efficient solution by encapsulating and protecting mRNA, facilitating transfection and intracellular delivery. This review discusses the pathophysiological mechanisms of neurological disorders, including Parkinson's disease (PD), Alzheimer's disease (AD), multiple sclerosis (MS), Huntington's disease (HD), ischemic stroke, spinal cord injury, and Friedreich's ataxia. Additionally, it explores the potential of LNP-mediated mRNA delivery as a therapeutic strategy for these diseases. Various approaches to overcoming BBB-related challenges and enhancing the delivery and efficacy of mRNA-LNPs are discussed, including non-invasive methods with strong potential for clinical translation. With advancements in artificial intelligence (AI)-guided mRNA and LNP design, targeted delivery, gene editing, and CAR-T cell therapy, mRNA-LNPs could significantly transform the treatment landscape for NDD, paving the way for future clinical applications.

RNA research for drug discovery: Recent advances and critical insight

The field of RNA research has experienced significant changes and is now at the forefront of contemporary drug development. This narrative overview explores the scientific developments and historical turning points in RNA research, emphasising the field's critical significance in the development of novel therapeutics. Important discoveries like antisense oligonucleotides (ASOs), mRNA therapies, and RNA interference (RNAi) have created novel treatment options that can be targeted, such as the ground-breaking mRNA vaccinations against COVID-19. Advances in high-throughput sequencing, single-cell RNA sequencing, and epitranscriptomics have further unravelled the complexity of RNA biology, shedding light on the intricacies of gene regulation and cellular diversity. The integration of computational tools and bioinformatics has propelled the identification of RNA-based biomarkers and the development of RNA therapeutics. Despite significant progress, challenges such as RNA stability, delivery, and off-target effects persist, necessitating continuous innovation and ethical considerations. This review provides a critical insight into the current state and prospects of RNA research, emphasising its transformative potential in drug discovery. By examining the interplay between technological advancements and therapeutic applications, we underscore the promising horizon for RNA-based interventions in treating a myriad of diseases, marking a new era in precision medicine.

State of the art in CAR-based therapy: In vivo CAR production as a revolution in cell-based cancer treatment

Chimeric antigen receptor (CAR) therapy has successfully treated relapsed/refractory hematological cancers. This strategy can effectively target tumor cells. However, despite positive outcomes in clinical applications, challenges remain to overcome. These hurdles pertain to the production of the drugs, solid tumor resistance, and side effects related to the treatment. Some cases have been missed during the drug preparation due to manufacturing issues, prolonged production times, and high costs. These challenges mainly arise from the in vitro manufacturing process, so reevaluating this process could minimize the number of missed patients. The immune cells are traditionally collected and sent to the laboratory; after several steps, the cells are modified to express the CAR gene before being injected back into the patient's body. During the in vivo method, the CAR gene is introduced to the immune cells inside the body. This allows for treatment to begin sooner, avoiding potential failures in drug preparation and the associated high costs. In this review, we will elaborate on the production and treatment process using in vivo CAR, examine the benefits and challenges of this approach, and ultimately present the available solutions for incorporating this treatment into clinical practice.

Spike protein-related proteinopathies: A focus on the neurological side of spikeopathies

BACKGROUND

The spike protein (SP) is an outward-projecting transmembrane glycoprotein on viral surfaces. SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), responsible for COVID-19 (Coronavirus Disease 2019), uses SP to infect cells that express angiotensin converting enzyme 2 (ACE2) on their membrane. Remarkably, SP has the ability to cross the blood-brain barrier (BBB) into the brain and cause cerebral damage through various pathomechanisms. To combat the COVID-19 pandemic, novel gene-based products have been used worldwide to induce human body cells to produce SP to stimulate the immune system. This artificial SP also has a harmful effect on the human nervous system.

STUDY DESIGN

Narrative review.

OBJECTIVE

This narrative review presents the crucial role of SP in neurological complaints after SARS-CoV-2 infection, but also of SP derived from novel gene-based anti-SARS-CoV-2 products (ASP).

METHODS

Literature searches using broad terms such as "SARS-CoV-2", "spike protein", "COVID-19", "COVID-19 pandemic", "vaccines", "COVID-19 vaccines", "post-vaccination syndrome", "post-COVID-19 vaccination syndrome" and "proteinopathy" were performed using PubMed. Google Scholar was used to search for topic-specific full-text keywords.

CONCLUSIONS

The toxic properties of SP presented in this review provide a good explanation for many of the neurological symptoms following SARS-CoV-2 infection and after injection of SP-producing ASP. Both SP entities (from infection and injection) interfere, among others, with ACE2 and act on different cells, tissues and organs. Both SPs are able to cross the BBB and can trigger acute and chronic neurological complaints. Such SP-associated pathologies (spikeopathies) are further neurological proteinopathies with thrombogenic, neurotoxic, neuroinflammatory and neurodegenerative potential for the human nervous system, particularly the central nervous system. The potential neurotoxicity of SP from ASP needs to be critically examined, as ASPs have been administered to millions of people worldwide.

Replicon RNA vaccines: design, delivery, and immunogenicity in infectious diseases and cancer

Replicon RNA (RepRNA) represents a cutting-edge technology in the field of vaccinology, fundamentally transforming vaccine design and development. This innovative approach facilitates the induction of robust immune responses against a range of infectious diseases and cancers. RepRNA vaccines leverage the inherent capabilities of RNA-dependent RNA polymerase associated with self-replicating repRNA, allowing for extreme replication within host cells. This process enhances antigen production and subsequently stimulates adaptive immunity. Additionally, the generation of double-stranded RNA during RNA replication can activate innate immune responses. Numerous studies have demonstrated that repRNA vaccines elicit potent humoral and cellular immune responses that are broader and more durable than those generated by conventional mRNA vaccines. These significant immune responses have been shown to provide protection in various models for infectious diseases and cancers. This article will explore the design and delivery of RepRNA vaccines, the mechanisms of immune activation, preclinical studies addressing infectious diseases and tumors, and related clinical trials that focus on safety and immunogenicity.

Non-Viral RNA Therapies for Non-Small Cell Lung Cancer and Their Corresponding Clinical Trials

Ribonucleic acid (RNA)-based therapies represent a promising class of drugs for the treatment of non-small cell lung cancer (NSCLC) due to their ability to modulate gene expression. Therapies leveraging small interfering RNA (siRNA), messenger RNA (mRNA), microRNA (miRNA), and antisense oligonucleotides (ASOs) offer various advantages over conventional treatments, including the ability to target specific genetic mutations and the potential for personalized medicine approaches. However, the clinical translation of these therapeutics for the treatment of NSCLC faces challenges in delivery due to their immunogenicity, negative charge, and large size, which can be mitigated with delivery platforms. In this review, we provide a description of the pathophysiology of NSCLC and an overview of RNA-based therapeutics, specifically highlighting their potential application in the treatment of NSCLC. We discuss relevant classes of RNA and their therapeutic potential for NSCLC. We then discuss challenges in delivery and non-viral delivery strategies such as lipid- and polymer-based nanoparticles that have been developed to address these issues in preclinical models. Furthermore, we provide a summary table of clinical trials that leverage RNA therapies for NSCLC [which includes their National Clinical Trial (NCT) numbers] to highlight the current progress in NSCLC. We also discuss how these NSCLC therapies can be integrated with existing treatment modalities to enhance their efficacy and improve patient outcomes. Overall, we aim to highlight non-viral strategies that tackle RNA delivery challenges while showcasing RNA's potential as a next-generation therapy for NSCLC treatment.

Incorporation of cellular membrane protein extracts into lipid nanoparticles enhances their cellular uptake and mRNA delivery efficiency

mRNA therapeutics enable transient expression of desired proteins within cells, holding great potential for advancements in vaccines, protein replacement therapies and gene editing approaches. Lipid nanoparticles (LNPs) are arguably the leading nanoplatform for mRNA delivery due to their scalability and transfection efficiency. However, their limited ability to target specific cell types, inefficient cellular uptake by many cell types, and endosomal entrapment represent challenges for improving targeted mRNA delivery. To address this, we evaluated a novel class of LNPs functionalized with cell-derived membrane proteins, that we refer to as hybrisomes. Membrane protein extracts (MPEs) were isolated from cultured cells using a mild detergent-based extraction protocol. Cy5-labeled mRNA encoding for eGFP was used to form LNPs and hybrisomes to investigate their internalization efficiency and mRNA delivery via flow cytometry and microscopy, with MPE content incorporated into hybrisomes during microfluidic mixing. MPEs were successfully incorporated into the lipid membrane of hybrisomes. Remarkably, the cellular uptake of hybrisomes was up to 15-fold higher than LNPs, while the mRNA delivery efficiency improved up to 8-fold depending on the MPE content incorporated into the hybrisomes. Further studies confirmed that the enhanced cellular uptake of hybrisomes and mRNA is partially explained by the presence of membrane proteins and hybrisomes' unique morphology including bleb-like structures. Moreover, the versatility of hybrisomes was demonstrated by producing formulations using MPEs isolated from different cell types, which led to variations in cellular uptake and mRNA delivery, suggesting that the cell type from which MPEs are derived influences their biological function. These findings pave the way for the development of more targeted and effective nanotherapeutic strategies.

Tailoring nanovectors for optimal neoantigen vaccine efficacy

The primary objective of neoantigen vaccines is to elicit a robust anti-tumor immune response by generating neoantigen-specific T cells that can eradicate tumor cells. Despite substantial advancements in personalized neoantigen prediction using next-generation sequencing, machine learning, and mass spectrometry, challenges remain in efficiently expanding neoantigen-specific T cell populations in vivo. This challenge impedes the widespread clinical application of neoantigen vaccines. Nanovector-based neoantigen delivery systems have emerged as a promising solutions to this challenge. These nanovectors offer several advantages, such as enhanced stability, targeted intracellular delivery, sustained release, and improved antigen-presenting cell (APC) activation. Notably, they effectively deliver various neoantigen vaccine formulations (DC cell-based, synthetic long peptide (SLP)-based or DNA/mRNA-based) to APCs or T cells, thereby activating both CD4+ T and CD8+ T cells. This ultimately induces a specific anti-tumor immune response. This review focuses on recent innovations in neoantigen vaccine delivery vectors. We aim to identify optimal design parameters for vectors tailored to different neoantigen vaccine types, with an emphasis on enhancing the tumor microenvironment and stimulating the production of neoantigen-specific cytotoxic T cells. By maximizing the potential of these delivery systems, we aim to accelerate the clinical translation of neoantigen nanovaccines and advance cancer immunotherapy.

DragonRNA: Generality of DNA-primed RNA-extension activities by DNA-directed RNA polymerases

RNA polymerases (RNAPs) transcribe DNA into RNA. Several RNAPs, including from bacteriophages Sp6 and T7, Escherichia coli, and wheat germ, had been shown to add ribonucleotides to DNA 3' ends. Mitochondria have their own RNAPs (mtRNAPs). Examining reaction products of RNAPs acting on DNA molecules with free 3' ends, we found yeast and human mtRNAP preparations exhibit a robust activity of extending DNA 3' ends with ribonucleotides. The resulting molecules are serial DNA→RNA chains with the input DNA on the 5' end and extended RNA on the 3' end. Such chains were produced from a wide variety of DNA oligonucleotide inputs with short complementarity in the sequence to the DNA 3' end with the sequence of the RNA portion complementary to the input DNA. We provide a set of fluorescence-based assays for facile detection of such products and show that this activity is a general property of diverse RNAPs, including phage RNAPs and multi-subunit E. coli RNAP. These results support a model in which DNA serves as both primer and template, with extension beginning when the 3' end of the DNA is elongated with a ribonucleotide. As this DNA→RNA class of molecule remains unnamed, we propose the name DragonRNA.

Lipid Nanoparticles for mRNA Delivery in Cancer Immunotherapy

Cancer immunotherapy is poised to be one of the major modalities for cancer treatment. Messenger RNA (mRNA) has emerged as a versatile and promising platform for the development of effective cancer immunotherapy. Delivery systems for mRNA therapeutics are pivotal for their optimal therapeutic efficacy and minimal adverse side effects. Lipid nanoparticles (LNPs) have demonstrated a great success for mRNA delivery. Numerous LNPs have been designed and optimized to enhance mRNA stability, facilitate transfection, and ensure intracellular delivery for subsequent processing. Nevertheless, challenges remain to, for example, improve the efficiency of endosomal escape and passive targeting. This review highlights key advancements in the development of mRNA LNPs for cancer immunotherapy. We delve into the design of LNPs for mRNA delivery, encompassing the chemical structures, characterization, and structure-activity relationships (SAR) of LNP compositions. We discuss the key factors influencing the transfection efficiency, passive targeting, and tropism of mRNA-loaded LNPs. We also review the preclinical and clinical applications of mRNA LNPs in cancer immunotherapy. This review can enhance our understanding in the design and application of LNPs for mRNA delivery in cancer immunotherapy.

A novel micelleplex for tumour-targeted delivery of CRISPR-Cas9 against KRAS-mutated lung cancer

CRISPR-Cas9 has emerged as a highly effective and customizable genome editing tool, holding significant promise for the treatment of KRAS mutations in lung cancer. In this study, we introduce a novel micelleplex, named C14-PEI, designed to co-deliver Cas9 mRNA and sgRNA efficiently to excise the mutated KRAS allele in lung cancer cells. C14-PEI is synthesised from 1,2-epoxytetradecane and branched PEI 600 Da via a ring-opening reaction. The resulting C14-PEI has a critical micelle concentration (CMC) of approximately 20.86 ± 0.15 mg L-1, indicating its ability to form stable micelles at low concentrations. C14-PEI efficiently encapsulates mRNA into micelleplexes through electrostatic interactions. When the mass ratio is 8 (w/w 8), the C14-PEI formulation exhibits conducive properties, which showed encapsulation efficiency of eGFP mRNA at 99% and led to a 130-fold increase in eGFP expression in A549 cells compared to untreated cells, demonstrating the robust delivery and expression capability of the micelleplexes. Importantly, toxicity tests using intracellular reduction of a tetrazolium salt revealed no significant cytotoxicity, underscoring the biocompatibility of C14-PEI. C14-PEI also shows high efficiency in co-encapsulating Cas9 mRNA and sgRNA, as confirmed by agarose gel electrophoresis. At an sgRNA to Cas9 mRNA molar ratio of 10, the micelleplexes successfully mediate the cutting of mutated KRAS with an indel efficiency exceeding 60%, as determined by the T7 Endonuclease I (T7EI) assay. Droplet digital polymerase chain reaction (ddPCR) further demonstrates that the gene editing efficiency, measured by edited gene copies, is 48.5% in the w/w 4 group and 37.8% in the w/w 8 group. Treatment with C14-PEI micelleplexes containing Cas9 mRNA and sgRNA targeting the KRAS G12S mutation significantly impairs the migration capability of A549 cells and increases apoptosis rates. These findings suggest that C14-PEI effectively disrupts KRAS signalling pathways, leading to reduced tumor cell proliferation and enhanced cell death.

mRNA vaccine platforms: linking infectious disease prevention and cancer immunotherapy

The advent of mRNA vaccines, accelerated by the global response to the COVID-19 pandemic, marks a transformative shift in vaccine technology. In this article, we discuss the development, current applications, and prospects of mRNA vaccines for both the prevention and treatment of infectious diseases and oncology. By leveraging the capacity to encode antigens within host cells directly, mRNA vaccines provide a versatile and scalable platform suitable for addressing a broad spectrum of pathogens and tumor-specific antigens. We highlight recent advancements in mRNA vaccine design, innovative delivery mechanisms, and ongoing clinical trials, with particular emphasis on their efficacy in combating infectious diseases, such as COVID-19, Zika, and influenza, as well as their emerging potential in cancer immunotherapy. We also address critical challenges, including vaccine stability, optimization of immune responses, and the broader issue of global accessibility. Finally, we review potential strategies for advancing next-generation mRNA vaccines, with the aim of overcoming current limitations in vaccine technology and enhancing both preventive and therapeutic approaches for infectious and oncological diseases.

Cyclic Poly(2-methyl-2-oxazoline)-Lipid Conjugates Are Good Alternatives to Poly(ethylene glycol)-Lipids for Lipid Nanoparticle mRNA Formulation

Lipid nanoparticles (LNPs) with ionizable cationic lipids have revolutionized RNA drug delivery, playing a key role in the success of mRNA-based therapeutics, such as COVID-19 vaccines. A vital component of these LNPs is the poly(ethylene glycol) (PEG)-lipid conjugate, which enhances colloidal stability but may trigger the production of anti-PEG antibodies, resulting in accelerated blood clearance (ABC) and diminished therapeutic efficacy. In this study, we explored poly(2-methyl-2-oxazoline) (PMOXA) as an alternative stabilizing agent for mRNA LNPs. We synthesized both cyclic and linear PMOXA, conjugated them to dialkyl lipids, and created lipid-polymer amphiphiles. We systematically evaluated how polymer topology influenced the physicochemical properties of LNPs, including in vitro cellular uptake, transfection efficiency, and protein corona formation, and directly compared these properties with those of PEG-stabilized counterparts. In vivo experiments in mice further assessed the biodistribution and protein translation efficiency of these LNPs following intravenous administration. Our results showed that cyclic PMOXA conjugates not only matched but potentially surpassed the performance of PEG-based analogues, highlighting their promise as a superior alternative in mRNA-LNP formulations.

Technological breakthroughs and advancements in the application of mRNA vaccines: a comprehensive exploration and future prospects

mRNA vaccines utilize single-stranded linear DNA as a template for in vitro transcription. The mRNA is introduced into the cytoplasm via the corresponding delivery system to express the target protein, which then performs its relevant biological function. mRNA vaccines are beneficial in various fields, including cancer vaccines, infectious disease vaccines, protein replacement therapy, and treatment of rare diseases. They offer advantages such as a simple manufacturing process, a quick development cycle, and ease of industrialization. Additionally, mRNA vaccines afford flexibility in adjusting antigen designs and combining sequences of multiple variants, thereby addressing the issue of frequent mutations in pathogenic microorganisms. This paper aims to provide an extensive review of the global development and current research status of mRNA vaccines, with a focus on immunogenicity, classification, design, delivery vector development, stability, and biomedical application. Moreover, the study highlights current challenges and offers insights into future directions for development.

Revolutionizing mRNA Vaccines Through Innovative Formulation and Delivery Strategies

Modernization of existing methods for the delivery of mRNA is vital in advanced therapeutics. Traditionally, mRNA has faced obstacles of poor stability due to enzymatic degradation. This work examines cutting-edge formulation and emerging techniques for safer delivery of mRNA vaccines. Inspired by the success of lipid nanoparticles (LNP) in delivering mRNA vaccines for COVID-19, a variety of other formulations have been developed to deliver mRNA vaccines for diverse infections. The meritorious features of nanoparticle-based mRNA delivery strategies, including LNP, polymeric, dendrimers, polysaccharide-based, peptide-derived, carbon and metal-based, DNA nanostructures, hybrid, and extracellular vesicles, have been examined. The impact of these delivery platforms on mRNA vaccine delivery efficacy, protection from enzymatic degradation, cellular uptake, controlled release, and immunogenicity has been discussed in detail. Even with significant developments, there are certain limitations to overcome, including toxicity concerns, limited information about immune pathways, the need to maintain a cold chain, and the necessity of optimizing administration methods. Continuous innovation is essential for improving delivery systems for mRNA vaccines. Future research directions have been proposed to address the existing challenges in mRNA delivery and to expand their potential prophylactic and therapeutic application.

A capless hairpin-protected mRNA vaccine encoding the full-length Influenza A hemagglutinin protects mice against a lethal Influenza A infection

The success of mRNA vaccines in controlling the COVID 19 pandemic has confirmed the efficacy of synthetically synthesized mRNA in humans and has also provided a blueprint on how to design them in terms of molecular structure and cost. We describe a mRNA vector that, unlike linear mRNAs used in current vaccines/therapeutics, does not require a 5' cap to function. The described mRNA vector initiates translation from an internal ribosomal entry site (IRES) and contains specially designed self-folding secondary structures (hairpins) to protect the 5' end against degradation, dramatically improving its stability. The produced mRNA did not require any additional modifications for functionality. The 5' hairpins completely inhibited cap-dependent translation, and all vectors containing them required an IRES to express protein. When this capless mRNA vector was constructed to express the full-length Influenza A membrane protein hemagglutinin (HA), complexed with pre-formed lipid-based nanoparticles, and then injected into mice as a vaccine, it generated high titers of anti-HA antibodies and protected mice against a lethal dose of Influenza A.

Biomimetic Nanoparticle Based Targeted mRNA Vaccine Delivery as a Novel Therapy for Glioblastoma Multiforme

The prognosis for patients with glioblastoma multiforme (GBM), an aggressive and deadly brain tumor, is poor due to the limited therapeutic options available. Biomimetic nanoparticles have emerged as a promising vehicle for targeted mRNA vaccine delivery, thanks to recent advances in nanotechnology. This presents a novel treatment method for GBM. This review explores the potential of using biomimetic nanoparticles to improve the specificity and effectiveness of mRNA vaccine against GBM. These nanoparticles can evade immune detection, cross the blood-brain barrier, & deliver mRNA directly to glioma cells by mimicking natural biological structures. This allows glioma cells to produce tumor-specific antigens that trigger strong immune responses against the tumor. This review discusses biomimetic nanoparticle design strategies, which are critical for optimizing transport and ensuring targeted action. These tactics include surface functionalization and encapsulation techniques. It also highlights the ongoing preclinical research and clinical trials that demonstrate the therapeutic advantages and challenges of this strategy. Biomimetic nanoparticles for mRNA vaccine delivery represent a new frontier in GBM treatment, which could impact the management of this deadly disease and improve patient outcomes by integrating cutting-edge nanotechnology with immunotherapy.

Ionizable Lipids with Branched Linkers Enhance the Delivery of mRNA Vaccines

The emergence of mRNA vaccines has heralded an epoch in disease prevention and treatment. Safe and efficient mRNA delivery systems are highly desired for the widespread application of mRNA therapeutics. Herein, we have designed a facile synthetic pathway for producing ionizable lipids featuring various branched linkers. These lipids have been integrated into lipid nanoparticles (LNPs) to improve the delivery of mRNA vaccines. The influence of linker structure on lipids and LNPs is currently underreported, yet it undeniably exerts a substantial impact on the outcomes. Through systematic screening and formulation optimization, we have identified that LNPs comprising ionizable lipids with a branched β-isobutylglutarate linker (bLNPs) exhibited superior transfection capabilities. In preclinical cancer prevention and treatment models, mRNA vaccines delivered by bLNPs (mRNA-bLNPs) have shown significant efficacy without causing systemic toxicity, highlighting the potential of bLNPs for clinical translation. Our synthetic strategy facilitates the expansion of the LNP library and provides valuable insights into the relationship between linker structures and delivery efficiency, thereby propelling the advancement of LNP technology.

Advancements in Melanoma Treatment: A Review of PD-1 Inhibitors, T-VEC, mRNA Vaccines, and Tumor-Infiltrating Lymphocyte Therapy in an Evolving Landscape of Immunotherapy

Melanoma, an aggressive skin cancer, presents significant therapeutic challenges. Consequently, innovative treatment strategies beyond conventional chemotherapy, radiation, and surgery are actively explored. This review discusses the evolution of immunotherapy in advanced melanoma, highlighting PD-1/PD-L1 inhibitors, mRNA vaccines, Talimogene Laherparepvec (T-VEC), and tumor-infiltrating lymphocyte (TIL) therapies. PD-1/PD-L1 inhibitors such as pembrolizumab and nivolumab block immune checkpoints, promoting T-cell cytotoxic activity and improving overall survival in patients with advanced melanoma. T-VEC, a modified oncolytic herpes virus, promotes a systemic anti-tumor response while simultaneously lysing malignant cells. mRNA vaccines, such as Moderna's mRNA-4157/V940, take advantage of malignant-cell-specific neoantigens to amplify the adaptive immune response while protecting healthy tissue. TIL therapy is a form of therapy involving ex vivo expansion and reinfusion of the patient's tumor-specific lymphocytes and has been shown to provide durable tumor control. While these therapies have demonstrated promising clinical outcomes, challenges such as tumor resistance, high financial burden, and limited accessibility pose challenges to their widespread use. This review explores combination therapies such as PD-L1 inhibitors with mRNA vaccines, or TIL therapy, which aim to enhance treatment through synergistic approaches. Further research is required to optimize these combinations, address barriers preventing their use, and control adverse events.

Beyond the Needle: Innovative Microneedle-Based Transdermal Vaccination

Vaccination represents a critical preventive strategy in the current global healthcare system, serving as an indispensable intervention against diverse pathogenic threats. Although conventional immunization relies predominantly on hypodermic needle-based administration, this method carries substantial limitations, including needle-associated fear, bloodborne pathogen transmission risks, occupational injuries among healthcare workers, waste management issues, and dependence on trained medical personnel. Microneedle technology has emerged as an innovative vaccine delivery system, offering convenient, effective, and minimally invasive administration. These microscale needle devices facilitate targeted antigen delivery to epidermal and dermal tissues, where abundant populations of antigen-presenting cells, specifically Langerhans and dermal dendritic cells, provide robust immunological responses. Multiple research groups have extensively investigated microneedle-based vaccination strategies. This transdermal delivery technique offers several advantages, notably circumventing cold-chain requirements and enabling self-administration. Numerous preclinical investigations and clinical trials have demonstrated the safety profile, immunogenicity, and patient acceptance of microneedle-mediated vaccine delivery across diverse immunization applications. This comprehensive review examines the fundamental aspects of microneedle-based immunization, including vaccination principles, transcutaneous immunization strategies, and microneedle-based transdermal delivery-including classifications, advantages, and barriers. Furthermore, this review addresses critical technical considerations, such as treatment efficacy, application methodologies, wear duration, dimensional optimization, manufacturing processes, regulatory frameworks, and sustainability considerations, followed by an analysis of the future perspective of this technology.

Development of non-viral targeted RNA delivery vehicles - a key factor in success of therapeutic RNA

Decade-long efforts in medicinal biotechnology have enabled large-scale in-vitro production of optimised therapeutic RNA constructs for stable in-vivo delivery and modify the expression of disease-related genes. The success of lipid nanoparticle-formulated mRNA vaccines against Severe acute respiratory syndrome Coronavirus-2 (SARS-Cov2) has opened a new era of RNA therapeutics and non-viral drug delivery systems. The major limiting factor in the clinical translation of RNA-based drugs is the availability of suitable delivery vehicles that can protect RNA payloads from degradation, offer controlled release, and pose minimal inherent toxicity. Unwanted immune response, payload size constraints, genome integration, and non-specific tissue targeting limit the application of conventional viral drug-delivery vehicles. This review summarises current research on nano-sized drug carriers, including lipid nanoparticles, polymer-based formulations, cationic nanoemulsion, and cell-penetrating peptides, for targeted therapeutic RNA delivery. Further, this paper highlights the biomimetic approaches (i.e. mimicking naturally occurring bio-compositions, molecular designs, and systems), including virus-like particles (VLPs), exosomes, and selective endogenous eNcapsidation (SEND) technology being explored as safer and more efficient alternatives.

Fluorinated polyethyleneimine vectors with serum resistance and adjuvant effect to deliver LMP2 mRNA vaccine for nasopharyngeal carcinoma therapy

Latent membrane protein 2 (LMP2), which is an important protein of Epstein-Barr virus (EBV) in the latent phase to mediate metastasis and recurrence, has shown great potential as a targeting antigen in mRNA vaccine for nasopharyngeal carcinoma (NPC) therapy. In this study, an LMP2 mRNA vaccine was developed based on a serum-resistant fluorinated polyethyleneimine (TKPF) with the self-adjuvant effect for achieving a strong anti-tumor immunity in NPC treatment. Specifically, the proposed vaccine PEG[TKPF/mLMP2] was comprised of a TKPF/mLMP2 core formed by the cationic TKPF and LMP2 mRNA, together with a dialdehyde poly (ethyl glycol) (OHC-PEG-CHO) coating. PEG[TKPF/mLMP2] showed less protein absorption to enable serum resistance to maintain ∼50 % transfection efficiency under 50 % FBS media. In addition, PEG[TKPF/mLMP2] could render enhanced internalization and lysosomal escape of mRNA by DC cells via positive charge and fluorine groups, followed by efficient transfection and expression, eventually triggering DC maturation and antigen presentation to T cells as demonstrated by in vitro studies. The activated antigen-specific T cells would attack tumor cells expressing LMP2 and release pro-inflammatory cytokines including IFN-γ, IL-6, and TNF-α. Furthermore, in vivo studies manifested effective spleen transfection and activated T cells by PEG[TKPF/mLMP2] to prevent tumor cell growth and prolong mouse survival in both prophylactical and therapeutical models. Notably, PEG[TKPF] revealed self-adjuvant effect to induce a strong immune response for boosting the anti-tumor potency of LMP2 mRNA. In summary, the fabricated LMP2 mRNA vaccine facilitated by the efficient and self-adjuvant vector induced robust immunotherapeutic efficacy, providing a possible solution for NPC therapy. STATEMENT OF SIGNIFICANCE: Latent membrane protein 2 (LMP2), which is a key Epstein-Barr virus (EBV) protein for metastasis and recurrence, can be targeted as an antigen for mRNA vaccine development to treat nasopharyngeal carcinoma (NPC). However, the current LMP2 vaccine is still inefficient in inducing potent anti-NPC immunity. Although mRNA has emerged as an effective tool to rejuvenate LMP2 vaccine development, it still suffers from vulnerability to serum conditions and weak immune response. In this study, we developed an LMP2 mRNA vaccine based on a serum-resistant fluorinated polyethyleneimine (TKPF) with self-adjuvant effects to achieve strong anti-tumor immunity in NPC treatment. The proposed PEG[TKPF/mLMP2] vaccine efficiently delivers to dendritic cells (DCs) for activating T cell maturation, ultimately suppressing the growth of LMP2-expressing tumors in both prophylactic and therapeutic mouse models.

Enhanced Pulmonary and Splenic mRNA Delivery Using DOTAP-Incorporated Poly(β-Amino Ester)-Lipid Nanoparticles

mRNA-based therapies hold tremendous promise for treating various diseases, yet their clinical success is hindered by delivery challenges. This study developed a library of 140 lipocationic Poly(β-amino ester)s (PBAEs) and formulated lipid-polymer hybrid nanoparticles (LPHs) with four helper lipids, including 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), to enhance mRNA delivery. Initial in vitro screening of four representative PBAEs identified the D/P4-1 formulation (DOTAP/PBAE molar ratio of 4:1) as the most effective. Further screening of the library using this formulation identified eight top-performing LPHs. In vivo experiments confirmed high luciferase expression in the spleen and lungs of mice following intravenous administration of Luc mRNA-loaded LPHs. Detailed analysis revealed that DOTAP incorporation influenced LPH properties, including apparent pKa, surface charge, and internal hydrophobicity, enabling enhanced mRNA release and cellular uptake. This study demonstrates potent approaches to modulate PBAE-lipid nanoparticle properties by altering PBAE structures and nanoparticle composition, offering insights for designing effective hybrid carriers for mRNA therapeutics.

Advancing Therapeutic Strategies with Polymeric Drug Conjugates for Nucleic Acid Delivery and Treatment

The effective clinical translation of messenger RNA (mRNA), small interfering RNA (siRNA), and microRNA (miRNA) for therapeutic purposes hinges on the development of efficient delivery systems. Key challenges include their susceptibility to degradation, limited cellular uptake, and inefficient intracellular release. Polymeric drug conjugates (PDCs) offer a promising solution, combining the benefits of polymeric carriers and therapeutic agents for targeted delivery and treatment. This comprehensive review explores the clinical translation of nucleic acid therapeutics, focusing on polymeric drug conjugates. It investigates how these conjugates address delivery obstacles, enhance systemic circulation, reduce immunogenicity, and provide controlled release, improving safety profiles. The review delves into the conjugation strategies, preparation methods, and various classes of PDCs, as well as strategic design, highlighting their role in nucleic acid delivery. Applications of PDCs in treating diseases such as cancer, immune disorders, and fibrosis are also discussed. Despite significant advancements, challenges in clinical adoption persist. The review concludes with insights into future directions for this transformative technology, underscoring the potential of PDCs to advance nucleic acid-based therapies and combat infectious diseases significantly.

Lipid-Based Nanocarriers for Targeted Gene Delivery in Lung Cancer Therapy: Exploring a Novel Therapeutic Paradigm

Lung cancer is a significant cause of cancer-related death worldwide. It can be broadly categorised into small-cell lung cancer (SCLC) and Non-small cell lung cancer (NSCLC). Surgical intervention, radiation therapy, and the administration of chemotherapeutic medications are among the current treatment modalities. However, the application of chemotherapy may be limited in more advanced stages of metastasis due to the potential for adverse effects and a lack of cell selectivity. Although small-molecule anticancer treatments have demonstrated effectiveness, they still face several challenges. The challenges at hand in this context comprise insufficient solubility in water, limited bioavailability at specific sites, adverse effects, and the requirement for epidermal growth factor receptor inhibitors that are genetically tailored. Bio-macromolecular drugs, including small interfering RNA (siRNA) and messenger RNA (mRNA), are susceptible to degradation when exposed to the bodily fluids of humans, which can reduce stability and concentration. In this context, nanoscale delivery technologies are utilised. These agents offer encouraging prospects for the preservation and regulation of pharmaceutical substances, in addition to improving the solubility and stability of medications. Nanocarrier-based systems possess the notable advantage of facilitating accurate and sustained drug release, as opposed to traditional systemic methodologies. The primary focus of scientific investigation has been to augment the therapeutic efficacy of nanoparticles composed of lipids. Numerous nanoscale drug delivery techniques have been implemented to treat various respiratory ailments, such as lung cancer. These technologies have exhibited the potential to mitigate the limitations associated with conventional therapy. As an illustration, applying nanocarriers may enhance the solubility of small-molecule anticancer drugs and prevent the degradation of bio-macromolecular drugs. Furthermore, these devices can administer medications in a controlled and extended fashion, thereby augmenting the therapeutic intervention's effectiveness and reducing adverse reactions. However, despite these promising results, challenges remain that must be addressed. Multiple factors necessitate consideration when contemplating the application of nanoparticles in medical interventions. To begin with, the advancement of more efficient delivery methods is imperative. In addition, a comprehensive investigation into the potential toxicity of nanoparticles is required. Finally, additional research is needed to comprehend these treatments' enduring ramifications. Despite these challenges, the field of nanomedicine demonstrates considerable promise in enhancing the therapy of lung cancer and other respiratory diseases.

mRNA cancer vaccines from bench to bedside: a new era in cancer immunotherapy

Harnessing the power of the immune system to target cancer cells is one of the most appealing approaches for cancer therapy. Among these immunotherapies, messenger ribonucleic acid (mRNA) cancer vaccines are worthy of consideration, as they have demonstrated promising results in clinical trials. These vaccines have proven to be safe and well-tolerated. They can be easily mass-produced in a relatively short time and induce a systemic immune response effective against both the primary tumor and metastases. Transcripts encoding immunomodulatory molecules can also be incorporated into the mRNA, enhancing its efficacy. On the other hand, there are some challenges associated with their application, including mRNA instability, insufficient uptake by immune cells, and intrinsic immunogenicity, which can block mRNA translation. Many innovations have been suggested to overcome these obstacles, including structural modification (such as 5' cap modification), optimizing delivery vehicles (especially dendritic cells (DCs) and nanoparticles), and using antigens that can enhance immunogenicity by circumventing tolerance mechanisms. A popular approach is to combine mRNA cancer vaccines with traditional and novel cancer treatments like chemotherapy, radiotherapy, and immune checkpoint blockade (ICB). They are most efficacious when combined with other therapies like ICBs. There is still a long way to go before these vaccines enter the standard of care for cancer patients, but with the incredible pace of development in this field, their clinical application will soon be witnessed. This review highlights the recent advances and challenges of mRNA cancer vaccines. Finally, some of the most prominent clinical applications of these vaccines will be reviewed.

Current status of nucleic acid therapy and its new progress in cancer treatment

Nucleic acid is an essential biopolymer in all living cells, performing the functions of storing and transmitting genetic information and synthesizing protein. In recent decades, with the progress of science and biotechnology and the continuous exploration of the functions performed by nucleic acid, more and more studies have confirmed that nucleic acid therapy for living organisms has great medical therapeutic potential. Nucleic acid drugs began to become independent therapeutic agents. As a new therapeutic method, nucleic acid therapy plays an important role in the treatment of genetic diseases, viral infections and cancers. There are currently 19 nucleic acid drugs approved by the Food and Drug Administration (FDA). In the following review, we start from principles and advantages of nucleic acid therapy, and briefly describe development history of nucleic acid drugs. And then we give examples of various RNA therapeutic drugs, including antisense oligonucleotides (ASO), mRNA vaccines, small interfering RNA (siRNA) and microRNA (miRNA), aptamers, and small activating RNA (saRNA). In addition, we also focused on the current status of nucleic acid drugs used in cancer therapy and the breakthrough in recent years. Clinical trials of nucleic acid drugs for cancer treatment are under way, conventional radiotherapy and chemotherapy combined with the immunotherapies such as checkpoint inhibitors and nucleic acid drugs may be the main prospects for successful cancer treatment.

Systematic evaluation of the induction of efficient neutralizing antibodies by recombinant multicomponent subunit vaccines against monkeypox virus

Mpox (formerly known as monkeypox), which has symptoms similar to smallpox, is a zoonotic disease caused by the monkeypox virus (MPXV). From 1 January 2022 to 31 March 2024, 117 countries, territories, or areas reported 95,226 laboratory-confirmed cases of Mpox (including 185 deaths) to the World Health Organization. However, as there is no licensed specific MPXV vaccine available globally, the vaccines currently used for mpox prevention are mostly smallpox vaccines. Thus, the rapid development of safe and effective vaccines is urgently required. In the present study, the key MPXV proteins A35, B6R, E8L, A29, M1R, and H3L were expressed and prepared using a prokaryotic expression system (Escherichia coli) and a eukaryotic expression system (yeast), and the fusion antigens A35-A29 and A35-M1R were constructed based on the dimerization characteristics of the A35 protein. By combining the antigens with aluminum hydroxide and CpG adjuvants in different combinations, we developed nine multicomponent MPXV subunit vaccine candidates. Each antigen (10 μg) and fusion antigen (20 μg) were used to immunize the mice. The first two doses produced a mean titer of 10(Petersen et al., 2016 [5]), and the third dose maintained the same potent antibody-specific response as the previous two immunizations. The protective activity of different antigen combinations was determined using the cell neutralization test of vaccinia virus (VACV), which showed that the subunit vaccine candidates with two to six components (MPXV6/5/4/3a/3b/Fa/2a) had good neutralizing activity, and antigens A35 and M1R could produce neutralizing antibodies against VACV. The neutralizing antibody titer of the fusion antigen MPXVFa (A35-M1R), detected 2 weeks after the second booster dose, was comparable with that of MPXV2a (A35 and M1R). The A35-M1R fusion protein not only provided a high level of protection as a protective antigen but also simplified the preparation of candidate antigens. In summary, we systematically investigated the different protective antigen candidates of MPXV that have been widely studied and provided critical insights into the key protective antigen composition for vaccines, thus establishing a technical and theoretical foundation for the development of MPXV subunit vaccines.

Applications of microfluidics in mRNA vaccine development: A review

The transformative potential of microfluidics in the development of mRNA vaccines is explored in this review, highlighting its pivotal role in enhancing easy-to-use functionality, efficacy, and production efficiency. Moreover, we examine the innovative applications of microfluidics in biomedical research, including its contribution to the rapid and cost-effective synthesis of lipid nanoparticles for mRNA delivery and delve into the advantages of mRNA vaccines, such as targeted delivery and controlled expression. Furthermore, it outlines the future prospects of microfluidic devices, their cutting-edge examples in both research and industry, and the potential to revolutionize vaccine formulation and production. The integration of microfluidics with mRNA vaccine development represents a significant advancement in public health and disease prevention strategies.

In Situ Tumor-Infiltrating Lymphocyte Therapy by Local Delivery of an mRNA Encoding Membrane-Anchored Anti-CD3 Single-Chain Variable Fragment

Tumor-infiltrating lymphocyte (TIL) therapy has shown promising responses in clinical trials for highly aggressive cancers such as advanced melanoma and metastatic colorectal cancer. However, TIL therapy is still limited in clinical practice due to the complex ex vivo cell preparation process. Here, we report an "in situ TIL therapy" for the treatment of solid tumors. We utilized lipid nanoparticles for the delivery of an mRNA encoding membrane-anchored anti-CD3 single-chain variable fragment (scFv) (MA-aCD3), efficiently engineering both tumor-associated macrophages (TAMs) and tumor cells following intratumoral delivery. Expression of MA-aCD3 resulted in enhanced TIL activation, proliferation, and tumor cell engagement directly within the tumor microenvironment. In B16F10 and MC38 tumor models, concurrent expression of MA-aCD3 on TAMs and tumor cells mediated by mRNA delivery resulted in significant antitumor effects via in situ polyclonal CD8+ TIL expansion and directed cytotoxic effector functions. In addition, combinatorial treatment of MA-aCD3-encoding mRNA and antiprogrammed cell death 1 (anti-PD-1) antibodies exhibited synergistic antitumor effects on anti-PD-1 refractory B16F10 tumors. Together, our findings suggest that in situ TIL therapy is a practical and effective mRNA-based therapeutic modality for the treatment of solid tumors.

Emerging prospects of mRNA cancer vaccines: mechanisms, formulations, and challenges in cancer immunotherapy

Cancer continues to pose an alarming threat to global health, necessitating the need for the development of efficient therapeutic solutions despite massive advances in the treatment. mRNA cancer vaccines have emerged as a hopeful avenue, propelled by the victory of mRNA technology in COVID-19 vaccines. The article delves into the intricate mechanisms and formulations of cancer vaccines, highlighting the ongoing efforts to strengthen mRNA stability and ensure successful translation inside target cells. Moreover, it discusses the design and mechanism of action of mRNA, showcasing its potential as a useful benchmark for developing efficacious cancer vaccines. The significance of mRNA therapy and selecting appropriate tumor antigens for the personalized development of mRNA vaccines are emphasized, providing insights into the immune mechanism. Additionally, the review explores the integration of mRNA vaccines with other immunotherapies and the utilization of progressive delivery platforms, such as lipid nanoparticles, to improve immune responses and address challenges related to immune evasion and tumor heterogeneity. While underscoring the advantages of mRNA vaccines, the review also addresses the challenges associated with the susceptibility of RNA to degradation and the difficulty in identifying optimum tumor-specific antigens, along with the potential solutions. Furthermore, it provides a comprehensive overview of the ongoing research efforts aimed at addressing these hurdles and enhancing the effectiveness of mRNA-based cancer vaccines. Overall, this review is a focused and inclusive impression of the present state of mRNA cancer vaccines, outlining their possibilities, challenges, and future predictions in the fight against cancer, ultimately aiding in the development of more targeted therapies against cancer.

Lung-Selective Delivery of mRNA-Encoding Anti-MERS-CoV Nanobody Exhibits Neutralizing Activity Both In Vitro and In Vivo

Background/Objectives: The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a highly pathogenic virus causing severe respiratory illness, with limited treatment options that are mostly supportive. The success of mRNA technology in COVID-19 vaccines has opened avenues for antibody development against MERS-CoV. mRNA-based antibodies, expressed in vivo, offer rapid adaptability to viral mutations while minimizing long-term side effects. This study aimed to develop a lung-targeted lipid nanoparticle (LNP) system for mRNA-encoding neutralizing nanobodies against MERS-CoV, proposing a novel therapeutic strategy. Methods: An mRNA-encoding nanobody NbMS10 (mRNA-NbMS10) was engineered for enhanced stability and reduced immunogenicity. This mRNA was encapsulated in lung-selective LNPs using microfluidics to form the LNP-mRNA-NbMS10 system. Efficacy was assessed through in vitro assays and in vivo mouse studies, focusing on antigen-binding, neutralization, and sustained nanobody expression in lung tissues. Results: The LNP-mRNA-NbMS10 system expressed the nanobody in vitro, showing strong antigen-binding and significant MERS-CoV pseudovirus neutralization. In vivo studies confirmed selective lung mRNA delivery, with high nanobody expression sustained for up to 24 h, confirming lung specificity and prolonged antiviral activity. Conclusions: Extensive in vitro and in vivo evaluations demonstrate the LNP-mRNA-NbMS10 system's potential as a scalable, cost-effective, and adaptable alternative to current MERS-CoV therapies. This innovative platform offers a promising solution for preventing and treating respiratory infections, and countering emerging viral threats.

Nanotechnology in healthcare, and its safety and environmental risks

Nanotechnology holds immense promise in revolutionising healthcare, offering unprecedented opportunities in diagnostics, drug delivery, cancer therapy, and combating infectious diseases. This review explores the multifaceted landscape of nanotechnology in healthcare while addressing the critical aspects of safety and environmental risks associated with its widespread application. Beginning with an introduction to the integration of nanotechnology in healthcare, we first delved into its categorisation and various materials employed, setting the stage for a comprehensive understanding of its potential. We then proceeded to elucidate the diverse healthcare applications of nanotechnology, spanning medical diagnostics, tissue engineering, targeted drug delivery, gene delivery, cancer therapy, and the development of antimicrobial agents. The discussion extended to the current situation surrounding the clinical translation and commercialisation of these cutting-edge technologies, focusing on the nanotechnology-based healthcare products that have been approved globally to date. We also discussed the safety considerations of nanomaterials, both in terms of human health and environmental impact. We presented the in vivo health risks associated with nanomaterial exposure, in relation with transport mechanisms, oxidative stress, and physical interactions. Moreover, we highlighted the environmental risks, acknowledging the potential implications on ecosystems and biodiversity. Lastly, we strived to offer insights into the current regulatory landscape governing nanotechnology in healthcare across different regions globally. By synthesising these diverse perspectives, we underscore the imperative of balancing innovation with safety and environmental stewardship, while charting a path forward for the responsible integration of nanotechnology in healthcare.

Recent advances in polymeric and lipid stimuli-responsive nanocarriers for cell-based cancer immunotherapy

Conventional cancer therapy has major limitations, including non-specificity, unavoidable side effects, low specific tumor accumulation and systemic toxicity. In recent years, more effective and precise treatment methods have been developed, including cell-based immunotherapy. Carriers that can accurately and specifically target cells and equip them to combat cancer cells are particularly important for developing this therapy. As a result, attention has been drawn to smart nanocarriers that can react to specific stimuli. Thus, stimuli-responsive nanocarriers have attracted increasing attention because they can change their physicochemical properties in response to stimulus conditions, such as pH, enzymes, redox agents, hypoxia, light and temperature. This review highlights recent advances in various stimuli-responsive nanocarriers, discussing loading, targeted delivery, cellular uptake, biocompatibility and immunomodulation in cell-based immunotherapy. Finally, future challenges and perspectives regarding the possible clinical translation of nanocarriers are discussed.

mRNA delivery enabled by metal-organic nanoparticles

mRNA therapeutics are set to revolutionize disease prevention and treatment, inspiring the development of platforms for safe and effective mRNA delivery. However, current mRNA delivery platforms face some challenges, including limited organ tropism for nonvaccine applications and inflammation induced by cationic nanoparticle components. Herein, we address these challenges through a versatile, noncationic nanoparticle platform whereby mRNA is assembled into a poly(ethylene glycol)-polyphenol network stabilized by metal ions. Screening a range of components and relative compositional ratios affords a library of stable, noncationic, and highly biocompatible metal-organic nanoparticles with robust mRNA transfection in vitro and in mice. Intravenous administration of the lead mRNA-containing metal-organic nanoparticles enables predominant protein expression and gene editing in the brain, liver, and kidney, while organ tropism is tuned by varying nanoparticle composition. This study opens an avenue for realizing metal-organic nanoparticle-enabled mRNA delivery, offering a modular approach to assembling mRNA therapeutics for health applications.

Better, Faster, Stronger: Accelerating mRNA-Based Immunotherapies With Nanocarriers

Messenger ribonucleic acid (mRNA) therapeutics are attracting attention as promising tools in cancer immunotherapy due to their ability to leverage the in vivo expression of all known protein sequences. Even small amounts of mRNA can have a powerful effect on cancer vaccines by promoting the synthesis of tumor-specific antigens (TSA) or tumor-associated antigens (TAA) by antigen-presenting cells (APC). These antigens are then presented to T cells, eliciting strong antitumor immune stimulation. The potential of mRNA can be further enhanced by expressing immunomodulatory agents, such as cytokines, antibodies, and chimeric antigen receptors (CAR), enhancing tumor immunity. Recent research also explores mRNA-encoded tumor death inducers or tumor microenvironment (TME) modulators. Despite its promise, the clinical translation of mRNA-based anticancer strategies faces challenges, including inefficient targeted delivery in vivo, failure of endosomal escape, and inadequate intracellular mRNA release, resulting in poor transfection efficiencies. Inspired by the approval of lipid nanoparticle-loaded mRNA vaccines against coronavirus disease 2019 (COVID-19) and the encouraging outcomes of mRNA-based cancer therapies in trials, innovative nonviral nanotechnology delivery systems have been engineered. These aim to advance mRNA-based cancer immunotherapies from research to clinical application. This review summarizes recent preclinical and clinical progress in lipid and polymeric nanomedicines for delivering mRNA-encoded antitumor therapeutics, including cytokines and antibody-based immunotherapies, cancer vaccines, and CAR therapies. It also addresses advanced delivery systems for direct oncolysis or TME reprogramming and highlights key challenges in translating these therapies to clinical use, exploring future perspectives, including the role of artificial intelligence and machine learning in their development.

Current status of vaccine immunotherapy for gastrointestinal cancers

Recent advances in tumor immunology and molecular drug development have ushered in a new era of cancer immunotherapy. Immunotherapy has shown promising results for several types of tumors, such as advanced melanoma, non-small cell lung cancer, renal cell carcinoma, bladder cancers, and refractory Hodgkin's lymphoma. Similarly, efforts have been made to develop immunotherapies such as adoptive T-cell transplantation, peptide vaccines, and dendritic cell vaccines, specifically for gastrointestinal tumors. However, before the advent of immune checkpoint inhibitors, immunotherapy did not work as well as expected. In this article, we review immunotherapy, focusing on cancer vaccines for gastrointestinal tumors, which generally target eliciting tumor-specific CD8 + cytotoxic T lymphocytes (CTLs). We also review various vaccine therapies and describe the relationship between vaccines and adjuvants. Finally, we discuss prospects for the combination of immunotherapy with immune checkpoint inhibitors.

Advancement in the development of mRNA-based vaccines for respiratory viruses

Acute respiratory infections are the leading cause of death and illness in children under 5 years old and represent a significant burden in older adults. Primarily caused by viruses infecting the lower respiratory tract, symptoms include cough, congestion, and low-grade fever, potentially leading to bronchiolitis and pneumonia. Messenger ribonucleic acid (mRNA)-based vaccines are biopharmaceutical formulations that employ mRNA molecules to induce specific immune responses, facilitating the expression of viral or bacterial antigens and promoting immunization against infectious diseases. Notably, this technology had significant relevance during the COVID-19 pandemic, as these formulations helped to limit SARS-CoV-2 virus infections, hospitalizations, and deaths. Importantly, mRNA vaccines promise to be implemented as new alternatives for fighting other respiratory viruses, such as influenza, human respiratory syncytial virus, and human metapneumovirus. This review article analyzes mRNA-based vaccines' main contributions, perspectives, challenges, and implications against respiratory viruses.

Advancements in monkeypox vaccines development: a critical review of emerging technologies

Monkeypox (mpox) is a zoonotic illness caused by the monkeypox virus (MPXV), with higher health concerns among people who are pregnant, children, and persons who are immunocompromised, including people with untreated and advanced HIV disease. Significant progress has been made in developing vaccines against mpox, yet critical challenges and limitations persist in ensuring their effectiveness, safety, and accessibility. The pertinence of this review is highlighted by the World Health Organization's declaration of a global health emergency on August 14, 2024, due to the recent mpox outbreak, underscoring the critical necessity for effective vaccine solutions in the face of a rapidly evolving virus. Here, we comprehensively analyze various vaccine platforms utilized in mpox prevention, including attenuated and non-replicating virus vaccines, viral vector-based vaccines, recombinant protein vaccines, and DNA and mRNA vaccines. We evaluate the advantages and limitations of each platform, highlighting the urgent need for ongoing research and innovation to enhance vaccine efficacy and safety. Recent advancements, such as incorporating immunostimulatory sequences, improved delivery systems, and developing polyvalent vaccines, are explored for their potential to offer broader protection against diverse orthopoxvirus strains. This work underscores the need to optimize currently available vaccines and investigate novel vaccination strategies to address future public health emergencies effectively. By focusing on these advanced methodologies, we aim to contribute to the development of robust and adaptable vaccine solutions for mpox and other related viral threats.

Personalized mRNA vaccines in glioblastoma therapy: from rational design to clinical trials

Glioblastomas (GBMs) are the most common and aggressive malignant brain tumors, presenting significant challenges for treatment due to their invasive nature and localization in critical brain regions. Standard treatment includes surgical resection followed by radiation and adjuvant chemotherapy with temozolomide (TMZ). Recent advances in immunotherapy, including the use of mRNA vaccines, offer promising alternatives. This review focuses on the emerging use of mRNA vaccines for GBM treatment. We summarize recent advancements, evaluate current obstacles, and discuss notable successes in this field. Our analysis highlights that while mRNA vaccines have shown potential, their use in GBM treatment is still experimental. Ongoing research and clinical trials are essential to fully understand their therapeutic potential. Future developments in mRNA vaccine technology and insights into GBM-specific immune responses may lead to more targeted and effective treatments. Despite the promise, further research is crucial to validate and optimize the effectiveness of mRNA vaccines in combating GBM.

Advancements and challenges in mRNA and ribonucleoprotein-based therapies: From delivery systems to clinical applications

The use of mRNA and ribonucleoproteins (RNPs) as therapeutic agents is a promising strategy for treating diseases such as cancer and infectious diseases. This review provides recent advancements and challenges in mRNA- and RNP-based therapies, focusing on delivery systems such as lipid nanoparticles (LNPs), which ensure efficient delivery to target cells. Strategies such as microfluidic devices are employed to prepare LNPs loaded with mRNA and RNPs, demonstrating effective genome editing and protein expression in vitro and in vivo. These applications extend to cancer treatment and infectious disease management, with promising results in genome editing for cancer therapy using LNPs encapsulating Cas9 mRNA and single-guide RNA. In addition, tissue-specific targeting strategies offer potential for improved therapeutic outcomes and reduced off-target effects. Despite progress, challenges such as optimizing delivery efficiency and targeting remain. Future research should enhance delivery efficiency, explore tissue-specific targeting, investigate combination therapies, and advance clinical translation. In conclusion, mRNA- and RNP-based therapies offer a promising avenue for treating various diseases and have the potential to revolutionize medicine, providing new hope for patients worldwide.

Therapeutic potential of RNA-enriched extracellular vesicles: The next generation in RNA delivery via biogenic nanoparticles

Exosomes are extracellular vesicles (EVs) (∼50-150 nm) that have emerged as promising vehicles for therapeutic applications and drug delivery. These membrane-bound particles, released by all actively dividing cells, have the ability to transfer effector molecules, including proteins, RNA, and even DNA, from donor cells to recipient cells, thereby modulating cellular responses. RNA-based therapeutics, including microRNAs, messenger RNAs, long non-coding RNAs, and circular RNAs, hold great potential in controlling gene expression and treating a spectrum of medical conditions. RNAs encapsulated in EVs are protected from extracellular degradation, making them attractive for therapeutic applications. Understanding the intricate biology of cargo loading and transfer within EVs is pivotal to unlocking their therapeutic potential. This review discusses the biogenesis and classification of EVs, methods for loading RNA into EVs, their advantages as drug carriers over synthetic-lipid-based systems, and the potential applications in treating neurodegenerative diseases, cancer, and viral infections. Notably, EVs show promise in delivering RNA cargo across the blood-brain barrier and targeting tumor cells, offering a safe and effective approach to RNA-based therapy in these contexts.

Unleashing the potential of mRNA therapeutics for inherited neurological diseases

Neurological monogenic loss-of-function diseases are hereditary disorders resulting from gene mutations that decrease or abolish the normal function of the encoded protein. These conditions pose significant therapeutic challenges, which may be resolved through the development of innovative therapeutic strategies. RNA-based technologies, such as mRNA replacement therapy, have emerged as promising and increasingly viable treatments. Notably, mRNA therapy exhibits significant potential as a mutation-agnostic approach that can address virtually any monogenic loss-of-function disease. Therapeutic mRNA carries the information for a healthy copy of the defective protein, bypassing the problem of targeting specific genetic variants. Moreover, unlike conventional gene therapy, mRNA-based drugs are delivered through a simplified process that requires only transfer to the cytoplasm, thereby reducing the mutagenic risks related to DNA integration. Additionally, mRNA therapy exerts a transient effect on target cells, minimizing the risk of long-term unintended consequences. The remarkable success of mRNA technology for developing coronavirus disease 2019 vaccines has rekindled interest in mRNA as a cost-effective method for delivering therapeutic proteins. However, further optimization is required to enhance mRNA delivery, particularly to the CNS, while minimizing adverse drug reactions and toxicity. In this comprehensive review, we delve into past, present and ongoing applications of mRNA therapy for neurological monogenic loss-of-function diseases. We also discuss the promises and potential challenges presented by mRNA therapeutics in this rapidly advancing field. Ultimately, we underscore the full potential of mRNA therapy as a game-changing therapeutic approach for neurological disorders.

Advances in targeted delivery of mRNA into immune cells for enhanced cancer therapy

Messenger RNA (mRNA) therapy has been applied to the treatment of various human diseases including malignant tumors. Increasing evidences have shown that mRNA can enhance the efficacy of cancer immunotherapy by modulating the functions of immune cells and stimulating their activity. However, mRNA is a type of negatively charged biomacromolecules that are susceptible to serum nucleases and cannot readily cross the cell membrane. In the past few decades, various nanoparticles (NPs)-based delivery systems have been rationally designed and developed to facilitate the intracellular uptake and cytosolic delivery of mRNA. More importantly, by means of the specific recognition between the targeting ligands decorated on NP surface and receptors specifically expressed on immune cells, these mRNA delivery systems could be functionalized to target immune cells to further enhance the mRNA-based cancer immunotherapy. In this review, we briefly introduced the advancements of mRNA in cancer therapy, discussed the challenges faced by mRNA delivery, and systematically summarized the recent development in NPs-based mRNA delivery systems targeting various types of immune cells for cancer immunotherapy. The future development of NPs-mediated targeted mRNA delivery and their challenges in clinical translation are also discussed.

The Road Ahead in Pancreatic Cancer: Emerging Trends and Therapeutic Prospects

This review explores the challenges and emerging trends in pancreatic cancer therapy. In particular, we focus on the tumor microenvironment and the potential of immunotherapy for pancreatic cancer. Pancreatic ductal adenocarcinoma, characterized by its dense stromal architecture, presents unique challenges for effective treatment. Recent advancements have emphasized the role of the tumor microenvironment in therapeutic resistance and disease progression. We discuss novel strategies targeting the desmoplastic barrier and immunosuppressive cells to enhance immune cell infiltration and activation. Recent clinical trials, particularly those involving novel immunotherapeutic agents and tumor vaccines, are examined to understand their efficacy and limitations. Our analysis reveals that combining immunotherapy with chemotherapy, radiation therapy, or drugs targeting epigenetic processes shows promise, improving overall survival rates and response to treatment. For instance, trials utilizing checkpoint inhibitors in combination with standard chemotherapies have extended disease-free survival by up to 6 months compared to chemotherapy alone. Importantly, vaccines targeting specific tumor neoantigens have shown the potential to increase patient survival. However, these approaches also face significant challenges, including overcoming the immunosuppressive tumor microenvironment and enhancing the delivery and efficacy of therapeutic agents. By providing an overview of both the promising results and the obstacles encountered, this review aims to highlight ongoing efforts to refine immunotherapy approaches for better patient outcomes.

Small-molecule in cancer immunotherapy: Revolutionizing cancer treatment with transformative, game-changing breakthroughs

Immunotherapy has revolutionized cancer management, with antibody-based treatments leading the charge due to their superior pharmacodynamics, including enhanced effectiveness and specificity. However, these therapies are hampered by limitations such as prolonged half-lives, poor tissue and tumor penetration, and minimal oral bioavailability. Additionally, their immunogenic nature can cause adverse effects. Consequently, the focus is shifting towards small-molecule-based immunotherapies, which potentially overcome these drawbacks. Emerging as a promising alternative, small molecules offer the benefits of therapeutic antibodies and immunomodulators, often yielding synergistic effects when combined. Recent advancements in small-molecule cancer immunotherapy are notable, featuring inhibitors, agonists, and degraders that act as immunomodulators. This article delves into the current landscape of small-molecule immunotherapy in cancer treatment, highlighting novel agents targeting key pathways such as Toll-like receptors (TLR), PD-1/PD-L1, chemokine receptors, and stimulators of interferon genes (STING). The review emphasizes newly discovered molecular entities and their modulatory roles in tumorigenesis, many of which have progressed to clinical trials, that aims to provide a comprehensive snapshot of the evolving frontier in cancer treatment, driven by small-molecule immunomodulators.

mRNA vaccines in tumor targeted therapy: mechanism, clinical application, and development trends

Malignant tumors remain a primary cause of human mortality. Among the various treatment modalities for neoplasms, tumor vaccines have consistently shown efficacy and promising potential. These vaccines offer advantages such as specificity, safety, and tolerability, with mRNA vaccines representing promising platforms. By introducing exogenous mRNAs encoding antigens into somatic cells and subsequently synthesizing antigens through gene expression systems, mRNA vaccines can effectively induce immune responses. Katalin Karikó and Drew Weissman were awarded the 2023 Nobel Prize in Physiology or Medicine for their great contributions to mRNA vaccine research. Compared with traditional tumor vaccines, mRNA vaccines have several advantages, including rapid preparation, reduced contamination, nonintegrability, and high biodegradability. Tumor-targeted therapy is an innovative treatment modality that enables precise targeting of tumor cells, minimizes damage to normal tissues, is safe at high doses, and demonstrates great efficacy. Currently, targeted therapy has become an important treatment option for malignant tumors. The application of mRNA vaccines in tumor-targeted therapy is expanding, with numerous clinical trials underway. We systematically outline the targeted delivery mechanism of mRNA vaccines and the mechanism by which mRNA vaccines induce anti-tumor immune responses, describe the current research and clinical applications of mRNA vaccines in tumor-targeted therapy, and forecast the future development trends of mRNA vaccine application in tumor-targeted therapy.

Low-Dose Mildronate-Derived Lipidoids for Efficient mRNA Vaccine Delivery with Minimal Inflammation Side Effects

mRNA vaccines have been revolutionizing disease prevention and treatment. However, their further application is hindered by inflammatory side effects, primarily caused by delivery systems such as lipid nanoparticles (LNPs). In response to this issue, we prepared cationic lipids (mLPs) derived from mildronate, a small-molecule drug, and subsequently developed the LNP (mLNP-69) comprising a low dose of mLP. Compared with the LNP (sLNP) based on SM-102, a commercially available ionizable lipid, mLNP-69 ensures effective mRNA delivery while significantly reducing local inflammation. In preclinical prophylactic and therapeutic B16-OVA melanoma models, mLNP-69 demonstrated successful mRNA cancer vaccine delivery in vivo, effectively preventing tumor occurrence or impeding tumor progression. The results suggest that the cationic lipids derived from mildronate, which exhibit efficient delivery capabilities and minimal inflammatory side effects, hold great promise for clinical application.