Lipid-Polymer Hybrid Nanoparticles for mRNA Delivery to Dendritic Cells: Impact of Lipid Composition on Performance in Different Media

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.

Efficacy of Chitosan-N-Arginine Chitosomes in mRNA Delivery and Cell Viability Enhancement

Cationic lipid-based carriers are recognized for their ability to complex with mRNA and effectively deliver the mRNA for vaccination and therapeutic purposes. However, the significant cytotoxicity of these carriers often restricts their practical application. In the present study, polymer-lipid hybrid nanoparticles, termed chitosomes, incorporating chitosan-N-arginine (CSA) with the DOTAP cationic lipid and the DOPE helper lipid, were synthesized and evaluated. The addition of CSA to the lipid formulations improved their physicochemical stability and enhanced mRNA complexation, resulting in high transfection rates in the HeLa and HEK293T cell lines. However, the transfection efficiency was low in the NIH-3T3 cell line, indicating a cell type-specific response to chitosomes. Importantly, CSA significantly reduced the cytotoxicity typically associated with DOTAP. Overall, the present study indicated that optimizing the ratio of CSA to DOTAP is crucial for developing mRNA nanocarriers to achieve high transfection efficiency and reduce cytotoxicity across different cell lines.

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.

Design and development of mRNA and self-amplifying mRNA vaccine nanoformulations

The rapid evolution of mRNA vaccines, highlighted by Pfizer-BioNTech and Moderna's COVID-19 vaccines, has transformed vaccine development and therapeutic approaches. Self-amplifying mRNA (saRNA) vaccines, a groundbreaking advancement in RNA-based vaccines, offer promising possibilities for disease prevention and treatment, including potential applications in cancer and neurodegenerative diseases. This review explores the complex design and development of these innovative vaccines, with a focus on their nanoscale formulations that utilize nanotechnology to improve their delivery and effectiveness. It articulates the fundamental principles of mRNA and saRNA vaccines, their mechanisms of action, and the role of synthetic mRNA in eliciting immune responses. The review further elaborates on various nanoscale delivery systems (e.g., lipid nanoparticles, polymeric nanoparticles and other nanocarriers), emphasizing their advantages in enhancing mRNA stability and cellular uptake. It addresses advanced nanoscale delivery techniques such as microfluidics and discusses the challenges in formulating mRNA and saRNA vaccines. By incorporating the latest technologies and current research, this review provides a thorough overview of recent mRNA and saRNA nanovaccines advancements, highlighting their potential to revolutionize vaccine technology and broaden clinical applications.

Stable Polymer-Lipid Hybrid Nanoparticles Based on mcl-Polyhydroxyalkanoate and Cationic Liposomes for mRNA Delivery

Background/Objectives: The development of polymer-lipid hybrid nanoparticles (PLNs) is a promising area of research, as it can help increase the stability of cationic lipid carriers. Hybrid PLNs are core-shell nanoparticle structures that combine the advantages of both polymer nanoparticles and liposomes, especially in terms of their physical stability and biocompatibility. Natural polymers such as polyhydroxyalkanoate (PHA) can be used as a matrix for the PLNs' preparation. Methods: In this study, we first obtained stable cationic hybrid PLNs using a cationic liposome (CL) composed of a polycationic lipid 2X3 (1,26-bis(cholest-5-en-3β-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride), helper lipid DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine), and the hydrophobic polymer mcl-PHA, which was produced by the soil bacterium Pseudomonas helmantisensis P1. Results: The new polymer-lipid carriers effectively encapsulated and delivered model mRNA-eGFP (enhanced green fluorescent protein mRNA) to BHK-21 cells. We then evaluated the role of mcl-PHA in increasing the stability of cationic PLNs in ionic solutions using dynamic light scattering data, electrophoretic mobility, and transmission electron microscopy techniques. Conclusions: The results showed that increasing the concentration of PBS (phosphate buffered saline) led to a decrease in the stability of the CLs. At high concentrations of PBS, the CLs aggregate. In contrast, the presence of isotonic PBS did not result in the aggregation of PLNs, and the particles remained stable for 120 h when stored at +4 °C. The obtained results show that PLNs hold promise for further in vivo studies on nucleic acid delivery.

Leveraging high-throughput screening technologies in targeted mRNA delivery

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

The development and technologies of RNA therapeutics

Since it was discovered for over 20 years ago, the potentiality of siRNAs in gene silencing in vitro and in vivo models has been recognized. Several studies in the new generation, molecular mechanisms, target attachment, and purification of RNA have supported the development of RNA therapeutics for a variety of applications. RNA therapeutics are growing rapidly with various platforms contributing to the standard of personalized medicine and rare disease treatment. Therefore, understanding the development and technologies of RNA therapeutics becomes a crucial point for new drug generation. Here, the primary purpose of this review is to provide a general view of six therapeutic categories that make up RNA-based therapeutic approaches, including RNA-target therapeutics, protein-targeted therapeutics, cellular reprogramming and tissues engineering, RNA-based protein replacement therapeutics, RNA-based genome editing, and RNA-based immunotherapies based on non-coding RNAs and coding RNA. Furthermore, we present an overview of the RNA strategies regarding viral approaches and nonviral approaches in designing a new generation of RNA technologies. The advantages and challenges of using RNA therapeutics are also discussed along with various approaches for RNA delivery. Therefore, this review is designed to provide updated reference evidence of RNA therapeutics in the battle against rare or difficult-to-treat diseases for researchers in this field.

mRNA nanodelivery systems: targeting strategies and administration routes

With the great success of coronavirus disease (COVID-19) messenger ribonucleic acid (mRNA) vaccines, mRNA therapeutics have gained significant momentum for the prevention and treatment of various refractory diseases. To function efficiently in vivo and overcome clinical limitations, mRNA demands safe and stable vectors and a reasonable administration route, bypassing multiple biological barriers and achieving organ-specific targeted delivery of mRNA. Nanoparticle (NP)-based delivery systems representing leading vector approaches ensure the successful intracellular delivery of mRNA to the target organ. In this review, chemical modifications of mRNA and various types of advanced mRNA NPs, including lipid NPs and polymers are summarized. The importance of passive targeting, especially endogenous targeting, and active targeting in mRNA nano-delivery is emphasized, and different cellular endocytic mechanisms are discussed. Most importantly, based on the above content and the physiological structure characteristics of various organs in vivo, the design strategies of mRNA NPs targeting different organs and cells are classified and discussed. Furthermore, the influence of administration routes on targeting design is highlighted. Finally, an outlook on the remaining challenges and future development toward mRNA targeted therapies and precision medicine is provided.