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1.
Nano Today ; 48:101730, 2023.
Article in English | ScienceDirect | ID: covidwho-2165731

ABSTRACT

Despite the various vaccines that have been developed to combat the coronavirus disease 2019 (COVID-19) pandemic, the persistent and unpredictable mutations of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) require innovative and unremitting solutions to cope with the resultant immune evasion and establish a sustainable immune barrier. Here we introduce a vaccine-delivery system with a combination of a needle-free injection (NFI) device and a SARS-CoV-2-Spike-specific mRNA-Lipid Nanoparticle (LNP) vaccine. The benefits are duller pain and a significant increase of immunogenicity compared to the canonical needle injection (NI). From physicochemical and bioactivity analyses, the structure of the mRNA-LNP maintains stability upon NFI, contradictory to the belief that LNPs are inclined towards destruction under the high-pressure conditions of NFI. Moreover, mRNA-LNP vaccine delivered by NFI induces significantly more binding and neutralizing antibodies against SARS-CoV-2 variants than the same vaccine delivered by NI. Heterogeneous vaccination of BA.5-LNP vaccine with NFI enhanced the generation of neutralizing antibodies against Omicron BA.5 variants in rabbits previously vaccinated with non-BA.5-specific mRNA-LNP or other COVID-19 vaccines. NFI parameters can be adjusted to deliver mRNA-LNP subcutaneously or intramuscularly. Taken together, our results suggest that NFI-based mRNA-LNP vaccination is an effective substitute for the traditional NI-based mRNA-LNP vaccination.

2.
Virol Sin ; 37(5): 731-739, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-2150803

ABSTRACT

Latent varicella-zoster virus (VZV) may be reactivated to cause herpes zoster, which affects one in three people during their lifetime. The currently available subunit vaccine Shingrix™ is superior to the attenuated vaccine Zostavax® in terms of both safety and efficacy, but the supply of its key adjuvant component QS21 is limited. With ionizable lipid nanoparticles (LNPs) that were recently approved by the FDA for COVID-19 mRNA vaccines as carriers, and oligodeoxynucleotides containing CpG motifs (CpG ODNs) approved by the FDA for a subunit hepatitis B vaccine as immunostimulators, we developed a LNP vaccine encapsulating VZV-glycoprotein E (gE) and CpG ODN, and compared its immunogenicity with Shingrix™ in C57BL/6J mice. The results showed that the LNP vaccine induced comparable levels of gE-specific IgG antibodies to Shingrix™ as determined by enzyme-linked immunosorbent assay (ELISA). Most importantly, the LNP vaccine induced comparable levels of cell-mediated immunity (CMI) that plays decisive roles in the efficacy of zoster vaccines to Shingrix™ in a VZV-primed mouse model that was adopted for preclinical studies of Shingrix™. Number of IL-2 and IFN-γ secreting splenocytes and proportion of T helper 1 (Th1) cytokine-expressing CD4+ T cells in LNP-CpG-adjuvanted VZV-gE vaccinated mice were similar to that of Shingrix™ boosted mice. All of the components in this LNP vaccine can be artificially and economically synthesized in large quantities, indicating the potential of LNP-CpG-adjuvanted VZV-gE as a more cost-effective zoster vaccine.


Subject(s)
COVID-19 , Herpes Zoster Vaccine , Herpes Zoster , Viral Envelope Proteins/immunology , Adjuvants, Immunologic , Animals , Antibodies, Viral , Hepatitis B Vaccines , Herpes Zoster/prevention & control , Herpesvirus 3, Human/genetics , Immunoglobulin G , Interleukin-2 , Liposomes , Mice , Mice, Inbred C57BL , Nanoparticles , Oligodeoxyribonucleotides , Vaccines, Attenuated , Vaccines, Subunit
3.
J Control Release ; 2022 Nov 19.
Article in English | MEDLINE | ID: covidwho-2131388

ABSTRACT

The recent clinical success of multiple mRNA-based SARS-CoV-2 vaccines has proven the potential of RNA formulated in lipid nanoparticles (LNPs) in humans, and products based on base-modified RNA, sequence-optimized RNA, and self-replicating RNAs formulated in LNPs are all in various stages of clinical development. However, much remains to be learned about critical parameters governing the manufacturing and use of LNP-RNA formulations. One important issue that has received limited attention in the literature to date is the identification of optimal storage conditions for LNP-RNA that preserve long-term activity of the formulations. Here, we analyzed the physical structure, in vivo expression characteristics, and functional activity of alphavirus-derived self-replicating RNA (repRNA)-loaded LNPs encoding HIV vaccine antigens following storage in varying temperatures, solvents, and in the presence or absence of cryoprotectants. We found that for lipid nanoparticles with compositions similar to clinically-used LNPs, storage in RNAse-free PBS containing 10% (w/vol) sucrose at -20 °C was able to maintain vaccine stability and in vivo potency at a level equivalent to freshly prepared vaccines following 30 days of storage. LNP(repRNA) could also be lyophilized with retention of bioactivity.

4.
Eur J Pharm Biopharm ; 2022 Nov 18.
Article in English | MEDLINE | ID: covidwho-2130702

ABSTRACT

During the SARS-CoV2 pandemic mRNA vaccines in the form of lipid nanoparticles (LNPs) containing the mRNA, have set the stage for a new area of vaccines. Analytical methods to quantify changes in size and structure of LNPs are crucial, as changes in these parameters could have implications for potency. We investigated the application of sedimentation velocity analytical ultracentrifugation (SV-AUC) as quantitative stability-indicating method to detect structural changes of mRNA-LNP vaccines upon relevant stress factors (freeze/thaw, heat and mechanical stress), in comparison to qualitative dynamic light scattering (DLS) analysis. DLS was capable to qualitatively determine size and homogeneity of mRNA-LNPs with sufficient precision. Stress factors, in particular freeze/thaw and mechanical stress, led to increased particle size and content of larger species in DLS and SV-AUC. Changes upon heat stress at 50 °C were only detected as increased flotation rates by SV-AUC. In addition, SV-AUC was able to observe changes in particle density, which cannot be detected by DLS. In conclusion, SV-AUC can be used as a highly valuable quantitative stability-indicating method for characterization of LNPs.

5.
Expert Rev Vaccines ; 21(12): 1739-1761, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2120948

ABSTRACT

INTRODUCTION: The vaccines being used against COVID-19 are composed of either non-viral or viral nanoparticles (NPs). Nanotechnology-based vaccine technology was studied for its potentially transformative advancement of medicine. AREAS COVERED: NPs protect the encapsulated mRNA in vaccines, thereby enhancing the stability of the ribonucleic acids and facilitating their intact delivery to their specific targets. Compared to liposomes, lipid nanoparticles (LNPs) are unique and, through their rigid morphology and better cellular penetrability, render enhanced cargo stability. To explore nanotechnology-mediated vaccine delivery and its potential in future pandemics, we assessed articles from various databases, such as PubMed, Embase, and Scopus, including editorial/research notes, expert opinions, and collections of data from several clinical research trials. In the current review, we focus on the nanoparticulate approach of the different SARS-CoV-2 vaccines and explore their success against the pandemic. EXPERT OPINION: The mRNA-based vaccines, with their tremendous efficacy of ~95% (under phase III-IV clinical trials) and distinct nanocarriers (LNPs), represent a new medical front alongside DNA and siRNA-based vaccines.

6.
Chem Pharm Bull (Tokyo) ; 69(12): 1141-1159, 2021.
Article in English | MEDLINE | ID: covidwho-2115208

ABSTRACT

Considerable efforts have been made on the development of lipid nanoparticles (LNPs) for delivering of nucleic acids in LNP-based medicines, including a first-ever short interfering RNA (siRNA) medicine, Onpattro, and the mRNA vaccines against the coronavirus disease 2019 (COVID-19), which have been approved and are currently in use worldwide. The successful rational design of ionizable cationic lipids was a major breakthrough that dramatically increased delivery efficiency in this field. The LNPs would be expected to be useful as a platform technology for the delivery of various therapeutic modalities for genome editing and even for undiscovered therapeutic mechanisms. In this review, the current progress of my research, including the molecular design of pH-sensitive cationic lipids, their applications for various tissues and cell types, and for delivering various macromolecules, including siRNA, antisense oligonucleotide, mRNA, and the clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) system will be described. Mechanistic studies regarding relationships between the physicochemical properties of LNPs, drug delivery, and biosafety are also summarized. Furthermore, current issues that need to be addressed for next generation drug delivery systems are discussed.


Subject(s)
Drug Carriers/chemistry , Lipids/chemistry , Liposomes/chemistry , Nanoparticles/chemistry , COVID-19/immunology , COVID-19/prevention & control , COVID-19/virology , Cations/chemistry , Hydrogen-Ion Concentration , RNA, Guide/chemistry , RNA, Guide/metabolism , RNA, Small Interfering/chemistry , RNA, Small Interfering/metabolism , SARS-CoV-2/isolation & purification , /metabolism
7.
Chinese Journal of New Drugs ; 31(21):2109-2113, 2022.
Article in Chinese | EMBASE | ID: covidwho-2111996

ABSTRACT

Messenger ribonucleic acid (mRNA) vaccine is characteristic of subunit vaccines and live attenuated vectors. It can simultaneously induce humoral and cellular immunity, and has the advantage of easy to produce on a large scale. Therefore, great application prospects are seen in the field of infectious diseases and the treatment of major diseases. In the field of biomedicine, mRNA vaccine has been deeply cultivated for decades. With the outbreak of the COVID-19 epidemic and the pandemic, the process of listing mRNA vaccines has been greatly accelerated and promoted. The COVID-19 mRNA vaccines, with lipid nanoparticles (LNPs) as the carrier which deliver the mRNA encoding the COVID-19 spike protein antigen information to host cells, were successfully launched, showing good safety and efficacy. Meanwhile, the development of the delivery system, as the key technology of mRNA vaccines, has also become a "battlefield" for the development of mRNA technology. Various delivery technologies, including LNPs, are being actively developed in China and abroad. Safe and effective delivery with independent intellectual property rights will become the key to promote the marketing of mRNA products, which will obtain benefits in the future. This article reviews the mRNA vaccine delivery system and research progress. Copyright © 2022, Chinese Journal of New Drugs Co. Ltd. All right reserved.

8.
Immunity ; 55(11): 1993-2005, 2022 Nov 08.
Article in English | MEDLINE | ID: covidwho-2105131

ABSTRACT

The lipid nanoparticle (LNP)-encapsulated, nucleoside-modified mRNA platform has been used to generate safe and effective vaccines in record time against COVID-19. Here, we review the current understanding of the manner whereby mRNA vaccines induce innate immune activation and how this contributes to protective immunity. We discuss innate immune sensing of mRNA vaccines at the cellular and intracellular levels and consider the contribution of both the mRNA and the LNP components to their immunogenicity. A key message that is emerging from recent observations is that the LNP carrier acts as a powerful adjuvant for this novel vaccine platform. In this context, we highlight important gaps in understanding and discuss how new insight into the mechanisms underlying the effectiveness of mRNA-LNP vaccines may enable tailoring mRNA and carrier molecules to develop vaccines with greater effectiveness and milder adverse events in the future.


Subject(s)
COVID-19 , Humans , COVID-19/prevention & control , Vaccines, Synthetic , RNA, Messenger/genetics , Immunity, Innate
9.
Front Oncol ; 12: 975408, 2022.
Article in English | MEDLINE | ID: covidwho-2093772

ABSTRACT

mRNA cancer vaccines show therapeutic potential for malignant tumors, including hepatocellular carcinoma (HCC). We optimized and synthesized stable mRNA encoding costimulator Oxford 40 ligand (OX40L). For systemic delivery, OX40L mRNAs were loaded into lipid nanoparticles (LNPs). The expression and costimulatory effects of OX40L were investigated in vitro. OX40L was expressed on the cell surface and costimulated T cells. In vivo, intratumoral injection of LNPs encapsulating OX40L mRNAs significantly reduced tumor growth and increased the survival of mice bearing H22 tumors. Importantly, CD4+ and CD8+ T cells were significantly increased in the OX40L mRNA group in vivo. Taken together, our findings provide a promising clinical strategy for immunotherapy for HCC using mRNA vaccines.

10.
ACS Nano ; 16(11): 18936-18950, 2022 Nov 22.
Article in English | MEDLINE | ID: covidwho-2087127

ABSTRACT

Ionizable cationic lipid-containing lipid nanoparticles (LNPs) are the most clinically advanced non-viral gene delivery platforms, holding great potential for gene therapeutics. This is exemplified by the two COVID-19 vaccines employing mRNA-LNP technology from Pfizer/BioNTech and Moderna. Herein, we develop a chemical library of ionizable cationic lipids through a one-step chemical-biological enzyme-catalyzed esterification method, and the synthesized ionizable lipids were further prepared to be LNPs for mRNA delivery. Through orthogonal design of experiment methodology screening, the top-performing AA3-DLin LNPs show outstanding mRNA delivery efficacy and long-term storage capability. Furthermore, the AA3-DLin LNP COVID-19 vaccines encapsulating SARS-CoV-2 spike mRNAs successfully induced strong immunogenicity in a BALB/c mouse model demonstrated by the antibody titers, virus challenge, and T cell immune response studies. The developed AA3-DLin LNPs are an excellent mRNA delivery platform, and this study provides an overall perspective of the ionizable cationic lipids, from aspects of lipid design, synthesis, screening, optimization, fabrication, characterization, and application.


Subject(s)
COVID-19 , Nanoparticles , Mice , Animals , Humans , RNA, Messenger/genetics , RNA, Messenger/chemistry , COVID-19 Vaccines , Lipids/chemistry , COVID-19/prevention & control , SARS-CoV-2/genetics , Nanoparticles/chemistry , Liposomes , Cations , Catalysis
11.
Curr Issues Mol Biol ; 44(10): 5013-5027, 2022 Oct 19.
Article in English | MEDLINE | ID: covidwho-2082119

ABSTRACT

Lipid nanoparticles (LNPs) are an emerging vehicle for gene delivery that accommodate both nucleic acid and protein. Based on the experience of therapeutic liposomes, current LNPs have been developed based on the chemistry of lipids and RNA and on the biology of human disease. LNPs have been used for the development of Onpattro, an siRNA drug for transthyretin-mediated amyloidosis, in 2018. The subsequent outbreak of COVID-19 required a vaccine for its suppression. LNP-based vaccine production received much attention for this and resulted in great success. In this review, the essential technology of LNP gene delivery has been described according to the chemistry for LNP production and biology for its clinical application.

12.
Vaccines (Basel) ; 10(10)2022 Oct 12.
Article in English | MEDLINE | ID: covidwho-2071935

ABSTRACT

The COVID-19 pandemic highlighted mRNA as a promising platform for vaccines and therapeutics. Many of the analytical tools used to characterize the critical quality attributes of mRNA are inherently singleplex and are not necessarily optimal from a labor and cost perspective. Here, we demonstrate the feasibility of a multiplexed platform (VaxArray) for efficient identity verification and concentration determination for both monovalent and multivalent mRNA formulations. A model system comprising mRNA constructs for influenza hemagglutinin and neuraminidase was used to characterize the analytical performance metrics for a VaxArray mRNA assay. The assay presented herein had a time to result of less than 2 h, required no PCR-based amplification nor extraction of mRNA from lipid nanoparticles, and exhibited high construct specificity that enabled application to the bivalent mixture. The sensitivity for influenza hemagglutinin and neuraminidase mRNA was sub-µg/mL, which is vaccine-relevant, and the average accuracy (%recovery of a check standard) and precision were 104 ± 2% and 9 ± 2%, respectively.

13.
Polymers (Basel) ; 14(19)2022 Oct 06.
Article in English | MEDLINE | ID: covidwho-2066334

ABSTRACT

Messenger RNA (mRNA) vaccines have shown great preventive potential in response to the novel coronavirus (COVID-19) pandemic. The lipid nanoparticle (LNP), as a non-viral vector with good safety and potency factors, is applied to mRNA delivery in the clinic. Among the recently FDA-approved SARS-CoV-2 mRNA vaccines, lipid-based nanoparticles have been shown to be well-suited to antigen presentation and enhanced immune stimulation to elicit potent humoral and cellular immune responses. However, a design strategy for optimal mRNA-LNP vaccines has not been fully elaborated. In this review, we comprehensively and systematically discuss the research strategies for mRNA-LNP vaccines against COVID-19, including antigen and lipid carrier selection, vaccine preparation, quality control, and stability. Meanwhile, we also discuss the potential development directions for mRNA-LNP vaccines in the future. We also conduct an in-depth review of those technologies and scientific insights in regard to the mRNA-LNP field.

14.
Expert Opin Drug Deliv ; 19(10): 1381-1395, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-2062738

ABSTRACT

INTRODUCTION: During past years, lipid nanoparticles (LNPs) have emerged as promising carriers for RNA delivery, with several clinical trials focusing on both infectious diseases and cancer. More recently, the success of messenger RNA (mRNA) vaccines for the treatment of severe diseases, such as acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is partially justified by the development of LNPs encapsulating mRNA for efficient cytosolic delivery. AREAS COVERED: This review examines the production and formulation of LNPs by using microfluidic devices, the status of mRNA-loaded LNPs therapeutics and explores spray drying process, as a promising dehydration process to enhance LNP stability and provide alternative administration routes. EXPERT OPINION: Microfluidic techniques for preparation of LNPs based on organic solvent injection method promotes the generation of stable, uniform, and monodispersed nanoparticles enabling higher encapsulation efficiency. In particular, the application of microfluidics for the fabrication of mRNA-loaded LNPs is based on rapid mixing of small volumes of ethanol solution containing lipids and aqueous solution containing mRNA. Control of operating parameters and formulation has enabled the optimization of nanoparticle physicochemical characteristics and encapsulation efficiency.


Subject(s)
COVID-19 , Nanoparticles , Vaccines , Humans , Microfluidics , RNA, Messenger/genetics , Lipids , SARS-CoV-2/genetics , COVID-19/prevention & control , RNA, Small Interfering
15.
Tissue Engineering - Part A ; 28:345-346, 2022.
Article in English | EMBASE | ID: covidwho-2062827

ABSTRACT

Purpose/Objectives: The delivery of nucleic acids to cells has revolutionized medicine and enabled new technologies such as mRNA vaccines and stem cell therapies. These recent advances rely on delivery vehicles to stabilize the genetic payload and increase cellular transfection. While engineered viruses are efficient vectors for ex vivo cellular reprogramming, they are not ideal for in vivo gene therapies as repeated dosing leads to anti-vector immunity. Lipid nanoparticles have thus emerged as the best alternative to viral vectors for in vivo nucleic acid delivery. However, all FDA-approved lipid nanoparticles have been linked to inflammatory responses, undesirable for regenerative medicine applications that require precise immunomodulation. Thus, non-immunogenic delivery materials must be developed to fulfill the immense potential of gene therapy in regenerative medicine. Lipid nanoparticles typically comprise 4 different lipids, with the ionizable amino lipid being the main driver of potency and immunogenicity. A way to reduce immunogenicity is to develop lipid nanoparticles that minimize the amount of lipids per gram of nucleic acids. To do so, we developed a novel class of ionizable amino lipids with high charge density. Our primary objective is to design a lipid nanoparticle that maximizes RNA delivery and minimizes immunogenicity. Methodology: We designed a library of proprietary ionizable lipids based on the structure of a poly(amido amine) dendron. The structure is modular, which allowed us to systematically vary molecular motifs to optimize important physiochemical parameters: Lipid-to-RNA ratio;apparent pKa;surface zeta potential;size distribution;and RNA encapsulation These structures are also designed to include a higher number of amines compared to current ionizable lipids. This improves ionization charge density of the lipid and lowers the amount of lipid required to encapsulate RNA. In this study, lipid nanoparticles contain an ionizable lipid selected from our library, cholesterol, a phospholipid, and a PEG-lipid. The lipids and formulation conditions were selected to mimic Moderna's COVID-19 vaccine (SpikeVax), albeit with different lipid-to-RNA ratios. C57BL/6 mice were injected intramuscularly with nanoparticles co-formulated with a firefly luciferase mRNA and ovalbumin mRNA to simultaneously study transfection efficiency and antigen-specific immune responses. Nanoparticles that comprise SM-102, the ionizable lipid used in SpikeVax, were used as a comparative control due to their high potency and immunogenicity. Luciferase activity was detected using an IVIS Spectrum, and key organs were harvested for immune phenotyping. Results: We have so far determined the effect of hydrophobic motifs on apparent pKa and RNA encapsulation. Our best lipids with optimized tails did not induce IFN-I responses in vitro and demonstrated comparable in vivo efficacy to SM-102. We are currently in the process of collecting immunogenicity data which we expect to complete prior to the conference. Conclusion/Significance: We have produced a novel set of lipid nanoparticles that efficiently transfect cells in vivo. These new particles deliver RNA with half of the lipid mass used in SpikeVax, which can reduce the amount of material-induced immunogenicity. This result opens the door to developing mRNA vaccines with fewer side effects and equitable gene therapies for untreatable diseases such as inflammatory and autoimmune disorders.

16.
Int J Pharm ; 627: 122256, 2022 Nov 05.
Article in English | MEDLINE | ID: covidwho-2049315

ABSTRACT

Throughout the COVID-19 pandemic, many prophylactic and therapeutic drugs have been evaluated and introduced. Among these treatments, monoclonal antibodies (mAbs) that bind to and neutralize SARS-CoV-2 virus have been applied as complementary and alternative treatments to vaccines. Although different methodologies have been utilized to produce mAbs, traditional hybridoma fusion technology is still commonly used for this purpose due to its unmatched performance record. In this study, we coupled the hybridoma fusion strategy with mRNA-lipid nanoparticle (LNP) immunization. This time-saving approach can circumvent biological and technical hurdles, such as difficult-to-express membrane proteins, antigen instability, and the lack of posttranslational modifications on recombinant antigens. We used mRNA-LNP immunization and hybridoma fusion technology to generate mAbs against the receptor binding domain (RBD) of SARS-CoV-2 spike (S) protein. Compared with traditional protein-based immunization approaches, inoculation of mice with RBD mRNA-LNP induced higher titers of serum antibodies and markedly increased serum neutralizing activity. The mAbs we obtained can bind to SARS-CoV-2 RBDs from several variants. Notably, RBD-mAb-3 displayed particularly high binding affinities and neutralizing potencies against both Alpha and Delta variants. In addition to introducing specific mAbs against SARS-CoV-2, our data generally demonstrate that mRNA-LNP immunization may be useful to quickly generate highly functional mAbs against emerging infectious diseases.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Mice , Animals , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/metabolism , Pandemics , Antibody Formation , RNA, Messenger , COVID-19/prevention & control , Antibodies, Viral , Antibodies, Monoclonal/chemistry , Immunization
17.
Mol Ther ; 30(5): 1941-1951, 2022 05 04.
Article in English | MEDLINE | ID: covidwho-1663945

ABSTRACT

Lipid nanoparticle (LNP)-formulated nucleoside-modified mRNA vaccines have proven to be very successful in the fight against the coronavirus disease 2019 (COVID-19) pandemic. They are effective, safe, and can be produced in large quantities. However, the long-term storage of mRNA-LNP vaccines without freezing is still a challenge. Here, we demonstrate that nucleoside-modified mRNA-LNPs can be lyophilized, and the physicochemical properties of the lyophilized material do not significantly change for 12 weeks after storage at room temperature and for at least 24 weeks after storage at 4°C. Importantly, we show in comparative mouse studies that lyophilized firefly luciferase-encoding mRNA-LNPs maintain their high expression, and no decrease in the immunogenicity of a lyophilized influenza virus hemagglutinin-encoding mRNA-LNP vaccine was observed after 12 weeks of storage at room temperature or for at least 24 weeks after storage at 4°C. Our studies offer a potential solution to overcome the long-term storage-related limitations of nucleoside-modified mRNA-LNP vaccines.


Subject(s)
COVID-19 , Influenza Vaccines , Nanoparticles , Animals , COVID-19/prevention & control , Freeze Drying , Liposomes , Mice , Nanoparticles/chemistry , Nucleosides , RNA, Messenger/genetics , Vaccines, Synthetic , mRNA Vaccines
18.
Acta Pharmaceutica Hungarica ; 91(3-4):120, 2021.
Article in English | EMBASE | ID: covidwho-2033589

ABSTRACT

A drawback of the current mRNA-lipid nanoparticle (LNP) COVID-19 vaccines is that they have to be stored at (ultra)low temperatures (2). Understanding the root cause of the instability of these vaccines may help to rationally improve mRNALNP product stability and thereby ease the temperature conditions for storage. In this presentation we discuss proposed structures of mRNALNPs, factors that impact mRNA-LNP stability and strategies to optimize mRNA-LNP product stability. Analysis of mRNA-LNP structures reveals that mRNA, the ionizable cationic lipid and water are present in the LNP core. The neutral helper lipids are mainly positioned in the outer, encapsulating, wall. mRNA hydrolysis is an important driver for mRNA-LNP instability. It is currently a matter of debate whether water in the LNP core can freely interact with the mRNA and to what extent the degradation prone sites of mRNA are protected through a coat of ionizable cationic lipids. To improve the stability of mRNALNP vaccines, optimization of the mRNA nucleotide composition should be prioritized. Secondly, a better understanding of the milieu the mRNA is exposed to in the core of LNPs may help to rationalize adjustments to the LNP structure to preserve mRNA integrity. Moreover, drying techniques, such as lyophilization, are promising options still to be explored. As vaccines turn out to be the major weapon against the COVID-19 viral attack, the urge to develop more stable formulations is still growing and alternative, not-mRNA based products, may come to the forefront in situations where the (ultra) cold chain cannot be guaranteed. (Table Presented).

19.
Pharmaceuticals (Basel) ; 15(8)2022 Aug 18.
Article in English | MEDLINE | ID: covidwho-2023984

ABSTRACT

mRNA delivery has recently gained substantial interest for possible use in vaccines. Recently approved mRNA vaccines are administered intramuscularly where they transfect antigen-presenting cells (APCs) near the site of administration, resulting in an immune response. The spleen contains high numbers of APCs, which are located near B and T lymphocytes. Therefore, transfecting APCs in the spleen would be expected to produce a more efficient immune response, but this is a challenging task due to the different biological barriers. Success requires the development of an efficient system that can transfect different immune cells in the spleen. In this study, we report on the development of mRNA-loaded lipid nanoparticles (LNPs) targeting immune cells in the spleen with the goal of eliciting an efficient immune response against the antigen encoded in the mRNA. The developed system is composed of mRNA loaded in LNPs whose lipid composition was optimized for maximum transfection into spleen cells. Dendritic cells, macrophages and B cells in the spleen were efficiently transfected. The optimized LNPs produced efficient dose-dependent cytotoxic T lymphocyte activities that were significantly higher than that produced after local administration. The optimized LNPs encapsulating tumor-antigen encoding mRNA showed both prophylactic and therapeutic antitumor effects in mice.

20.
Proc Natl Acad Sci U S A ; 119(39): e2204624119, 2022 09 27.
Article in English | MEDLINE | ID: covidwho-2017031

ABSTRACT

The high transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a primary driver of the COVID-19 pandemic. While existing interventions prevent severe disease, they exhibit mixed efficacy in preventing transmission, presumably due to their limited antiviral effects in the respiratory mucosa, whereas interventions targeting the sites of viral replication might more effectively limit respiratory virus transmission. Recently, intranasally administered RNA-based therapeutic interfering particles (TIPs) were reported to suppress SARS-CoV-2 replication, exhibit a high barrier to resistance, and prevent serious disease in hamsters. Since TIPs intrinsically target the tissues with the highest viral replication burden (i.e., respiratory tissues for SARS-CoV-2), we tested the potential of TIP intervention to reduce SARS-CoV-2 shedding. Here, we report that a single, postexposure TIP dose lowers SARS-CoV-2 nasal shedding, and at 5 days postinfection, infectious virus shed is below detection limits in 4 out of 5 infected animals. Furthermore, TIPs reduce shedding of Delta variant or WA-1 from infected to uninfected hamsters. Cohoused "contact" animals exposed to infected, TIP-treated animals exhibited significantly lower viral loads, reduced inflammatory cytokines, no severe lung pathology, and shortened shedding duration compared to animals cohoused with untreated infected animals. TIPs may represent an effective countermeasure to limit SARS-CoV-2 transmission.


Subject(s)
COVID-19 , RNA, Messenger , RNA, Small Interfering , SARS-CoV-2 , Virus Shedding , Animals , COVID-19/therapy , COVID-19/transmission , Cricetinae , RNA, Messenger/administration & dosage , RNA, Small Interfering/administration & dosage , SARS-CoV-2/genetics , SARS-CoV-2/physiology
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