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1.
J Phys Chem Lett ; 12(45): 11199-11205, 2021 Nov 18.
Article in English | MEDLINE | ID: covidwho-1510547

ABSTRACT

Recent advances in RNA-based medicine have provided new opportunities for the global current challenge, i.e., the COVID-19 pandemic. Novel vaccines are based on a messenger RNA (mRNA) motif with a lipid nanoparticle (LNP) vector, consisting of high content of unique pH-sensitive ionizable lipids (ILs). Here we provide molecular insights into the role of the ILs and lipid mixtures used in current mRNA vaccines. We observed that the lipid mixtures adopted a nonlamellar organization, with ILs separating into a very disordered, pH-sensitive phase. We describe structural differences of the two ILs leading to their different congregation, with implications for the vaccine stability. Finally, as RNA interacts preferentially with IL-rich phases located at the regions with high curvature of lipid phase, local changes in RNA flexibility and base pairing are induced by lipids. A proper atomistic understanding of RNA-lipid interactions may enable rational tailoring of LNP composition for efficient RNA delivery.


Subject(s)
COVID-19 Vaccines/chemistry , Lipids/chemistry , RNA, Messenger/chemistry , Humans , Lipid Bilayers/chemistry , Models, Molecular , Molecular Dynamics Simulation
2.
Sci Rep ; 11(1): 21849, 2021 11 08.
Article in English | MEDLINE | ID: covidwho-1505527

ABSTRACT

The huge worldwide demand for vaccines targeting SARS-CoV-2 has necessitated the continued development of novel improved formulations capable of reducing the burden of the COVID-19 pandemic. Herein, we evaluated novel protein subunit vaccine formulations containing a resistin-trimerized spike antigen, SmT1. When combined with sulfated lactosyl archaeol (SLA) archaeosome adjuvant, formulations induced robust antigen-specific humoral and cellular immune responses in mice. Antibodies had strong neutralizing activity, preventing viral spike binding and viral infection. In addition, the formulations were highly efficacious in a hamster challenge model reducing viral load and body weight loss even after a single vaccination. The antigen-specific antibodies generated by our vaccine formulations had stronger neutralizing activity than human convalescent plasma, neutralizing the spike proteins of the B.1.1.7 and B.1.351 variants of concern. As such, our SmT1 antigen along with SLA archaeosome adjuvant comprise a promising platform for the development of efficacious protein subunit vaccine formulations for SARS-CoV-2.


Subject(s)
Adjuvants, Immunologic/chemistry , Antigens, Archaeal/chemistry , COVID-19 Vaccines/therapeutic use , Lipids/chemistry , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Body Weight , COVID-19/therapy , Chlorocebus aethiops , Cricetinae , Cytokines/metabolism , Female , Humans , Immunity, Cellular , Immunity, Humoral , Immunization, Passive , Mesocricetus , Mice , Mice, Inbred C57BL , Neutralization Tests , Peptides/chemistry , Protein Domains , SARS-CoV-2 , Toll-Like Receptors/immunology , Vero Cells , Viral Load
3.
Sci Rep ; 11(1): 21308, 2021 10 29.
Article in English | MEDLINE | ID: covidwho-1493219

ABSTRACT

The aim of this study was to present and evaluate novel oral vaccines, based on self-amplifying RNA lipid nanparticles (saRNA LNPs), saRNA transfected Lactobacillus plantarum LNPs, and saRNA transfected Lactobacillus plantarum, to neutralize severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) variants alpha and delta. After invitro evaluation of the oral vaccines on HEK293T/17 cells, we found that saRNA LNPs, saRNA transfected Lactobacillus plantarum LNPs, and saRNA transfected Lactobacillus plantarum could express S-protein at both mRNA and protein levels. In the next step, BALB/c mice were orally vaccinated with saRNA LNPs, saRNA transfected Lactobacillus plantarum LNPs, and saRNA transfected Lactobacillus plantarum at weeks 1 and 3. Importantly, a high titer of IgG and IgA was observed by all of them, sharply in week 6 (P < 0.05). In all study groups, their ratio of IgG2a/IgG1 was upper 1, indicating Th1-biased responses. Wild-type viral neutralization assay showed that the secreted antibodies in vaccinated mice and recovered COVID-19 patients could neutralize SARS-COV-2 variants alpha and delta. After oral administration of oral vaccines, biodistribution assay was done. It was found that all of them had the same biodistribution pattern. The highest concentration of S-protein was seen in the small intestine, followed by the large intestine and liver.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Lactobacillus plantarum/genetics , Lipids/chemistry , Nanoparticles/chemistry , SARS-CoV-2/immunology , Transfection/methods , Vaccination/methods , Vaccines, Synthetic/administration & dosage , Administration, Oral , Adult , Animals , COVID-19/blood , COVID-19/virology , COVID-19 Vaccines/pharmacokinetics , Female , HEK293 Cells , Humans , Immunoglobulin A/blood , Immunoglobulin A/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Intestine, Small/metabolism , Lactobacillus plantarum/metabolism , Male , Mice , Mice, Inbred BALB C , Middle Aged , Models, Animal , Neutralization Tests , RNA, Messenger/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Tissue Distribution
4.
Sci Rep ; 11(1): 20866, 2021 10 21.
Article in English | MEDLINE | ID: covidwho-1479816

ABSTRACT

A causal relationship between plasma ceramide concentration and respiratory distress symptoms in COVID-19 patients is inferred. In this study, plasma samples of 52 individuals infected with COVID-19 were utilized in a lipidomic analysis. Lipids belonging to the ceramide class exhibited a 400-fold increase in total plasma concentration in infected patients. Further analysis led to the demonstration of concentration dependency for severe COVID-19 respiratory symptoms in a subclass of ceramides. The subclasses Cer(d18:0/24:1), Cer(d18:1/24:1), and Cer(d18:1/22:0) were shown to be increased by 48-, 40-, and 33-fold, respectively, in infected plasma samples and to 116-, 91- and 50-fold, respectively, in plasma samples with respiratory distress. Hence, monitoring plasma ceramide concentration, can be a valuable tool for measuring effects of therapies on COVID-19 respiratory distress patients.


Subject(s)
COVID-19/blood , COVID-19/complications , Ceramides/blood , Respiratory Distress Syndrome/blood , Respiratory Distress Syndrome/complications , Adult , Aged , Aged, 80 and over , Chromatography, Liquid , Drug Design , Female , Humans , Ions , Lipids/chemistry , Male , Metabolomics , Middle Aged , Principal Component Analysis , Software , Tandem Mass Spectrometry , Virus Diseases , Young Adult
5.
Acc Chem Res ; 54(21): 4001-4011, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1475239

ABSTRACT

Since the U.S. Food and Drug Administration (FDA) granted emergency use authorization for two mRNA vaccines against SARS-CoV-2, mRNA-based technology has attracted broad attention from the scientific community to investors. When delivered intracellularly, mRNA has the ability to produce various therapeutic proteins, enabling the treatment of a variety of illnesses, including but not limited to infectious diseases, cancers, and genetic diseases. Accordingly, mRNA holds significant therapeutic potential and provides a promising means to target historically hard-to-treat diseases. Current clinical efforts harnessing mRNA-based technology are focused on vaccination, cancer immunotherapy, protein replacement therapy, and genome editing. The clinical translation of mRNA-based technology has been made possible by leveraging nanoparticle delivery methods. However, the application of mRNA for therapeutic purposes is still challenged by the need for specific, efficient, and safe delivery systems.This Account highlights key advances in designing and developing combinatorial synthetic lipid nanoparticles (LNPs) with distinct chemical structures and properties for in vitro and in vivo intracellular mRNA delivery. LNPs represent the most advanced nonviral nanoparticle delivery systems that have been extensively investigated for nucleic acid delivery. The aforementioned COVID-19 mRNA vaccines and one LNP-based small interfering RNA (siRNA) drug (ONPATTRO) have received clinical approval from the FDA, highlighting the success of synthetic ionizable lipids for in vivo nucleic acid delivery. In this Account, we first summarize the research efforts from our group on the development of bioreducible and biodegradable LNPs by leveraging the combinatorial chemistry strategy, such as the Michael addition reaction, which allows us to easily generate a large set of lipidoids with diverse chemical structures. Next, we discuss the utilization of a library screening strategy to identify optimal LNPs for targeted mRNA delivery and showcase the applications of the optimized LNPs in cell engineering and genome editing. Finally, we outline key challenges to the clinical translation of mRNA-based therapies and propose an outlook for future directions of the chemical design and optimization of LNPs to improve the safety and specificity of mRNA drugs. We hope this Account provides insight into the rational design of LNPs for facilitating the development of mRNA therapeutics, a transformative technology that promises to revolutionize future medicine.


Subject(s)
COVID-19 Vaccines/pharmacology , Gene Editing , Gene Transfer Techniques , Lipids/chemistry , Nanoparticles/chemistry , RNA, Messenger/pharmacology , COVID-19/drug therapy , COVID-19 Vaccines/chemistry , Genetic Therapy , Humans , RNA, Messenger/chemistry , SARS-CoV-2/drug effects
6.
ACS Chem Biol ; 16(5): 844-856, 2021 05 21.
Article in English | MEDLINE | ID: covidwho-1457790

ABSTRACT

Interferon-induced transmembrane proteins (IFITMs) are S-palmitoylated proteins in vertebrates that restrict a diverse range of viruses. S-palmitoylated IFITM3 in particular engages incoming virus particles, prevents their cytoplasmic entry, and accelerates their lysosomal clearance by host cells. However, how S-palmitoylation modulates the structure and biophysical characteristics of IFITM3 to promote its antiviral activity remains unclear. To investigate how site-specific S-palmitoylation controls IFITM3 antiviral activity, we employed computational, chemical, and biophysical approaches to demonstrate that site-specific lipidation of cysteine 72 enhances the antiviral activity of IFITM3 by modulating its conformation and interaction with lipid membranes. Collectively, our results demonstrate that site-specific S-palmitoylation of IFITM3 directly alters its biophysical properties and activity in cells to prevent virus infection.


Subject(s)
Antiviral Agents/chemistry , Cell Membrane/metabolism , Interferons/chemistry , Lipids/chemistry , Membrane Proteins/metabolism , RNA-Binding Proteins/metabolism , Amino Acid Sequence , Antiviral Agents/pharmacology , Binding Sites , Cell Membrane/ultrastructure , Computational Biology , Drug Design , Humans , Interferons/pharmacology , Lipoylation , Lysosomes/metabolism , Molecular Dynamics Simulation , Protein Binding , Protein Conformation , Signal Transduction
7.
Commun Biol ; 4(1): 956, 2021 08 11.
Article in English | MEDLINE | ID: covidwho-1354120

ABSTRACT

Lipid Nanoparticles (LNPs) are used to deliver siRNA and COVID-19 mRNA vaccines. The main factor known to determine their delivery efficiency is the pKa of the LNP containing an ionizable lipid. Herein, we report a method that can predict the LNP pKa from the structure of the ionizable lipid. We used theoretical, NMR, fluorescent-dye binding, and electrophoretic mobility methods to comprehensively measure protonation of both the ionizable lipid and the formulated LNP. The pKa of the ionizable lipid was 2-3 units higher than the pKa of the LNP primarily due to proton solvation energy differences between the LNP and aqueous medium. We exploited these results to explain a wide range of delivery efficiencies in vitro and in vivo for intramuscular (IM) and intravascular (IV) administration of different ionizable lipids at escalating ionizable lipid-to-mRNA ratios in the LNP. In addition, we determined that more negatively charged LNPs exhibit higher off-target systemic expression of mRNA in the liver following IM administration. This undesirable systemic off-target expression of mRNA-LNP vaccines could be minimized through appropriate design of the ionizable lipid and LNP.


Subject(s)
Gene Expression , Ions/chemistry , Lipids/chemistry , Nanoparticles/chemistry , RNA, Messenger/chemistry , RNA, Messenger/genetics , Administration, Intravenous , Animals , Drug Compounding , Humans , Hydrogen-Ion Concentration , Injections, Intramuscular , Mice , Molecular Structure , Nanoparticles/ultrastructure , RNA, Messenger/administration & dosage , RNA, Messenger/pharmacokinetics , Spectrum Analysis , Tissue Distribution , Transfection
8.
Mol Pharm ; 18(8): 2867-2888, 2021 08 02.
Article in English | MEDLINE | ID: covidwho-1310776

ABSTRACT

Despite the many advances that have occurred in the field of vaccine adjuvants, there are still unmet needs that may enable the development of vaccines suitable for more challenging pathogens (e.g., HIV and tuberculosis) and for cancer vaccines. Liposomes have already been shown to be highly effective as adjuvant/delivery systems due to their versatility and likely will find further uses in this space. The broad potential of lipid-based delivery systems is highlighted by the recent approval of COVID-19 vaccines comprising lipid nanoparticles with encapsulated mRNA. This review provides an overview of the different approaches that can be evaluated for the design of lipid-based vaccine adjuvant/delivery systems for protein, carbohydrate, and nucleic acid-based antigens and how these strategies might be combined to develop multicomponent vaccines.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Antigens/administration & dosage , Drug Delivery Systems , Lipids/chemistry , Nanoparticles/chemistry , Vaccines/administration & dosage , COVID-19 Vaccines/administration & dosage , Humans , Liposomes , SARS-CoV-2/immunology , Vaccines/chemistry
9.
J Allergy Clin Immunol ; 148(1): 91-95, 2021 07.
Article in English | MEDLINE | ID: covidwho-1291943

ABSTRACT

BACKGROUND: The mechanisms underpinning allergic reactions to the BNT162b2 (Pfizer) COVID-19 vaccine remain unknown, with polyethylene glycol (PEG) contained in the lipid nanoparticle suspected as being the cause. OBJECTIVE: Our aim was to evaluate the performance of skin testing and basophil activation testing to PEG, polysorbate 80, and the BNT162b2 (Pfizer) and AZD1222 (AstraZeneca) COVID-19 vaccines in patients with a history of PEG allergy. METHODS: Three known individuals with PEG allergy and 3 healthy controls were recruited and evaluated for hypersensitivity to the BNT162b2 and AZD1222 vaccines, and to related compounds by skin testing and basophil activation, as measured by CD63 upregulation using flow cytometry. RESULTS: We found that the BNT162b2 vaccine induced positive skin test results in patients with PEG allergy, whereas the result of traditional PEG skin testing was negative in 2 of 3 patients. One patient was found to be cosensitized to both the BNT162b2 and AZD1222 vaccines because of cross-reactive PEG and polysorbate allergy. The BNT162b2 vaccine, but not PEG alone, induced dose-dependent activation of all patients' basophils ex vivo. Similar basophil activation could be induced by PEGylated liposomal doxorubicin, suggesting that PEGylated lipids within nanoparticles, but not PEG in its native state, are able to efficiently induce degranulation. CONCLUSIONS: Our findings implicate PEG, as covalently modified and arranged on the vaccine lipid nanoparticle, as a potential trigger of anaphylaxis in response to BNT162b2, and highlight shortcomings of current skin testing protocols for allergy to PEGylated liposomal drugs.


Subject(s)
Anaphylaxis/immunology , Basophils/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , Doxorubicin/analogs & derivatives , Drug Hypersensitivity/immunology , Nanoparticles/adverse effects , Polyethylene Glycols/adverse effects , SARS-CoV-2/physiology , Adult , Cell Degranulation , Cells, Cultured , Doxorubicin/adverse effects , Doxorubicin/chemistry , Female , Humans , Lipids/chemistry , Male , Middle Aged , Nanoparticles/chemistry , Polyethylene Glycols/chemistry , Skin Tests , Young Adult
10.
J Colloid Interface Sci ; 602: 732-739, 2021 Nov 15.
Article in English | MEDLINE | ID: covidwho-1267733

ABSTRACT

Cholesterol has been shown to affect the extent of coronavirus binding and fusion to cellular membranes. The severity of Covid-19 infection is also known to be correlated with lipid disorders. Furthermore, the levels of both serum cholesterol and high-density lipoprotein (HDL) decrease with Covid-19 severity, with normal levels resuming once the infection has passed. Here we demonstrate that the SARS-CoV-2 spike (S) protein interferes with the function of lipoproteins, and that this is dependent on cholesterol. In particular, the ability of HDL to exchange lipids from model cellular membranes is altered when co-incubated with the spike protein. Additionally, the S protein removes lipids and cholesterol from model membranes. We propose that the S protein affects HDL function by removing lipids from it and remodelling its composition/structure.


Subject(s)
Lipids/chemistry , Lipoproteins, HDL/chemistry , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , COVID-19 , Humans , Spike Glycoprotein, Coronavirus/chemistry
11.
Molecules ; 26(9)2021 May 04.
Article in English | MEDLINE | ID: covidwho-1238922

ABSTRACT

Quercetin is a poorly water-soluble flavonoid with many benefits to human health. Besides the natural food resources that may provide Quercetin, the interest in delivery systems that could enhance its bioavailability in the human body has seen growth in recent years. Promising delivery system candidates are represented by Solid Lipid Nanoparticles (SLNs) which are composed of well-tolerated compounds and provide a relatively high encapsulation efficiency and suitable controlled release. In this study, Quercetin-loaded and negatively charged Solid Lipid Nanoparticles were synthesized based on a coacervation method, using stearic acid as a core lipid and Arabic Gum as a stabilizer. Samples were qualitatively characterized by Dynamic light scattering (DLS), Zeta Potential, Surface infrared spectroscopy (FTIR-ATR), and Time of flight secondary ion mass spectrometry (ToF-SIMS). Encapsulation efficiency, drug release, and antioxidant effect against ABTS•+ were evaluated in vitro by UV-VIS spectrophotometry.


Subject(s)
Drug Carriers/chemistry , Lipids/chemistry , Nanoparticles/chemistry , Quercetin/pharmacology , Antioxidants/pharmacology , Delayed-Action Preparations , Dynamic Light Scattering , Particle Size , Spectrometry, Mass, Secondary Ion , Spectroscopy, Fourier Transform Infrared , Static Electricity , Time Factors
12.
Mol Ther ; 29(7): 2219-2226, 2021 07 07.
Article in English | MEDLINE | ID: covidwho-1228174

ABSTRACT

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in humans. Despite several emerging vaccines, there remains no verifiable therapeutic targeted specifically to the virus. Here we present a highly effective small interfering RNA (siRNA) therapeutic against SARS-CoV-2 infection using a novel lipid nanoparticle (LNP) delivery system. Multiple siRNAs targeting highly conserved regions of the SARS-CoV-2 virus were screened, and three candidate siRNAs emerged that effectively inhibit the virus by greater than 90% either alone or in combination with one another. We simultaneously developed and screened two novel LNP formulations for the delivery of these candidate siRNA therapeutics to the lungs, an organ that incurs immense damage during SARS-CoV-2 infection. Encapsulation of siRNAs in these LNPs followed by in vivo injection demonstrated robust repression of virus in the lungs and a pronounced survival advantage to the treated mice. Our LNP-siRNA approaches are scalable and can be administered upon the first sign of SARS-CoV-2 infection in humans. We suggest that an siRNA-LNP therapeutic approach could prove highly useful in treating COVID-19 disease as an adjunctive therapy to current vaccine strategies.


Subject(s)
COVID-19/drug therapy , Drug Delivery Systems/methods , Lipids/chemistry , Nanoparticles/chemistry , RNA, Double-Stranded/administration & dosage , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/genetics , SARS-CoV-2/genetics , Administration, Intravenous , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/metabolism , COVID-19/virology , Female , Gene Silencing , HEK293 Cells , Humans , Lung/metabolism , Male , Mice , Mice, Transgenic , RNA, Double-Stranded/genetics , RNA, Viral/genetics , Transcriptome/drug effects , Treatment Outcome
13.
Eur J Pharm Biopharm ; 163: 252-265, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1144592

ABSTRACT

Lipid-based nanoparticles for RNA delivery (LNP-RNA) are revolutionizing the nanomedicine field, with one approved gene therapy formulation and two approved vaccines against COVID-19, as well as multiple ongoing clinical trials. As for other innovative nanopharmaceuticals (NPhs), the advancement of robust methods to assess their quality and safety profiles-in line with regulatory needs-is critical for facilitating their development and clinical translation. Asymmetric-flow field-flow fractionation coupled to multiple online optical detectors (MD-AF4) is considered a very versatile and robust approach for the physical characterisation of nanocarriers, and has been used successfully for measuring particle size, polydispersity and physical stability of lipid-based systems, including liposomes and solid lipid nanoparticles. However, the unique core structure of LNP-RNA, composed of ionizable lipids electrostatically complexed with RNA, and the relatively labile lipid-monolayer coating, is more prone to destabilization during focusing in MD-AF4 than previously characterised nanoparticles, resulting in particle aggregation and sample loss. Hence characterisation of LNP-RNA by MD-AF4 needs significant adaptation of the methods developed for liposomes. To improve the performance of MD-AF4 applied to LNP-RNA in a systematic and comprehensive manner, we have explored the use of the frit-inlet channel where, differently from the standard AF4 channel, the particles are relaxed hydrodynamically as they are injected. The absence of a focusing step minimizes contact between the particle and the membrane, reducing artefacts (e.g. sample loss, particle aggregation). Separation in a frit-inlet channel enables satisfactory reproducibility and acceptable sample recovery in the commercially available MD-AF4 instruments. In addition to slice-by-slice measurements of particle size, MD-AF4 also allows to determine particle concentration and the particle size distribution, demonstrating enhanced versatility beyond standard sizing measurements.


Subject(s)
Drug Carriers/chemistry , Lipids/chemistry , Nanoparticles/chemistry , RNA/administration & dosage , RNA/chemistry , Fractionation, Field Flow/methods , Humans , Nanomedicine/methods , Particle Size , Pharmaceutical Preparations/administration & dosage , Pharmaceutical Preparations/chemistry
14.
Proc Natl Acad Sci U S A ; 118(11)2021 03 16.
Article in English | MEDLINE | ID: covidwho-1125727

ABSTRACT

The mosquito protein AEG12 is up-regulated in response to blood meals and flavivirus infection though its function remained elusive. Here, we determine the three-dimensional structure of AEG12 and describe the binding specificity of acyl-chain ligands within its large central hydrophobic cavity. We show that AEG12 displays hemolytic and cytolytic activity by selectively delivering unsaturated fatty acid cargoes into phosphatidylcholine-rich lipid bilayers. This property of AEG12 also enables it to inhibit replication of enveloped viruses such as Dengue and Zika viruses at low micromolar concentrations. Weaker inhibition was observed against more distantly related coronaviruses and lentivirus, while no inhibition was observed against the nonenveloped virus adeno-associated virus. Together, our results uncover the mechanistic understanding of AEG12 function and provide the necessary implications for its use as a broad-spectrum therapeutic against cellular and viral targets.


Subject(s)
Antiviral Agents/metabolism , Hemolytic Agents/metabolism , Insect Proteins/metabolism , Lipids , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Cell Line , Cell Membrane/metabolism , Culicidae , Erythrocytes/drug effects , Fatty Acids, Unsaturated/metabolism , Hemolytic Agents/chemistry , Hemolytic Agents/pharmacology , Humans , Hydrophobic and Hydrophilic Interactions , Insect Proteins/chemistry , Insect Proteins/pharmacology , Ligands , Lipids/chemistry , Protein Binding , Protein Structure, Tertiary , Viral Envelope/metabolism , Viruses/drug effects , Viruses/metabolism
15.
Pharm Res ; 38(3): 473-478, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-1117456

ABSTRACT

The COVID-19 pandemic has left scientists and clinicians no choice but a race to find solutions to save lives while controlling the rapid spreading. Messenger RNA (mRNA)-based vaccines have become the front-runners because of their safety profiles, precise and reproducible immune response with more cost-effective and faster production than other types of vaccines. However, the physicochemical properties of naked mRNA necessitate innovative delivery technologies to ferry these 'messengers' to ribosomes inside cells by crossing various barriers and subsequently induce an immune response. Intracellular delivery followed by endosomal escape represents the key strategies for cytoplasmic delivery of mRNA vaccines to the target. This Perspective provides insights into how state-of-the-art nanotechnology helps break the delivery barriers and advance the development of mRNA vaccines. The challenges remaining and future perspectives are outlined.


Subject(s)
COVID-19 Vaccines/therapeutic use , COVID-19/prevention & control , Cytoplasm/metabolism , Drug Carriers , Lipids/chemistry , Nanoparticles , Ribosomes/metabolism , Vaccines, Synthetic/therapeutic use , Animals , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/chemistry , COVID-19 Vaccines/pharmacokinetics , Drug Compounding , Humans , Nanomedicine , Vaccines, Synthetic/chemistry
16.
Mar Drugs ; 19(1)2021 Jan 10.
Article in English | MEDLINE | ID: covidwho-1033055

ABSTRACT

Microalgae are at the start of the food chain, and many are known producers of a significant amount of lipids with essential fatty acids. However, the bioactivity of microalgal lipids for anti-inflammatory and antithrombotic activities have rarely been investigated. Therefore, for a sustainable source of the above bioactive lipids, the present study was undertaken. The total lipids of microalga Chlorococcum sp., isolated from the Irish coast, were fractionated into neutral-, glyco-, and phospho-lipids, and were tested in vitro for their anti-inflammatory and antithrombotic activities. All tested lipid fractions showed strong anti-platelet-activating factor (PAF) and antithrombin activities in human platelets (half maximal inhibitory concentration (IC50) values ranging ~25-200 µg of lipid) with the highest activities in glyco- and phospho-lipid fractions. The structural analysis of the bioactive lipid fraction-2 revealed the presence of specific sulfoquinovosyl diacylglycerols (SQDG) bioactive molecules and the HexCer-t36:2 (t18:1/18:1 and 18:2/18:0) cerebrosides with a phytosphingosine (4-hydrosphinganine) base, while fraction-3 contained bioactive phosphatidylcholine (PC) and phosphatidylethanolamine (PE) molecules. These novel bioactive lipids of Chlorococcum sp. with putative health benefits may indicate that marine microalgae can be a sustainable alternative source for bioactive lipids production for food supplements and nutraceutical applications. However, further studies are required towards the commercial technology pathways development and biosafety analysis for the use of the microalga.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Fibrinolytic Agents/chemistry , Fibrinolytic Agents/pharmacology , Lipids/chemistry , Lipids/pharmacology , Microalgae/chemistry , Antithrombins/pharmacology , Blood Platelets/drug effects , Fatty Acids/chemistry , Fatty Acids/pharmacology , Humans , Platelet Activating Factor/antagonists & inhibitors , Platelet Aggregation/drug effects , Water Microbiology
17.
J Control Release ; 330: 305-316, 2021 02 10.
Article in English | MEDLINE | ID: covidwho-988296

ABSTRACT

The era of Nanomedicine has arrived with the approval of ONPATTRO™ by the FDA in 2018. Lipid nanoparticle (LNP) technology has succeeded in delivering siRNA to the human liver in genetic diseases and has also been applied to mRNA vaccinations for COVID-19 using a similar LNP technology. In this review, we focus on the current status of new lipids for use in LNP formulations including our original lipids (CL4H6/CL4C6/CL4D6) as well as mechanisms of targeting without a ligand. Clinical applications of nano DDS are moving forward rapidly in the field of cancer immunology since the successful introduction of OPDIVO™ in 2014. Antigen presentation and the maturation of immune cells can be controlled by nano DDS for cancer immunotherapy. YSK12-C4, a newly designed ionizable amino lipid can induce successful immune activation by silencing mRNA in DC and NK cells, which are expected to be evaluated for clinical use. Finally, new cancer therapy by targeting mitochondria involving the use of a MITO-Porter, a membrane fusion-type mitochondrial delivery system, has been introduced. The importance of delivering a photo sensitizer to mitochondria was clearly demonstrated in photodynamic cancer therapy. Clinical applications of MITO-Porters started in collaborative efforts with LUCA Science Co., Ltd. And was established in 2018. The future direction of Nanomedicine is discussed.


Subject(s)
COVID-19 Vaccines/chemistry , Drug Delivery Systems , Nanomedicine/trends , Animals , COVID-19 , Drug Compounding , Humans , Immunotherapy , Lipids/chemistry
18.
J Control Release ; 330: 529-539, 2021 02 10.
Article in English | MEDLINE | ID: covidwho-988295

ABSTRACT

The current health crisis of corona virus disease 2019 (COVID-19) highlights the urgent need for vaccine systems that can generate potent and protective immune responses. Protein vaccines are safe, but conventional approaches for protein-based vaccines often fail to elicit potent and long-lasting immune responses. Nanoparticle vaccines designed to co-deliver protein antigens and adjuvants can promote their delivery to antigen-presenting cells and improve immunogenicity. However, it remains challenging to develop vaccine nanoparticles that can preserve and present conformational epitopes of protein antigens for induction of neutralizing antibody responses. Here, we have designed a new lipid-based nanoparticle vaccine platform (NVP) that presents viral proteins (HIV-1 and SARS-CoV-2 antigens) in a conformational manner for induction of antigen-specific antibody responses. We show that NVP was readily taken up by dendritic cells (DCs) and promoted DC maturation and antigen presentation. NVP loaded with BG505.SOSIP.664 (SOSIP) or SARS-CoV-2 receptor-binding domain (RBD) was readily recognized by neutralizing antibodies, indicating the conformational display of antigens on the surfaces of NVP. Rabbits immunized with SOSIP-NVP elicited strong neutralizing antibody responses against HIV-1. Furthermore, mice immunized with RBD-NVP induced robust and long-lasting antibody responses against RBD from SARS-CoV-2. These results suggest that NVP is a promising platform technology for vaccination against infectious pathogens.


Subject(s)
AIDS Vaccines/chemistry , COVID-19 Vaccines/chemistry , Immunity, Humoral/drug effects , Lipids/chemistry , Nanoparticles , Viral Vaccines/chemistry , AIDS Vaccines/administration & dosage , Adjuvants, Immunologic , Animals , Antigen Presentation , Antigen-Antibody Reactions , COVID-19 Vaccines/administration & dosage , Dendritic Cells/immunology , Dendritic Cells/metabolism , HIV-1 , Humans , Lymph Nodes/immunology , Mice , Mice, Inbred BALB C , Rabbits , SARS-CoV-2 , Viral Vaccines/administration & dosage
20.
Nanoscale ; 12(47): 23959-23966, 2020 Dec 21.
Article in English | MEDLINE | ID: covidwho-947558

ABSTRACT

Lipid nanoparticle (LNP) formulations of nucleic acid are leading vaccine candidates for COVID-19, and enabled the first approved RNAi therapeutic, Onpattro. LNPs are composed of ionizable cationic lipids, phosphatidylcholine, cholesterol, and polyethylene glycol (PEG)-lipids, and are produced using rapid-mixing techniques. These procedures involve dissolution of the lipid components in an organic phase and the nucleic acid in an acidic aqueous buffer (pH 4). These solutions are then combined using a continuous mixing device such as a T-mixer or microfluidic device. In this mixing step, particle formation and nucleic acid entrapment occur. Previous work from our group has shown that, in the absence of nucleic acid, the particles formed at pH 4 are vesicular in structure, a portion of these particles are converted to electron-dense structures in the presence of nucleic acid, and the proportion of electron-dense structures increases with nucleic acid content. What remained unclear from previous work was the mechanism by which vesicles form electron-dense structures. In this study, we use cryogenic transmission electron microscopy and dynamic light scattering to show that efficient siRNA entrapment occurs in the absence of ethanol (contrary to the established paradigm), and suggest that nucleic acid entrapment occurs through inversion of preformed vesicles. We also leverage this phenomenon to show that specialized mixers are not required for siRNA entrapment, and that preformed particles at pH 4 can be used for in vitro transfection.


Subject(s)
COVID-19 , Lab-On-A-Chip Devices , Lipids , Nanoparticles , RNA, Small Interfering , SARS-CoV-2 , Animals , Cell Line , Hydrogen-Ion Concentration , Lipids/chemistry , Lipids/pharmacology , Mice , Nanoparticles/chemistry , Nanoparticles/therapeutic use , RNA, Small Interfering/chemistry , RNA, Small Interfering/pharmacology
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