A versatile antibody capture system drives specific in vivo delivery of mRNA-loaded lipid nanoparticles.

Efficient and precise delivery of mRNA is critical to advance mRNA therapies beyond their current use as vaccines. Lipid nanoparticles (LNPs) efficiently encapsulate and protect mRNA, but non-specific cellular uptake may lead to off-target delivery and minimal delivery to target cells. Functionalizing LNPs with antibodies enables targeted mRNA delivery, but traditional modification techniques require complex conjugation and purification, which often reduces antibody affinity.

Cryo-EM structure of endogenous Pfs230 and Pfs48/45 fertilization complex.

Malaria parasite fertilization occurs in the midgut of a female mosquito. Blocking fertilization within the mosquito can prevent malaria transmission. Pfs230 and Pfs48/45 are critical for male fertility and transmission of the malaria parasite.

Impact of ionizable lipid type on the pharmacokinetics and biodistribution of mRNA-lipid nanoparticles after intravenous and subcutaneous injection.

Ionizable lipids play a crucial role in mRNA-lipid nanoparticle (LNP) formulations by facilitating mRNA encapsulation, promoting cell uptake, and enhancing endosomal escape of mRNA-LNPs. Despite their importance in mRNA delivery, the specific effects of ionizable lipids on mRNA-LNP in vivo pharmacokinetics (PK) and biodistribution remain underexplored. This study examines the effect of SM-102, ALC-0315, DLin-MC3-DMA (MC3), and 113-O12B ionizable lipids in mRNA-LNP formulations on plasma PK of lipid and mRNA, and biodistribution of expressed protein following subcutaneous (SC) and intravenous (IV) administration in mice.

Efficient mRNA delivery to resting T cells to reverse HIV latency.

A major hurdle to curing HIV is the persistence of integrated proviruses in resting CD4 T cells that remain in a transcriptionally silent, latent state. One strategy to eradicate latent HIV is to activate viral transcription, followed by elimination of infected cells through virus-mediated cytotoxicity or immune-mediated clearance. We hypothesised that mRNA-lipid nanoparticle (LNP) technology would provide an opportunity to deliver mRNA encoding proteins able to reverse HIV latency in resting CD4 T cells.

Lipid-Polyhydroxyalkanoate Hybrid Nanoparticles as Sustainable Platform for mRNA delivery.

The success of mRNA vaccines for the treatment of COVID-19 has generated enormous interest in mRNA therapeutics for various diseases, highlighting the need for robust delivery platforms. Combining the excellent transfection properties of lipids with the high stability of polymeric nanoparticles in a single hybrid system has become an attractive approach to generate next generation mRNA delivery systems. We introduce a modular lipid-polymer hybrid nanoparticle (LPHNP) design based on medium-chain-length polyhydroxyalkanoates (mcl-PHAs) as sustainable alternative to poly(lactic-co-glycolic acid) (PLGA), and a polymer-lipid (DMG-PEG, or poly(2-ethyl-2-oxazoline-myristic acid (PEtOx-MA)).

Transient inhibition of type I interferon enhances CD8+ T cell stemness and vaccine protection.

Developing vaccines that promote CD8+ T cell memory is a challenge for infectious disease and cancer immunotherapy. TCF-1+ stem cell-like memory CD8+ T (TSCM) cells are important determinants of long-lived memory. Yet, the developmental requirements for TSCM cell formation are unclear.

An LNP-mRNA vaccine modulates innate cell trafficking and promotes polyfunctional Th1 CD4 T cell responses to enhance BCG-induced protective immunity against Mycobacterium tuberculosis.

Background: Mycobacterium tuberculosis remains the largest infectious cause of mortality worldwide, even with over a century of widespread administration of the only licenced tuberculosis (TB) vaccine, Bacillus Calmette-Guérin (BCG). mRNA technology remains an underexplored approach for combating chronic bacterial infections such as TB.

Methods: We have developed a lipid nanoparticle (LNP)-mRNA vaccine, termed mRNA, encoding for the M.

mRNA vaccines encoding membrane-anchored RBDs of SARS-CoV-2 mutants induce strong humoral responses and can overcome immune imprinting.

We investigated mRNA vaccines encoding a membrane-anchored receptor-binding domain (RBD), each a fusion of a variant RBD, the transmembrane (TM) and cytoplasmic tail fragments of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. In naive mice, RBD-TM mRNA vaccines against SARS-CoV-2 variants induced strong humoral responses against the target RBD. Multiplex surrogate viral neutralization (sVNT) assays revealed broad neutralizing activity against a range of variant RBDs.

Conversion of vaccines from low to high immunogenicity by antibodies with epitope complementarity.

Existing antibodies (Abs) have varied effects on humoral immunity during subsequent infections. Here, we leveraged in vivo systems that allow precise control of antigen-specific Abs and B cells to examine the impact of Ab dose, affinity, and specificity in directing B cell activation and differentiation. Abs competing with the B cell receptor (BCR) epitope showed affinity-dependent suppression.

Replacing poly(ethylene glycol) with RAFT lipopolymers in mRNA lipid nanoparticle systems for effective gene delivery.

Lipid nanoparticles (LNPs) have emerged as promising carriers to efficiently transport mRNA into cells for protein translation, as seen with the mRNA vaccines used against COVID-19. However, they contain a widely used polymer - poly(ethylene glycol) (PEG) - which lacks the functionality to be easily modified (which could effectively control the physicochemical properties of the LNPs such as its charge), and is also known to be immunogenic. Thus, it is desirable to explore alternative polymers which can replace the PEG component in mRNA LNP vaccines and therapeutics, while still maintaining their efficacy.

Therapeutic applications of cell engineering using mRNA technology.

Engineering and reprogramming cells has significant therapeutic potential to treat a wide range of diseases, by replacing missing or defective proteins, to provide transcription factors (TFs) to reprogram cell phenotypes, or to provide enzymes such as RNA-guided Cas9 derivatives for CRISPR-based cell engineering. While viral vector-mediated gene transfer has played an important role in this field, the use of mRNA avoids safety concerns associated with the integration of DNA into the host cell genome, making mRNA particularly attractive for in vivo applications. Widespread application of mRNA for cell engineering is limited by its instability in the biological environment and challenges involved in the delivery of mRNA to its target site.

Tailored Monoacyl Poly(2-oxazoline)- and Poly(2-oxazine)-Lipids as PEG-Lipid Alternatives for Stabilization and Delivery of mRNA-Lipid Nanoparticles.

The successful use of lipid nanoparticles (LNPs) for clinical development of the COVID-19 mRNA vaccines marked a breakthrough in mRNA-LNP therapeutics. As one of the vital components of LNPs, poly(ethylene glycol)-lipid conjugates (PEG-lipids) influence particle biophysical properties and stability, as well as interactions within biological environments. Reports suggesting that anti-PEG antibodies can be detected quite commonly within the human population raise concerns that PEG content in commercial LNP products could further stimulate immune responses to PEG.

CRISPR-Cas13b-mediated suppression of HBV replication and protein expression.

Background & Aims: New antiviral approaches that target multiple aspects of the HBV replication cycle to improve rates of functional cure are urgently required. HBV RNA represents a novel therapeutic target. Here, we programmed CRISPR-Cas13b endonuclease to specifically target the HBV pregenomic RNA and viral mRNAs in a novel approach to reduce HBV replication and protein expression.

Delivery and Expression of mRNA in the Secondary Lymphoid Organs Drive Immune Responses to Lipid Nanoparticle-mRNA Vaccines after Intramuscular Injection.

Lipid nanoparticles (LNPs) are the prime delivery vehicle for mRNA vaccines. Previous hypotheses suggested that LNPs contribute to innate reactogenicity and lead to the establishment of a vaccine adaptive response. It has not been clear whether LNP adjuvancy in the muscle is the prime driver of adaptive immune responses or whether delivery to secondary lymphatic organs is necessary to induce strong adaptive responses.

Molecular Dynamics Simulation Studies of Bile, Bile Salts, Lipid-Based Drug Formulations, and mRNA-Lipid Nanoparticles: A Review.

Lipid-based formulation (LBF) is an effective approach for delivering hydrophobic drugs into the systemic circulation by oral administration. However, much of the physical detail regarding the colloidal behavior of LBFs and their interactions with the contents of the gastrointestinal (GI) environment is not well characterized. Recently, researchers have started to use molecular dynamics (MD) simulations to investigate the colloidal behavior of LBF systems and their interactions with bile and other materials present in the GI tract.

Broad immunity to SARS-CoV-2 variants of concern mediated by a SARS-CoV-2 receptor-binding domain protein vaccine.

Background: The SARS-CoV-2 global pandemic has fuelled the generation of vaccines at an unprecedented pace and scale. However, many challenges remain, including: the emergence of vaccine-resistant mutant viruses, vaccine stability during storage and transport, waning vaccine-induced immunity, and concerns about infrequent adverse events associated with existing vaccines.

Methods: We report on a protein subunit vaccine comprising the receptor-binding domain (RBD) of the ancestral SARS-CoV-2 spike protein, dimerised with an immunoglobulin IgG1 Fc domain.

TGFβ3, dibutyryl cAMP and a notch inhibitor modulate phenotype late in stem cell-derived dopaminergic neuron maturation.

The generation of midbrain dopaminergic neurons (mDAs) from pluripotent stem cells (hPSC) holds much promise for both disease modelling studies and as a cell therapy for Parkinson's disease (PD). Generally, dopaminergic neuron differentiation paradigms rely on inhibition of smad signalling for neural induction followed by hedgehog signalling and an elevation of β-catenin to drive dopaminergic differentiation. Post-patterning, differentiating dopaminergic neuron cultures are permitted time for maturation after which the success of these differentiation paradigms is usually defined by expression of tyrosine hydroxylase (TH), the rate limiting enzyme in the synthesis of dopamine.

Targeting Melanocortin Receptors Using SAr-Type Macrocyclization: A Doubly Orthogonal Route to Cyclic Peptide Conjugates.

While a range of strategies exist to accomplish peptide macrocyclization, they are frequently limited by the need for orthogonal protection or provide little opportunity for structural diversification. We have evaluated an efficient macrocyclization method that employs nucleophilic aromatic substitution (SAr) to create thioether macrocycles. This versatile macrocyclization, orthogonal to conventional peptide synthesis, can be performed in solution on unprotected peptidomimetics or on resin-bound peptides with side-chain protection in place.

Resolving subcellular pH with a quantitative fluorescent lifetime biosensor.

Changes in sub-cellular pH play a key role in metabolism, membrane transport, and triggering cargo release from therapeutic delivery systems. Most methods to measure pH rely on intensity changes of pH sensitive fluorophores, however, these measurements are hampered by high uncertainty in the inferred pH and the need for multiple fluorophores. To address this, here we combine pH dependant fluorescent lifetime imaging microscopy (pHLIM) with deep learning to accurately quantify sub-cellular pH in individual vesicles.

Polymeric Nanotubes as Drug Delivery Vectors─Comparison of Covalently and Supramolecularly Assembled Constructs.

Rod-shaped nanoparticles have been identified as promising drug delivery candidates. In this report, the in vitro cell uptake and in vivo pharmacokinetic/bio-distribution behavior of molecular bottle-brush (BB) and cyclic peptide self-assembled nanotubes were studied in the size range of 36-41 nm in length. It was found that BB possessed the longest plasma circulation time ( > 35 h), with the cyclic peptide system displaying an intermediate half-life (14.

delivery of plasmid DNA by lipid nanoparticles: the influence of ionizable cationic lipids on organ-selective gene expression.

Ionizable cationic lipids play a critical role in developing new gene therapies for various biomedical applications, including COVID-19 vaccines. However, it remains unclear whether the formulation of lipid nanoparticles (LNPs) using DLin-MC3-DMA, an optimized ionizable lipid clinically used for small interfering RNA (siRNA) therapy, also facilitates high liver-selective transfection of other gene therapies such as plasmid DNA (pDNA). Here we report the first investigation into pDNA transfection efficiency in different mouse organs after intramuscular and intravenous administration of lipid nanoparticles (LNPs) where DLin-MC3-DMA, DLin-KC2-DMA or DODAP are used as the ionizable cationic lipid component of the LNP.

Quantifying the Endosomal Escape of pH-Responsive Nanoparticles Using the Split Luciferase Endosomal Escape Quantification Assay.

All nanoparticles have the potential to revolutionize the delivery of therapeutic cargo such as peptides, proteins, and RNA. However, effective cytosolic delivery of cargo from nanoparticles represents a significant challenge in the design of more efficient drug delivery vehicles. Recently, research has centered on designing nanoparticles with the capacity to escape endosomes by responding to biological stimuli such as changes in pH, which occur when nanoparticles are internalized into the endo-/lysosomal pathway.

Inhibition of β-catenin dependent WNT signalling upregulates the transcriptional repressor NR0B1 and downregulates markers of an A9 phenotype in human embryonic stem cell-derived dopaminergic neurons: Implications for Parkinson's disease.

In this study we investigate how β-catenin-dependent WNT signalling impacts midbrain dopaminergic neuron (mDA) specification. mDA cultures at day 65 of differentiation responded to 25 days of the tankyrase inhibitor XAV969 (XAV, 100nM) with reduced expression of markers of an A9 mDA phenotype (KCNJ6, ALDH1A1 and TH) but increased expression of the transcriptional repressors NR0B1 and NR0B2. Overexpression of NR0B1 and or NR0B2 promoted a loss of A9 dopaminergic neuron phenotype markers (KCNJ6, ALDH1A1 and TH).