Lipid Nanoparticles Research Articles

Mechanism of modified mRNA structure in COVID-19 vaccines for inducing neutralizing antibodies

The development of SARS-CoV-2 mRNA vaccines is closely linked to advancements in mRNA manufacturing technology. Structural modifications, such as replacing uridine with 1-methylpseudouridine (1mψ), enhance translation efficiency and help the mRNA evade immune detection. Lipid nanoparticles (LNPs) serve as an effective delivery system. Vaccines like BNT162b2 and mRNA-1273 target the receptor-binding domain (RBD) of the spike (S) protein, prompting B cells to produce neutralizing antibodies that block the RBD from binding to the Angiotensin-Converting Enzyme 2 (ACE2) receptor, preventing infection. These vaccines also stimulate adaptive immune responses by activating CD4+ and CD8+ T cells, with mRNA functioning as an endogenous antigen. Antigen-presenting cells (APCs) present the vaccine antigens via major histocompatibility complex (MHC) class I and II pathways, with CD8+ T cells recognizing MHC class I and destroying infected cells, while CD4+ T cells recognize MHC class II and assist in B cell maturation and antibody production. While mRNA vaccines have proven effective in neutralizing SARS-CoV-2, challenges remain, including the decline in neutralizing antibody titers over time and the emergence of new viral variants.

Accelerated Ten-Gram-Scale Synthesis of One-Component Multifunctional Sequence-Defined Ionizable Amphiphilic Janus Dendrimer 97.

One-component multifunctional sequence-defined ionizable amphiphilic Janus dendrimers (IAJDs) were discovered in our laboratories in 2021 to represent a new class of synthetic vectors for the targeted delivery of messenger RNA (mRNA). They coassemble with mRNA by simple injection of their ethanol solution into a pH 4 acetate buffer containing the nucleic acid into monodisperse dendrimersome nanoparticles (DNPs) with predictable dimensions. DNPs are competitive with 4-component lipid nanoparticles (LNPs), which are used in commercial COVID-19 vaccines, except that IAJDs are prepared in fewer reaction steps than each individual component of the LNPs. This simple methodology for the synthesis of IAJDs and their coassembly with mRNA into DNPs, together with the precise placement of their individual components and indefinite stability at room temperature in air, make them attractive candidates for the development of nanomedicine-based targeted mRNA delivery. Access to the large-scale synthesis of IAJDs without the need for sophisticated technologies, instrumentation, and synthetic skills is expected to open numerous new opportunities worldwide in nanomedicine. The goal of this publication is to report an accelerated ten-gram-scale synthesis of IAJD97 from inexpensive food additives obtained from renewable plant phenolic acid starting materials by methodologies accessible to any laboratory. This accelerated synthesis can be accomplished in 4 days. We expect that the work reported here will impact the field of nanomedicine in both developed and less developed countries.

In situ engineering of mRNA-CAR T cells using spleen-targeted ionizable lipid nanoparticles to eliminate cancer cells

Chimeric antigen receptor (CAR) T cell therapy has implemented impressive advances in the treatment of B-cell lymphoma. However, the complex production process of CAR T cells and hindrance of solid tumor penetration remain substantial challenges. Intriguingly, cell-targeting delivery of messenger RNA (mRNA) with ionizable lipid nanoparticles (mRNA-LNPs) is able to efficiently and precisely engineer T cells and other immune cells in vivo to perform their functions. Herein, we harnessed the ionizable LNPs to encapsulate mRNA encoding anti-tyrosinase related protein 1 (TRP1) CAR (CAR-LNPs) for in vivo generation of mRNA-CAR T cells to eliminate melanoma cells. Specifically, the anti-CD3 antibody (aCD3) armed mRNA-LNPs (CD3-mRNA-LNPs) selectively targeted T cells, resulting in the production of functional and therapeutic levels of CAR T cells both ex vivo and in vivo. These CD3-CAR-LNPs engineered CAR T cells were capable of infiltrating into the solid tumor and effectively eliminating melanoma cells with high TRP1 expression, significantly hindering tumor progression. Critically, CD3–7CAR-LNPs containing mRNA encoding both CAR and interleukin-7 (IL-7) generated 7CAR T cells that secreted IL-7, thereby enhancing the activity and proliferation of both CAR T cells and other intratumoral cytotoxic T cells. Alternatively, the employment of anti-programmed cell death protein 1 antibody (aPD-1) protected mRNA-CAR T cells from exhaustion, especially in combination with CD3–7CAR-LNPs, could significantly enhance the antitumor capability of CAR T cells without causing acute cytokine release syndrome (CRS).

Design of a Robust Flow Cytometric Approach for Phenotypical and Functional Analysis of Human Monocyte Subsets in Health and Disease.

Human monocytes can be subdivided into phenotypically and functionally different classical, intermediate and non-classical monocytes according to the cell surface expression of CD14 and CD16. A precise identification and characterisation of monocyte subsets is necessary to unravel their role in inflammatory diseases. Here, we compared three different flow cytometric strategies (A-C) and found that strategy C, which included staining against CD11b, HLA-DR, CD14 and CD16, followed by several gating steps, most reliably identified monocyte subtypes in blood samples from healthy volunteers and from patients with stable coronary heart disease (CHD) or ST-elevation myocardial infarction (STEMI). Additionally, we established a fixation and permeabilisation protocol to enable the analysis of intracellular markers. We investigated the phagocytosis of lipid nanoparticles, the uptake of 2-NBD-glucose and the intracellular levels of CD74 and HLA-DM. This revealed that classical and intermediate monocytes from patients with STEMI showed the highest uptake of 2-NBD-glucose, whereas classical and intermediate monocytes from patients with CHD took up the largest amounts of lipid nanoparticles. Interestingly, intermediate monocytes had the highest expression level of HLA-DM. Taken together, we present a robust flow cytometric approach for the identification and functional characterisation of monocyte subtypes in healthy humans and patients with diseases.

RNA lipid nanoparticles as efficient in vivo CRISPR-Cas9 gene editing tool for therapeutic target validation in glioblastoma cancer stem cells

In vitro and ex-vivo target identification strategies often fail to predict in vivo efficacy, particularly for glioblastoma (GBM), a highly heterogenous tumor rich in resistant cancer stem cells (GSCs). An in vivo screening tool can improve prediction of therapeutic efficacy by considering the complex tumor microenvironment and the dynamic plasticity of GSCs driving therapy resistance and recurrence. This study proposes lipid nanoparticles (LNPs) as an efficient in vivo CRISPR-Cas9 gene editing tool for target validation in mesenchymal GSCs. LNPs co-delivering mRNA (mCas9) and single-guide RNA (sgRNA) were successfully formulated and optimized facilitating both in vitro and in vivo gene editing. In vitro, LNPs achieved up to 67 % reduction in green fluorescent protein (GFP) expression, used as a model target, outperforming a commercial transfection reagent. Intratumoral administration of LNPs in GSCs resulted in ∼80 % GFP gene knock-out and a 2-fold reduction in GFP signal by day 14. This study showcases the applicability of CRISPR-Cas9 LNPs as a potential in vivo screening tool in GSCs, currently lacking effective treatment. By replacing GFP with a pool of potential targets, the proposed platform presents an exciting prospect for therapeutic target validation in orthotopic GSCs, bridging the gap between preclinical and clinical research.

Physicochemical and biological characterization of the lipid particles with bovine serum albumin corona

Diacylglycerol–based nanoparticles are promising bioactive delivery systems. However, limited understanding of their interaction with biological entities restricts their clinical use. This study investigated the protein corona formed on medium and long chain diacylglycerol (MLCD)-based solid lipid nanoparticles (NPs) modified by Polyoxethylene stearate (PEG) and compared to glyceryl tristearate (TG) and cetyl palmitate (CP) nanoparticles. Bovine serum albumin (BSA) formed corona with MLCD NPs through hydrophobic interactions and hydrogen bonding, contributing to a decrease in α–helix, an increase in β–sheet and a change in the microenvironment of Tyr residues. Owing to higher lipid hydrophilicity, MLCD NPs showed a much lower affinity for BSA than TG and CP NPs, and the binding constant with BSA was increased for larger NPs. PEG modification and the protein corona reduced the uptake of NPs by macrophages but exerted little influence on B16 cell. Among the NPs with different lipid core, the MLCD NPs showed a lower macrophages cell uptake but higher B16 cell uptake, suggesting a longer circulation time in blood but higher cancer cell internalization. This work shed light on the interactions between MLCD NPs and proteins, which is significant for application as nanocarriers with improved biological efficacy.

Betulin-NLC-hydrogel for the Treatment of Psoriasis-like Skin Inflammation: Optimization, Characterisation, and In vitro and In vivo Evaluation.

Psoriasis is a chronic inflammatory skin disorder that poses significant challenges regarding effective and targeted drug delivery. Bioactive substances like betulin have shown tremendous utility in treating these conditions; however, they pose limited utility owing to their physicochemical characteristics. Here, we aimed to develop a novel topical dosage form for treating psoriasis, utilising betulin-loaded solid lipid nanoparticles (NLCs) incorporated into a hydrogel matrix. The optimization of the formulation was meticulously conducted using a design of experiments methodology, and its diverse physicochemical attributes were thoroughly examined. Evaluating betulin's in vitro release pattern from the NLC-hydrogel demonstrated consistent and regulated drug release properties. Additionally, the formulation demonstrated improved skin penetration abilities as determined by in vitro skin permeation experiments employing Franz diffusion cells- furthermore, the therapeutic effectiveness of the betulin-NLC-hydrogel was assessed by an in vivo experiment carried out using an imiquimod-induced psoriasis-like skin inflammation model in BALB/c female mice. The NLCs exhibited a pH of 5.67±0.86, particle size of 148.16±12.66 nm, and zeta potential of -22.84±2.37 mV, ensuring stability and suitability for topical use. The gel, with a pH of 6.05±0.43 and viscosity of 17550±120 cPs, showed enhanced skin hydration and lipid restoration. Drug release studies indicated a slower release from NLCs and gel, improving skin retention. Stability tests revealed that the formulations were stable at room temperature but not at elevated temperatures. The in vitro safety profile of the formulation revealed no significant adverse effects on HaCaT cell lines. The NLC gel demonstrated significant anti-psoriatic activity, reducing inflammation and cytokine levels. The betulin-NLC-hydrogel formulation exhibited promising characteristics for the topical treatment of psoriasis, showcasing optimised drug delivery, sustained release, and notable therapeutic efficacy. The findings from this study provide a foundation for the potential clinical translation of this innovative topical dosage form for improved psoriasis management.

A biodegradable lipid nanoparticle delivers a Cas9 ribonucleoprotein for efficient and safe in situ genome editing in melanoma

The development of melanoma is closely related to Braf gene, which is a suitable target for CRISPR/Cas9 based gene therapy. CRISPR/Cas9-sgRNA ribonucleoprotein complexes (RNPs) stand out as the safest format compared to plasmid and mRNA delivery. Similarly, lipid nanoparticles (LNPs) emerge as a safer alternative to viral vectors for delivering the CRISPR/Cas9-sgRNA gene editing system. Herein, we have designed multifunctional cationic LNPs specifically tailored for the efficient delivery of Cas9 RNPs targeting the mouse Braf gene through transdermal delivery, aiming to treat mouse melanoma. LNPs are given a positive charge by the addition of a newly synthesized polymer, deoxycholic acid modified polyethyleneimine (PEI-DOCA). Positive charge enables LNPs to be delivered in vivo by binding to negatively charged cell membranes and proteins, thereby facilitating efficient skin penetration and enhancing the delivery of RNPs into melanoma cells for gene editing purposes. Our research demonstrates that these LNPs enhance drug penetration through the skin, successfully delivering the Cas9 RNPs system and specifically targeting the Braf gene. Cas9 RNPs loaded LNPs exert a notable impact on gene editing in melanoma cells, significantly suppressing their proliferation. Furthermore, in mice experiments, the LNPs exhibited skin penetration and tumor targeting capabilities. This innovative LNPs delivery system offers a promising gene therapy approach for melanoma treatment and provides fresh insights into the development of safe and effective delivery systems for Cas9 RNPs in vivo. Statement of significanceCRISPR/Cas9 technology brings new hope for cancer treatment. Cas9 ribonucleoprotein offers direct genome editing, yet delivery challenges persist. For melanoma, transdermal delivery minimizes toxicity but faces skin barrier issues. We designed multifunctional lipid nanoparticles (LNPs) for Cas9 RNP delivery targeting the Braf gene. With metal microneedle pretreatment, our LNPs effectively edited melanoma cells, reducing Braf expression and inhibiting tumor growth. Our study demonstrates LNPs' potential for melanoma therapy and paves the way for efficient in vivo Cas9 RNP delivery systems in cancer therapy.

Designing a multi-epitope construct using immuno-informatic tools to prepare a messenger RNA vaccine against Rhipicephalus microplus ticks

Background and Aim: Ticks are blood-feeding ectoparasites that transmit pathogens to animals and humans. One of the most important hard ticks in animals is Rhipicephalus microplus, which transmits Babesia and Anaplasma spp. Although many potential tick vaccine candidates have been identified, no effective vaccine that can provide sterile immunity against R. microplus tick infestations has been developed. This study aimed to design a construct using different computational tools to identify and predict immunogenic epitopes within protein sequences and to prepare a messenger RNA (mRNA) vaccine against R. microplus based on lipid nanoparticles (LNPs). Materials and Methods: The R. microplus proteins (Bm86, Subolesin, and ATAQ) were selected and their consensus sequence was obtained from the National Center for Biotechnology Information in FASTA format. The Immune Epitope Database and Analysis Resource (IEBD) server was used for the prediction of helper T-cell epitopes, the NetCTL 1.2 server was used to predict cytotoxic T-cell epitopes, and the ABCpred server was used for B-cell epitope prediction. Antigenicity testing, allergenicity assessment, and toxicity screening were immuno-informatic techniques used to identify potent epitopes within protein sequences. The multi-epitope construct was prepared and cloned into the pVAX1 plasmid. Plasmids were transformed in compatible competent cells, and restriction analysis was performed. After restriction analysis of the transformed plasmid, in vitro transcription was performed to prepare mRNA. The mRNA was purified, quantified, and converted into complementary DNA, and gene-specific primers were used to confirm the in vitro transcription of mRNA. A mixture of four lipids containing 1,2-dioleoyl-3-dimethylammonium-propane (DODAP), Distearoylphosphatidylcholine (DSPC, cholesterol, and 1,2-Dimyristoyl-sn-glycero-3-methoxypolyethylene glycol-2000 (DMG PEG-2000 was used to prepare LNPs. LNPs were characterized using a scanning electron microscope, Zeta potential, and Zeta Sizer tests. Results: More than 1000 epitopes were predicted, from which only nine helper T-lymphocytes, 18 cytotoxic T-lymphocytes, and nine B-cell epitopes of all three proteins were selected with high antigenic scores of 0.958 for Bm86, 0.752 for Subolesin, and 0.964 for ATAQ, respectively. An adjuvant was used to enhance immune responses, all of which were linked to one another using GPGPG, AAY, and KK linkers, respectively. The physiochemical properties predicted that the instability index of the construct would be <40%, indicating that the construct is stable. Plasmids were transformed in compatible competent cells, and white-transformed colonies were observed. Restriction analysis was performed, DNA was transcribed into mRNA, and LNPs were prepared and characterized. Conclusion: More than 1000 epitopes were predicted using immune informatic tools, and only high-scoring epitopes were selected. A multi-epitope construct was designed using bio-informatic tools, and its physicochemical properties were predicted. The design construct was inserted into the pVAX1 plasmid, and in vitro transcription was performed to prepare the mRNA. LNPs of mRNA were prepared and characterized to be used as vaccines. It was found that LNPs were stable and nanometer-sized. Keywords: immuno-informatic tools, lipid nanoparticles, multiepitope construct, Rhipicephalus microplus.

Profiling patent compounds in lipid nanoparticle formulations of siRNA

Lipid nanoparticles (LNPs) have emerged as a prominent delivery system for nucleic acid drugs, attracting significant attention especially through the successful development of several commercial products. As a key component in LNPs, cationic lipids along serve as key technical barrier to block competitors by building up complex patent thicket. However, there have been few studies as yet that have comprehensively analyzed the patented compounds in LNP formulations, despite a large number of technical reviews and original articles. In the context, this study focuses on analyzing the macroscopic landscapes and microscopic molecular characteristics of LNP patents, aiming to provide a valuable reference for researchers and developers in making informed technological and commercial decisions. By mining 2,994 patents, 265 formulas, 7,674 compounds and 28,789 fragments, this work sketched the empirical golden ratio of lipid materials in LNP formulation, disclosed the advanced technology in the formulation, characterized high-frequency fragments of heads, linkers and tails in both novel cationic lipids as well as targeting lipids, and established a virtual focus library of LNP materials.

Enhancing RNA encapsulation quantification in lipid nanoparticles: Sustainable alternatives to Triton X-100 in the RiboGreen assay

To quantify concentration and encapsulation efficiency (EE) of mRNA in lipid nanoparticles (LNPs) the RiboGreen assay is extensively used. As part of this assay, a surfactant is used to release mRNA from LNPs for detection with the RiboGreen dye. So far, the surfactant of choice has been Triton X-100, which is harmful to human health and the environment. Alternatives to Triton X-100 are therefore needed, but surprisingly no such effort has yet been described in the literature. Here we show how three, less harmful, surfactants (Brij 93, Zwittergent 3–14 and Tween 20) compare to Triton X-100 for releasing mRNA from LNPs for detection with the RiboGreen assay. We found that Zwittergent 3–14 and Tween 20 at high concentrations (0.5 %) are at the minimum as effective as Triton X-100 at high concentration (0.5 %) across three different mRNA-LNP formulations. Interestingly, Tween 20 was the most effective at releasing mRNA from LNPs, across all concentration ranges explored (0.0025 %, 0.01 %, 0.1 % and to 0.5 % (v/v)) highlighting its potency at solubilizing the three different LNP formulations. Our results show that Tween 20 can be used as an alternative to Triton X-100 in the RiboGreen assay, resulting in more accurate quantification of the total mRNA concentration and EE%, as well as making the assay more environmentally friendly. Such improvement could potentially increase the likelihood of identifying therapeutically attractive hard-to-solubilize LNP-mRNA formulations that would be discharged when using Triton X-100 due to their apparent low EE values, as well as ensure more accurate mRNA dosing in both in vitro and in vivo studies.

Cytokine Storms and Anaphylaxis Following COVID-19 mRNA-LNP Vaccination: Mechanisms and Therapeutic Approaches.

Acute adverse reactions to COVID-19 mRNA vaccines are a major concern, as autopsy reports indicate that deaths most commonly occur on the same day of or one day following vaccination. These acute reactions may be due to cytokine storms triggered by lipid nanoparticles (LNPs) and anaphylaxis induced by polyethene glycol (PEG), both of which are vital constituents of the mRNA-LNP vaccines. Kounis syndrome, in which anaphylaxis triggers acute coronary syndrome (ACS), may also be responsible for these cardiovascular events. Furthermore, COVID-19 mRNA-LNP vaccines encompass adjuvants, such as LNPs, which trigger inflammatory cytokines, including interleukin (IL)-1β and IL-6. These vaccines also produce spike proteins which facilitate the release of inflammatory cytokines. Apart from this, histamine released from mast cells during allergic reactions plays a critical role in IL-6 secretion, which intensifies inflammatory responses. In light of these events, early reduction of IL-1β and IL-6 is imperative for managing post-vaccine cytokine storms, ACS, and myocarditis. Corticosteroids can restrict inflammatory cytokines and mitigate allergic responses, while colchicine, known for its IL-1β-reducing capabilities, could also prove effective. The anti-IL-6 antibody tocilizumab also displays promising treatment of cytokine release syndrome. Aside from its significance for treating anaphylaxis, epinephrine can induce coronary artery spasms and myocardial ischemia in Kounis syndrome, making accurate diagnosis essential. The upcoming self-amplifying COVID-19 mRNA-LNP vaccines also contain LNPs. Given that these vaccines can cause a cytokine storm and allergic reactions post vaccination, it is crucial to consider corticosteroids and measure IL-6 levels for effective management.

Lipid nanoparticles as nano-Trojan-horses for siRNA delivery and gene-knockdown

The therapeutic messenger RNA strategies, such as those using small interfering RNAs, take several advantages (versatility, efficiency and selectivity) over plasmid DNA-based strategies. However, the challenge remains to find nanovectors capable of properly loading the genetic material, transporting it through troublesome environments, like a tumoral site, and delivering it into the cytoplasm of target cells. Here, lipid nanoparticles, consisting of a Gemini cationic/neutral helper lipid mixture, are proposed as siRNA nanovector. Cells from cervical and brain cancer overexpressing the green fluorescent protein (GFP) were chosen to analyse the biological response as well as the efficiency and safety of the siRNA-loaded nanovector according to the cell phenotype. Flow cytometry and epifluorescence or confocal microscopy were used to follow the gene knockdown in these overexpressed cells. The effect of the nanovector on cellular proliferation was evaluated with cytotoxicity assays while their potential oxidative stress generation was determined by quantifying the generation of reactive oxygen species. To explore the mechanism of cellular uptake, different inhibitors of endocytic pathways were used during incubation with cells. Finally, nanovectors were incubated in 3D-grown cells (spheroids) to see whether they can penetrate the complex tumoral microenvironments, their efficiency to knockdown GFP expression being monitored by confocal microscopy.

Importance of RNase monitoring during large-scale manufacturing and analysis of mRNA-LNP based vaccines

Ribonucleases (RNases) are ubiquitous in nature, being able to cleave a wide range of polyribonucleotides. While the presence of microbial and viral contamination in sterile manufacturing is highly studied and controlled, there are no standardized practices for evaluating RNase in the production facility. Since the COVID-19 pandemic, mRNA-LNP based vaccines have become part of routine large-scale manufacturing. The unstable nature of mRNA poses new challenges to safeguard the working efficacy of mRNA – Lipid nanoparticle (LNP) based vaccines or therapeutics, where the presence of RNase in the formulation process could have a profound impact on the mRNA integrity. In this article, lessons learned are presented with respect to the evaluation of RNase contamination during LNP drug product formulation and analysis. Using sensitive detection methods, the potential presence of RNase in the manufacturing of mRNA-LNPs was investigated. Additionally, capillary gel electrophoresis (CGE) data, used to measure mRNA integrity, demonstrate the quality of the active mRNA substance and importance of suitable RNase control strategies. The results and cases presented in this paper should pave the way forward for evaluation and control strategies dedicated to mRNA-LNP based vaccines and therapeutics.

Poly(β-amino ester) polymer library with monomer variation for mRNA delivery

Non-viral vectors for mRNA delivery primarily include lipid nanoparticles (LNPs) and polymers. While LNPs are known for their high mRNA delivery efficiency, they can induce excessive immune responses and cause off-target effects, potentially leading to side effects. In this study, we aimed to explore polymer-based mRNA delivery systems as a viable alternative to LNPs, focusing on their mRNA delivery efficiency and potential application in mRNA vaccines. We created a library of poly(β-amino ester) (PBAE) polymers by combining various amine monomers and acrylate monomers. Through screening this polymer library, we identified specific polymer nanoparticles (PNPs) that demonstrated high mRNA expression efficiency, with sustained mRNA expression for up to two weeks. Furthermore, the PNPs showed mRNA expression only at the injection site and did not exhibit liver toxicity. Additionally, when assessing immune activation, the PNPs significantly induced T-cell immune activation and were effective in the plaque reduction neutralization test. These results suggest that polymer-based mRNA delivery systems not only hold potential for use in mRNA vaccines but also show promise for therapeutic applications.

Combinatorial design of siloxane-incorporated lipid nanoparticles augments intracellular processing for tissue-specific mRNA therapeutic delivery.

Systemic delivery of messenger RNA (mRNA) for tissue-specific targeting using lipid nanoparticles (LNPs) holds great therapeutic potential. Nevertheless, how the structural characteristics of ionizable lipids (lipidoids) impact their capability to target cells and organs remains unclear. Here we engineered a class of siloxane-based ionizable lipids with varying structures and formulated siloxane-incorporated LNPs (SiLNPs) to control in vivo mRNA delivery to the liver, lung and spleen in mice. The siloxane moieties enhance cellular internalization of mRNA-LNPs and improve their endosomal escape capacity, augmenting their mRNA delivery efficacy. Using organ-specific SiLNPs to deliver gene editing machinery, we achieve robust gene knockout in the liver of wild-type mice and in the lungs of both transgenic GFP and Lewis lung carcinoma (LLC) tumour-bearing mice. Moreover, we showed effective recovery from viral infection-induced lung damage by delivering angiogenic factors with lung-targeted Si5-N14 LNPs. We envision that our SiLNPs will aid in the clinical translation of mRNA therapeutics for next-generation tissue-specific protein replacement therapies, regenerative medicine and gene editing.

Optimized lipid nanoparticles enable effective CRISPR/Cas9-mediated gene editing in dendritic cells for enhanced immunotherapy

Immunotherapy has emerged as a revolutionary approach to treat immune-related diseases. Dendritic cells (DCs) play a pivotal role in orchestrating immune responses, making them an attractive target for immunotherapeutic interventions. Modulation of gene expression in DCs using genome editing techniques, such as the CRISPR-Cas system, is important for regulating DC functions. However, the precise delivery of CRISPR-based therapies to DCs has posed a significant challenge. While lipid nanoparticles (LNPs) have been extensively studied for gene editing in tumor cells, their potential application in DCs has remained relatively unexplored. This study investigates the important role of cholesterol in regulating the efficiency of BAMEA-O16B lipid-assisted nanoparticles (BLANs) as carriers of CRISPR/Cas9 for gene editing in DCs. Remarkably, BLANs with low cholesterol density exhibit exceptional mRNA uptake, improved endosomal escape, and efficient single-guide RNA release capabilities. Administration of BLANmCas9/gPD-L1 results in substantial PD-L1 gene knockout in conventional dendritic cells (cDCs), accompanied by heightened cDC1 activation, T cell stimulation, and significant suppression of tumor growth. The study underscores the pivotal role of cholesterol density within LNPs, revealing potent influence on gene editing efficacy within DCs. This strategy holds immense promise for the field of cancer immunotherapy, offering a novel avenue for treating immune-related diseases.

Establishment of enterically transmitted hepatitis virus animal models using lipid nanoparticle-based full-length viral genome RNA delivery system

BackgroundEnterically transmitted hepatitis viruses, such as hepatitis A virus (HAV) and hepatitis E virus (HEV), remain notable threats to public health. However, stable and reliable animal models of HAV and...

The role of mRNA-galsomes and LNPs in enhancing HIV-specific T cell responses across various lymphoid organs

mRNA nanoparticles have been investigated in the context of prophylactic vaccination against HIV but their effectivity has not been widely investigated in therapeutic vaccination. It has been suggested that a profound CD8+ T-cell response within lymphoid tissues, a primary site for viral reservoirs, is crucial for achieving optimal viral control, potentially correlating with protection. This study aimed to evaluate the effectiveness of mRNA lipid nanoparticles (LNPs), including a modified variant containing α-galactosylceramide as an adjuvant, termed galsomes. C57BL/6 mice were immunized intramuscularly with nucleoside-modified mRNA encoding ovalbumin (li80tOVA), revealing that mRNA-galsomes induced slightly higher proliferation levels of li80tOVA-specific CD8+ T cells in lymphoid tissues across various anatomical sites compared to mRNA-LNPs. In addition, immunization with nucleoside-modified HIV-1 Gag mRNA elicited a notable Gag-specific immune response in both formulations even at low mRNA doses. Remarkably, mRNA-galsomes induced lower polyfunctional responses in CD4+ T cells, but similar polyfunctional responses in CD8+ T cells in the spleen compared to mRNA LNPs. Importantly, the Gag-specific CD8+ T cells demonstrated cytolytic capacity against target cells in both the spleen and lymphoid tissues, including gut-associated lymph nodes. These findings underscore the potential of both mRNA-galsomes and mRNA-LNPs as tools for therapeutic vaccination against HIV.

Comprehensive Optimization of a Freeze-Drying Process Achieving Enhanced Long-Term Stability and In Vivo Performance of Lyophilized mRNA-LNPs

The success of mRNA vaccines against SARS-CoV-2 has prompted interest in mRNA-based pharmaceuticals due to their rapid production, adaptability, and safety. Despite these advantages, the inherent instability of mRNA and its rapid degradation in vivo underscores the need for an encapsulation system for the administration and delivery of RNA-based therapeutics. Lipid nanoparticles (LNPs) have proven the most robust and safest option for in vivo applications. However, the mid- to long-term storage of mRNA-LNPs still requires sub-zero temperatures along the entire chain of supply, highlighting the need to develop alternatives to improve mRNA vaccine stability under non-freezing conditions to facilitate logistics and distribution. Lyophilization presents itself as an effective alternative to prolong the shelf life of mRNA vaccines under refrigeration conditions, although a complex optimization of the process parameters is needed to maintain the integrity of the mRNA-LNPs. Recent studies have demonstrated the feasibility of freeze-drying LNPs, showing that lyophilized mRNA-LNPs retain activity and stability. However, long-term functional data remain limited. Herein, we focus on obtaining an optimized lyophilizable mRNA-LNP formulation through the careful selection of an optimal buffer and cryoprotectant and by tuning freeze-drying parameters. The results demonstrate that our optimized lyophilization process maintains LNP characteristics and functionality for over a year at refrigerated temperatures, offering a viable solution to the logistical hurdles of mRNA vaccine distribution.