Combinatorial design of nanoparticles for pulmonary mRNA delivery and genome editing

Development and applications of lipid hydrophilic headgroups for nucleic acid therapy

Nucleic acid therapy is currently the most promising method for treating tumors and genetic diseases and for preventing infectious diseases. However, the biggest obstacle to this therapy is delivery of the nucleic acids to the target site, which requires overcoming problems such as capture by the immune system, the need to penetrate biofilms, and degradation of nucleic acid performance. Designing suitable delivery vectors is key to solving these problems. Lipids-which consist of a hydrophilic headgroup, a linker, and a hydrophobic tail-are crucial components for the construction of vectors. The headgroup is particularly important because it affects the drug encapsulation rate, the vector cytotoxicity, and the transfection efficiency. Herein, we focus on various headgroup structures (tertiary amines, quaternary ammonium salts, peptides, piperazines, dendrimers, and several others), and we summarize and classify important lipid-based carriers that have been developed in recent years. We also discuss applications of cationic lipids with various headgroups for delivery of nucleic acid drugs, and we analyze how headgroup structure affects transport efficiency and carrier toxicity. Finally, we briefly describe the challenges of developing novel lipid carriers, as well as their prospects.

Lung-specific supramolecular nanoparticles for efficient delivery of therapeutic proteins and genome editing nucleases

Protein therapeutics play a critical role in treating a large variety of diseases, ranging from infections to genetic disorders. However, their delivery to target tissues beyond the liver, such as the lungs, remains a great challenge. Here, we report a universally applicable strategy for lung-targeted protein delivery by engineering Lung-Specific Supramolecular Nanoparticles (LSNPs). These nanoparticles are designed through the hierarchical self-assembly of metal-organic polyhedra (MOP), featuring a customized surface chemistry that enables protein encapsulation and specific lung affinity after intravenous administration. Our design of LSNPs not only addresses the hurdles of cell membrane impermeability of protein and nonspecific tissue distribution of protein delivery, but also shows exceptional versatility in delivering various proteins, including those vital for anti-inflammatory and CRISPR-based genome editing to the lung, and across multiple animal species, including mice, rabbits, and dogs. Notably, the delivery of antimicrobial proteins using LSNPs effectively alleviates acute bacterial pneumonia, demonstrating a significant therapeutic potential. Our strategy not only surmounts the obstacles of tissue-specific protein delivery but also paves the way for targeted treatments in genetic disorders and combating antibiotic resistance, offering a versatile solution for precision protein therapy.

Fluorinated Polyethylenimine and Fluorinated Choline Phosphate Lipids Complex System for Efficient mRNA Delivery to Deep-Seated Tumor Tissues

Efficiently delivering mRNA to the deep-seated cells of diseased tissues for therapeutic purposes remains a significant challenge. To address this, we leveraged the dual hydrophobic properties of fluorine atoms to conjugate fluorinated polyethylenimine (FPEI) with fluorinated choline phosphate (FCP) lipids. When one adjusted the ratio of N/F atoms to 2/1 and a 15% FCP content, the mRNA@FPEI-FCP carrier was optimized, achieving significant circulation and accumulation in deep tumor regions. Compared to control carriers lacking FCP or FPEI, mRNA@FPEI-FCP exhibited a 3.94-fold increase in tumor targeting and a 3.0-fold increase in deep delivery. Delivery of IL-2 mRNA to 4T1 breast tumors resulted in a tumor inhibition rate of 91.9%, with IL-2 levels reaching 149.2 pg/mL and 12.1% of CD4+ cells throughout the tumor, with no abnormal blood indexes. This FPEI and FCP composite delivery system demonstrates potent targeting of mRNA delivery to deep tumor tissues.

Advancing mRNA Therapeutics: The Role and Future of Nanoparticle Delivery Systems

The coronavirus (COVID-19) pandemic has underscored the critical role of mRNA-based vaccines as powerful, adaptable, readily manufacturable, and safe methodologies for prophylaxis. mRNA-based treatments are emerging as a hopeful avenue for a plethora of conditions, encompassing infectious diseases, cancer, autoimmune diseases, genetic diseases, and rare disorders. Nonetheless, the in vivo delivery of mRNA faces challenges due to its instability, suboptimal delivery, and potential for triggering undesired immune reactions. In this context, the development of effective drug delivery systems, particularly nanoparticles (NPs), is paramount. Tailored with biophysical and chemical properties and susceptible to surface customization, these NPs have demonstrated enhanced mRNA delivery in vivo and led to the approval of several NPs-based formulations for clinical use. Despite these advancements, the necessity for developing a refined, targeted NP delivery system remains imperative. This review comprehensively surveys the biological, translational, and clinical progress in NPs-mediated mRNA therapeutics for both the prevention and treatment of diverse diseases. By addressing critical factors for enhancing existing methodologies, it aims to inform the future development of precise and efficacious mRNA-based therapeutic interventions.

Delivery of nucleic acid based genome editing platforms via lipid nanoparticles: Clinical applications

CRISPR/Cas technology presents a promising approach for treating a wide range of diseases, including cancer and genetic disorders. Despite its potential, the translation of CRISPR/Cas into effective in-vivo gene therapy encounters challenges, primarily due to the need for safe and efficient delivery mechanisms. Lipid nanoparticles (LNPs), FDA-approved for RNA delivery, show potential for delivering also CRISPR/Cas, offering the capability to efficiently encapsulate large mRNA molecules with single guide RNAs. However, achieving precise targeting in-vivo remains a significant obstacle, necessitating further research into optimizing LNP formulations. Strategies to enhance specificity, such as modifying LNP structures and incorporating targeting ligands, are explored to improve organ and cell type targeting. Furthermore, the development of base and prime editing technology presents a potential breakthrough, offering precise modifications without generating double-strand breaks (DSBs). Prime editing, particularly when delivered via targeted LNPs, holds promise for treating diverse diseases safely and precisely. This review assesses both the progress made and the persistent challenges faced in using LNP-encapsulated CRISPR-based technologies for therapeutic purposes, with a particular focus on clinical translation.

AGILE platform: a deep learning powered approach to accelerate LNP development for mRNA delivery

Ionizable lipid nanoparticles (LNPs) are seeing widespread use in mRNA delivery, notably in SARS-CoV-2 mRNA vaccines. However, the expansion of mRNA therapies beyond COVID-19 is impeded by the absence of LNPs tailored for diverse cell types. In this study, we present the AI-Guided Ionizable Lipid Engineering (AGILE) platform, a synergistic combination of deep learning and combinatorial chemistry. AGILE streamlines ionizable lipid development with efficient library design, in silico lipid screening via deep neural networks, and adaptability to diverse cell lines. Using AGILE, we rapidly design, synthesize, and evaluate ionizable lipids for mRNA delivery, selecting from a vast library. Intriguingly, AGILE reveals cell-specific preferences for ionizable lipids, indicating tailoring for optimal delivery to varying cell types. These highlight AGILE's potential in expediting the development of customized LNPs, addressing the complex needs of mRNA delivery in clinical practice, thereby broadening the scope and efficacy of mRNA therapies.

Redirecting Tumor Evolution with Nanocompiler Precision for Enhanced Therapeutic Outcomes

Precisely programming the highly plastic tumor expression profile to render it devoid of drug resistance and metastatic potential presents immense challenges. Here, a transformative nanocompiler designed to reprogram and stabilize the mutable state of tumor cells is introduced. This nanocompiler features a trio of components: 2-deoxy-d-glucose-modified lipid nanoparticles to inhibit glucose uptake, iron oxide nanoparticles to induce oxidative stress, and a deubiquitinase inhibitor to block adaptive protein profile changes in tumor cells. By specifically targeting the hypermetabolic nature of tumors, this approach disrupted their energy production, ultimately fostering a state of vulnerability and impeding their ability to adapt and resist. The results of this study indicate a substantial reduction in tumor growth and metastasis, thus demonstrating the potential of this strategy to manipulate tumor protein expression and fate. This proactive nanocompiler approach promises to steer cancer therapy toward more effective and lasting outcomes.

Stimuli-Responsive mRNA Vaccines to Induce Robust CD8+ T Cell Response via ROS-Mediated Innate Immunity Boosting

The messenger RNA (mRNA) vaccines hold great significance in contagion prevention and cancer immunotherapy. However, safely and effectively harnessing innate immunity to stimulate robust and durable adaptive immune protection is crucial, yet challenging. In this study, we synthesized a library of stimuli-responsive bivalent ionizable lipids (srBiv iLPs) with smart molecular blocks responsive to esterase, H2O2, cytochrome P450, alkaline phosphatase, nitroreductase, or glutathione (GSH), aiming to leverage physiological cues to trigger fast lipid degradation, promote mRNA translation, and induce robust antitumor immunity via reactive oxygen species (ROS)-mediated boosting. After subcutaneous immunization, esterase-responsive vaccine (eBiv-mVac) was rapidly internalized and transported into the draining lymph nodes. It then underwent fast decaging and self-immolative degradation in esterase-rich antigen-presenting cells, releasing sufficient mRNA for antigen translation and massive reactive quinone methides to elevate ROS levels. This resulted in broad activation of innate immunity to boost T cell response, prompting a large number of primed antigen-specific CD8+ T cells to circulate and infiltrate into tumors (>1000-fold versus unvaccinated control), thereby orchestrating innate and adaptive immunity to control tumor growth. Moreover, by further combining our vaccination strategy with immune checkpoint blockade, we demonstrated a synergism that significantly amplified the magnitude and function of antigen-specific CD8+ T cells. This, in turn, caused potent systemic antitumor efficacy and prolonged survival with high complete response rate in xenograft and metastasis models. Overall, our generalized stimuli-responsive mRNA delivery platform promises a paradigm shift in the design of potent vaccines for cancer immunotherapy, as well as effective and precise carriers for gene editing, protein replacement, and cell engineering.

Systematic optimization of prime editing for the efficient functional correction of CFTR F508del in human airway epithelial cells

Prime editing (PE) enables precise and versatile genome editing without requiring double-stranded DNA breaks. Here we describe the systematic optimization of PE systems to efficiently correct human cystic fibrosis (CF) transmembrane conductance regulator (CFTR) F508del, a three-nucleotide deletion that is the predominant cause of CF. By combining six efficiency optimizations for PE-engineered PE guide RNAs, the PEmax architecture, the transient expression of a dominant-negative mismatch repair protein, strategic silent edits, PE6 variants and proximal 'dead' single-guide RNAs-we increased correction efficiencies for CFTR F508del from less than 0.5% in HEK293T cells to 58% in immortalized bronchial epithelial cells (a 140-fold improvement) and to 25% in patient-derived airway epithelial cells. The optimizations also resulted in minimal off-target editing, in edit-to-indel ratios 3.5-fold greater than those achieved by nuclease-mediated homology-directed repair, and in the functional restoration of CFTR ion channels to over 50% of wild-type levels (similar to those achieved via combination treatment with elexacaftor, tezacaftor and ivacaftor) in primary airway cells. Our findings support the feasibility of a durable one-time treatment for CF.

Nonviral CRISPR/Cas9 mutagenesis for streamlined generation of mouse lung cancer models

Functional analysis in mouse models is necessary to establish the involvement of a set of genetic variations in tumor development. A modeling platform to facilitate and cost-effectively analyze the role of multiple genes in carcinogenesis would be valuable. Here, we present an innovative strategy for lung mutagenesis using CRISPR/Cas9 ribonucleoproteins delivered via cationic polymers. This approach allows the simultaneous inactivation of multiple genes. We validate the effectiveness of this system by targeting a group of tumor suppressor genes, specifically Rb1, Rbl1, Pten, and Trp53, which were chosen for their potential to cause lung tumors, namely small cell lung carcinoma (SCLC). Tumors with histologic and transcriptomic features of human SCLC emerged after intratracheal administration of CRISPR/polymer nanoparticles. These tumors carried loss-of-function mutations in all four tumor suppressor genes at the targeted positions. These findings were reproduced in two different pure genetic backgrounds. We provide a proof of principle for simplified modeling of lung tumorigenesis to facilitate functional testing of potential cancer-related genes.

Reformulating lipid nanoparticles for organ-targeted mRNA accumulation and translation

Fully targeted mRNA therapeutics necessitate simultaneous organ-specific accumulation and effective translation. Despite some progress, delivery systems are still unable to fully achieve this. Here, we reformulate lipid nanoparticles (LNPs) through adjustments in lipid material structures and compositions to systematically achieve the pulmonary and hepatic (respectively) targeted mRNA distribution and expression. A combinatorial library of degradable-core based ionizable cationic lipids is designed, following by optimisation of LNP compositions. Contrary to current LNP paradigms, our findings demonstrate that cholesterol and phospholipid are dispensable for LNP functionality. Specifically, cholesterol-removal addresses the persistent challenge of preventing nanoparticle accumulation in hepatic tissues. By modulating and simplifying intrinsic LNP components, concurrent mRNA accumulation and translation is achieved in the lung and liver, respectively. This targeting strategy is applicable to existing LNP systems with potential to expand the progress of precise mRNA therapy for diverse diseases.

Accelerating ionizable lipid discovery for mRNA delivery using machine learning and combinatorial chemistry

To unlock the full promise of messenger (mRNA) therapies, expanding the toolkit of lipid nanoparticles is paramount. However, a pivotal component of lipid nanoparticle development that remains a bottleneck is identifying new ionizable lipids. Here we describe an accelerated approach to discovering effective ionizable lipids for mRNA delivery that combines machine learning with advanced combinatorial chemistry tools. Starting from a simple four-component reaction platform, we create a chemically diverse library of 584 ionizable lipids. We screen the mRNA transfection potencies of lipid nanoparticles containing those lipids and use the data as a foundational dataset for training various machine learning models. We choose the best-performing model to probe an expansive virtual library of 40,000 lipids, synthesizing and experimentally evaluating the top 16 lipids flagged. We identify lipid 119-23, which outperforms established benchmark lipids in transfecting muscle and immune cells in several tissues. This approach facilitates the creation and evaluation of versatile ionizable lipid libraries, advancing the formulation of lipid nanoparticles for precise mRNA delivery.

Lipid Nanocarrier-Based mRNA Therapy: Challenges and Promise for Clinical Transformation

Due to the outbreak of novel coronavirus pneumonia, messenger RNA (mRNA) technology has attracted heated attention. A specific, safe, and efficient mRNA delivery system is needed. Lipid nanocarriers have become attractive carriers for mRNA delivery due to their high delivery efficiency, few side effects, and easy modification to change their structures and functions. To achieve the desired biological effect, lipid nanocarriers must reach the designated location for effective drug delivery. Therefore, the effects of the composition of lipid nanocarriers on their key properties are briefly reviewed. In addition, the progress of smart drug delivery by changing the composition of lipid nanocarriers is summarized, and the importance of component design and structure is emphasized. Subsequently, this review summarizes the latest progress in lipid nanocarrier-based mRNA technology and provides corresponding strategies for its current challenges, putting forward valuable information for the future design of lipid nanocarriers and mRNA.

A Lung-Expressing mRNA Delivery Platform with Tunable Activity in Hypoxic Environments

Messenger RNA (mRNA) delivery platforms often facilitate protein expression in the liver following intravenous injection and have been optimized for use in normally oxygenated cells (21% O2 atmosphere). However, there is a growing need for mRNA therapy in diseases affecting non-liver organs, such as the lungs. Additionally, many diseases are characterized by hypoxia (<21% O2 atmosphere), a state of abnormally low oxygenation in cells and tissues that can reduce the efficacy of mRNA therapies by upwards of 80%. Here, we report a Tunable Lung-Expressing Nanoparticle Platform (TULEP) for mRNA delivery, whose properties can be readily tuned for optimal expression in hypoxic environments. Briefly, our study begins with the synthesis and characterization of a novel amino acrylate polymer that can be effectively complexed with mRNA payloads into TULEPs. We study the efficacy and mechanism of mRNA delivery using TULEP, including analysis of the cellular association, endocytosis mechanisms, endosomal escape, and protein expression in a lung cell line. We then evaluate TULEP under hypoxic conditions and address hypoxia-related deficits in efficacy by making our system tunable with adenosine triphosphate (ATP). Finally, we conclude our study with an in vivo analysis of mRNA expression, biodistribution, and tolerability of the TULEP platform in mice. In presenting these data, we hope that our work highlights the utility of TULEPs for tunable and effective mRNA delivery while more broadly highlighting the utility of considering oxygen levels when developing mRNA delivery platforms.

Mechanisms and Delivery of tRNA Therapeutics

Transfer ribonucleic acid (tRNA) therapeutics will provide personalized and mutation specific medicines to treat human genetic diseases for which no cures currently exist. The tRNAs are a family of adaptor molecules that interpret the nucleic acid sequences in our genes into the amino acid sequences of proteins that dictate cell function. Humans encode more than 600 tRNA genes. Interestingly, even healthy individuals contain some mutant tRNAs that make mistakes. Missense suppressor tRNAs insert the wrong amino acid in proteins, and nonsense suppressor tRNAs read through premature stop signals to generate full length proteins. Mutations that underlie many human diseases, including neurodegenerative diseases, cancers, and diverse rare genetic disorders, result from missense or nonsense mutations. Thus, specific tRNA variants can be strategically deployed as therapeutic agents to correct genetic defects. We review the mechanisms of tRNA therapeutic activity, the nature of the therapeutic window for nonsense and missense suppression as well as wild-type tRNA supplementation. We discuss the challenges and promises of delivering tRNAs as synthetic RNAs or as gene therapies. Together, tRNA medicines will provide novel treatments for common and rare genetic diseases in humans.

Unlocking the Therapeutic Applicability of LNP-mRNA: Chemistry, Formulation, and Clinical Strategies

Messenger RNA (mRNA) has emerged as an innovative therapeutic modality, offering promising avenues for the prevention and treatment of a variety of diseases. The tremendous success of mRNA vaccines in effectively combatting coronavirus disease 2019 (COVID-19) evidences the unlimited medical and therapeutic potential of mRNA technology. Overcoming challenges related to mRNA stability, immunogenicity, and precision targeting has been made possible by recent advancements in lipid nanoparticles (LNPs). This review summarizes state-of-the-art LNP-mRNA-based therapeutics, including their structure, material compositions, design guidelines, and screening principles. Additionally, we highlight current preclinical and clinical trends in LNP-mRNA therapeutics in a broad range of treatments in ophthalmological conditions, cancer immunotherapy, gene editing, and rare-disease medicine. Particular attention is given to the translation and evolution of LNP-mRNA vaccines into a broader spectrum of therapeutics. We explore concerns in the aspects of inadequate extrahepatic targeting efficacy, elevated doses, safety concerns, and challenges of large-scale production procedures. This discussion may offer insights and perspectives on near- and long-term clinical development prospects for LNP-mRNA therapeutics.

Branched-Tail Lipid Nanoparticles for Intravenous mRNA Delivery to Lung Immune, Endothelial, and Alveolar Cells in Mice

Lipid nanoparticles (LNPs) are proven safe and effective delivery systems on a global scale. However, their efficacy has been limited primarily to liver and immune cell targets. To extend the applicability of mRNA drugs, 580 ionizable lipidoids are synthesized and tested for delivery to extrahepatocellular targets. Of these, over 40 enabled protein expression in mice, with the majority transfecting the liver. Beyond the liver, several LNPs containing new, branched-tail ionizable lipidoids potently delivered mRNA to the lungs, with cell-level specificity depending on helper lipid chemistry. Incorporation of the neutral helper lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) at 16 mol% enabled highly specific delivery to natural killer and dendritic cells within the lung. Although inclusion of the cationic lipid 1,2-di-(9Z-octadecenoyl)-3-trimethylammonium-propane (DOTAP) improved lung tropism, it decreased cell specificity, resulting in equal transfection of endothelial and lymphoid cells. DOTAP formulations are also less favorable than DOPE formulations because they elevated liver enzyme and cytokine levels. Together, these data identify a new branched-tailed LNP with a unique ability to selectively transfect lung immune cell populations without the use of toxicity-prone cationic helper lipids. This novel vehicle may unlock RNA therapies for lung diseases associated with immune cell dysregulation, including cancer, viral infections, and autoimmune disorders.

nCas9 Engineering for Improved Target Interaction Presents an Effective Strategy to Enhance Base Editing

Base editors (BEs) are a recent generation of genome editing tools that couple a cytidine or adenosine deaminase activity to a catalytically impaired Cas9 moiety (nCas9) to enable specific base conversions at the targeted genomic loci. Given their strong application potential, BEs are under active developments toward greater levels of efficiency and safety. Here, a previously overlooked nCas9-centric strategy is explored for enhancement of BE. Based on a cytosine BE (CBE), 20 point mutations associated with nCas9-target interaction are tested. Subsequently, from the initial positive X-to-arginine hits, combinatorial modifications are applied to establish further enhanced CBE variants (1.1-1.3). Parallel nCas9 modifications in other versions of CBEs including A3A-Y130F-BE4max, YEE-BE4max, CGBE, and split-AncBE4max, as well as in the context of two adenine BEs (ABE), likewise enhance their respective activities. The same strategy also substantially improves the efficiencies of high-fidelity nCas9/BEs. Further evidence confirms that the stabilization of nCas9-substrate interactions underlies the enhanced BE activities. In support of their translational potential, the engineered CBE and ABE variants respectively enable 82% and 25% higher rates of editing than the controls in primary human T-cells. This study thus demonstrates a highly adaptable strategy for enhancing BE, and for optimizing other forms of Cas9-derived tools.

In vivo editing of lung stem cells for durable gene correction in mice

In vivo genome correction holds promise for generating durable disease cures; yet, effective stem cell editing remains challenging. In this work, we demonstrate that optimized lung-targeting lipid nanoparticles (LNPs) enable high levels of genome editing in stem cells, yielding durable responses. Intravenously administered gene-editing LNPs in activatable tdTomato mice achieved >70% lung stem cell editing, sustaining tdTomato expression in >80% of lung epithelial cells for 660 days. Addressing cystic fibrosis (CF), NG-ABE8e messenger RNA (mRNA)-sgR553X LNPs mediated >95% cystic fibrosis transmembrane conductance regulator (CFTR) DNA correction, restored CFTR function in primary patient-derived bronchial epithelial cells equivalent to Trikafta for F508del, corrected intestinal organoids and corrected R553X nonsense mutations in 50% of lung stem cells in CF mice. These findings introduce LNP-enabled tissue stem cell editing for disease-modifying genome correction.

Gene editing flows to the lungs

Intravenous targeting of airway basal cells for cystic fibrosis gene therapy overcomes lung barriers.

Leveraging high-throughput screening technologies in targeted mRNA delivery

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

Revolutionizing Neurocare: Biomimetic Nanodelivery Via Cell Membranes

Brain disorders represent a significant challenge in medical science due to the formidable blood-brain barrier (BBB), which severely limits the penetration of conventional therapeutics, hindering effective treatment strategies. This review delves into the innovative realm of biomimetic nanodelivery systems, including stem cell-derived nanoghosts, tumor cell membrane-coated nanoparticles, and erythrocyte membrane-based carriers, highlighting their potential to circumvent the BBB's restrictions. By mimicking native cell properties, these nanocarriers emerge as a promising solution for enhancing drug delivery to the brain, offering a strategic advantage in overcoming the barrier's selective permeability. The unique benefits of leveraging cell membranes from various sources is evaluated and advanced technologies for fabricating cell membrane-encapsulated nanoparticles capable of masquerading as endogenous cells are examined. This enables the targeted delivery of a broad spectrum of therapeutic agents, ranging from small molecule drugs to proteins, thereby providing an innovative approach to neurocare. Further, the review contrasts the capabilities and limitations of these biomimetic nanocarriers with traditional delivery methods, underlining their potential to enable targeted, sustained, and minimally invasive treatment modalities. This review is concluded with a perspective on the clinical translation of these biomimetic systems, underscoring their transformative impact on the therapeutic landscape for intractable brain diseases.

CRISPR technologies for genome, epigenome and transcriptome editing

Our ability to edit genomes lags behind our capacity to sequence them, but the growing understanding of CRISPR biology and its application to genome, epigenome and transcriptome engineering is narrowing this gap. In this Review, we discuss recent developments of various CRISPR-based systems that can transiently or permanently modify the genome and the transcriptome. The discovery of further CRISPR enzymes and systems through functional metagenomics has meaningfully broadened the applicability of CRISPR-based editing. Engineered Cas variants offer diverse capabilities such as base editing, prime editing, gene insertion and gene regulation, thereby providing a panoply of tools for the scientific community. We highlight the strengths and weaknesses of current CRISPR tools, considering their efficiency, precision, specificity, reliance on cellular DNA repair mechanisms and their applications in both fundamental biology and therapeutics. Finally, we discuss ongoing clinical trials that illustrate the potential impact of CRISPR systems on human health.

Chemical Design Strategy of Ionizable Lipids for In Vivo mRNA Delivery

Lipid nanoparticles (LNPs) are the most clinically successful drug delivery systems that have accelerated the development of mRNA drugs and vaccines. Among various structural components of LNPs, more recent attention has been paid in ionizable lipids (ILs) that was supposed as the key component in determining the effectiveness of LNPs for in vivo mRNA delivery. ILs are typically comprised of three moieties including ionizable heads, linkers, and hydrophobic tails, which suggested that the combination of different functional groups in three moieties could produce ILs with diverse chemical structures and biological identities. In this concept article, we provide a summary of chemical design strategy for high-performing IL candidates and discuss their structure-activity relationships for shifting tissue-selective mRNA delivery. We also propose an outlook for the development of next-generation ILs, enabling the broader translation of mRNA formulated with LNPs.

In vivo LNP-CRISPR Approaches for the Treatment of Hemophilia

Hemophilia is a genetic disorder that is caused by mutations in coagulation factor VIII (hemophilia A) or IX (hemophilia B) genes resulting in blood clotting disorders. Despite advances in therapies, such as recombinant proteins and products with extended half-lives, the treatment of hemophilia still faces two major limitations: the short duration of therapeutic effect and production of neutralizing antibodies against clotting factors (inhibitor). To overcome these limitations, new hemophilia treatment strategies have been established such as gene therapy, bispecific antibody, and rebalancing therapy. Although these strategies have shown promising results, it is difficult to achieve a permanent therapeutic effect. Advances in the clustered regularly interspaced short palindromic repeat (CRISPR) technology have allowed sustainable treatment by correcting mutated genes. Since genome editing generates irreversible changes in host genome, safety must be ensured by delivering target organs. Therefore, the delivery tool of the CRISPR system is crucial for safe, accurate, and efficient genome editing. Recently, non-viral vector lipid nanoparticles (LNPs) have emerged as safer tools for delivering CRISPR systems than other viral vectors. Several previous hemophilia pre-clinical studies using LNP-CRISPR showed that sufficient and sustainable therapeutic effects, which means that LNP-CRISPR-mediated genome-editing therapy can be a valid option for the treatment of hemophilia. In this paper, we summarize the latest advancements in the successful treatment of hemophilia and the potential of CRISPR-mediated genome-editing therapy using LNPs.

Recent Progress in Nucleic Acid Pulmonary Delivery toward Overcoming Physiological Barriers and Improving Transfection Efficiency

Pulmonary delivery of therapeutic agents has been considered the desirable administration route for local lung disease treatment. As the latest generation of therapeutic agents, nucleic acid has been gradually developed as gene therapy for local diseases such as asthma, chronic obstructive pulmonary diseases, and lung fibrosis. The features of nucleic acid, specific physiological structure, and pathophysiological barriers of the respiratory tract have strongly affected the delivery efficiency and pulmonary bioavailability of nucleic acid, directly related to the treatment outcomes. The development of pharmaceutics and material science provides the potential for highly effective pulmonary medicine delivery. In this review, the key factors and barriers are first introduced that affect the pulmonary delivery and bioavailability of nucleic acids. The advanced inhaled materials for nucleic acid delivery are further summarized. The recent progress of platform designs for improving the pulmonary delivery efficiency of nucleic acids and their therapeutic outcomes have been systematically analyzed, with the application and the perspectives of advanced vectors for pulmonary gene delivery.

Oncolytic viral therapy for gliomas: Advances in the mechanisms and approaches to delivery

Glioma is a diverse category of tumors originating from glial cells encompasses various subtypes, based on the specific type of glial cells involved. The most aggressive is glioblastoma multiforme (GBM), which stands as the predominant primary malignant tumor within the central nervous system in adults. Despite the application of treatment strategy, the median survival rate for GBM patients still hovers around 15 months. Oncolytic viruses (OVs) are artificially engineered viruses designed to selectively target and induce apoptosis in cancer cells. While clinical trials have demonstrated encouraging results with intratumoral OV injections for some cancers, applying this approach to GBM presents unique challenges. Here we elaborate on current trends in oncolytic viral therapy and their delivery methods. We delve into the various methods of delivering OVs for therapy, exploring their respective advantages and disadvantages and discussing how selecting the optimal delivery method can enhance the efficacy of this innovative treatment approach.

Microfluidic Platform Enables Shearless Aerosolization of Lipid Nanoparticles for mRNA Inhalation

Leveraging the extensive surface area of the lungs for gene therapy, the inhalation route offers distinct advantages for delivery. Clinical nebulizers that employ vibrating mesh technology are the standard choice for converting liquid medicines into aerosols. However, they have limitations when it comes to delivering mRNA through inhalation, including severe damage to nanoparticles due to shearing forces. Here, we introduce a microfluidic aerosolization platform (MAP) that preserves the structural and physicochemical integrity of lipid nanoparticles, enabling safe and efficient delivery of mRNA to the respiratory system. Our results demonstrated the superiority of the MAP over the conventional vibrating mesh nebulizer, as it avoided problems such as particle aggregation, loss of mRNA encapsulation, and deformation of the nanoparticle morphology. Notably, aerosolized nanoparticles generated by the microfluidic device led to enhanced transfection efficiency across various cell lines. In vivo experiments with mice that inhaled these aerosolized nanoparticles revealed successful lung-specific mRNA transfection without observable signs of toxicity. This MAP may represent an advancement for the pulmonary gene therapy, enabling precise and effective delivery of aerosolized nanoparticles.

Lipid Nanoparticle-Associated Inflammation is Triggered by Sensing of Endosomal Damage: Engineering Endosomal Escape Without Side Effects

Lipid nanoparticles (LNPs) have emerged as the dominant platform for RNA delivery, based on their success in the COVID-19 vaccines and late-stage clinical studies in other indications. However, we and others have shown that LNPs induce severe inflammation, and massively aggravate pre-existing inflammation. Here, using structure-function screening of lipids and analyses of signaling pathways, we elucidate the mechanisms of LNP-associated inflammation and demonstrate solutions. We show that LNPs' hallmark feature, endosomal escape, which is necessary for RNA expression, also directly triggers inflammation by causing endosomal membrane damage. Large, irreparable, endosomal holes are recognized by cytosolic proteins called galectins, which bind to sugars on the inner endosomal membrane and then regulate downstream inflammation. We find that inhibition of galectins abrogates LNP-associated inflammation, both in vitro and in vivo . We show that rapidly biodegradable ionizable lipids can preferentially create endosomal holes that are smaller in size and reparable by the endosomal sorting complex required for transport (ESCRT) pathway. Ionizable lipids producing such ESCRT-recruiting endosomal holes can produce high expression from cargo mRNA with minimal inflammation. Finally, we show that both routes to non-inflammatory LNPs, either galectin inhibition or ESCRT-recruiting ionizable lipids, are compatible with therapeutic mRNAs that ameliorate inflammation in disease models. LNPs without galectin inhibition or biodegradable ionizable lipids lead to severe exacerbation of inflammation in these models. In summary, endosomal escape induces endosomal membrane damage that can lead to inflammation. However, the inflammation can be controlled by inhibiting galectins (large hole detectors) or by using biodegradable lipids, which create smaller holes that are reparable by the ESCRT pathway. These strategies should lead to generally safer LNPs that can be used to treat inflammatory diseases.

Topical gene editing therapeutics using lipid nanoparticles: 'gene creams' for genetic skin diseases?

Patients living with inherited skin diseases have benefited from recent advances in DNA sequencing technologies that provide new or improved diagnostics. However, developing and delivering new treatments for the 'genodermatoses' remains challenging. The goal of creating topical preparations that can recover the inherent gene pathology remains largely aspirational. However, recent progress in two fields - the chemistry of topical delivery formulations (lipid nanoparticles) and the molecular biology of gene repair (CRISPR-Cas9, base and prime editing) - presents new opportunities to address this unmet need. In this review, we discuss how lipid nanoparticle delivery vehicles could be used to deliver gene-editing tools to formulate topical 'gene creams' suitable for the treatment of genodermatoses. We summarize the historical landscape of topical therapeutics and advances in gene editing that may herald an era of new therapies for patients with inherited skin disorders.

Anticancer and Antibacterial Properties of Curcumin-Loaded Mannosylated Solid Lipid Nanoparticles for the Treatment of Lung Diseases

Lung cancer and Mycobacterium avium complex infection are lung diseases associated with high incidence and mortality rates. Most conventional anticancer drugs and antibiotics have certain limitations, including high drug resistance rates and adverse effects. Herein, we aimed to synthesize mannose surface-modified solid lipid nanoparticles (SLNs) loaded with curcumin (Man-CUR SLN) for the effective treatment of lung disease. The synthesized Man-CUR SLNs were analyzed using various instrumental techniques for structural and physicochemical characterization. Loading curcumin into SLNs improved the encapsulation efficiency and drug release capacity, as demonstrated by high-performance liquid chromatography analysis. Furthermore, we characterized the anticancer effect of curcumin using the A549 lung cancer cell line. Cells treated with Man-CUR SLN exhibited an increased cellular uptake and cytotoxicity. Moreover, treatment with free CUR could more effectively reduce cancer migration than treatment with Man-CUR SLNs. Similarly, free curcumin elicited a stronger apoptosis-inducing effect than that of Man-CUR SLNs, as demonstrated by reverse transcription-quantitative PCR analysis. Finally, we examined the antibacterial effects of free curcumin and Man-CUR SLNs against Mycobacterium intracellulare (M.i.) and M.i.-infected macrophages, revealing that Man-CUR SLNs exerted the strongest antibacterial effect. Collectively, these findings indicate that mannose-receptor-targeted curcumin delivery using lipid nanoparticles could be effective in treating lung diseases. Accordingly, this drug delivery system can be used to target a variety of cancers and immune cells.

Strategies for non-viral vectors targeting organs beyond the liver

In recent years, nanoparticles have evolved to a clinical modality to deliver diverse nucleic acids. Rising interest in nanomedicines comes from proven safety and efficacy profiles established by continuous efforts to optimize physicochemical properties and endosomal escape. However, despite their transformative impact on the pharmaceutical industry, the clinical use of non-viral nucleic acid delivery is limited to hepatic diseases and vaccines due to liver accumulation. Overcoming liver tropism of nanoparticles is vital to meet clinical needs in other organs. Understanding the anatomical structure and physiological features of various organs would help to identify potential strategies for fine-tuning nanoparticle characteristics. In this Review, we discuss the source of liver tropism of non-viral vectors, present a brief overview of biological structure, processes and barriers in select organs, highlight approaches available to reach non-liver targets, and discuss techniques to accelerate the discovery of non-hepatic therapies.

Recent trends in the delivery of RNA drugs: Beyond the liver, more than vaccine

RNAs are known for versatile functions and therapeutic utility. They have gained significant interest since the approval of several RNA drugs, including COVID-19 mRNA vaccines and therapeutic agents targeting liver diseases. There are increasing expectations for a new class of RNA drugs for broader applications. Successful development of RNA drugs for new applications hinges on understanding their diverse functions and structures. In this review, we explore the last five years of literature to understand current approaches to formulate a spectrum of RNA drugs, focusing on new efforts to expand their applications beyond vaccines and liver diseases.

Inhalable extracellular vesicle delivery of IL-12 mRNA to treat lung cancer and promote systemic immunity

Lung carcinoma is one of the most common cancers and has one of the lowest survival rates in the world. Cytokines such as interleukin-12 (IL-12) have demonstrated considerable potential as robust tumour suppressors. However, their applications are limited due to off-target toxicity. Here we report on a strategy involving the inhalation of IL-12 messenger RNA, encapsulated within extracellular vesicles. Inhalation and preferential uptake by cancer cells results in targeted delivery and fewer systemic side effects. The IL-12 messenger RNA generates interferon-γ production in both innate and adaptive immune-cell populations. This activation consequently incites an intense activation state in the tumour microenvironment and augments its immunogenicity. The increased immune response results in the expansion of tumour cytotoxic immune effector cells, the formation of immune memory, improved antigen presentation and tumour-specific T cell priming. The strategy is demonstrated against primary neoplastic lesions and provides profound protection against subsequent tumour rechallenge. This shows the potential for locally delivered cytokine-based immunotherapies to address orthotopic and metastatic lung tumours.

Assembling the RNA therapeutics toolbox

From the approval of COVID-19 mRNA vaccines to the 2023 Nobel Prize awarded for nucleoside base modifications, RNA therapeutics have entered the spotlight and are transforming drug development. While the term "RNA therapeutics" has been used in various contexts, this review focuses on treatments that utilize RNA as a component or target RNA for therapeutic effects. We summarize the latest advances in RNA-targeting tools and RNA-based technologies, including but not limited to mRNA, antisense oligos, siRNAs, small molecules and RNA editors. We focus on the mechanisms of current FDA-approved therapeutics but also provide a discussion on the upcoming workforces. The clinical utility of RNA-based therapeutics is enabled not only by the advances in RNA technologies but in conjunction with the significant improvements in chemical modifications and delivery platforms, which are also briefly discussed in the review. We summarize the latest RNA therapeutics based on their mechanisms and therapeutic effects, which include expressing proteins for vaccination and protein replacement therapies, degrading deleterious RNA, modulating transcription and translation efficiency, targeting noncoding RNAs, binding and modulating protein activity and editing RNA sequences and modifications. This review emphasizes the concept of an RNA therapeutic toolbox, pinpointing the readers to all the tools available for their desired research and clinical goals. As the field advances, the catalog of RNA therapeutic tools continues to grow, further allowing researchers to combine appropriate RNA technologies with suitable chemical modifications and delivery platforms to develop therapeutics tailored to their specific clinical challenges.

Pulmonary inhalation for disease treatment: Basic research and clinical translations

Pulmonary drug delivery has the advantages of being rapid, efficient, and well-targeted, with few systemic side effects. In addition, it is non-invasive and has good patient compliance, making it a highly promising drug delivery mode. However, there have been limited studies on drug delivery via pulmonary inhalation compared with oral and intravenous modes. This paper summarizes the basic research and clinical translation of pulmonary inhalation drug delivery for the treatment of diseases and provides insights into the latest advances in pulmonary drug delivery. The paper discusses the processing methods for pulmonary drug delivery, drug carriers (with a focus on various types of nanoparticles), delivery devices, and applications in pulmonary diseases and treatment of systemic diseases (e.g., COVID-19, inhaled vaccines, diagnosis of the diseases, and diabetes mellitus) with an updated summary of recent research advances. Furthermore, this paper describes the applications and recent progress in pulmonary drug delivery for lung diseases and expands the use of pulmonary drugs for other systemic diseases.

Data-balanced transformer for accelerated ionizable lipid nanoparticles screening in mRNA delivery

Despite the widespread use of ionizable lipid nanoparticles (LNPs) in clinical applications for messenger RNA (mRNA) delivery, the mRNA drug delivery system faces an efficient challenge in the screening of LNPs. Traditional screening methods often require a substantial amount of experimental time and incur high research and development costs. To accelerate the early development stage of LNPs, we propose TransLNP, a transformer-based transfection prediction model designed to aid in the selection of LNPs for mRNA drug delivery systems. TransLNP uses two types of molecular information to perceive the relationship between structure and transfection efficiency: coarse-grained atomic sequence information and fine-grained atomic spatial relationship information. Due to the scarcity of existing LNPs experimental data, we find that pretraining the molecular model is crucial for better understanding the task of predicting LNPs properties, which is achieved through reconstructing atomic 3D coordinates and masking atom predictions. In addition, the issue of data imbalance is particularly prominent in the real-world exploration of LNPs. We introduce the BalMol block to solve this problem by smoothing the distribution of labels and molecular features. Our approach outperforms state-of-the-art works in transfection property prediction under both random and scaffold data splitting. Additionally, we establish a relationship between molecular structural similarity and transfection differences, selecting 4267 pairs of molecular transfection cliffs, which are pairs of molecules that exhibit high structural similarity but significant differences in transfection efficiency, thereby revealing the primary source of prediction errors. The code, model and data are made publicly available at https://github.com/wklix/TransLNP.

Fluorinated Lipid Nanoparticles for Enhancing mRNA Delivery Efficiency

Lipid nanoparticles (LNPs), a nonviral nucleic acid delivery system, have shown vast potential for vaccine development and disease treatment. LNPs assist mRNA to cross physiological barriers such as cell membranes and endosomes/lysosomes, promoting the intracellular presentation of mRNA. However, the endosome escape efficiency and biosafety of currently commercialized LNPs are still unsatisfactory, resulting in underutilization of mRNA. Herein, we report that fluorinated modification of the 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-2000 (PEG-DSPE), termed as FPD, in the LNPs can improve the delivery efficiency of mRNA. FPD accounts for only 1.5% of lipids in LNPs but could mediate a 5-fold and nearly 2-fold enhancement of mRNA expression efficiency in B16F10 tumor cells and primary dendritic cells, respectively. Mechanism studies reveal that FPD promotes the cellular internalization of LNPs as well as endosome escape. In vivo studies substantiate that FPD can augment overall mRNA expression at least 3-fold, either by intravenous or intraperitoneal injection, compared to LNPs prepared with nonfluorinated PEG-lipids at a relatively low mRNA dose. Besides, with the introduction of FPD, mRNA expression in the spleen augmented compared to that of the DMG-PEG commercial formulations. Benefiting from a prudent dosage of fluorine, the fluorinated LNPs display favorable biosafety profiles at cellular and zoological levels.

Electrostatic adsorption of polyanions onto lipid nanoparticles controls uptake, trafficking, and transfection of RNA and DNA therapies

Rapid advances in nucleic acid therapies highlight the immense therapeutic potential of genetic therapeutics. Lipid nanoparticles (LNPs) are highly potent nonviral transfection agents that can encapsulate and deliver various nucleic acid therapeutics, including but not limited to messenger RNA (mRNA), silencing RNA (siRNA), and plasmid DNA (pDNA). However, a major challenge of targeted LNP-mediated systemic delivery is the nanoparticles' nonspecific uptake by the liver and the mononuclear phagocytic system, due partly to the adsorption of endogenous serum proteins onto LNP surfaces. Tunable LNP surface chemistries may enable efficacious delivery across a range of organs and cell types. Here, we describe a method to electrostatically adsorb bioactive polyelectrolytes onto LNPs to create layered LNPs (LLNPs). LNP cores varying in nucleic acid cargo and component lipids were stably layered with four biologically relevant polyanions: hyaluronate (HA), poly-L-aspartate (PLD), poly-L-glutamate (PLE), and polyacrylate (PAA). We further investigated the impact of the four surface polyanions on the transfection and uptake of mRNA- and pDNA-loaded LNPs in cell cultures. PLD- and PLE-LLNPs increased mRNA transfection twofold over unlayered LNPs in immune cells. HA-LLNPs increased pDNA transfection rates by more than twofold in epithelial and immune cells. In a healthy C57BL/6 murine model, PLE- and HA-LLNPs increased transfection by 1.8-fold to 2.5-fold over unlayered LNPs in the liver and spleen. These results suggest that LbL assembly is a generalizable, highly tunable platform to modify the targeting specificity, stability, and transfection efficacy of LNPs, as well as incorporate other charged targeting and therapeutic molecules into these systems.

Targeted nonviral delivery of genome editors in vivo

Cell-type-specific in vivo delivery of genome editing molecules is the next breakthrough that will drive biological discovery and transform the field of cell and gene therapy. Here, we discuss recent advances in the delivery of CRISPR-Cas genome editors either as preassembled ribonucleoproteins or encoded in mRNA. Both strategies avoid pitfalls of viral vector-mediated delivery and offer advantages including transient editor lifetime and potentially streamlined manufacturing capability that are already proving valuable for clinical use. We review current applications and future opportunities of these emerging delivery approaches that could make genome editing more efficacious and accessible in the future.

High-throughput barcoding of nanoparticles identifies cationic, degradable lipid-like materials for mRNA delivery to the lungs in female preclinical models

Lipid nanoparticles for delivering mRNA therapeutics hold immense promise for the treatment of a wide range of lung-associated diseases. However, the lack of effective methodologies capable of identifying the pulmonary delivery profile of chemically distinct lipid libraries poses a significant obstacle to the advancement of mRNA therapeutics. Here we report the implementation of a barcoded high-throughput screening system as a means to identify the lung-targeting efficacy of cationic, degradable lipid-like materials. We combinatorially synthesize 180 cationic, degradable lipids which are initially screened in vitro. We then use barcoding technology to quantify how the selected 96 distinct lipid nanoparticles deliver DNA barcodes in vivo. The top-performing nanoparticle formulation delivering Cas9-based genetic editors exhibits therapeutic potential for antiangiogenic cancer therapy within a lung tumor model in female mice. These data demonstrate that employing high-throughput barcoding technology as a screening tool for identifying nanoparticles with lung tropism holds potential for the development of next-generation extrahepatic delivery platforms.

In situ combinatorial synthesis of degradable branched lipidoids for systemic delivery of mRNA therapeutics and gene editors

The ionizable lipidoid is a key component of lipid nanoparticles (LNPs). Degradable lipidoids containing extended alkyl branches have received tremendous attention, yet their optimization and investigation are underappreciated. Here, we devise an in situ construction method for the combinatorial synthesis of degradable branched (DB) lipidoids. We find that appending branch tails to inefficacious lipidoids via degradable linkers boosts mRNA delivery efficiency up to three orders of magnitude. Combinatorial screening and systematic investigation of two libraries of DB-lipidoids reveal important structural criteria that govern their in vivo potency. The lead DB-LNP demonstrates robust delivery of mRNA therapeutics and gene editors into the liver. In a diet-induced obese mouse model, we show that repeated administration of DB-LNP encapsulating mRNA encoding human fibroblast growth factor 21 alleviates obesity and fatty liver. Together, we offer a construction strategy for high-throughput and cost-efficient synthesis of DB-lipidoids. This study provides insights into branched lipidoids for efficient mRNA delivery.

Nanotechnology's frontier in combatting infectious and inflammatory diseases: prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases, which continuously pose one of the most serious threats to human health, attributed to factors such as the emergence of new pathogens, increasing drug resistance, changes in living environments and lifestyles, and the aging population. Despite rapid advancements in mechanistic research and drug development for these diseases, current treatments often have limited efficacy and notable side effects, necessitating the development of more effective and targeted anti-inflammatory therapies. In recent years, the rapid development of nanotechnology has provided crucial technological support for the prevention, treatment, and detection of inflammation-associated diseases. Various types of nanoparticles (NPs) play significant roles, serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability. NPs can also directly combat pathogens and inflammation. In addition, nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases. This review categorizes and characterizes different types of NPs, summarizes their applications in the prevention, treatment, and detection of infectious and inflammatory diseases. It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects. In conclusion, nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.

Antibiotic-Free Gene Vectors: A 25-Year Journey to Clinical Trials

Until very recently, the major use, for gene therapy, specifically of linear or circular DNA, such as plasmids, was as ancillary products for viral vectors' production or as a genetic template for mRNA production. Thanks to targeted and more efficient physical or chemical delivery techniques and to the refinement of their structure, non-viral plasmid DNA are now under intensive consideration as pharmaceutical drugs. Plasmids traditionally carry an antibiotic resistance gene for providing the selection pressure necessary for maintenance in a bacterial host. Nearly a dozen different antibiotic-free gene vectors have now been developed and are currently assessed in preclinical assays and phase I/II clinical trials. Their reduced size leads to increased transfection efficiency and prolonged transgene expression. In addition, associating non-viral gene vectors and DNA transposons, which mediate transgene integration into the host genome, circumvents plasmid dilution in dividing eukaryotic cells which generate a loss of the therapeutic gene. Combining these novel molecular tools allowed a significantly higher yield of genetically engineered T and Natural Killer cells for adoptive immunotherapies due to a reduced cytotoxicity and increased transposition rate. This review describes the main progresses accomplished for safer, more efficient and cost-effective gene and cell therapies using non-viral approaches and antibiotic-free gene vectors.

Chemically Modified Platforms for Better RNA Therapeutics

RNA-based therapies have catalyzed a revolutionary transformation in the biomedical landscape, offering unprecedented potential in disease prevention and treatment. However, despite their remarkable achievements, these therapies encounter substantial challenges including low stability, susceptibility to degradation by nucleases, and a prominent negative charge, thereby hindering further development. Chemically modified platforms have emerged as a strategic innovation, focusing on precise alterations either on the RNA moieties or their associated delivery vectors. This comprehensive review delves into these platforms, underscoring their significance in augmenting the performance and translational prospects of RNA-based therapeutics. It encompasses an in-depth analysis of various chemically modified delivery platforms that have been instrumental in propelling RNA therapeutics toward clinical utility. Moreover, the review scrutinizes the rationale behind diverse chemical modification techniques aiming at optimizing the therapeutic efficacy of RNA molecules, thereby facilitating robust disease management. Recent empirical studies corroborating the efficacy enhancement of RNA therapeutics through chemical modifications are highlighted. Conclusively, we offer profound insights into the transformative impact of chemical modifications on RNA drugs and delineates prospective trajectories for their future development and clinical integration.

Investigating the Cytosolic Delivery of Proteins by Lipid Nanoparticles Using the Chloroalkane Penetration Assay

Protein therapeutics are an expanding area for research and drug development, and lipid nanoparticles (LNPs) are the most prominent nonviral vehicles for protein delivery. The most common methods for assessing protein delivery by LNPs include assays that measure the total amount of protein taken up by cells and assays that measure the phenotypic changes associated with protein delivery. However, assays for total cellular uptake include large amounts of protein that are trapped in endosomes or are otherwise nonfunctional. Assays for functional delivery are important, but the readouts are indirect and amplified, limiting the quantitative interpretation. Here, we apply an assay for cytosolic delivery, the chloroalkane penetration assay (CAPA), to measure the cytosolic delivery of a (-30) green fluorescent protein (GFP) fused to Cre recombinase (Cre(-30)GFP) fusion protein by LNPs. We compare these data to the data from total cellular uptake and functional delivery assays to provide a richer analysis of uptake and endosomal escape for LNP-mediated protein delivery. We also use CAPA for a screen of a small library of lipidoids, identifying those with a promising ability to deliver Cre(-30)GFP to the cytosol of mammalian cells. With careful controls and optimized conditions, we expect that CAPA will be a useful tool for investigating the rate, efficiency, and mechanisms of LNP-mediated delivery of therapeutic proteins.

Lipid nanovehicles overcome barriers to systemic RNA delivery: Lipid components, fabrication methods, and rational design

Lipid nanovehicles are currently the most advanced vehicles used for RNA delivery, as demonstrated by the approval of patisiran for amyloidosis therapy in 2018. To illuminate the unique superiority of lipid nanovehicles in RNA delivery, in this review, we first introduce various RNA therapeutics, describe systemic delivery barriers, and explain the lipid components and methods used for lipid nanovehicle preparation. Then, we emphasize crucial advances in lipid nanovehicle design for overcoming barriers to systemic RNA delivery. Finally, the current status and challenges of lipid nanovehicle-based RNA therapeutics in clinical applications are also discussed. Our objective is to provide a comprehensive overview showing how to utilize lipid nanovehicles to overcome multiple barriers to systemic RNA delivery, inspiring the development of more high-performance RNA lipid nanovesicles in the future.

Microfluidic platform enables shear-less aerosolization of lipid nanoparticles for messenger RNA inhalation

Leveraging the extensive surface area of the lungs for gene therapy, inhalation route offers distinct advantages for delivery. Clinical nebulizers that employ vibrating mesh technology are the standard choice for converting liquid medicines into aerosols. However, they have limitations when it comes to delivering mRNA through inhalation, including severe damage to nanoparticles due to shearing forces. Here, we introduce a novel microfluidic aerosolization platform (MAP) that preserves the structural and physicochemical integrity of lipid nanoparticles, enabling safe and efficient mRNA delivery to the respiratory system. Our results demonstrated the superiority of the novel MAP over the conventional vibrating mesh nebulizer, as it avoided problems such as particle aggregation, loss of mRNA encapsulation, and deformation of nanoparticle morphology. Notably, aerosolized nanoparticles generated by the microfluidic device led to enhanced transfection efficiency across various cell lines. In vivo experiments with mice that inhaled these aerosolized nanoparticles revealed successful, lung-specific mRNA transfection without observable signs of toxicity. This pioneering MAP represents a significant advancement for the pulmonary gene therapy, enabling precise and effective delivery of aerosolized nanoparticles.

The Current Situation and Development Prospect of Whole-Genome Screening

High-throughput genetic screening is useful for discovering critical genes or gene sequences that trigger specific cell functions and/or phenotypes. Loss-of-function genetic screening is mainly achieved through RNA interference (RNAi), CRISPR knock-out (CRISPRko), and CRISPR interference (CRISPRi) technologies. Gain-of-function genetic screening mainly depends on the overexpression of a cDNA library and CRISPR activation (CRISPRa). Base editing can perform both gain- and loss-of-function genetic screening. This review discusses genetic screening techniques based on Cas9 nuclease, including Cas9-mediated genome knock-out and dCas9-based gene activation and interference. We compare these methods with previous genetic screening techniques based on RNAi and cDNA library overexpression and propose future prospects and applications for CRISPR screening.