Strategies, design, and chemistry in siRNA delivery systems

Targeted delivery systems of siRNA based on ionizable lipid nanoparticles and cationic polymer vectors

As an emerging therapeutic tool, small interfering RNA (siRNA) had the capability to down-regulate nearly all human mRNAs via sequence-specific gene silencing. Numerous studies have demonstrated the substantial potential of siRNA in the treatment of broad classes of diseases. With the discovery and development of various delivery systems and chemical modifications, six siRNA-based drugs have been approved by 2024. The utilization of siRNA-based therapeutics has significantly propelled efforts to combat a wide array of previously incurable diseases and advanced at a rapid pace, particularly with the help of potent targeted delivery systems. Despite encountering several extracellular and intracellular challenges, the efficiency of siRNA delivery has been gradually enhanced. Currently, targeted strategies aimed at improving potency and reducing toxicity played a crucial role in the druggability of siRNA. This review focused on recent advancements on ionizable lipid nanoparticles (LNPs) and cationic polymer (CP) vectors applied for targeted siRNA delivery. Based on various types of targeted modifications, we primarily described delivery systems modified with receptor ligands, peptides, antibodies, aptamers and amino acids. Finally, we discussed the challenges and opportunities associated with siRNA delivery systems based on ionizable LNPs and CPs vectors.

Poly-lysine-modified recombinant protein nanocages for effective delivery of small activating RNA

Small activating RNA (saRNA) holds significant promise as a therapeutic platform for various diseases. However, the development of efficient nanocarriers that can overcome existing delivery challenges and ensure effective cellular uptake remains a critical hurdle. In this study, we aimed to address this issue by genetically modifying four lysine residues at the N-terminus of the FTH gene through gene recombinant technology, resulting in the creation of poly-lysine-H-apoferrin (4LF) vectors. These vectors were designed to efficiently deliver saRNA encoding the Sirtuin1 (Sirt1) protein to chondrocytes, thereby mitigating cartilage damage. The poly-lysine modification conferred the ability of 4LF@saRNA nanoparticles (NPs) to escape from lysosomes via proton sponge effects and to release saRNA into the cytoplasm through the pH-induced degradation of the 4LF vector, ultimately activating the target gene. To enhance the retention of NPs within the joint cavity and facilitate intra-articular delivery, we incorporated the 4LF@saRNA NPs into a thermosensitive self-healing hydrogel composed of chitosan, oxidized chondroitin sulfate (OCS), and sodium β-glycerophosphate (β-GP). Experimental results demonstrated that the chitosan/OCS/β-GP-4LF@saRNA (OCCG-4LF@saRNA) delivery system effectively delivered the 4LF@saRNA NPs to chondrocytes both in vitro and in vivo, resulting in a significant increase in Sirt1 protein expression. This upregulation led to a reduction in chondrocyte apoptosis, enhanced cell migration, and improved cartilage protection, effectively alleviating symptoms of osteoarthritis. In conclusion, our findings suggested that the 4LF-based delivery system hold considerable potential for effective intracellular saRNA delivery, demonstrating promising biocompatibility, stability, and delivery efficiency, with significant therapeutic implications for cartilage repair.

Caffeic acid borate functionalized linear polyglycidol for targeted siRNA delivery in the treatment of primary biliary cholangitis

Interfering with protein arginine methyltransferase 5 (PRMT5) gene expression with siRNA targeting is a promising strategy for precision primary biliary cholangitis (PBC) therapy, yet achieving effective and specific delivery of therapeutic agents to the liver remains challenging. In this study, we develop a caffeic acid borate derived linear polyglycidol polymer micelle CAPG, which can efficiently deliver siRNA to liver. The degradation of borate and hydrazone bonds in the high-ROS and acidic environment of inflammatory cells triggers micelle disintegration, facilitating siRNA release. Comprehensive in vivo experiments demonstrate that siRNA1@CAPG can significantly reduce the concentration of liver inflammation-related biomarkers and pro-inflammatory factors and notably increase superoxide dismutase (SOD) levels in mice, outperforming free siRNA1 in suppressing PRMT5 expression. Therefore, our study offers valuable reference for the treatment of primary biliary cholangitis.

A Metabolite Co-Delivery Strategy to Improve mRNA Lipid Nanoparticle Delivery

Lipid nanoparticles (LNPs) effectively protect mRNA and facilitate its entry into target cells for protein synthesis. Despite these successes, cellular entry alone may not be enough for optimal protein expression, as mRNA translation also depends on the availability of essential metabolites, including metabolic energy sources, coenzymes, and amino acids. Without adequate metabolites, mRNA translation may be less efficient, potentially leading to higher dosing requirements or poorer therapeutic outcomes for LNP therapies. To address this, we develop a metabolite co-delivery strategy by encapsulating essential metabolites within mRNA LNPs, hypothesizing that our approach can uniformly improve mRNA delivery. Instead of adding a fifth component to the organic phase, our strategy involves mixing the metabolite with the mRNA payload in the aqueous phase, while maintaining the molar ratio of the components in the organic phase during LNP formulation. We verify our approach in vitro and in vivo, highlighting the broad applicability of our strategy through mechanism and efficacy studies across multiple cell lines, and physiological conditions, such as normoxia (i.e., 21% oxygen), hypoxia (i.e., 1% oxygen), and in mice. Taken collectively, we anticipate that our metabolite co-delivery strategy may serve as a generalizable strategy to enhance in vitro and in vivo protein expression using mRNA LNPs, potentially offering broad applicability for the study and treatment of disease.

The emerging functions and clinical implications of circRNAs in acute myeloid leukaemia

Acute myeloid leukaemia (AML) is a prevalent haematologic malignancy characterized by significant heterogeneity. Despite the application of aggressive therapeutic approaches, AML remains associated with poor prognosis. Circular RNAs (circRNAs) constitute a unique class of single-stranded RNAs featuring covalently closed loop structures that are ubiquitous across species. These molecules perform crucial regulatory functions in the pathogenesis of various diseases through diverse mechanisms, including acting as miRNA sponges, interacting with DNA or proteins, and encoding functional proteins/polypeptides. Recently, numerous circRNAs have been confirmed to have aberrant expression patterns in AML patients. In particular, certain circRNAs are closely associated with specific clinicopathological characteristics and thus have great potential as diagnostic/prognostic biomarkers and therapeutic targets in AML. Herein, we systematically summarize the biogenesis, degradation, and functional mechanisms of circRNAs while highlighting their clinical relevance. We also outline a series of online databases and analytical tools available to facilitate circRNA research. Finally, we discuss the current challenges and future research priorities in this evolving field.

Lactobacillus acidophilus extracellular vesicles-coated UiO-66-NH2@siRNA nanoparticles for ulcerative colitis targeted gene therapy and gut microbiota modulation

Ulcerative colitis (UC) is a complex and chronic inflammatory bowel disease whose pathogenesis involves genetic and environmental factors, which poses a challenge for treatment. Here, we have designed an innovative integrated therapeutic strategy using Lactobacillus acidophilus extracellular vesicles (EVs) to encapsulate UiO-66-NH2 nanoparticles bounded with TNF-α siRNA (EVs@UiO-66-NH2@siRNA) for UC treatment. This system shows superior affinity to inflammation-related cells due to the Lactobacillus acidophilus EVs can maintain immune homeostasis by regulating the secretion of cytokines in vitro. siRNA can specifically target the key inflammatory TNF-α in UC and silence its gene expression, thereby regulating the process of inflammatory response. After oral administration, EVs@UiO-66-NH2@siRNA demonstrates an accurate delivery of TNF-α siRNA to colonize the colon site and exerts a siRNA therapeutic effect by inhibiting the expression of TNF-α, which alleviates the intestinal inflammation in DSS-induced UC model. Moreover, this system can modulate the types and compositional structures of gut microbiota and metabolites to achieve an anti-inflammatory phenotype, which is helpful for the repair of intestinal homeostasis. We also have proved that UiO-66-NH2 nanoparticles exhibit a high loading capacity for TNF-α siRNA and good pH responsiveness, improving the potent release of siRNA in colon tissue. Collectively, the EVs@UiO-66-NH2@siRNA nano-delivery system demonstrate a feasible combination therapeutic strategy for UC through gut microecology modulation, immune regulation and TNF-α siRNA silence, which may provide a potential targeted treatment approach for inflammatory bowel disease.

Evolution of Lipo-Xenopeptide Carriers for siRNA Delivery: Interplay of Stabilizing Subunits

Although small interfering RNA (siRNA) holds immense promise for treating genetic diseases and cancers, its clinical application is constrained by instability, cellular uptake barriers, and inefficient cytosolic delivery, underscoring the need for effective delivery systems. Therefore, this study focuses on screening novel T-shaped lipo-xenopeptide (XP) nanocarriers for siRNA polyplex formulation, integrating two single succinoyl-tetraethylene pentamine (Stp) units for electrostatic interaction and tyrosine tripeptides (Y3) for aromatic stabilization, along with structural modifications such as the addition of histidine (H) with or without terminal cysteines (C), and the incorporation of various fatty acids (FAs). A systematic evaluation of siRNA binding, nanoparticle stability, and gene silencing efficiency in multiple cell lines illustrated that the novel Stp1-HC lipo-XPs carriers outperform their Stp2-HC analogs, despite having fewer cationizable Stp units. This advantage stems from increased fatty acid, Y3, and C density, which compensates for reduced electrostatic interactions. The presence of H in combination with unsaturated FAs significantly improved the functional siRNA delivery. Our findings highlight the complex interplay of electrostatic, hydrophobic, covalent, hydrogen-bonded, and aromatic interactions to achieve efficient siRNA delivery, which is best-balanced in the oleic acid-containing Stp1-HC/OleA lipo-XP, exceeding the previously best standard carrier Stp2-HC/OleA in efficiency.

Recent Update on siRNA Therapeutics

Small interfering RNA (siRNA) has been deemed a promising therapeutic method for treating diverse diseases. siRNA-based therapeutics provide a distinct mechanism of action by selectively targeting and silencing disease-causing genes at the post-transcriptional level. This paper provides an overview of the present state of siRNA-based therapeutics, highlighting their potential in different therapeutic areas. The first section of this review introduces the basic principles of siRNA technology, including its mechanism of action and delivery methods. Subsequently, we discuss the impediments associated with siRNA delivery and manufacturing development and the strategies for overcoming these obstacles. The clinical advancement of siRNA therapeutics in various disease areas, including cancer, genetic disorders, viral infections, and inflammatory diseases, is summarized. Lastly, we summarize the successes, failures, and lessons learned from the development of siRNAs. With advancements in delivery systems and improvements in target selection, the field of medicine can be revolutionized, and siRNA therapeutics can offer new treatment options for patients.

Enhanced siRNA delivery with novel smart chitosan-based formulations

This study aims to develop an innovative multifunctional and dual responsive drug formulation for precise siRNA delivery to breast cancer sites, addressing the challenges posed by conventional cancer treatments which often result in adverse side effects due to their non-specific nature. The formulation made by incorporating gold coated superparamagnetic iron oxide nanoparticles (Au-SPIONs) into chitosan microspheres, which were subsequently loaded with siRNA. Comprehensive characterization, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDS) confirmed the formulation's favourable morphology, particle size distribution, chemical composition, and stability, indicating its strong potential for effective siRNA drug delivery applications. The developed formulation demonstrated siRNA encapsulation efficiencies ranging from 27.4 % to 88.6 % and loading capacity from 0.291 % to 1.59 %, these values particularly higher for medium molecular weight chitosan. These results were compared across different formulations, showing that variations in chitosan type and crosslinker concentration significantly influenced encapsulation efficiency and drug release profiles. Additionally, our results were compared to previous studies on chitosan microspheres encapsulating organic drugs and siRNA, where the developed system demonstrated similar encapsulation and release properties.. The type of chitosan and the choice of crosslinker significantly influenced the drug release patterns. Diverse release profiles across batches highlighted the necessity for precise formulation control. Incorporating SPIONs into chitosan microspheres presents a promising strategy for magnetically driven, site-specific drug delivery. The dual pH-responsive and magnetic properties enable rapid and targeted siRNA release, leveraging the acidic tumor microenvironment as an internal stimulus in addition to external magnetic stimuli. This novel combination of SPIONs, chitosan microspheres, and siRNA encapsulation represents a new approach for targeted drug delivery. While further research is needed to refine and optimize this approach, our study provides a proof of concept for advancing targeted cancer therapies.

A Methionine Allocation Nanoregulator for the Suppression of Cancer Stem Cells and Support to the Immune Cells by Epigenetic Regulation

Epigenetic dysregulation is prevalent in human cancers, affecting gene expression and metabolic patterns to meet the demands of malignant evolution and abnormal epigenetic processes, and resulting in a protumor immune microenvironment. Tumors require a steady supply of methionine for maintaining epigenetic flexibility, which is the only exogenous precursor of methyl donor S-adenosylmethionine for methylation, crucial for their resistance to therapies and survival in a nutrient-deficient microenvironment. Thus, tumor cells upregulate the Lat4 transporter to compete and deprive methionine in the microenvironment, sustaining their malignant phenotypes and also impairing immune cell functions. Addressing this methionine addiction is the key to overcoming drug resistance and improving immune response. Despite the challenge of lacking specific Lat4 inhibitors, an oxaliplatin prodrug crosslinked fluorinated polycation/anti-Lat4 small interfering RNA complex nanoregulator (AS-F-NP) has been designed and developed here. This nanoregulator restricted the greedy methionine uptake of tumor cells by knocking down Lat4, which in turn inhibited the malignant evolution of the tumor while restoring the viability and function of tumor-infiltrating immune cells.

GalNac-siRNA conjugate delivery technology promotes the treatment of typical chronic liver diseases

INTRODUCTION

Nucleic acid-based therapeutics have become a key pillar of the 'third wave' of modern medicine, following the eras of small molecule inhibitors and antibody drugs. Their rapid progress is heavily dependent on delivery technologies, with the development of N-acetylgalactosamine (GalNAc) conjugates marking a breakthrough in targeting liver diseases. This technology has gained significant attention for its role in addressing chronic conditions like chronic hepatitis B (CHB) and nonalcoholic steatohepatitis (NASH), which are challenging to treat with conventional methods.

AREAS COVERED

This review explores the origins, mechanisms, and advantages of GalNAc-siRNA delivery systems, highlighting their ability to target hepatocytes via the asialoglycoprotein receptor (ASGPR). The literature reviewed covers preclinical and clinical advancements, particularly in CHB and NASH. Key developments in stabilization chemistry and conjugation technologies are examined, emphasizing their impact on enhancing therapeutic efficacy and patient compliance.

EXPERT OPINION

GalNAc-siRNA technology represents a transformative advancement in RNA interference (RNAi) therapies, addressing unmet needs in liver-targeted diseases. While significant progress has been made, challenges remain, including restricted targeting scope and scalability concerns. Continued innovation is expected to expand applications, improve delivery efficiency, and overcome limitations, establishing GalNAc-siRNA as a cornerstone for future nucleic acid-based treatments.

Streamlining Bacterial Gene Regulation via Nucleic Acid Delivery with Gold Nanoclusters

Delivery of exogenous nucleic acids (NAs) for gene regulation in bacteria, bypassing the barrier of the cell wall, is essential for advancing fundamental microbiology and genetic engineering, and the treatment of bacterial diseases. However, current methods that rely on electrical or chemical interventions are limited by their complexity, specialized expertise, and laboratory-specific instrumentation. This study explores the capability of gold nanoclusters (AuNCs) as carriers for delivering small-interfering RNA and antisense oligonucleotides into bacteria for targeted gene regulation while shielding them from degradation during transport. By enhancing the cytoplasmic membrane permeability, the AuNCs enable efficient internalization of NAs into both Gram-positive and Gram-negative bacteria while exerting negligible influence on bacterial activity. It is demonstrated that the rationally designed NAs can be released from the AuNCs within bacteria, enabling ~70% knockdown of mecA in Methicillin-resistant Staphylococcus aureus (MRSA). This significantly reduces MRSA's antibiotic resistance and enhances oxacillin treatment efficacy. Furthermore, the successful silencing of ligA in Escherichia coli and pilQ in Pseudomonas aeruginosa highlights the broad adaptability of the approach across diverse bacterial species. The AuNCs-based next-generation NA delivery system has the potential to transform bacterial gene regulation-previously restricted to laboratory settings-into a versatile and scalable solution for real-world application.

Neutrophil-like cell membrane-coated metal-organic frameworks for siRNA delivery targeting NOX4 to alleviate oxidative stress in acute ischemic injury

Although reperfusion is the most effective treatment for acute ischemic stroke, it often results in serious secondary ischemia/reperfusion (I/R) injury due to oxidative stress. This oxidative stress primarily results from the overproduction of reactive oxygen species (ROS) during reperfusion which, in turn, is largely induced by high expression of NADPH oxidase 4 (NOX4). Inhibiting NOX4 gene expression has therefore been proposed as a direct approach to reduce ROS production and promote angiogenesis. Recognizing both the potential of siRNA-based therapies for selective gene silencing and the critical role of neutrophil-endothelial interactions during I/R injury, here we present a unique therapeutic approach where neutrophil-like cell membrane coated porous metal-organic framework nanoparticles are loaded with siNOX4 (M-MOF-siNOX4) and designed to target damaged brain microvascular tissue. These then mitigate oxidative stress by suppressing NOX4 expression. Using an in vitro oxygen-glucose deprivation/re-oxygenation model, we demonstrate that M-MOF-siNOX4 nanoparticles specifically bind to activated endothelial cells, effectively reducing NOX4 expression, decreasing both ROS production and cell apoptosis, and restoring cell viability. Use of an in vivo mouse model of middle cerebral artery occlusion further confirmed M-MOF-siNOX4 nanoparticles to substantially alleviate brain damage and protect neurological function following ischemic stroke. Taken together, our study presents an innovative and effective siRNA-based strategy for reducing oxidative stress in ischemic stroke therapy. STATEMENT OF SIGNIFICANCE: Ischemia/reperfusion (I/R) injury, a major complication of acute ischemic stroke, is primarily driven by oxidative stress due to the excessive production of reactive oxygen species (ROS). Current treatments targeting oxidative stress and cell death often lack specificity, leading to off-target effects. This study introduces an innovative nanoparticle-based therapy using neutrophil-like cell membrane-coated metal-organic frameworks (MOFs) to deliver siNOX4, an siRNA targeting NOX4, a key ROS-producing enzyme. This approach enhances targeted delivery, reduces ROS production and cell death, and significantly improves neurological recovery in stroke models. By overcoming the limitations of existing therapies, this strategy holds strong potential for revolutionizing ischemic stroke treatment and addressing other disorders related to oxidative stress.

Autologous platelet delivery of siRNAs by autologous plasma protein self-assembled nanoparticles for the treatment of acute kidney injury

Acute kidney injury (AKI) involves the activation of intrarenal hemostatic and inflammatory pathways. Platelets rapidly migrate to affected sites of AKI and release extracellular vesicles (EVs) laden with bioactive mediators that regulate inflammation and hemostasis. While small interfering RNA (siRNA) is a potent gene-silencing tool for biomedical applications, its therapeutic application in vivo remains challenging. We developed an innovative nucleic acid delivery platform by hybridizing synthetic transformation-related protein 53 (p53) siRNA with autologous plasma and incubating the complex with autologous platelets. These engineered platelets selectively delivered p53 siRNA to injured renal tubular cells via EV-mediated cargo release, resulting in targeted p53 suppression in renal cells and subsequent attenuation of AKI progression. This platelet-centric translational strategy demonstrates significant potential for advancing precision therapies in AKI by exploiting endogenous platelet trafficking to deliver therapeutics directly to injury sites.

Targeted drug delivery of cancer cell-derived extracellular vesicles decorated with a VEGFR-binding peptide

Chemotherapy is commonly used to manage cancer lesions, but its use is limited or has a high risk of failure due to the side effects of the drugs. The use of a drug delivery system can minimize the side effects of drugs and maximize their anticancer effects. This study investigated the potential of tumor cell-derived small extracellular vesicles (sEV) as drug delivery vehicles for doxorubicin (Dox). In addition, the decoration of vascular endothelial growth factor receptor (VEGFR)-targeting peptide on the sEV provided an enhance specific cancer cell-targeting effect in vitro or homing capacity in vivo. The extrusion method was effective in loading Dox and displaying targeting peptide. The effective Dox release was resulted under acidic condition, an endosome pH. The growth of tumor masses on MCF-7 xenografted mice were significantly inhibited by this drug delivery system. We believe that our results will provide useful information for the development of chemotherapeutic drug delivery systems.

Astrocytic BEST1 can serve as a target for functional recovery after ischemic stroke

Solid evidence from animal experiments supported the concept of peri-infarct tonic inhibition. Related drug targets have the potential to be translated for clinical stroke treatment. Recently, we reported the contribution of neuronal bestrophin-1 (BEST1)-mediated glutamate release to acute ischemic damage exacerbation in rodents. Now, we found a switch of abnormal BEST1 expression and function from neurons to astrocytes in the peri-infarct cortex following astrocytic activation. Excessive GABA was released through astrocytic BEST1 channel during the subacute phase of stroke, leading to sustained tonic inhibition. Astrocyte-specific knockdown of BEST1 promoted motor functional recovery, depending on reduced tonic inhibition. Moreover, we prepared self-assembled nanoparticles encapsulating siBest1 (SNP-siBest1), which displayed high brain accumulation and long circulation and knocked down astrocytic BEST1 effectively and safely. Systemic treatment with SNP-siBest1 after ischemic stroke showed a therapeutic effect in mice. Therefore, BEST1 is a potential target for stroke therapy from acute to subacute phase, and selective BEST1 blockers beyond nanoparticles are worth developing.

Transfection via RNA-Based Nanoparticles: Comparing Encapsulation vs Adsorption Approaches of RNA Incorporation

Historically, RNA delivery via nanoparticles has primarily relied on encapsulation, as demonstrated by lipid nanoparticles in SARS-CoV-2 vaccines. Concerns about RNA degradation on nanoparticle surfaces initially limited the exploration of adsorption-based approaches. However, recent advancements have renewed interest in adsorption as a viable alternative. This Viewpoint explores the approaches of RNA incorporation in nanoparticles, comparing encapsulation, adsorption, and the combination of encapsulation and adsorption, and presents a framework to guide the selection of the most suitable strategy based on general characteristics.

Landscape of small nucleic acid therapeutics: moving from the bench to the clinic as next-generation medicines

The ability of small nucleic acids to modulate gene expression via a range of processes has been widely explored. Compared with conventional treatments, small nucleic acid therapeutics have the potential to achieve long-lasting or even curative effects via gene editing. As a result of recent technological advances, efficient small nucleic acid delivery for therapeutic and biomedical applications has been achieved, accelerating their clinical translation. Here, we review the increasing number of small nucleic acid therapeutic classes and the most common chemical modifications and delivery platforms. We also discuss the key advances in the design, development and therapeutic application of each delivery platform. Furthermore, this review presents comprehensive profiles of currently approved small nucleic acid drugs, including 11 antisense oligonucleotides (ASOs), 2 aptamers and 6 siRNA drugs, summarizing their modifications, disease-specific mechanisms of action and delivery strategies. Other candidates whose clinical trial status has been recorded and updated are also discussed. We also consider strategic issues such as important safety considerations, novel vectors and hurdles for translating academic breakthroughs to the clinic. Small nucleic acid therapeutics have produced favorable results in clinical trials and have the potential to address previously "undruggable" targets, suggesting that they could be useful for guiding the development of additional clinical candidates.

Current views and trends of nanomaterials as vectors for gene delivery since the 21st century: a bibliometric analysis

BACKGROUND

Gene therapy is garnering increasing support due to its potential for a "once-delivered, lifelong benefit." The limitations of traditional gene delivery methods have spurred the advancement of bionanomaterials. Despite this progress, a thorough analysis of the evolution, current state, key contributors, focal studies, and future directions of nanomaterials in gene delivery remains absent.

METHODS

This study scrutinizes articles from the Web of Science, spanning 1 January 2 000, to 31 December 2023, employing various online tools for analysis and visualization.

RESULTS

The 21st century has witnessed consistent growth in scholarly work in this domain globally, with notable contributions from China and the US. At the same time, the Chinese Academy of Sciences (CAS), Harvard University, and Massachusetts Institute of Technology (MIT) have emerged as the most productive institutions, with CAS's academician Weihong Tan becoming the field's leading author. While drug delivery and nanoparticles (NPs) have been central themes for two decades, the research focus has shifted from modifying NPs and ultrafine particles to exploring polymer-hybrid NPs, mRNA vaccines, immune responses, green synthesis, and CRISPR/Cas tools.

CONCLUSIONS

This shift marks the transition from nanomaterials to bionanomaterials. The insights provided by this research offer a comprehensive overview of the field and valuable guidance for future investigations.

Zwitterionic lipid nanoparticles for efficient siRNA delivery and hypercholesterolemia therapy with rational charge self-transformation

Rationale: Effective delivery of small interfering RNA (siRNA) remains a significant challenge in treating hypercholesterolemia due to biocompatibility, cellular uptake, and endosomal escape issues. Rational regulation of carrier surface charge contributes to efficient siRNA delivery in vivo. Methods: This study introduces zwitterionic lipid nanoparticles (ZwiLNPs) as a novel solution to these challenges. By leveraging the unique properties of zwitterionic polymers, we achieved robust siRNA encapsulation and targeted delivery. The design of ZwiLNPs facilitates charge self-transformation in response to physiological conditions, which enhances their biocompatibility and cellular uptake efficiency. Result: In vivo studies demonstrated significant liver-targeting capabilities of ZwiLNPs, with improved endosomal escape following cellular internalization. Comparative analyses confirmed that ZwiLNPs outperform conventional lipid nanoparticles in terms of both cellular uptake and endosomal release. Conclusion: These findings position ZwiLNPs as a promising platform for RNA interference therapies, particularly for hypercholesterolemia and other lipid-related disorders.

Bioengineered protein nanocarrier facilitating siRNA escape from lysosomes for targeted RNAi therapy in glioblastoma

RNA interference (RNAi) represents a promising gene-specific therapy against tumors. However, its clinical translation is impeded by poor performance of lysosomal escape and tumor targeting. This challenge is especially prominent in glioblastoma (GBM) therapy, necessitating the penetration of the blood-brain barrier (BBB). Leveraging the intrinsic tumor-targeting and BBB traversing capability of human H-ferritin, we designed a series of ferritin variants with positively charged cavity and truncated carboxyl terminus, termed tHFn(+). These nanocarriers respond to weak acid and disassemble in endosomal compartments, exposing the internal positive charges to facilitate the lysosomal escape of loaded small interfering RNA (siRNA). Functioning as universal siRNA nanocarriers, tHFn(+) significantly enhanced the uptake of different siRNAs and suppressed gene expressions associated with GBM progression. Furthermore, tHFn(+) traversed the BBB and targeted glioma in vivo by binding to its receptors (e.g., transferrin receptor 1). tHFn(+)-delivered siRNAs exhibited exceptional therapeutic effects against glioma in vivo, advancing RNAi therapeutics beyond GBM for the treatment of various diseases.

Non-Coding RNAs in Cancer: Structure, Function, and Clinical Application

We are on the brink of a paradigm shift in both theoretical and clinical oncology. Genomic and transcriptomic profiling, alongside personalized approaches that account for individual patient variability, are increasingly shaping discourse. Discussions on the future of personalized cancer medicine are mainly dominated by the potential of non-coding RNAs (ncRNAs), which play a prominent role in cancer progression and metastasis formation by regulating the expression of oncogenic or tumor suppressor proteins at transcriptional and post-transcriptional levels; furthermore, their cell-free counterparts might be involved in intercellular communication. Non-coding RNAs are considered to be promising biomarker candidates for early diagnosis of cancer as well as potential therapeutic agents. This review aims to provide clarity amidst the vast body of literature by focusing on diverse species of ncRNAs, exploring the structure, origin, function, and potential clinical applications of miRNAs, siRNAs, lncRNAs, circRNAs, snRNAs, snoRNAs, eRNAs, paRNAs, YRNAs, vtRNAs, and piRNAs. We discuss molecular methods used for their detection or functional studies both in vitro and in vivo. We also address the challenges that must be overcome to enter a new era of cancer diagnosis and therapy that will reshape the future of oncology.

An oligo walk to identify siRNAs against the circular Tau 12->7 RNA

Circular RNAs are associated with numerous diseases and recent evidence shows that they can be translated into proteins after undergoing RNA modification. Circular RNAs differ from their 'linear' mRNA counterparts in their backsplice site, allowing selective targeting using RNA interference, which however limits the options to place the siRNA. We tested all possible siRNAs against the backsplice site of the circTau 12->7 RNA after it was subjected to adenosine to inosine RNA editing, a modification that promotes translation of the circRNA. Most siRNAs reduced the circRNA and protein abundance, which however did not correlate. We identified an siRNA with an IC50 of 750 pmol efficacy on protein expression. This circRNA fulfilled six of the eight criteria for siRNAs targeting mRNAs. Thus, modified circRNAs expressing protein can be targeted with siRNAs, but their optimal sequence needs to be determined empirically.

A Chemoinformatic-Guided Synthesis of a Spleen-Expressing mRNA Lipid Nanoparticle Platform

mRNA lipid nanoparticles (LNPs) are a powerful technology that are actively being investigated for their ability to prevent, treat, and study disease. However, a major limitation remains: achieving extrahepatic mRNA expression. The development of new carriers could enable the expression of mRNA in non-liver targets, thus expanding the utility of mRNA-based medicines. In this study, we use a combination of chemoinformatic-guided material synthesis and design of experiment optimization for the development of a spleen-expressing lipid nanoparticle (SE-LNP). We begin with the synthesis of a novel cholesterol derivative followed by SE-LNP formulation and design of experiment-guided optimization to identify three lead SE-LNPs. We then evaluate their in vitro delivery mechanism, in vivo biodistribution, and protein expression in mice, ultimately achieving spleen-preferential expression. The goal of this paper is thus to create LNPs that preferentially express mRNA in the spleen upon intravenous delivery, demonstrating the potential of LNPs to modulate gene expression in extrahepatic tissues for disease treatment.

A Novel Cell-Penetrating Peptide-Vascular Endothelial Growth Factor Small Interfering Ribonucleic Acid Complex That Mediates the Inhibition of Angiogenesis by Human Umbilical Vein Endothelial Cells and in an Ex Vivo Mouse Aorta Ring Model

Angiogenesis is mediated by vascular endothelial growth factor (VEGF), a protein that plays a key role in wound healing, inflammatory diseases, cardiovascular processes, ocular diseases, and tumor growth. Indeed, modulation of angiogenesis represents a potential approach to treating cancer and, as such, therapeutic approaches targeting VEGF and its receptors have been widely investigated as part of the broader search for curative interventions. Equally, RNA interference is a powerful tool for treating diseases, but its application as a disease treatment has been limited in part because of a lack of efficient small interfering RNA (siRNA) delivery systems. The purpose of this study was to characterize an amphipathic cell-penetrating peptide, Ara27, and its potential as an effective delivery vehicle as a conjugate with VEGF siRNA (siVEGF). In our study, we demonstrate that exposure of human umbilical vein endothelial cells (HUVECs) with Ara27-siVEGF complexes did not lead to cytotoxicity and can lead to down-regulation of cellular levels of both VEGF mRNA and protein. Moreover, treatment with the Ara27-siVEGF complex attenuates the phosphorylation of VEGFR2, Akt, and ERK in HUVECs and inhibits their capacity for wound healing and tube formation, both of which characteristics reflective of angiogenesis. In addition, we performed an ex vivo study to find that treatment with the Ara27-siVEGF complex inhibits aorta ring sprouting. Furthermore, the complex did not induce immunotoxicity in THP-1 and RAW264.7 cells. Taken together, our studies demonstrate that an Ara27-siVEGF conjugate is efficient for knockdown of VEGF in HUVECs to inhibit angiogenesis, without marked cytotoxic and immunotoxic effects.

Co-delivery of antioxidants and siRNA-VEGF: promising treatment for age-related macular degeneration

Current treatments for retinal disorders are anti-angiogenic agents, laser photocoagulation, and photodynamic therapies. These conventional treatments focus on reducing abnormal blood vessel formation in the retina, which, in a low-oxygen environment, can lead to harmful proliferation of endothelial cells. This results in dysfunctional, leaky blood vessels that cause retinal edema, hemorrhage, and vision loss. Age-related Macular Degeneration is a primary cause of vision loss and blindness in the elderly, impacting around 20% of those over 50 years old. This complex disease is also closely related to oxidative stress in retina. In this review, we explore the challenge of treating retinal diseases, alternatives and possibilities of enhancing the effectiveness of therapies using co-delivery systems containing both antiangiogenic and antioxidant therapeutic agents. Despite recent proposals potential, the lack of extensive clinical studies on the long-term outcomes and optimal combinations of therapies means that the full risk profile and effectiveness of combined therapy are not yet completely understood. These factors must be carefully considered and managed by healthcare providers to optimize treatment outcomes and ensure patient safety.

Recent Developments in Nanotechnology and Immunotherapy for the Diagnosis and Treatment of Pancreatic Cancer

Pancreatic cancer kills millions of people worldwide each year and is one of the most prevalent causes of mortality that requires prompt therapy. A large number of people suffering from pancreatic cancer are detected at an advanced stage, with incurable and drug-resistant tumor, hence the overall survival rate of pancreatic cancer is less. The advance phase of this cancer is generated because of expression of the cancer-causing gene, inactivation of the tumorsuppressing gene, and deregulation of molecules in different cellular signalling pathways. The prompt diagnosis through the biomarkers significantly evades the progress and accelerates the survival rates. The overexpression of Mesothelin, Urokinase plasminogen activator, IGFR, Epidermal growth factor receptor, Plectin-1, Mucin-1 and Zinc transporter 4 were recognized in the diagnosis of pancreatic cancer. Nanotechnology has led to the development of nanocarriersbased formulations (lipid, polymer, inorganic, carbon based and advanced nanocarriers) which overcome the hurdles of conventional therapy, chemotherapy and radiotherapy which causes toxicity to adjacent healthy tissues. The biocompatibility, toxicity and large-scale manufacturing are the hurdles associated with the nanocarriers-based approaches. Currently, Immunotherapybased techniques emerged as an efficient therapeutic alternative for the prevention of cancer. Immunological checkpoint targeting techniques have demonstrated significant efficacy in human cancers. Recent advancements in checkpoint inhibitors, adoptive T cell therapies, and cancer vaccines have shown potential in overcoming the immune evasion mechanisms of pancreatic cancer cells. Combining these immunotherapeutic approaches with nanocarriers holds great promise in enhancing the antitumor response and improving patient survival.

Tumor Microenvironment-Responsive Polymer-Based RNA Delivery Systems for Cancer Treatment

Ribonucleic acid (RNA) therapeutics offer a broad prospect in cancer treatment. However, their successful application requires overcoming various physiological barriers to effectively deliver RNAs to the target sites. Currently, a number of RNA delivery systems based on polymeric nanoparticles are developed to overcome these barriers in RNA delivery. This work provides an overview of the existing RNA therapeutics for cancer gene therapy, and particularly summarizes those that are entering the clinical phase. This work then discusses the core features and latest research developments of tumor microenvironment-responsive polymer-based RNA delivery carriers which are designed based on the pathological characteristics of the tumor microenvironment. Finally, this work also proposes opportunities for the transformation of RNA therapies into cancer immunotherapy methods in clinical applications.

Tailored polysaccharide entrapping metal-organic framework for RNAi therapeutics and diagnostics in atherosclerosis

Metal-organic frameworks (MOFs) hold promise as theranostic carriers for atherosclerosis. However, to further advance their therapeutic effects with higher complexity and functionality, integrating multiple components with complex synthesis procedures are usually involved. Here, we reported a facile and general strategy to prepare multifunctional anti-atherosclerosis theranostic platform in a single-step manner. A custom-designed multifunctional polymer, poly(butyl methacrylate-co-methacrylic acid) branched phosphorylated β-glucan (PBMMA-PG), can effectively entrap different MOFs via coordination, simultaneously endow the MOF with enhanced stability, lesional macrophages selectivity and enhanced endosome escape. Sequential ex situ characterization and computational studies elaborated the potential mechanism. This facile post-synthetic modification granted the administered nanoparticles atherosclerotic tropism by targeting Dectin-1+ macrophages, enhancing in situ MR signal intensity by 72 %. Delivery of siNLRP3 effectively mitigated NLRP3 inflammasomes activation, resulting a 43 % reduction of plaque area. Overall, the current study highlights a simple and general approach for fabricating a MOF-based theranostic platform towards atherosclerosis conditioning, which may also expand to other indications targeting the lesional macrophages.

Recent Insights into Nano-mediated siRNA Drug Delivery

Gene silencing is the characteristic that inhibits gene expression afforded by siRNA interference. The efficacy of the delivery system in terms of precision, efficacy, and stability can be enhanced by genebased drug delivery options. The delivery challenges and their associated side effects create a challenge for the delivery of gene-based drug delivery carriers. Nano-based delivery systems were reported to improve the efficacy of therapy. The absence of an efficient delivery mechanism that shields siRNA from nuclease degradation delivers it to cancer cells, and releases it into the cytoplasm of specific cancer cells without causing side effects is currently the greatest obstacle to the practical implementation of siRNA therapy. This article focuses on general aspects of siRNA and various siRNA nanocarrier-based formulations. In the near future, we will move towards the siRNA-based drug delivery approach.

Polymers for mRNA Delivery

mRNA delivery has emerged as a transformative approach in biotechnology and medicine, offering a versatile platform for the development of novel therapeutics. Unlike traditional small molecule drugs or protein-based biologics, mRNA therapeutics have the unique ability to direct cells to generate therapeutic proteins, allowing for precise modulation of biological processes. The delivery of mRNA into target cells is a critical step in realizing the therapeutic potential of this technology. In this review, our focus is on the latest advancements in designing functional polymers to achieve efficient mRNA delivery. Biodegradable polymers and low molecular weight polymers in addressing the balance in mRNA binding and release are summarized. Benefiting from the excellent performance of lipid nanoparticles in mRNA delivery, polymer/lipid hybrid nanostructures are also included. Finally, the challenges and future prospects in the development of polymer-based mRNA delivery systems are discussed.

Non-Coding RNAs in Breast Cancer: Diagnostic and Therapeutic Implications

Breast cancer (BC) is one of the most prevalent forms of cancer globally, and has recently become the leading cause of cancer-related mortality in women. BC is a heterogeneous disease comprising various histopathological and molecular subtypes with differing levels of malignancy, and each patient has an individual prognosis. Etiology and pathogenesis are complex and involve a considerable number of genetic alterations and dozens of alterations in non-coding RNA expression. Non-coding RNAs are part of an abundant family of single-stranded RNA molecules acting as key regulators in DNA replication, mRNA processing and translation, cell differentiation, growth, and overall genomic stability. In the context of breast cancer, non-coding RNAs are involved in cell cycle control and tumor cell migration and invasion, as well as treatment resistance. Alterations in non-coding RNA expression may contribute to the development and progression of breast cancer, making them promising biomarkers and targets for novel therapeutic approaches. Currently, the use of non-coding RNAs has not yet been applied to routine practice; however, their potential has been very well studied. The present review is a literature overview of current knowledge and its objective is to delineate the function of diverse classes of non-coding RNAs in breast cancer, with a particular emphasis on their potential utility as diagnostic and prognostic markers or as therapeutic targets and tools.

Isosteric 3D Bicyclo[1.1.1]Pentane (BCP) Core-Based Lipids for mRNA Delivery and CRISPR/Cas Gene Editing

Lipid nanoparticles (LNPs) are an essential component of messenger RNA (mRNA) vaccines and genome editing therapeutics. Ionizable amino lipids, which play the most crucial role in enabling mRNA to overcome delivery barriers, have, to date, been restricted to two-dimensional (2D) architectures. Inspired by improved physicochemical properties resulting from the incorporation of three-dimensionality (3D) into small-molecule drugs, we report the creation of 3D ionizable lipid designs through the introduction of bicyclo[1.1.1]pentane (BCP) core motifs. BCP-based lipids enabled efficient in vivo mRNA delivery to the liver and spleen with significantly greater performance over 2D benzene- and cyclohexane-based analogues. Notably, lead BCP-NC2-C12 LNPs mediated ∼90% reduction in the PCSK9 serum protein level via CRISPR/Cas9 gene knockout, outperforming 2D controls and clinically used DLin-MC3-DMA LNPs at the same dose. Here, we introduce BCP-based designs with superior in vivo activity, thereby expanding the chemical scope of ionizable amino lipids from 2D to 3D and offering a promising avenue to improve mRNA and gene editing efficiency for the continued development of genetic medicines.

A Novel Pot-Economy Approach to the Synthesis of Triantennary GalNAc-Oligonucleotide

N-Acetylgalactosamine (GalNAc) is an efficient and multifunctional delivery tool in the development and synthesis of chemically modified oligonucleotide therapeutics (conjugates). Such therapeutics demonstrate improved potency in vivo due to the selective and efficient delivery to hepatocytes in the liver via receptor-mediated endocytosis, which is what drives the high interest in this molecule. The ways to synthesize such structures are relatively new and have not been optimized in terms of the yields and stages both in lab and large-scale synthesis. Another significant criterion, especially in large-scale synthesis, is to match ecological norms and perform the synthesis in accordance with the Green Chemistry approach, i.e., to control and minimize the amounts of reagents and resources consumed and the waste generated. Here, we provide a robust and resource effective pot-economy method for the synthesis of triantennary GalNAc and GalNAc phosphoramidite/CPG optimized for laboratory scales.

In Vivo Delivery Processes and Development Strategies of Lipid Nanoparticles

Lipid nanoparticles (LNPs) represent an advanced and highly efficient delivery system for RNA molecules, demonstrating exceptional biocompatibility and remarkable delivery efficiency. This is evidenced by the clinical authorization of three LNP formulations: Patisiran, BNT162b2, and mRNA-1273. To further maximize the efficacy of RNA-based therapy, it is imperative to develop more potent LNP delivery systems that can effectively protect inherently unstable and negatively charged RNA molecules from degradation by nucleases, while facilitating their cellular uptake into target cells. Therefore, this review presents feasible strategies commonly employed for the development of efficient LNP delivery systems. The strategies encompass combinatorial chemistry for large-scale synthesis of ionizable lipids, rational design strategy of ionizable lipids, functional molecules-derived lipid molecules, the optimization of LNP formulations, and the adjustment of particle size and charge property of LNPs. Prior to introducing these developing strategies, in vivo delivery processes of LNPs, a crucial determinant influencing the clinical translation of LNP formulations, is described to better understand how to develop LNP delivery systems.

Current status of nucleic acid therapy and its new progress in cancer treatment

Nucleic acid is an essential biopolymer in all living cells, performing the functions of storing and transmitting genetic information and synthesizing protein. In recent decades, with the progress of science and biotechnology and the continuous exploration of the functions performed by nucleic acid, more and more studies have confirmed that nucleic acid therapy for living organisms has great medical therapeutic potential. Nucleic acid drugs began to become independent therapeutic agents. As a new therapeutic method, nucleic acid therapy plays an important role in the treatment of genetic diseases, viral infections and cancers. There are currently 19 nucleic acid drugs approved by the Food and Drug Administration (FDA). In the following review, we start from principles and advantages of nucleic acid therapy, and briefly describe development history of nucleic acid drugs. And then we give examples of various RNA therapeutic drugs, including antisense oligonucleotides (ASO), mRNA vaccines, small interfering RNA (siRNA) and microRNA (miRNA), aptamers, and small activating RNA (saRNA). In addition, we also focused on the current status of nucleic acid drugs used in cancer therapy and the breakthrough in recent years. Clinical trials of nucleic acid drugs for cancer treatment are under way, conventional radiotherapy and chemotherapy combined with the immunotherapies such as checkpoint inhibitors and nucleic acid drugs may be the main prospects for successful cancer treatment.

Nanotechnology used for siRNA delivery for the treatment of neurodegenerative diseases: Focusing on Alzheimer's disease and Parkinson's disease

Neurodegenerative diseases (ND) are often accompanied by dementia, motor dysfunction, or disability. Caring for these patients imposes a significant psychological and financial burden on families. Until now, there are no effective methods for the treatment of NDs. Among them, Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common. Recently, studies have revealed that the overexpression of certain genes may be linked to the occurrence of AD and PD. Small interfering RNAs (siRNAs) are a powerful tool for gene silencing because they can specifically bind to and cleave target mRNA. However, the intrinsic properties of naked siRNA and various physiological barriers limit the application of siRNA in the brain. Nanotechnology is a promising option for addressing these issues. Nanoparticles are not only able to protect siRNA from degradation but also have the advantage of crossing various physiological barriers to reach the brain target of siRNA. In this review, we aim to introduce diverse nanotechnology used for delivering siRNA to treat AD and PD. Finally, we will briefly discuss our perspectives on this promising field.

Comparison of Cell-Penetrating and Fusogenic TAT-HA2 Peptide Performance in Peptideplex, Multicomponent, and Conjugate siRNA Delivery Systems

In this study, the performance of the cell-penetrating and fusogenic peptide, TAT-HA2, which consists of a cell-permeable HIV trans-activator of transcription (TAT) protein transduction domain and a pH-responsive influenza A virus hemagglutinin protein (HA2) domain, was comparatively evaluated for the first time in peptideplex, multicomponent, and conjugate siRNA delivery systems. TAT-HA2 in all three systems protected siRNA from degradation, except in the conjugate system with a low Peptide/siRNA ratio. The synergistic effect of different peptide domains enhanced the transfection efficiency of multicomponent and conjugate systems compared to that of peptideplexes, which was attributed to the surface configuration of TAT-HA2 peptides depending on the nature of attachment. Particularly, the multicomponent system showed better cellular uptake and endosomal escape than the peptideplexes, resulting in enhanced siRNA delivery in the cytoplasm. In addition, the presence of cleavable disulfide bonds in multicomponent and conjugate systems promoted the effective siRNA delivery in the cytoplasm, resulting in improved gene silencing activity. The multicomponent system reduced the level of luciferase expression in SKOV3 cells to 45% (±4). In contrast, the conjugate system and the commercially available siRNA transfection agent, Lipofectamine RNAiMax, caused luciferase suppression down to 55% (±2) at a siRNA dose of 100 nM. For the same dose, the peptideplex system could only reduce the luciferase expression to 65% (±5). None of the developed systems showed significant toxicity at any dose. Overall, the TAT-HA2 peptide is promising as a siRNA delivery vector; however, its performance depends on the nature of attachment and, as a result, its surface configuration on the developed delivery system.

Elucidating siRNA Cellular Delivery Mechanism Mediated by Quaternized Starch Nanoparticles

Starch-based nanoparticles are highly utilized in the realm of drug delivery taking advantage of their biocompatibility and biodegradability. Studies have utilized Quaternized starch (Q-starch) for small interfering RNA (siRNA) delivery, in which quaternary amines enable interaction with negatively charged siRNA, resulting in self-assembly complexation. Although reports present numerous applications, the demonstrated efficacy is nonetheless limited due to undiscovered cellular mechanistic delivery. In this study, a deep dive into Q-starch/siRNA complexes' cellular mechanism and kinetics at the cellular level is revealed using single-particle tracking and cell population level using imaging flow cytometry. Uptake studies depict the efficient cellular internalization via endocytosis while a significant fraction of complexes' intracellular fate is lysosome. Utilizing single-particle tracking, it is found that an average of 15% of cellular detected complexes escape the endosome which holds the potential for the integration in the cytoplasmatic gene silencing mechanism. Additional experimental manipulations (overcoming endosomal escape) demonstrate that the complex's disassembly is the rate-limiting step, correlating Q-starch's structure-function properties as siRNA carrier. Structure-function properties accentuating the high affinity of the interaction between Q-starch's quaternary groups and siRNA's phosphate groups that results in low release efficiency. However, low-frequency ultrasound (20 kHz) application may have induced siRNA release resulting in faster gene silencing kinetics.

Utilizing ionic liquids as eco-friendly and sustainable carriers for delivering nucleic acids: A review on the revolutionary advancement in nano delivery systems

Ionic liquids (ILs) are an extremely versatile class of chemicals. It has been shown that they can effectively pass through many biological barriers in the human body to deliver medications. ILs are solvents noted for their ecological friendliness; they contain equal amounts of cations and anions and remain liquid at temperatures below 100 °C. Hence, these are ideal for biomedical applications owing to their advantageous properties such as biocompatibility, solubility, and adaptability. ILs are widely reported to improve the solubility and stability of nucleic acids (DNA and RNA) in aqueous conditions, allowing for more effective delivery. Certain ILs have shown the ability to enhance the absorption of nucleic acids into cells. In addition, ILs can also be used to create vectors for gene delivery, such as liposomes and nanoparticles, thereby improving the transfection efficiency of plasmid DNA and siRNA. Subsequently, the application of ILs for nucleic acid delivery has increased significantly in recent years. In this context, we believe that using ILs to enhance the transport of nucleic acids will have a considerable effect as a novel and crucial therapeutic method in the upcoming decades. The use of ILs as solvents to preserve the natural structure of DNA and RNA shows promise for a variety of biotechnological and medical applications. Notably, ILs may be utilized for a variety of functions, including extracting, concentrating, stabilizing, and spreading nucleic acids inside cells. Our review emphasizes the key findings of research works published in this domain, wherein outstanding effectiveness of delivering RNA to the desired areas was achieved, and was made possible through the utilization of ILs.

siRNAEfficacyDB: An experimentally supported small interfering RNA efficacy database

Small interfering RNA (siRNA) has revolutionised biomedical research and drug development through precise post-transcriptional gene silencing technology. Despite its immense potential, siRNA therapy still faces technical challenges, such as delivery efficiency, targeting specificity, and molecular stability. To address these challenges and facilitate siRNA drug development, we have developed siRNAEfficacyDB, a comprehensive database that integrates experimentally validated siRNA efficacy data. This database contains 3544 siRNA records, covering 42 target genes and 5 cell lines. It provides detailed information on siRNA sequences, target genes, inhibition efficiencies, experimental techniques, cell lines, siRNA concentrations, and incubation times. siRNAEfficacyDB offers a user-friendly web interface that makes it easy to query, browse and analyse data, enabling efficient access to siRNA-related information. In summary, siRNAEfficacyDB provides a useful data foundation for siRNA drug design and optimisation, serving as a valuable resource for advancing computer-aided siRNA design research and nucleic acid drug development. siRNAEfficacyDB is freely available at https://cellknowledge.com.cn/siRNAEfficacy for non-commercial use.

Liposome-based RNAi delivery in honeybee for inhibiting parasite Nosema ceranae

Nosema ceranae, a parasite that parasitizes and reproduces in the gut of honeybees, has become a serious threat to the global apiculture industry. RNA interference (RNAi) technology can be used to inhibit N. ceranae growth by targeting silencing the thioredoxin reductase (TrxR) in N. ceranae. However, suitable carriers are one of the reasons limiting the application of RNAi due to the easy degradation of dsRNA in honeybees. As a vesicle composed of a lipid bilayer, liposomes are a good carrier for nucleic acid delivery, but studies in honeybees are lacking. In this study, liposomes were used for double-stranded RNA (dsRNA) dsTrxR delivery triggering RNAi to inhibit the N. ceranae growth in honeybees. Compared to naked dsTrxR, liposome-dsTrxR reduced N. ceranae numbers in the midgut and partially restored midgut morphology without affecting bee survival and gut microbial composition. The results of this study confirmed that liposomes could effectively protect dsRNA from entering the honeybee gut and provide a reference for using RNAi technology to suppress honeybee pests and diseases.

Nucleic acid drugs: recent progress and future perspectives

High efficacy, selectivity and cellular targeting of therapeutic agents has been an active area of investigation for decades. Currently, most clinically approved therapeutics are small molecules or protein/antibody biologics. Targeted action of small molecule drugs remains a challenge in medicine. In addition, many diseases are considered 'undruggable' using standard biomacromolecules. Many of these challenges however, can be addressed using nucleic therapeutics. Nucleic acid drugs (NADs) are a new generation of gene-editing modalities characterized by their high efficiency and rapid development, which have become an active research topic in new drug development field. However, many factors, including their low stability, short half-life, high immunogenicity, tissue targeting, cellular uptake, and endosomal escape, hamper the delivery and clinical application of NADs. Scientists have used chemical modification techniques to improve the physicochemical properties of NADs. In contrast, modified NADs typically require carriers to enter target cells and reach specific intracellular locations. Multiple delivery approaches have been developed to effectively improve intracellular delivery and the in vivo bioavailability of NADs. Several NADs have entered the clinical trial recently, and some have been approved for therapeutic use in different fields. This review summarizes NADs development and evolution and introduces NADs classifications and general delivery strategies, highlighting their success in clinical applications. Additionally, this review discusses the limitations and potential future applications of NADs as gene therapy candidates.

Gene therapy for cardiac diseases: methods, challenges, and future directions

Gene therapy is advancing at an unprecedented pace, and the recent success of clinical trials reinforces optimism and trust among the scientific community. Recently, the cardiac gene therapy pipeline, which had progressed more slowly than in other fields, has begun to advance, overcoming biological and technical challenges, particularly in treating genetic heart pathologies. The primary rationale behind the focus on monogenic cardiac diseases is the well-defined molecular mechanisms driving their phenotypes, directly linked to the pathogenicity of single genetic mutations. This aspect makes these conditions a remarkable example of 'genetically druggable' diseases. Unfortunately, current treatments for these life-threatening disorders are few and often poorly effective, underscoring the need to develop therapies to modulate or correct their molecular substrates. In this review we examine the latest advancements in cardiac gene therapy, discussing the pros and cons of different molecular approaches and delivery vectors, with a focus on their therapeutic application in cardiac inherited diseases. Additionally, we highlight the key factors that may enhance clinical translation, drawing insights from previous trials and the current prospects of cardiac gene therapy.

Biomimetic Modification of siRNA/Chemo Drug Nanoassemblies for Targeted Combination Therapy in Breast Cancer

The development and progression of tumors are characterized by intricate biological processes. Monotherapy not only struggles to achieve effective treatment but also tends to precipitate a series of issues, including multidrug resistance and limited antitumor effect. Consequently, it is imperative to adopt a synergistic multitherapy approach to enhance the efficacy of tumor treatment. The integration of chemotherapy drug with oligonucleotide drug for combinational treatment has shown significant promise in improving tumor therapeutic efficiency. However, the effective in vivo codelivery of oligonucleotide drugs and chemotherapy drugs faces substantial challenges such as poor stability of oligonucleotide drugs during the circulation time, limited tumor accumulation, and uncertain delivery ratios of different payloads. To overcome these obstacles, we have engineered cyclic Arg-Gly-Asp (cRGD)-modified red blood cell membrane (RBCm)-coated multidrug nanocomplexes, which were self-assembled from the Polo-like kinase 1 siRNA (siPlk1) and an irreversible tyrosine kinase inhibitor neratinib targeted to human epidermal growth factor receptor 2 (HER2) overexpressed in breast cancer. Through electrostatic and amphiphilic interactions between the positively charged neratinib and negatively charged siPlk1, we have successfully fabricated uniform multidrug nanoparticles. The cRGD-modified red blood cell membranes coated on the surface of the multidrug nanoparticles could enhance drug stability in circulation and tumor accumulation. This targeted combinational therapy significantly enhanced the antitumor efficiency in HER2-positive breast cancer in vitro and in vivo.

Overcoming limitations and advancing the therapeutic potential of antibody-oligonucleotide conjugates (AOCs): Current status and future perspectives

As cancer incidence rises due to an aging population, the importance of precision medicine continues to grow. Antibody-drug conjugates (ADCs) exemplify targeted therapies by delivering cytotoxic agents to specific antigens. Building on this concept, researchers have developed antibody-oligonucleotide conjugates (AOCs), which combine antibodies with oligonucleotides to regulate gene expression. This review highlights the mechanism of AOCs, emphasizing their unique ability to selectively target and modulate disease-causing proteins. It also explores the components of AOCs and their application in tumor therapy while addressing key challenges such as manufacturing complexities, endosomal escape, and immune response. The article underscores the significance of AOCs in precision oncology and discusses future directions, highlighting their potential in treating cancers driven by genetic mutations and abnormal protein expression.

Nanoparticles Bounded to Interfering RNAs as a Therapy for Pancreatic Cancer: A Systematic Review

Pancreatic cancer is one of the tumors with poor prognosis and low survival due to late diagnosis, high resistance, and very limited effective therapeutic options. Thus, new pharmacological treatments are necessary to improve the prognosis of patients. In this context, nanoparticles represent an efficient system for transporting and administering therapeutic molecules. Furthermore, siRNA can be used in cancer treatment to selectively inhibit the expression of any target gene. Therefore, nanoparticles associated with siRNA have been tested as a new therapeutic strategy to solve the pancreatic cancer treatment failure in the clinical setting. The current article presents a systematic revision of the literature of the last 10 years in which nanoparticles loading siRNA are used in pancreatic cancer. This research was carried out in three databases (PubMed, Scopus, and Web of Science) obtaining 164 articles from which 37 were selected. Our results show an overall view of the high effectiveness of this new therapy that combines nanoparticles with genetic therapy in pancreatic cancer suggesting that siRNA-based medicines will likely open up a new therapeutic era in the treatment of this type of tumors.

Breaking the final barrier: Evolution of cationic and ionizable lipid structure in lipid nanoparticles to escape the endosome

In the past decade, nucleic acid therapies have seen a boon in development and clinical translation largely due to advances in nanotechnology that have enabled their safe and targeted delivery. Nanoparticles can protect nucleic acids from degradation by serum enzymes and can facilitate entry into cells. Still, achieving endosomal escape to allow nucleic acids to enter the cytoplasm has remained a significant barrier, where less than 5% of nanoparticles within the endo-lysosomal pathway are able to transfer their cargo to the cytosol. Lipid-based drug delivery vehicles, particularly lipid nanoparticles (LNPs), have been optimized to achieve potent endosomal escape, and thus have been the vector of choice in the clinic as demonstrated by their utilization in the COVID-19 mRNA vaccines. The success of LNPs is in large part due to the rational design of lipids that can specifically overcome endosomal barriers. In this review, we chart the evolution of lipid structure from cationic lipids to ionizable lipids, focusing on structure-function relationships, with a focus on how they relate to endosomal escape. Additionally, we examine recent advancements in ionizable lipid structure as well as discuss the future of lipid design.