siRNA: Mechanism of action, challenges, and therapeutic approaches

Recent advancements in small interfering RNA based therapeutic approach on breast cancer

Breast cancer (BC) is the most common and malignant tumor diagnosed in women, with 2.9 million cases in 2023 and the fifth highest cancer-causing mortality worldwide. Recent developments in targeted therapy options for BC have demonstrated the promising potential of small interfering RNA (siRNA)-based cancer therapeutic approaches. As BC continues to be a global burden, siRNA therapy emerges as a potential treatment strategy to regulate disease-related genes in other types of cancers, including BC. siRNAs are tiny RNA molecules that, by preventing their expression, can specifically silence genes linked to the development of cancer. In order to increase the stability and effectiveness of siRNA delivery to BC cells, minimize off-target effects, and improve treatment efficacy, advanced delivery technologies such as lipid nanoparticles and nanocarriers have been created. Additionally, combination therapies, such as siRNAs that target multiple pathways are used in conjunction with conventional chemotherapy agents, have shown synergistic effects in various preclinical studies, opening up new treatment options for breast cancer that are personalized and precision medicine-oriented. Targeting important genes linked to BC growth, metastasis, and chemo-resistance has been reported in BC research using siRNA-based therapies. This study reviews recent reports on therapeutic approaches to siRNA for advanced treatment of BC. Furthermore, this review evaluates the role and mechanisms of siRNA in BC and demonstrates the potential of exploiting siRNA as a novel target for BC therapy.

Exploring dose and downregulation dynamics in lipid nanoparticles based siRNA therapy: Systematic review and meta-analysis

Small interfering RNA (siRNA) holds promise as a therapeutic approach for various diseases, yet challenges persist in achieving efficient delivery, biodistribution, and minimizing off-target effects. Lipidic nanoformulations are being developed to address these hurdles, but the optimal dose for preclinical investigations remains unclear. This systematic review and meta-analysis aims to determine the optimal dose of nanoformulated siRNA and explore factors influencing dose and biodistribution, informing future research in this field. A comprehensive search across four electronic databases identified 25 potential studies, with 15 selected for meta-analysis after screening. Quality assessment was conducted using SYRCLE's risk of bias tool modified for animal studies based on research question. Study found an average siRNA dose of 1.513 ± 0.377 mg/kg with mean downregulation of 65.79 % achieved, with siRNA-LNPs mainly accumulating in the liver. While individual factors showed no significant correlation, a positive association between dose and downregulation was observed, alongside other influencing factors. Extrapolating intravenous doses to potential oral doses, we suggest an initial oral dose range of 1.5 to 8 mg/kg, considering siRNA-LNPs bioavailability. These findings contribute to advancing RNA interference research and encourage further exploration of siRNA-based treatments in personalized medicine.

Evaluation of the effect of RNA secondary structure on Cas13d-mediated target RNA cleavage

The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas13d system was adapted as a powerful tool for targeting viral RNA sequences, making it a promising approach for antiviral strategies. Understanding the influence of template RNA structure on Cas13d binding and cleavage efficiency is crucial for optimizing its therapeutic potential. In this study, we investigated the effect of local RNA secondary structure on Cas13d activity. To do so, we varied the stability of a hairpin structure containing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) target sequence, allowing us to determine the threshold RNA stability at which Cas13d activity is affected. Our results demonstrate that Cas13d possesses the ability to effectively bind and cleave highly stable RNA structures. Notably, we only observed a decrease in Cas13d activity in the case of exceptionally stable RNA hairpins with completely base-paired stems, which are rarely encountered in natural RNA molecules. A comparison of Cas13d and RNA interference (RNAi)-mediated cleavage of the same RNA targets demonstrated that RNAi is more sensitive for local target RNA structures than Cas13d. These results underscore the suitability of the CRISPR-Cas13d system for targeting viruses with highly structured RNA genomes.

Separation and Characterization of Therapeutic Oligonucleotide Isomer Impurities by Cyclic Ion Mobility Mass Spectrometry

Therapeutic oligonucleotides such as antisense oligonucleotide (ASO) and small interfering RNA (siRNA) are among the most remarkable modalities in modern medicine. ASOs and siRNA are composed of single- or double-stranded 15-25 mer synthesized oligonucleotides, which can be used to modulate gene expression. Liquid chromatography-mass spectrometry (LC/MS) is a necessary technique for the quality control of therapeutic oligonucleotides; it is used to evaluate the quantities of target oligonucleotides and their impurities. The widely applied oligonucleotide therapeutic quantitation method uses both ultraviolet (UV) absorbance and the MS signal intensity. Peaks separated from the main peak, which contains full-length product, are generally quantitated by UV. However, coeluting impurities, such as n - 1 shortmers, abasic oligonucleotides, and PS → PO (phosphorothiate to phosphodiester) oligonucleotides, are quantitated by MS. These coeluting impurities can also be comprised of various isomers with the same modification, thus increasing the difficulty in their separation and relative quantitation by LC/MS. It is possible that a specific isomer with a certain structural form induces toxicities. Therefore, characterization of each isomer separation is in high demand. In this study, we separated and characterized oligonucleotide isomers by employing a cyclic ion mobility mass spectrometry (cyclic IMS) system, which allows the separation of ions with the same m/z ratio based on their structural differences. Patisiran antisense and sense strands and their n - 1 and abasic isomers were used as sample sequences, and their ratio characterization was achieved by cyclic IMS. In addition, we evaluated the PS → PO conversion isomers of the antisense strand of givosiran, which originally contained four PS modification sites. The PS → PO isomers exhibited specific and distinguishable mobiligram patterns. We believe that cyclic IMS is a promising method for evaluating therapeutic oligonucleotide isomers.

A drug delivery system of HIF-1α siRNA nanoparticles loaded by mesenchymal stem cells on choroidal neovascularization

Aim: To assess mesenchymal stem cells (MSCs) as carriers for HIF-1α siRNA-loaded nanoparticles (NPs) for targeted therapy of experimental choroidal neovascularization (CNV).Materials & methods: A poly (lactic-co-glycolic acid) (PLGA)-core/lipid-shell hybrid NP was designed. The transfection efficacy of MSCs with the hybrid NPs was assessed. Mice were intravenously injected with MSCs after laser photocoagulation and CNV was assessed at 7 days post-injection.Results & conclusion: The transfection efficiency of hybrid NPs into MSCs was 72.7%. HIF-1α mRNA expression in 661w cells co-cultured with MSC-hybrid-siRNA NPs was significantly lower. Intravenous delivery of MSC-hybrid-siRNA NPs greatly reduced CNV area and length. Intravenous injection of MSC-hybrid-siRNA NPs achieved therapeutic efficacy in reducing CNV area. The MSC-mediated homing enabled targeted inhibition of ocular angiogenesis.

Ferroptosis-based advanced therapies as treatment approaches for metabolic and cardiovascular diseases

Ferroptosis has attracted attention throughout the last decade because of its tremendous clinical importance. Here, we review the rapidly growing body of literature on how inhibition of ferroptosis may be harnessed for the treatment of common diseases, and we focus on metabolic and cardiovascular unmet medical needs. We introduce four classes of preclinically established ferroptosis inhibitors (ferrostatins) such as iron chelators, radical trapping agents that function in the cytoplasmic compartment, lipophilic radical trapping antioxidants and ninjurin-1 (NINJ1) specific monoclonal antibodies. In contrast to ferroptosis inducers that cause serious untoward effects such as acute kidney tubular necrosis, the side effect profile of ferrostatins appears to be limited. We also consider ferroptosis as a potential side effect itself when several advanced therapies harnessing small-interfering RNA (siRNA)-based treatment approaches are tested. Importantly, clinical trial design is impeded by the lack of an appropriate biomarker for ferroptosis detection in serum samples or tissue biopsies. However, we discuss favorable clinical scenarios suited for the design of anti-ferroptosis clinical trials to test such first-in-class compounds. We conclude that targeting ferroptosis exhibits outstanding treatment options for metabolic and cardiovascular diseases, but we have only begun to translate this knowledge into clinically relevant applications.

Systematic Review of Genetic Substrate Reduction Therapy in Lysosomal Storage Diseases: Opportunities, Challenges and Delivery Systems

BACKGROUND

Genetic substrate reduction therapy (gSRT), which involves the use of nucleic acids to downregulate the genes involved in the biosynthesis of storage substances, has been investigated in the treatment of lysosomal storage diseases (LSDs).

OBJECTIVE

To analyze the application of gSRT to the treatment of LSDs, identifying the silencing tools and delivery systems used, and the main challenges for its development and clinical translation, highlighting the contribution of nanotechnology to overcome them.

METHODS

A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines was performed. PubMed, Scopus, and Web of Science databases were used for searching terms related to LSDs and gene-silencing strategies and tools.

RESULTS

Fabry, Gaucher, and Pompe diseases and mucopolysaccharidoses I and III are the only LSDs for which gSRT has been studied, siRNA and lipid nanoparticles being the silencing strategy and the delivery system most frequently employed, respectively. Only in one recently published study was CRISPR/Cas9 applied to treat Fabry disease. Specific tissue targeting, availability of relevant cell and animal LSD models, and the rare disease condition are the main challenges with gSRT for the treatment of these diseases. Out of the 11 studies identified, only two gSRT studies were evaluated in animal models.

CONCLUSIONS

Nucleic acid therapies are expanding the clinical tools and therapies currently available for LSDs. Recent advances in CRISPR/Cas9 technology and the growing impact of nanotechnology are expected to boost the clinical translation of gSRT in the near future, and not only for LSDs.

PAI-1 siRNA-loaded biomimetic nanoparticles for ameliorating diminished ovarian reserve and inhibiting ovarian fibrosis

With specific and inherent mRNA cleaving activity, small interfering RNA against pro-fibrosis factor (PAI-1 siRNA, siPAI-1) has demonstrated the fucntion for preventing diminished ovarian reserve (DOR). Moreover, safe nanomaterials have provided ideal tools for delivering siRNA to the targeted cells to obtain high therapeutic efficacy. In order to improve the preventing capability of siPAI-1 for DOR, we synthesized one kind of biomimetic Poly (lactic-co-glycolic acid) copolymer (PLGA)-based nanoparticles (siPAI-1@PLGA@M-FSHL, abbreviated as SPMF). siPAI-1 was assembled into cationic PLGA nanoparticles, following with macrophage membrane coating (M) and FSHL81-95 peptide modification. SPMF NPs significantly enhanced cellular uptake and gene silencing efficiency in KGN cells in vitro. In vivo assay demonstrated that SPMF NPs can targetedly accumulate in the ovarian of DOR mice with Cyclophosphamide treatment (80 mg/kg/week, 2 weeks) and remarkably downregulate the levels of PAI-1 in ovarian, which finally resulted in the effective suppression of ovary fibrosis and improved the chemotherapy-induced follicle loss to increase the number of primordial, secondary, antral follicles by 62.05 %, 54.92 % and 64.37 %, respectively, compared with DOR group. In summary, this study demonstrates that siPAI-1-loaded SPMF with high safety and efficacy can potentially alleviate DOR by inhibiting the overexpression of PAI-1 in the ovarian.

Circadian control of polycyclic aromatic hydrocarbon-induced dysregulation of endothelial tight junctions and mitochondrial bioenergetics

The study evaluates the impact of environmental toxicants, such as polycyclic aromatic hydrocarbons (PAHs), on circadian regulations and functions of brain endothelial cells, which form the main structural element of the blood-brain barrier (BBB). PAH are lipophilic and highly toxic environmental pollutants that accumulate in human and animal tissues. Environmental factors related to climate change, such as an increase in frequency and intensity of wildfires or enhanced strength of hurricanes or tropical cyclones, may lead to redistribution of these toxicants and enhanced human exposure. These natural disasters are also associated with disruption of circadian rhythms in affected populations, linking increased exposure to environmental toxicants to alterations of circadian rhythm pathways. Several vital physiological processes are coordinated by circadian rhythms, and disruption of the circadian clock can contribute to the development of several diseases. The blood-brain barrier (BBB) is crucial for protecting the brain from blood-borne harmful substances, and its integrity is influenced by circadian rhythms. Exposure of brain endothelial cells to a human and environmentally-relevant PAH mixture resulted in dose-dependent alterations of expression of critical circadian modulators, such as Clock, Bmal1, Cry1/2, and Per1/2. Moreover, silencing of the circadian Clock gene potentiated the impact of PAHs on the expression of the main tight junction genes and proteins (namely, claudin-5, occludin, JAM-2, and ZO-2), as well as mitochondrial bioenergetics. Findings from this study contribute to a better understanding of pathological influence of PAH-induced health effects, especially those related to circadian rhythm disruption.

Poly (β-amino esters)/Mobil Composition of Matter 41-mediated delivery of siIL-1β alleviates deep vein thrombosis in rat hind limbs

Introduction: Deep vein thrombosis (DVT) is a major cause of cardiovascular disease-related deaths worldwide and is considered a thrombotic inflammatory disorder. IL-1β, as a key promoter of venous thrombus inflammation, is a potential target for DVT treatment. Constructing a nanocarrier system for intracellular delivery of siIL-1β to silence IL-1β may be an effective strategy for alleviating DVT. Methods: ELISA was used to detect the expression levels of IL-1β and t-PA in the serum of DVT patients and healthy individuals. In vitro, HUVEC cells were treated with IL-1β, and changes in VWF and t-PA expression levels were assessed. PBAE/MCM-41@siIL-1β (PM@siIL-1β) nano-complexes were synthesized, the characterization and biocompatibility of PM@siIL-1β were evaluated. A rat hind limb DVT model was established, and PM@siIL-1β was used to treat DVT rats. Morphology of the inferior vena cava, endothelial cell count, IL-1β, vWF, and t-PA levels, as well as changes in the p38 MAPK and NF-κB pathways, were examined in the different groups. Results: IL-1β and t-PA were highly expressed in DVT patients, and IL-1β treatment induced a decrease in VWF levels and an increase in t-PA levels in HUVEC cells. The synthesized PM@siIL-1β exhibited spherical shape, good stability, high encapsulation efficiency, and high drug loading capacity, with excellent biocompatibility. In the DVT model rats, the inferior vena cava was filled with blood clots, endothelial cells increased, IL-1β and VWF levels significantly increased, while t-PA levels were significantly downregulated. Treatment with PM@siIL-1β resulted in reduced thrombus formation, decreased endothelial cell count, and reversal of IL-1β, VWF, and t-PA levels. Furthermore, PM@siIL-1β treatment significantly inhibited p38 phosphorylation and upregulation of NF-κB expression in the DVT model group. Conclusion: IL-1β can be considered a therapeutic target for suppressing DVT inflammation. The synthesized PM@siIL-1β achieved efficient delivery and gene silencing of siIL-1β, demonstrating good therapeutic effects on rat hind limb DVT, including anti-thrombotic and anti-inflammatory effects, potentially mediated through the p38 MAPK and NF-κB pathways.

Advances in carrier-delivered small interfering RNA based therapeutics for treatment of neurodegenerative diseases

Neurodegenerative diseases are devastating diseases that severely affect the health of people all over the world. RNA therapies have become one of the most promising critical drug treatments for neurodegenerative diseases due to their excellent gene and protein editing effects. However, the successful transport of RNA via the systemic route to the central nervous system remains one of the major obstacles in treating neurodegenerative diseases. This review will focus on therapeutic RNA that can successfully overcome the blood-brain barrier (BBB), with particular attention to small interfering RNAs (siRNAs), focusing on different types of neurodegenerative disease treatment strategies and accelerating their translation into clinical practice.

The advancement of siRNA-based nanomedicine for tumor therapy

Small interfering RNA (siRNA) has been proved to be able to effectively down-regulate gene expression through the RNAi mechanism. Thus, siRNA-based drugs have become one of the hottest research directions due to their high efficiency and specificity. However, challenges such as instability, off-target effects and immune activation hinder their clinical application. This review explores the mechanisms of siRNA and the challenges in siRNA-based tumor therapy. It highlights the use of various nanomaterials - including lipid nanoparticles, polymeric nanoparticles and inorganic nanoparticles - as carriers for siRNA delivery in different therapeutic modalities. The application strategies of siRNA-based nanomedicine in chemotherapy, phototherapy and immunotherapy are discussed in detail, along with recent clinical advancements. Aiming to provide insights for future research and therapeutic approaches.

Sustained release of MAPK14-targeting siRNA from polyelectrolyte complex hydrogels mitigates MSC osteogenesis in vitro with potential application in growth plate injury

The growth plate is a cartilage structure at the end of long bones which mediates growth in children. When fractured, the formation of bony repair tissue known as a "bony bar" can occur and cause limb deformities. There are currently no effective clinical solutions for the prevention of the bony bar formation or regeneration of healthy growth plate cartilage after a fracture. This study employs previously developed alginate/chitosan polyelectrolyte complex (PEC) hydrogels as a sustained release vehicle for the delivery of short-interfering RNA (siRNA). Specifically, the siRNA targets the p38-MAPK pathway in mesenchymal stem cells (MSCs) to prevent their osteogenic differentiation. In vitro experimental findings show sustained release of siRNA from the hydrogels for 6 months. Flow cytometry and confocal imaging indicate that the hydrogels release siRNA to effectively knockdown GFP expression over a sustained period. MAPK-14 targeting siRNA was used to knockdown the expression of MAPK-14 and correspondingly decrease the expression of other osteogenic genes in MSCs in vitro over the span of 21 days. These hydrogels were used in a rat model of growth plate injury to determine whether siMAPK-14 released from the gels could inhibit bony bar formation. No significant reduction of bony bar formation was seen in vivo at the one concentration of siRNA examined. This PEC hydrogel represents a significant advancement for siRNA sustained delivery, and presents an interesting potential therapeutic delivery system for growth plate injuries and other regenerative medicine applications.

Nucleic Acid Armor: Fortifying RNA Therapeutics through Delivery and Targeting Innovations for Immunotherapy

RNA is a promising nucleic acid-based biomolecule for various treatments because of its high efficacy, low toxicity, and the tremendous availability of targeting sequences. Nevertheless, RNA shows instability and has a short half-life in physiological environments such as the bloodstream in the presence of RNAase. Therefore, developing reliable delivery strategies is important for targeting disease sites and maximizing the therapeutic effect of RNA drugs, particularly in the field of immunotherapy. In this mini-review, we highlight two major approaches: (1) delivery vehicles and (2) chemical modifications. Recent advances in delivery vehicles employ nanotechnologies such as lipid-based nanoparticles, viral vectors, and inorganic nanocarriers to precisely target specific cell types to facilitate RNA cellular entry. On the other hand, chemical modification utilizes the alteration of RNA structures via the addition of covalent bonds such as N-acetylgalactosamine or antibodies (antibody-oligonucleotide conjugates) to target specific receptors of cells. The pros and cons of these technologies are enlisted in this review. We aim to review nucleic acid drugs, their delivery systems, targeting strategies, and related chemical modifications. Finally, we express our perspective on the potential combination of RNA-based click chemistry with adoptive cell therapy (e.g., B cells or T cells) to address the issues of short duration and short half-life associated with antibody-oligonucleotide conjugate drugs.

Nanosized DNA Hydrogel Functionalized with a DNAzyme Tetrahedron for Highly Efficient Gene Silencing

DNAzymes are DNA oligonucleotides that have catalytic activity without the assistance of protein enzymes. In particular, RNA-cleaving DNAzymes were considered as ideal candidates for gene therapy due to their unique characteristics. Nevertheless, efforts to use DNAzyme as a gene therapeutic agent are limited by issues such as their low physiological stability in serum and intracellular delivery efficiency. In this study, we developed a nanosized synthetic DNA hydrogel functionalized with a DNAzyme tetrahedron (TDz Dgel) to overcome these limitations. We observed remarkable improvement in the gene-silencing effect as well as intracellular uptake without the support of gene transfection reagents using TDz Dgel. The improved catalytic activity of the DNAzyme resulted from the combination of the cell-penetrating DNA tetrahedron structure and high stability of DNA hydrogel. We envision that this approach will become a convenient and efficient strategy for gene-silencing therapy using DNAzyme in the future.

Antifibrotic and Pro-regenerative Effects of SMAD3 siRNA and Collagen I mRNA-Loaded Lipid Nanoparticles in Human Tenocytes

Tendinopathy involves the inflammation and degeneration of the tendon due to repetitive strain injury. Current treatments primarily target inflammation resolution, yet they do not aim at tissue regeneration. In this study, a microfluidics approach is harnessed to develop a platform of lipid nanoparticles (LNPs) loaded simultaneously with SMAD3 siRNA and collagen I mRNA, aiming to explore its potential dual antifibrotic and regenerative effects in human tenocytes. The developed LNPs displayed size homogeneity and colloidal stability and exhibited high cytocompatibility in human tenocytes. Moreover, LNPs allowed for efficient uptake and transfection efficiency of the RNAs. In the in vitro efficacy studies, the gene expression and production of SMAD3 and collagen I were tested by real-time quantitative chain polymerase reaction and immuno- and intracellular staining, revealing collagen I production enhancement, SMAD3 inhibition, and modulation of other tendon repair factors by the LNPs. Overall, the potential of this platform of RNA-loaded LNPs to be used as a dual therapeutic approach to prevent fibrosis and promote tissue remodeling in late stages of tendon diseases was confirmed.

Genetic insights into the complexity of premature ovarian insufficiency

Premature Ovarian Insufficiency (POI) is a highly heterogeneous condition characterized by ovarian dysfunction in women occurring before the age of 40, representing a significant cause of female infertility. It manifests through primary or secondary amenorrhea. While more than half of POI cases are idiopathic, genetic factors play a pivotal role in all instances with known causes, contributing to approximately 20-25% of cases. This article comprehensively reviews the genetic factors associated with POI, delineating the primary candidate genes. The discussion delves into the intricate relationship between these genes and ovarian development, elucidating the functional consequences of diverse mutations to underscore the fundamental impact of genetic effects on POI. The identified genetic factors, encompassing gene mutations and chromosomal abnormalities, are systematically classified based on whether the resulting POI is syndromic or non-syndromic. Furthermore, this paper explores the genetic interplay between mitochondrial genes, such as Required for Meiotic Nuclear Division 1 homolog Gene (RMND1), Mitochondrial Ribosomal Protein S22 Gene (MRPS22), Leucine-rich Pentapeptide Repeat Gene (LRPPRC), and non-coding RNAs, including both microRNAs and Long non-coding RNAs, with POI. The insights provided serve to consolidate and enhance our understanding of the etiology of POI, contributing to establishing a theoretical foundation for diagnosing and treating POI patients, as well as for exploring the mechanisms underlying the disease.

ALDH1+ tumor stem cells promote the progression of malignant fibrous tissue sarcoma by inhibiting SYNPO2 through hsa-mir-206

This research aims to explore the mechanism by which microRNAs may regulate the biological behavior of tumor cells in ALDH1+ fibrosarcoma. We identified differentially expressed miRNAs in ALDH + NMFH-1 cells, screened genes related to sarcoma metastasis in the TCGA database, and finally obtained key genes regulated by miRNAs that are involved in metastasis. The function and mechanism of these key genes were then validated at the cellular level. Using the ULCAN database, a significant correlation was found between hsa-mir-206 and mortality in sarcoma patients. WGCNA analysis identified 352 genes related to tumor metastasis. Through Venn diagrams, we obtained 15 metastasis-related genes regulated by hsa-mir-206. Survival analysis showed that SYNPO2 expression is significantly correlated with survival rate and is significantly underexpressed in multiple tumors. SYNPO2 showed a negative correlation with macrophages and a positive correlation with CD8+ T cells. After inhibiting the expression of hsa-mir-206 with siRNA plasmids, the mRNA expression of SYNPO2 was significantly upregulated. The results of CCK8 assay, scratch assay, and transwell assay showed that the proliferation and migration ability of NFMH-1 cells were promoted after SYNPO2 was inhibited. ALDH1+ tumor stem cells promote the proliferation and invasion of malignant fibrous histiocytoma cells by inhibiting SYNPO2 through hsa-mir-206.

The Role of Inhaled Chitosan-Based Nanoparticles in Lung Cancer Therapy

Lung cancer is the leading cause of cancer-related mortality worldwide, largely due to the limited efficacy of anticancer drugs, which is primarily attributed to insufficient doses reaching the lungs. Additionally, patients undergoing treatment experience severe systemic adverse effects due to the distribution of anticancer drugs to non-targeted sites. In light of these challenges, there has been a growing interest in pulmonary administration of drugs for the treatment of lung cancer. This route allows drugs to be delivered directly to the lungs, resulting in high local concentrations that can enhance antitumor efficacy while mitigating systemic toxic effects. However, pulmonary administration poses the challenge of overcoming the mechanical, chemical, and immunological defenses of the respiratory tract that prevent the inhaled drug from properly penetrating the lungs. To overcome these drawbacks, the use of nanoparticles in inhaler formulations may be a promising strategy. Nanoparticles can assist in minimizing drug clearance, increasing penetration into the lung epithelium, and enhancing cellular uptake. They can also facilitate increased drug stability, promote controlled drug release, and delivery to target sites, such as the tumor environment. Among them, chitosan-based nanoparticles demonstrate advantages over other polymeric nanocarriers due to their unique biological properties, including antitumor activity and mucoadhesive capacity. These properties have the potential to enhance the efficacy of the drug when administered via the pulmonary route. In view of the above, this paper provides an overview of the research conducted on the delivery of anticancer drug-loaded chitosan-based nanoparticles incorporated into inhaled drug delivery devices for the treatment of lung cancer. Furthermore, the article addresses the use of emerging technologies, such as siRNA (small interfering RNA), in the context of lung cancer therapy. Particularly, recent studies employing chitosan-based nanoparticles for siRNA delivery via the pulmonary route are described.

Readers of RNA Modification in Cancer and Their Anticancer Inhibitors

Cancer treatment has always been a challenge for humanity. The inadequacies of current technologies underscore the limitations of our efforts against this disease. Nevertheless, the advent of targeted therapy has introduced a promising avenue, furnishing us with more efficacious tools. Consequently, researchers have turned their attention toward epigenetics, offering a novel perspective in this realm. The investigation of epigenetics has brought RNA readers to the forefront, as they play pivotal roles in recognizing and regulating RNA functions. Recently, the development of inhibitors targeting these RNA readers has emerged as a focal point in research and holds promise for further strides in targeted therapy. In this review, we comprehensively summarize various types of inhibitors targeting RNA readers, including non-coding RNA (ncRNA) inhibitors, small-molecule inhibitors, and other potential inhibitors. We systematically elucidate their mechanisms in suppressing cancer progression by inhibiting readers, aiming to present inhibitors of readers at the current stage and provide more insights into the development of anticancer drugs.

Quantitative 31P NMR Spectroscopy Platform Method for the Assay of Oligonucleotides as Pure Drug Substances and in Drug Product Formulations Using the Internal Standard Method

One of the most widely used techniques for the quantification of small interfering ribonucleic acid (siRNA) is the ultraviolet (UV) spectroscopy method. However, due to uncertainties in the extinction coefficient affecting the accuracy of the method and a sample preparation including several dilution steps, the purpose of this study was to explore the possibility of determining the content of siRNA by a platform method using quantitative 31P nuclear magnetic resonance (31P-qNMR) and the internal standard method. In this paper, acquisition time, selection of a suitable internal certified reference material, signal selection used for quantification, relaxation delay, and precision are discussed. In addition, the robustness of the method and the ability to apply this platform method to both drug substance (DS) and drug product samples is also discussed. Quantifications of siRNA determined by the 31P-qNMR platform method were on average 98.5%w/w when adjusting for the sodium and water contents. The data confirmed the applicability of 31P-qNMR in siRNA content determinations. The quantifications were compared to quantifications determined by the traditional UV spectroscopy method by F- and t-tests. The statistical tests showed that the platform 31P-qNMR method provided more accurate results (mass balance close to 100% w/w) compared to the traditional UV spectroscopy method when analyzing DS samples.

Genetic and Epigenetic Landscape for Drug Development in Polycystic Ovary Syndrome

The treatment of polycystic ovary syndrome (PCOS) faces challenges as all known treatments are merely symptomatic. The US Food and Drug Administration has not approved any drug specifically for treating PCOS. As the significance of genetics and epigenetics rises in drug development, their pivotal insights have greatly enhanced the efficacy and success of drug target discovery and validation, offering promise for guiding the advancement of PCOS treatments. In this context, we outline the genetic and epigenetic advancement in PCOS, which provide novel insights into the pathogenesis of this complex disease. We also delve into the prospective method for harnessing genetic and epigenetic strategies to identify potential drug targets and ensure target safety. Additionally, we shed light on the preliminary evidence and distinctive challenges associated with gene and epigenetic therapies in the context of PCOS.

Decoding the Non-coding: Tools and Databases Unveiling the Hidden World of "Junk" RNAs for Innovative Therapeutic Exploration

Non-coding RNAs are pivotal regulators of gene and protein expression, exerting crucial influences on diverse biological processes. Their dysregulation is frequently implicated in the onset and progression of diseases, notably cancer. A profound comprehension of the intricate mechanisms governing ncRNAs is imperative for devising innovative therapeutic interventions against these debilitating conditions. Significantly, nearly 80% of our genome comprises ncRNAs, underscoring their centrality in cellular processes. The elucidation of ncRNA functions is pivotal for grasping the complexities of gene regulation and its implications for human health. Modern genome sequencing techniques yield vast datasets, stored in specialized databases. To harness this wealth of information and to understand the crosstalk of non-coding RNAs, knowledge of available databases is required, and many new sophisticated computational tools have emerged. These tools play a pivotal role in the identification, prediction, and annotation of ncRNAs, thereby facilitating their experimental validation. This Review succinctly outlines the current understanding of ncRNAs, emphasizing their involvement in disease development. It also highlights the databases and tools instrumental in classifying, annotating, and evaluating ncRNAs. By extracting meaningful biological insights from seemingly "junk" data, these tools empower scientists to unravel the intricate roles of ncRNAs in shaping human health.

Delivery Strategies of siRNA Therapeutics for Hair Loss Therapy

Therapeutic needs for hair loss are intended to find small interfering ribonucleic acid (siRNA) therapeutics for breakthrough. Since naked siRNA is restricted to meet a druggable target in clinic,, delivery systems are indispensable to overcome intrinsic and pathophysiological barriers, enhancing targetability and persistency to ensure safety, efficacy, and effectiveness. Diverse carriers repurposed from small molecules to siRNA can be systematically or locally employed in hair loss therapy, followed by the adoption of new compositions associated with structural and environmental modification. The siRNA delivery systems have been extensively studied via conjugation or nanoparticle formulation to improve their fate in vitro and in vivo. In this review, we introduce clinically tunable siRNA delivery systems for hair loss based on design principles, after analyzing clinical trials in hair loss and currently approved siRNA therapeutics. We further discuss a strategic research framework for optimized siRNA delivery in hair loss from the scientific perspective of clinical translation.

Recent Advances in RNA Interference-Based Therapy for Hepatocellular Carcinoma: Emphasis on siRNA

Even though RNA treatments were first proposed as a way to change aberrant signaling in cancer, research in this field is currently ongoing. The term "RNAi" refers to the use of several RNAi technologies, including ribozymes, riboswitches, Aptamers, small interfering RNA (siRNA), antisense oligonucleotides (ASOs), and CRISPR/Cas9 technology. The siRNA therapy has already achieved a remarkable feat by revolutionizing the treatment arena of cancers. Unlike small molecules and antibodies, which need administration every three months or even every two years, RNAi may be given every quarter to attain therapeutic results. In order to overcome complex challenges, delivering siRNAs to the targeted tissues and cells effectively and safely and improving the effectiveness of siRNAs in terms of their action, stability, specificity, and potential adverse consequences are required. In this context, the three primary techniques of siRNA therapies for hepatocellular carcinoma (HCC) are accomplished for inhibiting angiogenesis, decreasing cell proliferation, and promoting apoptosis, are discussed in this review. We also deliberate targeting issues, immunogenic reactions to siRNA therapy, and the difficulties with their intrinsic chemistry and transportation.

Thermosensitive gel-nano system against esophageal cancer via restoring p53 activity and boosting T-cell immunity

In esophageal cancer (EC), clinical specimen testing has uncovered a significant increase in BTB and CNC homolog 1 (BACH1) expression and a shift towards an immunosuppressive environment, alongside a notable decrease in p53 protein expression. Therefore, therapeutic strategies focusing on BACH1 inhibition and p53 upregulation appear promising. Traditional oral treatments for EC lack precision and efficacy. Here, we propose a novel approach employing tumor-targeted nanoparticles (NPs) for drug delivery. However, the formation of a drug reservoir at the esophageal site, crucial for the sustained release of therapeutics, presents significant challenges in nano-delivery systems for EC treatment. To address this, we developed a thermosensitive hydrogel composed of F127 and tannic acid, serving as a vehicle for NP loading. These NPs, synthesized through the emulsion/volatization methods of mPEG-PLGA-PLL-cRGD, facilitate in situ drug delivery. Upon contacting esophageal tissue, the hydrogel transitions to a gel, adhering to the lining and enabling sustained release of encapsulated therapeutics. The formulation encompasses NPs laden with small interfering RNA targeting BACH1 (siBACH1) and the p53 activator PRIMA-1, creating a cohesive gel-nano system. Preliminary biological assessments demonstrate that this injectable, thermosensitive gel-nano system adheres effectively to esophageal tissue and targets EC cells. For better modeling clinical outcomes, a patient-derived organoid xenograft (PDOX) model was innovated, involving transplantation of EC-derived organoids into humanized mice, reconstructed with peripheral blood mononuclear cells (PBMCs). Post-treatment analysis showed substantial EC growth inhibition (89.51% tumor inhibition rate), significant BACH1 level reduction, restored anti-tumor immune responses, and pronounced tumor apoptosis. In summary, our study introduces a thermosensitive gel-nano system for EC treatment via restoring p53 activity and boosting T-cell immunity, with potential for clinical application.

Application of Model-Informed Drug Development in Dose Selection and Optimization for siRNA Therapies

The application of model-informed drug development (MIDD) has revolutionized drug development and regulatory decision making, transforming the process into one that is more efficient, effective, and patient centered. A critical application of MIDD is to facilitate dose selection and optimization, which play a pivotal role in improving efficacy, safety, and tolerability profiles of a candidate drug. With the surge of interest in small interfering RNA (siRNA) drugs as a promising class of therapeutics, their applications in various disease areas have been extensively studied preclinically. However, dosing selection and optimization experience for siRNA in humans is limited. Unique challenges exist for the dose evaluation of siRNA due to the temporal discordance between pharmacokinetic and pharmacodynamic profiles, as well as limited available clinical experience and considerable interindividual variability. This review highlights the pivotal role of MIDD in facilitating dose selection and optimization for siRNA therapeutics. Based on past experiences with approved siRNA products, MIDD has demonstrated its ability to aid in dose selection for clinical trials and enabling optimal dosing for the general patient population. In addition, MIDD presents an opportunity for dose individualization based on patient characteristics, enhancing the precision and effectiveness of siRNA therapeutics. In conclusion, the integration of MIDD offers substantial advantages in navigating the complex challenges of dose selection and optimization in siRNA drug development, which in turn accelerates the development process, supports regulatory decision making, and ultimately improves the clinical outcomes of siRNA-based therapies, fostering advancements in precision medicine across a diverse range of diseases.

Gene therapy in pediatrics - Clinical studies and approved drugs (as of 2023)

Gene therapy in pediatrics represents a cutting-edge therapeutic strategy for treating a range of genetic disorders that manifest in childhood. Gene therapy involves the modification or correction of a mutated gene or the introduction of a functional gene into a patient's cells. In general, it is implemented through two main modalities namely ex vivo gene therapy and in vivo gene therapy. Currently, a noteworthy array of gene therapy products has received valid market authorization, with several others in various stages of the approval process. Additionally, a multitude of clinical trials are actively underway, underscoring the dynamic progress within this field. Pediatric genetic disorders in the fields of hematology, oncology, vision and hearing loss, immunodeficiencies, neurological, and metabolic disorders are areas for gene therapy interventions. This review provides a comprehensive overview of the evolution and current progress of gene therapy-based treatments in the clinic for pediatric patients. It navigates the historical milestones of gene therapies, currently approved gene therapy products by the U.S. Food and Drug Administration (FDA) and/or European Medicines Agency (EMA) for children, and the promising future for genetic disorders. By providing a thorough compilation of approved gene therapy drugs and published results of completed or ongoing clinical trials, this review serves as a guide for pediatric clinicians to get a quick overview of the situation of clinical studies and approved gene therapy products as of 2023.

Inclisiran: the preclinical discovery and development of a novel therapy for the treatment of atherosclerosis

INTRODUCTION

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of global morbidity and mortality. Lipid lowering therapy (LLT) constitutes the cornerstone of ASCVD prevention and treatment. However, several patients fail to achieve therapeutic goals due to low treatment adherence or limitations of standard-of-care (SoC) LLTs. Inclisiran represents a pivotal low-density lipoprotein cholesterol (LDL-C) lowering agent aiming to address current unmet needs in LLT. It is the first available small interfering RNA (siRNA) LLT, specifically targeting PCSK9 mRNA and leading to post-transcriptional gene silencing (PTGS) of the PCSK9 gene.

AREAS COVERED

Promising phase III trials revealed an ~ 50% reduction in LDL-C levels with subcutaneous inclisiran administration on days 1 and 90, followed by semiannual booster shots. Coupled with inclisiran's favorable safety profile, these findings led to its approval by both the EMA and FDA. Herein, the authors highlight the preclinical discovery and development of this agent and provide the reader with their expert perspectives.

EXPERT OPINION

The evolution of gene-silencing treatments offers new perspectives in therapeutics. Inclisiran appears to have the potential to revolutionize ASCVD prevention and treatment, benefiting millions of patients. Ensuring widespread availability of Inclisiran, as well as managing additional healthcare costs that may arise, should be of paramount importance.

Ultrasound-Mediated Lysozyme Microbubbles Targeting NOX4 Knockdown Alleviate Cisplatin-Exposed Cochlear Hair Cell Ototoxicity

The nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) protein plays an essential role in the cisplatin (CDDP)-induced generation of reactive oxygen species (ROS). In this study, we evaluated the suitability of ultrasound-mediated lysozyme microbubble (USMB) cavitation to enhance NOX4 siRNA transfection in vitro and ex vivo. Lysozyme-shelled microbubbles (LyzMBs) were constructed and designed for siNOX4 loading as siNOX4/LyzMBs. We investigated different siNOX4-based cell transfection approaches, including naked siNOX4, LyzMB-mixed siNOX4, and siNOX4-loaded LyzMBs, and compared their silencing effects in CDDP-treated HEI-OC1 cells and mouse organ of Corti explants. Transfection efficiencies were evaluated by quantifying the cellular uptake of cyanine 3 (Cy3) fluorescein-labeled siRNA. In vitro experiments showed that the high transfection efficacy (48.18%) of siNOX4 to HEI-OC1 cells mediated by US and siNOX4-loaded LyzMBs significantly inhibited CDDP-induced ROS generation to almost the basal level. The ex vivo CDDP-treated organ of Corti explants of mice showed an even more robust silencing effect of the NOX4 gene in the siNOX4/LyzMB groups treated with US sonication than without US sonication, with a marked abolition of CDDP-induced ROS generation and cytotoxicity. Loading of siNOX4 on LyzMBs can stabilize siNOX4 and prevent its degradation, thereby enhancing the transfection and silencing effects when combined with US sonication. This USMB-derived therapy modality for alleviating CDDP-induced ototoxicity may be suitable for future clinical applications.

Multicompartment Polyion Complex Micelles Based on Triblock Polypept(o)ides Mediate Efficient siRNA Delivery to Cancer-Associated Fibroblasts for Antistromal Therapy of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent type of primary liver cancer and the third leading cause for cancer-related death worldwide. The tumor is difficult-to-treat due to its inherent resistance to chemotherapy. Antistromal therapy is a novel therapeutic approach, targeting cancer-associated fibroblasts (CAF) in the tumor microenvironment. CAF-derived microfibrillar-associated protein 5 (MFAP-5) is identified as a novel target for antistromal therapy of HCC with high translational relevance. Biocompatible polypept(o)ide-based polyion complex micelles (PICMs) constructed with a triblock copolymer composed of a cationic poly(l-lysine) complexing anti-MFAP-5 siRNA (siMFAP-5) via electrostatic interaction, a poly(γ-benzyl-l-glutamate) block loading cationic amphiphilic drug desloratatine (DES) via π-π interaction as endosomal escape enhancer and polysarcosine poly(N-methylglycine) for introducing stealth properties, are generated for siRNA delivery. Intravenous injection of siMFAP-5/DES PICMs significantly reduces the hepatic tumor burden in a syngeneic implantation model of HCC, with a superior MFAP-5 knockdown effect over siMFAP-5 PICMs or lipid nanoparticles. Transcriptome and histological analysis reveal that MFAP-5 knockdown inhibited CAF-related tumor vascularization, suggesting the anti-angiogenic effect of RNA interference therapy. In conclusion, multicompartment PICMs combining siMFAP-5 and DES in a single polypept(o)ide micelle induce a specific knockdown of MFAP-5 and demonstrate a potent antitumor efficacy (80% reduced tumor burden vs untreated control) in a clinically relevant HCC model.

siRNA therapy in osteoarthritis: targeting cellular pathways for advanced treatment approaches

Osteoarthritis (OA) is a common joint disorder characterized by the degeneration of cartilage and inflammation, affecting millions worldwide. The disease's complex pathogenesis involves various cell types, such as chondrocytes, synovial cells, osteoblasts, and immune cells, contributing to the intricate interplay of factors leading to tissue degradation and pain. RNA interference (RNAi) therapy, particularly through the use of small interfering RNA (siRNA), emerges as a promising avenue for OA treatment due to its capacity for specific gene silencing. siRNA molecules can modulate post-transcriptional gene expression, targeting key pathways involved in cellular proliferation, apoptosis, senescence, autophagy, biomolecule secretion, inflammation, and bone remodeling. This review delves into the mechanisms by which siRNA targets various cell populations within the OA milieu, offering a comprehensive overview of the potential therapeutic benefits and challenges in clinical application. By summarizing the current advancements in siRNA delivery systems and therapeutic targets, we provide a solid theoretical foundation for the future development of novel siRNA-based strategies for OA diagnosis and treatment, paving the way for innovative and more effective approaches to managing this debilitating disease.

siRNA-based therapy for gastric adenocarcinoma: what's next step?

Gastric cancer continues to have a high death rate despite advancements in their diagnosis and treatment. Novel treatment techniques are thus desperately needed. This is where double-stranded RNA molecules known as small interfering RNA (siRNA), which may selectively target the mRNA of disease-causing genes, may find use in medicine. For siRNAs to function properly in the human body, they must be shielded from deterioration. Furthermore, in order to maintain organ function, they must only target the tumor and spare normal tissue. siRNAs have been designed using clever delivery mechanisms including polymers and lipids to achieve these objectives. Although siRNA protection is not hard to acquire, it is still challenging to target cancer cells with them. Here, we first discuss the basic characteristics of gastric cancer before describing the properties of siRNA and typical delivery methods created specifically for gastric tumors. Lastly, we provide a succinct overview of research using siRNAs to treat gastric tumors.

Small interfering RNA (siRNA) as a potential gene silencing strategy for diabetes and associated complications: challenges and future perspectives

Objective

This article critically reviews the recent search on the use of Small Interfering RNA (siRNA) in the process of gene regulation that has been harnessed to silence specific genes in various cell types, including those involved in diabetes complications.

Significance

Diabetes, a prevalent and severe condition, poses life-threatening risks due to elevated blood glucose levels. It results from inadequate insulin production by the pancreas or ineffective insulin utilization by the body. Recent research suggests siRNA could hold promise in addressing diabetes complications.

Methods

In this review, we discussed several subjects, including diabetes; its function, and common treatment options. An in-depth analysis of gene silencing method for siRNA and role of siRNA in diabetes, focusing on its impact on glucose homeostasis, diabetic retinopathy, wound healing, diabetic nephropathy and peripheral neuropathy, diabetic foot ulcers, diabetic atherosclerosis, and diabetic cardiomyopathy.

Result

siRNA-based treatment has the potential to target specific genes without disrupting several other endogenous pathways, which decreases the risk of off-target effects. In addition, siRNA has the capability to provide long-term efficacy with a single dose which will reduce treatment options and enhance patient compliance.

Conclusion

In the context of diabetic complications, siRNA has been explored as a potential therapeutic tool to modulate the expression of genes involved in various processes associated with diabetes-related issues such as Diabetic Retinopathy, Neuropathy, Nephropathy, wound healing. The use of siRNA in these contexts is still largely experimental, and challenges such as delivery to specific tissues, potential off-target effects, and long-term safety need to be addressed. Additionally, the development of siRNA-based therapies for clinical use in diabetic complications is an active area of research.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01405-7.

siRNA incorporated in slow-release injectable hydrogel continuously silences DDIT4 and regulates nucleus pulposus cell pyroptosis through the ROS/TXNIP/NLRP3 axis to alleviate intervertebral disc degeneration

Aims

In this investigation, we administered oxidative stress to nucleus pulposus cells (NPCs), recognized DNA-damage-inducible transcript 4 (DDIT4) as a component in intervertebral disc degeneration (IVDD), and devised a hydrogel capable of conveying small interfering RNA (siRNA) to IVDD.

Methods

An in vitro model for oxidative stress-induced injury in NPCs was developed to elucidate the mechanisms underlying the upregulation of DDIT4 expression, activation of the reactive oxygen species (ROS)-thioredoxin-interacting protein (TXNIP)-NLRP3 signalling pathway, and nucleus pulposus pyroptosis. Furthermore, the mechanism of action of small interfering DDIT4 (siDDIT4) on NPCs in vitro was validated. A triplex hydrogel named siDDIT4@G5-P-HA was created by adsorbing siDDIT4 onto fifth-generation polyamidoamine (PAMAM) dendrimer using van der Waals interactions, and then coating it with hyaluronic acid (HA). In addition, we established a rat puncture IVDD model to decipher the hydrogel's mechanism in IVDD.

Results

A correlation between DDIT4 expression levels and disc degeneration was shown with human nucleus pulposus and needle-punctured rat disc specimens. We confirmed that DDIT4 was responsible for activating the ROS-TXNIP-NLRP3 axis during oxidative stress-induced pyroptosis in rat nucleus pulposus in vitro. Mitochondria were damaged during oxidative stress, and DDIT4 contributed to mitochondrial damage and ROS production. In addition, siDDIT4@G5-P-HA hydrogels showed good delivery activity of siDDIT4 to NPCs. In vitro studies illustrated the potential of the siDDIT4@G5-P-HA hydrogel for alleviating IVDD in rats.

Conclusion

DDIT4 is a key player in mediating pyroptosis and IVDD in NPCs through the ROS-TXNIP-NLRP3 axis. Additionally, siDDIT4@G5-P-HA hydrogel has been found to relieve IVDD in rats. Our research offers an innovative treatment option for IVDD.

Untacking small RNA profiling and RNA fragment footprinting: Approaches and challenges in library construction

Small RNAs (sRNAs) with sizes ranging from 15 to 50 nucleotides (nt) are critical regulators of gene expression control. Prior studies have shown that sRNAs are involved in a broad range of biological processes, such as organ development, tumorigenesis, and epigenomic regulation; however, emerging evidence unveils a hidden layer of diversity and complexity of endogenously encoded sRNAs profile in eukaryotic organisms, including novel types of sRNAs and the previously unknown post-transcriptional RNA modifications. This underscores the importance for accurate, unbiased detection of sRNAs in various cellular contexts. A multitude of high-throughput methods based on next-generation sequencing (NGS) are developed to decipher the sRNA expression and their modifications. Nonetheless, distinct from mRNA sequencing, the data from sRNA sequencing suffer frequent inconsistencies and high variations emanating from the adapter contaminations and RNA modifications, which overall skew the sRNA libraries. Here, we summarize the sRNA-sequencing approaches, and discuss the considerations and challenges for the strategies and methods of sRNA library construction. The pros and cons of sRNA sequencing have significant implications for implementing RNA fragment footprinting approaches, including CLIP-seq and Ribo-seq. We envision that this review can inspire novel improvements in small RNA sequencing and RNA fragment footprinting in future. This article is categorized under: RNA Evolution and Genomics > Computational Analyses of RNA RNA Processing > Processing of Small RNAs Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs.

New insights into the therapeutic approaches for the treatment of tauopathies

Tauopathies are a group of neurological disorders, including Alzheimer's disease and frontotemporal dementia, which involve progressive neurodegeneration, cognitive deficits, and aberrant tau protein accumulation. The development of tauopathies cannot currently be stopped or slowed down by treatment measures. Given the significant contribution of tau burden in primary tauopathies and the strong association between pathogenic tau accumulation and cognitive deficits, there has been a lot of interest in creating therapies that can alleviate tau pathology and render neuroprotective effects. Recently, small molecules, immunotherapies, and gene therapy have been used to reduce the pathological tau burden and prevent neurodegeneration in animal models of tauopathies. However, the major pitfall of the current therapeutic approach is the difficulty of drugs and gene-targeting modalities to cross the blood-brain barrier and their unintended side effects. In this review, the current therapeutic strategies used for tauopathies including the use of oligonucleotide-based gene therapy approaches that have shown a promising result for the treatment of tauopathies and Alzheimer's disease in preclinical animal models, have been discussed.

A biomimetic camouflaged metal organic framework for enhanced siRNA delivery in the tumor environment

Gene silencing through RNA interference (RNAi), particularly using small double-stranded RNA (siRNA), has been identified as a potent strategy for targeted cancer treatment. Yet, its application faces challenges such as nuclease degradation, inefficient cellular uptake, endosomal entrapment, off-target effects, and immune responses, which have hindered its effective delivery. In the past few years, these challenges have been addressed significantly by using camouflaged metal-organic framework (MOF) nanocarriers. These nanocarriers protect siRNA from degradation, enhance cellular uptake, and reduce unintended side effects by effectively targeting desired cells while evading immune detection. By combining the properties of biomimetic membranes and MOFs, these nanocarriers offer superior benefits such as extended circulation times, enhanced stability, and reduced immune responses. Moreover, through ligand-receptor interactions, biomimetic membrane-coated MOFs achieve homologous targeting, minimizing off-target adverse effects. The MOFs, acting as the core, efficiently encapsulate and protect siRNA molecules, while the biomimetic membrane-coated surface provides homologous targeting, further increasing the precision of siRNA delivery to cancer cells. In particular, the biomimetic membranes help to shield the MOFs from the immune system, avoiding unwanted immune responses and improving their biocompatibility. The combination of siRNA with innovative nanocarriers, such as camouflaged-MOFs, presents a significant advancement in cancer therapy. The ability to deliver siRNA with precision and effectiveness using these camouflaged nanocarriers holds great promise for achieving more personalized and efficient cancer treatments in the future. This review article discusses the significant progress made in the development of siRNA therapeutics for cancer, focusing on their effective delivery through novel nanocarriers, with a particular emphasis on the role of metal-organic frameworks (MOFs) as camouflaged nanocarriers.

Nucleic acids based integrated macromolecular complexes for SiRNA delivery: Recent advancements

The therapeutic potential of small interfering RNA (siRNA) is monumental, offering a pathway to silence disease-causing genes with precision. However, the delivery of siRNA to target cells in-vivo remains a formidable challenge, owing to degradation by nucleases, poor cellular uptake and immunogenicity. This overview examines recent advancements in the design and application of nucleic acid-based integrated macromolecular complexes for the efficient delivery of siRNA. We dissect the innovative delivery vectors developed in recent years, including lipid-based nanoparticles, polymeric carriers, dendrimer complexes and hybrid systems that incorporate stimuli-responsive elements for targeted and controlled release. Advancements in bioconjugation techniques, active targeting strategies and nanotechnology-enabled delivery platforms are evaluated for their contribution to enhancing siRNA delivery. It also addresses the complex interplay between delivery system design and biological barriers, highlighting the dynamic progress and remaining hurdles in translating siRNA therapies from bench to bedside. By offering a comprehensive overview of current strategies and emerging technologies, we underscore the future directions and potential impact of siRNA delivery systems in personalized medicine.

Lipid nanoparticles for RNA delivery: Self-assembling vs driven-assembling strategies

Among non-viral vectors, lipid nanovectors are considered the gold standard for the delivery of RNA therapeutics. The success of lipid nanoparticles for RNA delivery, with three products approved for human use, has stimulated further investigation into RNA therapeutics for different pathologies. This requires decoding the pathological intracellular processes and tailoring the delivery system to the target tissue and cells. The complexity of the lipid nanovectors morphology originates from the assembling of the lipidic components, which can be elicited by various methods able to drive the formation of nanoparticles with the desired organization. In other cases, pre-formed nanoparticles can be mixed with RNA to induce self-assembly and structural reorganization into RNA-loaded nanoparticles. In this review, the most relevant lipid nanovectors and their potentialities for RNA delivery are described on the basis of the assembling mechanism and of the particle architecture.

Navigating the future: Microfluidics charting new routes in drug delivery

Microfluidics has emerged as a transformative force in the field of drug delivery, offering innovative avenues to produce a diverse range of nano drug delivery systems. Thanks to its precise manipulation of small fluid volumes and its exceptional command over the physicochemical characteristics of nanoparticles, this technology is notably able to enhance the pharmacokinetics of drugs. It has initiated a revolutionary phase in the domain of drug delivery, presenting a multitude of compelling advantages when it comes to developing nanocarriers tailored for the delivery of poorly soluble medications. These advantages represent a substantial departure from conventional drug delivery methodologies, marking a paradigm shift in pharmaceutical research and development. Furthermore, microfluidic platformsmay be strategically devised to facilitate targeted drug delivery with the objective of enhancing the localized bioavailability of pharmaceutical substances. In this paper, we have comprehensively investigated a range of significant microfluidic techniques used in the production of nanoscale drug delivery systems. This comprehensive review can serve as a valuable reference and offer insightful guidance for the development and optimization of numerous microfluidics-fabricated nanocarriers.

Polymer-lipid hybrid nanomedicines to deliver siRNA in and against glioblastoma cells

Small interfering RNA (siRNA) holds great potential to treat many difficult-to-treat diseases, but its delivery remains the central challenge. This study aimed at investigating the suitability of polymer-lipid hybrid nanomedicines (HNMeds) as novel siRNA delivery platforms for locoregional therapy of glioblastoma. Two HNMed formulations were developed from poly(lactic-co-glycolic acid) polymer and a cationic lipid: 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) or 3ß-[N-(N',N'-dimethylaminoethane)-carbamoyl]cholesterol (DC-Chol). After characterization of the HNMeds, a model siRNA was complexed onto their surface to form HNMed/siRNA complexes. The physicochemical properties and siRNA binding ability of complexes were assessed over a range of nitrogen-to-phosphate (N/P) ratios to optimize the formulations. At the optimal N/P ratio of 10, complexes effectively bound siRNA and improved its protection from enzymatic degradation. Using the NIH3T3 mouse fibroblast cell line, DOTAP-based HNMeds were shown to possess higher cytocompatibility in vitro over the DC-Chol-based ones. As proof-of-concept, uptake and bioefficacy of formulations were also assessed in vitro on U87MG human glioblastoma cell line expressing luciferase gene. Complexes were able to deliver anti-luciferase siRNA and induce a remarkable suppression of gene expression. Noteworthy, the effect of DOTAP-based formulation was not only about three-times higher than DC-Chol-based one, but also comparable to lipofectamine model transfection reagent. These findings set the basis to exploit this nanosystem for silencing relevant GB-related genes in further in vitro and in vivo studies.

Co-delivery of siBcl-2 and PTX with mitochondria-targeted functions to overcoming multidrug resistance

Multidrug resistance (MDR) poses a significant impediment to the efficacy of chemotherapy in clinical settings. Despite Paclitaxel (PTX) being designated as the primary pharmaceutical agent for treating recurrent and metastatic breast cancer, the emergence of PTX resistance frequently results in therapeutic shortcomings, representing a substantial obstacle in clinical breast cancer management. In response, we developed a delivery system exhibiting dual specificity for both tumors and mitochondria. This system facilitated the sequential administration of small interfering B-cell lymphoma-2 (siBcl-2) and PTX to the tumor cytoplasm and mitochondria, respectively, with the aim of surmounting PTX resistance in tumor cells through the activation of the mitochondrial apoptosis pathway. Notably, we employed genetic engineering techniques to fabricate a recombinant ferritin containing the H-subunit (HFn), known for its tumor-targeting capabilities, for loading siBcl-2. This HFn-siBcl-2 complex was then combined with positively charged Triphenylphosphine-Liposome@PTX (TL@PTX) nanoparticles (NPs) to formulate HFn/siBcl-2@TL/PTX. Guided by HFn, these nanoparticles efficiently entered cells and released siBcl-2 through the action of triphenylphosphine (TPP)-mediated "proton sponge," thereby precisely modulating the expression of Bcl-2 protein. Simultaneously, PTX was directed to the mitochondria through the accurate targeting of TL@PTX, synergistically initiating the mitochondrial apoptosis pathway and effectively suppressing PTX resistance both in vitro and in vivo. In conclusion, the development of this dual-targeting delivery system presents a promising therapeutic strategy for overcoming PTX resistance in the clinical treatment of breast cancer.

Biological functions and clinical significance of tRNA-derived small fragment (tsRNA) in tumors: Current state and future perspectives

A new class of noncoding RNAs, tsRNAs are not only abundant in humans but also have high tissue specificity. Recently, an increasing number of studies have explored the correlations between tsRNAs and tumors, showing that tsRNAs can affect biological behaviors of tumor cells, such as proliferation, apoptosis and metastasis, by modulating protein translation, RNA transcription or posttranscriptional regulation. In addition, tsRNAs are widely distributed and stably expressed, which endows them with broad application prospects in diagnosing and predicting the prognosis of tumors, and they are expected to become new biomarkers. However, notably, the current research on tsRNAs still faces problems that need to be solved. In this review, we describe the characteristics of tsRNAs as well as their unique features and functions in tumors. Moreover, we also discuss the potential opportunities and challenges in clinical applications and research of tsRNAs.

Monocytic microRNAs-Novel targets in atherosclerosis therapy

Atherosclerosis is a chronic proinflammatory disease of the vascular wall resulting in narrowing of arteries due to plaque formation, thereby causing reduced blood supply that is the leading cause for diverse end-organ damage with high mortality rates. Monocytes/macrophages, activated by elevated circulating lipoproteins, are significantly involved in the formation and development of atherosclerotic plaques. The imbalance between proinflammatory and anti-inflammatory macrophages, arising from dysregulated macrophage polarization, appears to be a driving force in this process. Proatherosclerotic processes acting on monocytes/macrophages include accumulation of cholesterol in macrophages leading to foam cell formation, as well as dysfunctional efferocytosis, all of which contribute to the formation of unstable plaques. In recent years, microRNAs (miRs) were identified as factors that could modulate monocyte/macrophage function and may therefore interfere with the atherosclerotic process. In this review, we present effects of monocyte/macrophage-derived miRs on atherosclerotic processes in order to reveal new treatment options using miRmimics or antagomiRs.

The current perspective and opportunities of small nucleic acid-based therapeutics

Compared to traditional small molecule and antibody drugs, RNA-based drugs offer a simple design, short research and development cycles, high specificity, broad treatment fields, and long-term efficacy. As a result, RNA-based drugs are extensively used to treat genetic diseases, tumors, viral infections, and other illnesses, suggesting that they have the potential to become the third-largest drug class after small molecule and antibody drugs. Currently, more than 10 small nucleic acid drugs have gained regulatory approval. The commercialization successes of small nucleic acid drugs will stimulate the development of RNA-based drugs. Small nucleic acid drugs primarily target liver diseases, metabolic diseases, genetic diseases, and tumors, and there is also significant potential for expanding indications in the future. This review provides a brief overview of the advantages and development of small nucleic acid-based therapeutics and shows a focus on platform technologies such as chemical modifications and delivery systems that have enabled the clinical translation of small nucleic acid-based therapeutics. Additionally, we summarize the latest clinical progress in small nucleic acid-based therapeutics for the treatment of various diseases, including rare diseases, liver diseases, metabolic diseases, and tumors. Finally, we highlight the future prospects for this promising treatment approach.

Cm-siRPred: Predicting chemically modified siRNA efficiency based on multi-view learning strategy

The rational modification of siRNA molecules is crucial for ensuring their drug-like properties. Machine learning-based prediction of chemically modified siRNA (cm-siRNA) efficiency can significantly optimize the design process of siRNA chemical modifications, saving time and cost in siRNA drug development. However, existing in-silico methods suffer from limitations such as small datasets, inadequate data representation capabilities, and lack of interpretability. Therefore, in this study, we developed the Cm-siRPred algorithm based on a multi-view learning strategy. The algorithm employs a multi-view strategy to represent the double-strand sequences, chemical modifications, and physicochemical properties of cm-siRNA. It incorporates a cross-attention model to globally correlate different representation vectors and a two-layer CNN module to learn local correlation features. The algorithm demonstrates exceptional performance in cross-validation experiments, independent dataset, and case studies on approved siRNA drugs, and showcasing its robustness and generalization ability. In addition, we developed a user-friendly webserver that enables efficient prediction of cm-siRNA efficiency and assists in the design of siRNA drug chemical modifications. In summary, Cm-siRPred is a practical tool that offers valuable technical support for siRNA chemical modification and drug efficiency research, while effectively assisting in the development of novel small nucleic acid drugs. Cm-siRPred is freely available at https://cellknowledge.com.cn/sirnapredictor/.

The role of ncRNAs in depression

Depressive disorders have a significant impact on public health, and depression have an unsatisfactory recurrence rate and are challenging to treat. Non-coding RNAs (ncRNAs) are RNAs that do not code protein, which have been shown to be crucial for transcriptional regulation. NcRNAs are important to the onset, progress and treatment of depression because they regulate various physiological functions. This makes them distinctively useful as biomarkers for diagnosing and tracking responses to therapy among individuals with depression. It is important to seek out and summarize the research findings on the impact of ncRNAs on depression since significant advancements have been made in this area recently. Hence, we methodically outlined the findings of published researches on ncRNAs and depression, focusing on microRNAs. Above all, this review aims to improve our understanding of ncRNAs and provide new insights of the diagnosis and treatment of depression.

Treatment with siRNAs is commonly associated with GPX4 up-regulation and target knockdown-independent sensitization to ferroptosis

Small interfering RNAs (siRNAs) are widely used in biomedical research and in clinical trials. Here, we demonstrate that siRNA treatment is commonly associated with significant sensitization to ferroptosis, independently of the target protein knockdown. Genetically targeting mitochondrial antiviral-signaling protein (MAVS) reversed the siRNA-mediated sensitizing effect, but no activation of canonical MAVS signaling, which involves phosphorylation of IkBα and interferon regulatory transcription factor 3 (IRF3), was observed. In contrast, MAVS mediated a noncanonical signal resulting in a prominent increase in mitochondrial ROS levels, and increase in the BACH1/pNRF2 transcription factor ratio and GPX4 up-regulation, which was associated with a 50% decrease in intracellular glutathione levels. We conclude that siRNAs commonly sensitize to ferroptosis and may severely compromise the conclusions drawn from silencing approaches in biomedical research. Finally, as ferroptosis contributes to a variety of pathophysiological processes, we cannot exclude side effects in human siRNA-based therapeutical concepts that should be clinically tested.

Liver fibrosis pathologies and potentials of RNA based therapeutics modalities

Liver fibrosis (LF) occurs when the liver tissue responds to injury or inflammation by producing excessive amounts of scar tissue, known as the extracellular matrix. This buildup stiffens the liver tissue, hinders blood flow, and ultimately impairs liver function. Various factors can trigger this process, including bloodborne pathogens, genetic predisposition, alcohol abuse, non-steroidal anti-inflammatory drugs, non-alcoholic steatohepatitis, and non-alcoholic fatty liver disease. While some existing small-molecule therapies offer limited benefits, there is a pressing need for more effective treatments that can truly cure LF. RNA therapeutics have emerged as a promising approach, as they can potentially downregulate cytokine levels in cells responsible for liver fibrosis. Researchers are actively exploring various RNA-based therapeutics, such as mRNA, siRNA, miRNA, lncRNA, and oligonucleotides, to assess their efficacy in animal models. Furthermore, targeted drug delivery systems hold immense potential in this field. By utilizing lipid nanoparticles, exosomes, nanocomplexes, micelles, and polymeric nanoparticles, researchers aim to deliver therapeutic agents directly to specific biomarkers or cytokines within the fibrotic liver, increasing their effectiveness and reducing side effects. In conclusion, this review highlights the complex nature of liver fibrosis, its underlying causes, and the promising potential of RNA-based therapeutics and targeted delivery systems. Continued research in these areas could lead to the development of more effective and personalized treatment options for LF patients.