Nanoparticles and siRNA: A new era in therapeutics?

Nanocarrier-mediated siRNA delivery: a new approach for the treatment of traumatic brain injury-related Alzheimer's disease

Traumatic brain injury and Alzheimer's disease share pathological similarities, including neuronal loss, amyloid-β deposition, tau hyperphosphorylation, blood-brain barrier dysfunction, neuroinflammation, and cognitive deficits. Furthermore, traumatic brain injury can exacerbate Alzheimer's disease-like pathologies, potentially leading to the development of Alzheimer's disease. Nanocarriers offer a potential solution by facilitating the delivery of small interfering RNAs across the blood-brain barrier for the targeted silencing of key pathological genes implicated in traumatic brain injury and Alzheimer's disease. Unlike traditional approaches to neuroregeneration, this is a molecular-targeted strategy, thus avoiding non-specific drug actions. This review focuses on the use of nanocarrier systems for the efficient and precise delivery of siRNAs, discussing the advantages, challenges, and future directions. In principle, siRNAs have the potential to target all genes and non-targetable proteins, holding significant promise for treating various diseases. Among the various therapeutic approaches currently available for neurological diseases, siRNA gene silencing can precisely "turn off" the expression of any gene at the genetic level, thus radically inhibiting disease progression; however, a significant challenge lies in delivering siRNAs across the blood-brain barrier. Nanoparticles have received increasing attention as an innovative drug delivery tool for the treatment of brain diseases. They are considered a potential therapeutic strategy with the advantages of being able to cross the blood-brain barrier, targeted drug delivery, enhanced drug stability, and multifunctional therapy. The use of nanoparticles to deliver specific modified siRNAs to the injured brain is gradually being recognized as a feasible and effective approach. Although this strategy is still in the preclinical exploration stage, it is expected to achieve clinical translation in the future, creating a new field of molecular targeted therapy and precision medicine for the treatment of Alzheimer's disease associated with traumatic brain injury.

Chitosan nanovectors for siRNA delivery: New horizons for nonviral gene therapy

The growing interest in RNA-based therapeutics has positioned small interfering RNA (siRNA) as a promising tool for gene silencing with high specificity and efficacy. However, the successful clinical application of siRNA therapies requires efficient delivery systems to overcome extracellular and intracellular barriers. Chitosan, a naturally derived polysaccharide, has gained significant attention as a non-viral vector due to its biodegradability, biocompatibility, mucoadhesive properties, and capacity to enhance cellular uptake. These attributes make chitosan an attractive alternative to lipid-based nanoparticles, which currently dominate siRNA delivery platforms. Recent advancements in chitosan-based nanoformulations, including chemical modifications and functionalization strategies, have improved siRNA stability, targeting efficiency, and transfection potential, addressing key limitations such as low bioavailability and immunogenicity. Despite these advances, challenges remain in achieving optimal release kinetics, scalability, and consistent therapeutic efficacy. Future research efforts will focus on engineering chitosan derivatives with enhanced physicochemical properties, integrating multifunctional nanocarriers, and refining formulation strategies to bridge the gap between preclinical research and clinical translation. The continued development of chitosan-based siRNA therapeutics holds significant potential for advancing precision medicine and expanding treatment options for a variety of diseases, including cancer, metabolic disorders, and inflammatory conditions.

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.

siRNA-based delivery systems: Technologies, carriers, applications, and approved products

Ribonucleic acid (RNA) therapeutics are a novel category of therapeutic agents that use different types of RNAs to regulate genes and modulate protein synthesis to treat a wide range of diseases. The main advantages of RNA therapeutics over conventional small molecule drugs would be the potential to target undruggable sites, ease of production and faster development process, and longer duration of action. Various types of RNA therapeutics including antisense oligonucleotides (ASO), RNA interference (RNAi), small interfering RNA (siRNA), microRNA (miRNA), and messenger RNA (mRNA), have been developed and used for various clinical applications, especially for gene and vaccine delivery purposes. This review is focused on various therapeutic applications of RNA-based delivery systems and then siRNA technologies are discussed in more detail. Next, the FDA-approved siRNA therapeutics and those are in clinical trials are listed and summarized. Then, various viral and non-viral vectors used for RNA delivery purposes are discussed. Finally, clinical applications of siRNA therapeutics are reviewed in detail.

ncRNAs as Key Regulators in Gastric Cancer: From Molecular Subtyping to Therapeutic Targets

Gastric cancer (GC) poses a major global health challenge, underscoring the need for advanced diagnostic and therapeutic approaches. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), have emerged as pivotal regulators in GC, with their dysregulated expression driving key processes such as tumorigenesis, metastasis, immune evasion, and chemoresistance. The functional diversity of ncRNAs across different GC molecular subtypes highlights their potential as biomarkers for improved subtype classification and patient stratification. Beyond their diagnostic value, ncRNAs demonstrate critical regulatory functions in tumor biology, establishing these RNA molecules as promising targets for therapeutic development. Strategies based on RNA hold considerable promise for addressing critical challenges such as immune escape and drug resistance by modulating key signaling pathways. These approaches can enhance immune responses, reprogram the tumor microenvironment, and reverse resistance mechanisms that compromise treatment efficacy, thereby improving clinical outcomes. Although ncRNAs represent a promising frontier in GC precision medicine, further research is required to fully harness their clinical potential.

Lipid-based nano-carriers for the delivery of anti-obesity natural compounds: advances in targeted delivery and precision therapeutics

Obesity is a major global health challenge, contributing to metabolic disorders such as type 2 diabetes, cardiovascular diseases, and hypertension. The increasing prevalence of obesity, driven by sedentary lifestyles, poor dietary habits, and genetic predisposition, underscores the urgent need for effective therapeutic strategies. Conventional pharmacological treatments, including appetite suppressants and metabolic modulators, often fail to provide sustainable weight loss due to side effects, poor adherence, and limited long-term efficacy. As a result, natural bioactive compounds have gained attention for their anti-obesity potential. However, their clinical application is hindered by poor bioavailability, rapid metabolism, and inefficient delivery. Lipid-based nano-carriers, including liposomes, solid lipid nanoparticles, and nanostructured lipid carriers, offer a promising solution by enhancing the solubility, stability, and targeted delivery of these compounds. These advanced delivery systems improve bioactive retention, enable controlled release, and enhance therapeutic action on adipose tissue and metabolic pathways. Additionally, functionalized and stimulus-responsive nanocarriers present innovative approaches for precision obesity treatment. Despite these advancements, challenges remain in large-scale production, regulatory approval, and long-term safety. Overcoming these barriers is critical to ensuring the successful clinical translation of nano-formulated therapies. This review explores the potential of lipid-based nano-carriers in optimizing the therapeutic efficacy of natural anti-obesity compounds and highlights their role in advancing next-generation obesity management strategies.

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.

Red Blood Cell Membrane Vesicles for siRNA Delivery: A Biocompatible Carrier With Passive Tumor Targeting and Prolonged Plasma Residency

Background

Despite many advances in gene therapy, the delivery of small interfering RNAs is still challenging. Erythrocytes are the most abundant cells in the human body, and their membrane possesses unique features. From them, erythrocytes membrane vesicles can be generated, employable as nano drug delivery system with prolonged blood residence and high biocompatibility.

Methods

Human erythrocyte ghosts were extruded in the presence of siRNA, and the objects were termed EMVs (erythrocyte membrane vesicles). An ultracentrifugation-based method was applied to select only the densest EMVs, ie, those containing siRNA. We evaluated their activity in vitro in B16F10 cells expressing fluorescent tdTomato and in vivo in B16F10 tumor-bearing mice after a single injection.

Results

The EMVs had a negative zeta potential, a particle size of 170 nm and excellent colloidal stability after one month of storage. With 0.3 nM siRNA, more than 75% gene knockdown was achieved in vitro, and 80% was achieved in vivo, at 2 days PI at 2.5 mg/kg. EMVs mostly accumulate around blood vessels in the lungs, brain and tumor. tdTomato fluorescence steadily decreased in tumor areas with higher EMVs concentration, which indicates efficient gene knockdown. Approximately 2% of the initial dose of EMVs was still present in the plasma after 2 days.

Conclusion

The entire production process of the purified siRNA-EMVs took approximately 4 hours. The erythrocyte marker CD47 offered protection against macrophage recognition in the spleen and in the blood. The excellent biocompatibility and pharmacokinetic properties of these materials make them promising platforms for future improvements, ie, active targeting and codelivery with conventional chemotherapeutics.

Shielding siRNA by peptide-based nanofibers: An efficient approach for turning off EGFR gene in breast cancer

Peptide-based self-assembled nanosystems show great promise as non-viral gene and siRNA delivery vectors. In the current study, we designed and functionalized nanofibers for the delivery of siRNA, targeting and silencing EGFR gene overexpressed in triple-negative breast cancer. The nanofiber-mediated siRNA delivery was characterized in terms of zeta potential, morphology, and structural stability by circular dichroism spectroscopy. In cytotoxicity studies, nanofibers presented high biocompatibility showing a negligible effect on cell viability both on healthy and cancer cell lines. The binding between nanofibers and EGFR-siRNA was investigated and ascertained by performing different biophysical studies. The complex siRNA:NF was stable over time, under fetal bovine serum, temperature and ionic strength effects. Moreover, nanofibers effectiveness in stabilizing and delivering an ad hoc selected siRNA for EGFR gene expression silencing was verified in a preclinical model of triple-negative breast cancer. Specifically, a significant gene knockdown was obtained with the complex siRNA:NF, that is comparable with the effect obtained by lipofectamine/siRNA transfection. This effective gene silencing derived from the successful internalization of nanofibers by cancer cells as observed by confocal microscopy. These results suggested that this peptide-based nanofiber could be an effective and safe systemic siRNA delivery system for application in biomedical areas.

Innovative lipid nanoparticles: A cutting-edge approach for potential renal cell carcinoma therapeutics

The kidney plays a crucial role in regulating homeostasis within the human body. Renal cell carcinoma (RCC) is the most common form of kidney cancer, accounting for nearly 90 % of all renal malignancies. Despite the availability of various therapeutic strategies, RCC remains a challenging disease due to its resistance to conventional treatments. Nanotechnology has emerged as a promising field, offering new opportunities in cancer therapeutics. It presents several advantages over traditional methods, enabling diverse biomedical applications, including drug delivery, prevention, diagnosis, and treatment. Lipid nanoparticles (LNPs), approximately 100 nm in size, are derived from a range of lipids and other biochemical compounds. these particulates are designed to overcome biological barriers, allowing them to selectively accumulate at diseased target sites for effective therapeutic action. Many pharmaceutically important compounds face challenges such as poor solubility in aqueous solutions, chemical and physiological instability, or toxicity. LNP technology stands out as a promising drug delivery system for bioactive organic compounds. This article reviews the applications of LNPs in RCC treatment and explores their potential clinical translation, identifying the most viable LNPs for medical use. With ongoing advancement in LNP-based anticancer strategies, there is a growing potential to improve the management and treatment of renal cancer.

Circular RNAs in programmed cell death: Regulation mechanisms and potential clinical applications in cancer: A review

Circular RNAs (circRNAs) are a novel class of non-coding RNAs with covalently closed structures formed by reverse splicing of precursor mRNAs. The widespread expression of circRNAs across species has been revealed by high-throughput sequencing and bioinformatics approaches, indicating their unique properties and diverse functions including acting as microRNA sponges and interacting with RNA-binding proteins. Programmed cell death (PCD), encompassing various forms such as apoptosis, necroptosis, pyroptosis, autophagy, and ferroptosis, is an essential process for maintaining normal development and homeostasis in the human body by eliminating damaged, infected, and aging cells. Many studies have demonstrated that circRNAs play crucial roles in tumourigenesis and development by regulating PCD in tumor cells, showing that circRNAs have the potential to be biomarkers and therapeutic targets in cancer. This review aims to comprehensively summarize the intricate associations between circRNAs and diverse PCD pathways in tumor cells, which play crucial roles in cancer development. Additionally, this review provides a detailed overview of the underlying mechanisms by which circRNAs modulate various forms of PCD for the first time. The ultimate objective is to offer valuable insights into the potential clinical significance of developing novel strategies based on circRNAs and PCD for cancer diagnosis, prognosis, and treatment.

In Vivo Applications of Dendrimers: A Step toward the Future of Nanoparticle-Mediated Therapeutics

Over the last few years, the development of nanotechnology has allowed for the synthesis of many different nanostructures with controlled sizes, shapes, and chemical properties, with dendrimers being the best-characterized of them. In this review, we present a succinct view of the structure and the synthetic procedures used for dendrimer synthesis, as well as the cellular uptake mechanisms used by these nanoparticles to gain access to the cell. In addition, the manuscript reviews the reported in vivo applications of dendrimers as drug carriers for drugs used in the treatment of cancer, neurodegenerative diseases, infections, and ocular diseases. The dendrimer-based formulations that have reached different phases of clinical trials, including safety and pharmacokinetic studies, or as delivery agents for therapeutic compounds are also presented. The continuous development of nanotechnology which makes it possible to produce increasingly sophisticated and complex dendrimers indicates that this fascinating family of nanoparticles has a wide potential in the pharmaceutical industry, especially for applications in drug delivery systems, and that the number of dendrimer-based compounds entering clinical trials will markedly increase during the coming years.