siRNA Delivery System Research Articles

Targeting SLITRK4 Restrains Proliferation and Liver Metastasis in Colorectal Cancer via Regulating PI3K/AKT/NFκB Pathway and Tumor-Associated Macrophage.

Liver metastasis is the major cause of death in colorectal cancer (CRC) due to the lack of effective treatment. To explore novel drivers of CRC liver metastasis, the transcriptomes of primary paracancerous, colorectal tumors and metastases from human patients are profiled. It is found that SLIT- and NTRK-like family member 4 (SLITRK4) is the top upregulated gene in liver metastases and is associated with worse overall survival of CRC patients. Multiple in vitro and in vivo models suggested SLITRK4 promoted CRC tumorigenesis, invasion, migration, and angiogenesis, and inhibition of it restrained CRC tumor growth and liver metastasis with a more profound effect on the tumor microenvironment (TME). Mechanistically, SLITRK4 overexpression significantly activated the PI3K/AKT/NFκB pathway, regulated extracellular matrix organization, and multiple cytokines expression. Furthermore, the results from coculture models and single-cell RNA sequencing analyses suggested SLITRK4 promoted tumor-associated macrophages (TAMs) infiltration and polarization. In addition, macrophage depletion significantly inhibited SLITRK4-induced liver metastasis in CRC. Finally, pharmacological inhibition of SLITRK4 by using lipid-polymer hybrid nanoparticles (NPs) for systemic siRNA delivery can effectively inhibit CRC liver metastasis. Taken together, these results pinpoint that SLITRK4 regulates CRC tumorigenesis and liver metastasis, and siRNA delivering NPs agents validate the therapeutic potential of targeting SLITRK4 in CRC.

Targeting FAP-positive chondrocytes in osteoarthritis: a novel lipid nanoparticle siRNA approach to mitigate cartilage degeneration

BackgroundOsteoarthritis (OA) is a common joint disease that leads to chronic pain and functional limitations. Recent research has revealed soluble fibroblast activation protein (FAP) secreted from OA synovium could degrade type II collagen (Col2) in cartilage to promote the progression of OA. This study aimed to reveal the role of FAP from chondrocytes in OA and develop a novel lipid nanoparticle (LNP)-FAP siRNA delivery system for OA treatment.MethodsThe expression of FAP in the cartilage of knee OA patients was investigated using [68 Ga]Ga-FAPI-04 PET in vivo and immunofluorescence, western blotting, and RT-qPCR in vitro. Cell senescence was determined by senescence-associated β-galactosidase (SA-β-Gal) assay after FAP overexpressing or knockdown in chondrocytes. An OA model with chondrocyte-specific FAP knockout mice was applied to investigate the role of FAP in chondrocyte senescence and OA development. The therapeutic effects of lipid nanoparticle (LNP) @FAP siRNA on cartilage degeneration were evaluated in the rat OA model.ResultsOur study found that higher [68 Ga]Ga-FAPI-04 uptake was detected in knee OA patients by PET/CT scan. FAP mRNA and protein levels were highly expressed in OA-damaged cartilage. Moreover, we found that overexpression of FAP promotes chondrocyte senescence, and the genetic knockout of FAP in chondrocytes alleviates OA. Knockdown FAP by siRNA could alleviate chondrocyte senescence and suppress the NF-κB pathway to reduce the senescence-associated secretory phenotype (SASP). In the rat model of OA, intraarticular injection of LNP@FAP siRNA can reduce senescent cells and ameliorate cartilage destruction.ConclusionFAP-positive chondrocytes play a significant role in the pathogenesis of OA. Targeting these cells selectively has the potential to mitigate the progression of the disease. Our study provides valuable insights into the intraarticular injection of LNP@FAP siRNA as a promising strategy for the treatment of OA.Graphical abstract

A pH-Sensitive cRGD-PEG-siRNA Conjugated Compound Targeting Glioblastoma.

Glioblastoma ranks among the most prevalent primary intracranial tumors, characterized by high mortality and poor prognosis. Chemotherapy remains a key treatment strategy for gliomas, though most current drugs suffer from limited efficacy and significant toxicity. This study focuses on a cRGD-siEGFR coupling compound synthesized in a previous stage. Prior research indicated that cRGD-siEGFR molecules exhibited certain targeting and antitumor properties but faced issues of inadequate targeting, low efficacy, and high renal toxicity. To enhance antitumor efficacy and mitigate side effects, a pH-responsive, long-circulating, and highly targeted siRNA delivery system, the cRGD-PEG-siEGFR conjugate, was developed. The targeting, antitumor effects, and biological distribution of cRGD-PEG-siEGFR were examined. The results demonstrated that cRGD-PEG-siEGFR was effectively taken up by αvβ3-positive U87MG cells, specifically silenced EGFR gene expression, and exhibited antitumor effects. In normal physiological conditions, it avoided uptake by normal cells, thereby reducing side effects. Furthermore, in vivo biodistribution experiments revealed that cRGD-PEG-siEGFR, compared to cRGD-siEGFR, significantly decreased renal accumulation and exhibited prolonged circulation. Consequently, cRGD-PEG-siRNA emerges as a promising drug candidate with attributes of long circulation, high targeting, pH responsiveness, and substantial antitumor efficacy.

Effect of Degree of Substitution and Molecular Weight on Transfection Efficacy of Starch-Based siRNA Delivery System

RNA interference (RNAi) is a promising approach for gene therapy in cancers, but it requires carriers to protect and deliver therapeutic small interfering RNA (siRNA) molecules to cancerous cells. Starch-based carriers, such as quaternized starch (Q-Starch), have been shown to be biocompatible and are able to form nanocomplexes with siRNA, but significant electrostatic interactions between the carrier and siRNA prevent its release at the target site. In this study, we aim to characterize the effects of the degree of substitution (DS) and molecular weight (Mw) of Q-Starch on the gene silencing capabilities of the Q-Starch/siRNA transfection system. We show that reducing the DS reduces the electrostatic interactions between Q-Starch and siRNA, which now decomplex at more physiologically relevant conditions, but also affects additional parameters such as complex size while mostly maintaining cellular uptake capabilities. Notably, reducing the DS renders Q-Starch more susceptible to enzymatic degradation by α-amylase during the initial Q-Starch pretreatment. Enzymatic cleavage leads to a reduction in the Mw of Q-Starch, resulting in a 25% enhancement in its transfection capabilities. This study provides a better understanding of the effects of the DS and Mw on the polysaccharide-based siRNA delivery system and indicates that the polysaccharide Mw may be the key factor in determining the transfection efficacy of this system.

LncOCMRL1 promotes oral squamous cell carcinoma growth and metastasis via the RRM2/EMT pathway

BackgroundLong noncoding RNAs (lncRNAs) are widely involved in cancer development and progression, but the functions of most lncRNAs have not yet been elucidated. Metastasis is the main factor restricting the therapeutic outcomes of various cancer types, including oral squamous cell carcinoma (OSCC). Therefore, exploring the key lncRNAs that regulate OSCC metastasis and elucidating their molecular mechanisms will facilitate the development of new strategies for effective OSCC therapy.MethodsWe analyzed the lncRNA expression profiles of tumor tissues from OSCC patients with and without cervical lymph node metastasis, and OSCC cell lines. We revealed high expression of oral squamous cell carcinoma metastasis-related lncRNA 1 (lncOCMRL1) in OSCC patient tumor tissues with lymph node metastasis and highly metastatic OSCC cell lines. The effects of lncOCMRL1 knockdown on the invasion, migration and proliferation abilities of OSCC cells were explored through qRT-PCR, Transwell, colony formation, and cell proliferation experiments. The mechanism by which lncOCMRL1 promotes OSCC metastasis and proliferation was explored through RNA pull-down, silver staining, mass spectrometry, RIP, and WB experiments. To increase its translational potential, we developed a reduction-responsive nanodelivery system to deliver siRNA for antitumor therapy.ResultsWe determined that lncOCMRL1 is highly expressed in OSCC metastatic tumor tissues and cells. Functional studies have shown that high lncOCMRL1 expression can promote the growth and metastasis of OSCC cells both in vivo and in vitro. Mechanistically, lncOCMRL1 could induce epithelial-mesenchymal transition (EMT) via the suppression of RRM2 ubiquitination and thereby promote the proliferation, invasion, and migration of OSCC cells. We further constructed reduction-responsive nanoparticles (NPs) for the systemic delivery of siRNAs targeting lncOCMRL1 and demonstrated their high efficacy in silencing lncOCMRL1 expression in vivo and significantly inhibited OSCC tumor growth and metastasis.ConclusionsOur results suggest that lncOCMRL1 is a reliable target for blocking lymph node metastasis in OSCC.

Supramolecular Bioconjugation Strategy for Antibody-Targeted Delivery of siRNA.

RNA interference is a widely used biological process by which double-stranded RNA induces sequence-specific gene silencing by targeting mRNA for degradation. However, the physicochemical properties of siRNAs make their delivery extremely challenging, thus limiting their bioavailability at the target site. In this context, we developed a versatile and selective siRNA delivery system of a trastuzumab-conjugated nanocarrier. These immunoconjugates consist of the assembly by electrostatic interactions of an oligonucleotide-modified antibody with a cationic micelle for the targeted delivery of siRNA in HER2-overexpressing cancer cells. Results show that, when associated with the corresponding siRNA at the appropriate N/P ratio, our supramolecular assembly was able to efficiently induce luciferase and PLK-1 gene silencing in a cell-selective manner in vitro.

LncRNA FAISL Inhibits Calpain 2-Mediated Proteolysis of FAK to Promote Progression and Metastasis of Triple Negative Breast Cancer.

Triple negative breast cancer (TNBC) is the most aggressive subtype in breast tumors. When re-analyzing TCGA breast cancer dataset, we found cell adhesion molecules are highly enriched in differentially expressed genes in TNBC samples, among which Focal Adhesion Kinase (FAK) is most significantly associated with poor survival of TNBC patients. FAK is precisely modulated in the focal adhesion dynamics. To investigate whether lncRNAs regulate FAK signaling, we performed RNA immunoprecipitation sequencing and found FAISL (FAK Interacting and Stabilizing LncRNA) abundantly enriched in FAK-interacting lncRNAs and frequently overexpressed in TCGA TNBC tissues. FAISL promotes TNBC cell adhesion, cytoskeleton spreading, proliferation, and anchor-independent survival. FAISL doesn't affect FAK mRNA but positively regulates FAK protein level by blocking Calpain 2-mediated proteolysis. FAISL interacts with the C-terminus domain of FAK, whereby masks the binding site of Calpain 2 and prevents FAK cleavage. High level of FAISL correlates with FAK expression in tumor tissues and poor prognosis of TNBC patients. A siRNA delivery system targeting FAISL using reduction-responsive nanoparticles effectively inhibits tumor growth and metastasis in TNBC mouse models. Together, these findings uncover a lncRNA-mediated mechanism of regulating FAK proteolysis in the TNBC progression, and highlight the potential of targeting lncRNA FAISL for TNBC treatment.

Lipopolymer/siRNA Nanoparticles Targeting the Signal Transducer and Activator of Transcription 5A Disrupts Proliferation of Acute Lymphoblastic Leukemia.

The therapeutic potential of small interfering RNAs (siRNAs) in gene-targeted treatments is substantial, but their suboptimal delivery impedes widespread clinical applications. Critical among these is the inability of siRNAs to traverse the cell membranes due to their anionic nature and high molecular weight. This limitation is particularly pronounced in lymphocytes, which pose additional barriers due to their smaller size and scant cytoplasm. Addressing this, we introduce an innovative lipid-conjugated polyethylenimine lipopolymer platform, engineered for delivery of therapeutic siRNAs into lymphocytes. This system utilizes the cationic nature of the polyethylenimine for forming stable complexes with anionic siRNAs, while the lipid component facilitates cellular entry of siRNA. The resulting lipopolymer/siRNA complexes are termed lipopolymer nanoparticles (LPNPs). We comprehensively profiled the efficacy of this platform in human peripheral blood mononuclear cells (PBMCs) as well as in vitro and in vivo models of acute lymphoblastic leukemia (ALL), emphasizing the inhibition of the oncogenic signal transducer and activator of transcription 5A (STAT5A) gene. The lipopolymers demonstrated high efficiency in delivering siRNA to ALL cell lines (RS4;11 and SUP-B15) and primary patient cells, effectively silencing the STAT5A gene. The resultant gene silencing induced apoptosis and significantly reduced colony formation in vitro. Furthermore, in vivo studies showed a significant decrease in tumor volumes without causing substantial toxicity. The lipopolymers did not induce the secretion of proinflammatory cytokines (IL-6, TNF-α, and INF-γ) in PBMCs from healthy volunteers, underscoring their immune safety profile. Our observations indicate that LPNP-based siRNA delivery systems offer a promising therapeutic approach for ALL in terms of both safety and therapeutic efficacy.

Research on Target Peptides and siRNA Delivery Systems in Lung Cancer Targeted Therapy

Research on Target Peptides and siRNA Delivery Systems in Lung Cancer Targeted Therapy

Enhancing photodynamic and radionuclide therapy by small interfering RNA (siRNA)-RAD51 transfection via self-emulsifying delivery systems (SNEDDS)

Background aimsGene-silencing by small interfering RNA (siRNA) is an attractive therapy to regulate cancer death, tumor recurrence or metastasis. Because siRNAs are easily degraded, it is necessary to develop transport and delivery systems to achieve efficient tumor targeting. Self-nanoemulsifying systems (SNEDDS) have been successfully used for pDNA transport and delivery, so they may be useful for siRNA. The aim of this work is to introduce siRNA-RAD51 into a SNEDDS prepared with Phospholipon-90G, Labrafil-M1944-CS and Cremophor-RH40 and evaluate its efficacy in preventing homologous recombination of DNA double-strand breaks caused by photodynamic therapy (PDT) and ionizing radiation (IR). MethodsThe siRNA-RAD51 was loaded into SNEDDS using chitosan. Transfection capacity was estimated by comparison with Lipofectamine-2000. ResultsSNEDDS(siRNA-RAD51) induced gene silencing effect on the therapies evaluated by cell viability and clonogenic assays using T47D breast cancer cells. ConclusionsSNEDDS(siRNA-RAD51) shown to be an effective siRNA-delivery system to decrease cellular resistance in PDT or IR.

Pyroptotic-Spatiotemporally Selective Delivery of siRNA against Pyroptosis and Autoimmune Diseases.

Small-interfering RNAs (siRNAs) offer promising prospects for treating pyroptosis-related autoimmune diseases. However, poor stability and off-target effects during in vivo transportation hinder their practical clinical applications. Precision delivery and adaptive release of siRNAs into inflamed tissues and immune cells could unleash their full therapeutic potential. This study establishes a pyroptotic-spatiotemporally selective siRNA delivery system (PMRC@siGSDME) that selectively targets inflammatory tissues, responds to pyroptosis, and exhibits remarkable therapeutic efficacy against various autoimmune diseases. Novel hybrid nanovesicles (NVs) are designed as a combination of pyroptotic macrophage membranes (PMs) and R8-cardiolipin-containing nanovesicles (RC-NVs). Evidence provides that PM-derived proteins involved in cell-cell interactions and membrane trafficking may contribute to the specificity of NVs to inflammatory tissue. In addition, cardiolipin anchored in the hybrid NVs increases its affinity for activated gasdermin E (GSDME) and achieves pyroptosis-adaptive release of siGSDME for the spatiotemporally selective suppression of immune responses. More importantly, PMRC@siGSDME displays significant anti-inflammatory and therapeutic effects in multiple mouse autoimmune disease models, including arthritis and inflammatory bowel disease (IBD). Collectively, an innovative siRNA delivery strategy precisely tailored for pyroptotic cells has been developed, paving the way for new treatments for autoimmune inflammatory diseases with minimal side effects and wide clinical applicability.

Spatial Organization of Lipid Nanoparticle siRNA Delivery Systems Revealed by an Integrated Magnetic Resonance Approach.

Lipid nanoparticles (LNPs) are increasingly finding applications in targeted drug delivery, including for subcutaneous, intravenous, inhalation, and vaccine administration. While a variety of microscopy techniques are widely used for LNP characterization, their resolution does not allow for characterization of the spatial organization of different components, such as the excipients, targeting agents, or even the active ingredient. Herein, an approach is presented to probe the spatial organization of individual constituent groups of LNPs used for siRNA-based drug delivery, currently in clinical trials, by multinuclear solid-state magic-angle-spinning nuclear magnetic resonance (MAS NMR) spectroscopy. Dynamic nuclear polarization is exploited (DNP) for sensitivity enhancement, together with judicious 2H labeing, to detect functionally important LNP constituents, the siRNA and the targeting agent (<1-2 w/v%), respectively, and achieve a structural model of the LNP locating the siRNA in the core, the targeting agent below the surface, and the sugars above the lipid bilayer at the surface. The integrated approach presented here is applicable for structural analysis of LNPs and can be extended more generally to other multi-component biological formulations.

ROS-Responsive Ferrocenyl Amphiphilic PAMAM Dendrimers for On-Demand Delivery of siRNA Therapeutics to Cancer Cells.

Small interfering RNA (siRNA) therapeutics, characterized by high specificity, potency, and durability, hold great promise in the treatment of cancer and other diseases. However, the clinic implementation of siRNA therapeutics critically depends on the safe and on-demand delivery of siRNA to the target cells. Here, we reported a family of ferrocenyl amphiphilic dendrimers (Fc-AmDs) for on-demand delivery of siRNA in response to the high ROS content in cancer cells. These dendrimers bear ROS-sensitive ferrocene moieties in the hydrophobic components and positively chargeable poly(amidoamine) dendrons as the hydrophilic entities, possessing favorable safety profiles and ROS responsive properties. One of these ferrocenyl amphiphilic dendrimers, Fc-C8-AmD 8A, outperforms in siRNA delivery, benefiting from its optimal balance of hydrophobicity and hydrophilicity. Its ROS feature facilitates specific and efficient disassembly of its complex with siRNA in ROS-rich cancer cells for effective siRNA delivery and gene silencing. Moreover, Fc-C8-AmD 8A also integrates the features and beneficial properties of both lipid and dendrimer vectors. Therefore, it represents a novel on-demand delivery system for cancer cell-specific siRNA delivery. This work opens new perspectives for designing self-assembly nanosystems for on-demand drug delivery.

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.

Bifunctional halloysite nanotube-based Ripk1 siRNA delivery system rescues cognitive impairment by targeting amyloid β plaques for clearance and reducing necrotic neurons in Alzheimer’s disease mice

Alzheimer’s disease (AD) is exacerbated by abnormal accumulation of toxic β-amyloid (Aβ) aggregates and Aβ-mediated neuronal cell death. Currently, no effective drugs for AD treatment are mainly due to the blood–brain barrier hindrance, which limits the most drugs for application in AD treatment. Accumulating evidence suggests that increased levels of Ripk1 and enhancement of Ripk1-mediated neuronal necroptosis are known to play an important role in neuronal death in AD. Targeting Ripk1 by pharmacological or genetic inhibition of Ripk1 has been demonstrated to prevent neuronal necroptosis and improve memory deficits in AD mice models. Here, we showed that halloysite (HNTs), one of the nanoclays, absorbed Aβ and reduced toxic Aβ aggregate production by inhibiting fibril formation and promoting the clearance of Aβ plaques. We also presented evidence that RVG29, a brain-penetrating peptide, bound directly to Aβ species and inhibited Aβ aggregation. In addition, Ripk1 is more dramatically expressed around Aβ plaques than those far from plaques in the brain of AD mice. Therefore, we designed a novel Aβ plaque-targeted nanomedicine (SH-RVG/siRipk1) via functionalizing with RVG29 onto short HNTs (SH) and loading Ripk1 siRNA (siRipk1) into the lumen of SH to prevent siRipk1 degradation. As we expected, SH-RVG/siRipk1 not only reduced plaques and improved memory impairment but also rescued necrotic neuronal loss around plaques by reducing Ripk1 expression around plaques in AD mice. These findings indicate that SH-RVG/siRipk1 may be an effective strategy for the treatment of AD.

Target Reprogramming the 3′UTR of Tumor‐Suppressor Genes by a siRNA Composite Nanoparticle for Glioblastoma Therapy

AbstractGlioblastoma multiforme (GBM) is the most aggressive and common adult brain tumor. Current therapies primarily involve surgical resection, followed by chemotherapy and radiotherapy. However, the low survival rate due to high toxicity, side effects, and poor targeting necessitates novel treatments. Post‐transcriptional regulation pathways, particularly the regulation of alternative polyadenylation based on the mRNA 3′UTR, play a critical role in cell growth and development and the progression of tumors. Targeting tumor cells and reprogramming the 3′UTR of tumor suppressor genes to achieve post‐transcriptional regulation is expected to be a new channel for GBM therapy. Herein, a novel siRNA delivery system is developed based on mesoporous silica nanoparticles: siRNA composite nanoparticles (siRNA CNP). Encapsulation in MSNs overcomes siRNA degradation and cellular entry issues, while lipid bilayer coating improves biocompatibility and stability. Surface‐modified nucleic acid aptamer SL1 (Apt‐SL1) significantly enhances GBM targeting, offering therapeutic potential. The findings show that siRNA CNP effectively silences the promoter CFIm25 of distal poly(A) in tumor cells, inducing gene reprogramming, inhibiting tumor growth, and promoting apoptosis in nude mice. The siRNA CNP demonstrates a significant effect in reprogramming tumor suppressor genes and treating GBM. It offers a novel and promising therapeutic avenue for GBM.

Long‐Term Storage Stable Vesicle‐Like Nanoparticles of Lipid and Polymer for siRNA and mRNA‐Mediated Cancer Immunotherapy

AbstractRNA‐based therapeutics have emerged as a promising strategy for cancer immunotherapy, encompassing the silencing of immune checkpoint genes, chimeric antigen receptor T (CAR‐T) cell production, and antitumor vaccines. Despite their tremendous potential, the urgent need for the development of clinically applicable delivery systems remains paramount. In this study, vesicle‐like nanoparticles (VNPs) are devised using clinically approved amphiphilic polymers and lipids as the delivery system for siRNA and mRNA. Through meticulous formulation adjustments of cationic lipids and ionizable lipids, a VNP formulation with exceptional transfection efficiency is identified. Notably, the VNPs maintained their remarkable transfection efficiency even after 6 months of storage. When loaded with siPD‐L1 and siCD47, these VNPs effectively silenced two critical immune checkpoint genes, enabling successful cancer immunotherapy. Moreover, when employed as a delivery system for mRNA vaccines, the VNPs induced a robust population of antigen‐specific CD8+ T cells in immunized mice. This led to the successful suppression of tumor growth (5 out of 8 subjects becoming tumor‐free) and nearly complete inhibition of lung metastasis. In summary, this lipid‐ and polymer‐based VNPs offer a long shelf life, excellent loading and transfection efficiency, versatility for various RNA types, and hold great promise as a delivery system for clinical applications.

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.

Imidazolyl Lipids Enhanced LNP Endosomal Escape for Ferroptosis RNAi Treatment of Cancer.

Treatments for cancer that incorporate small interfering RNA (siRNA) to target iron-dependent ferroptosis are thought to be highly promising. However, creating a reliable and clinically feasible siRNA delivery system continues to be a major obstacle in the field of cancer treatment. Here, three imidazole-based ionizable lipid nanoparticles (LNPs) with pH-sensitive effects are rationally designed and synthesized for siRNA delivery. LNPs formulated with the top-performing lipid (O12-D3-I3) encapsulating FVII siRNA (FVII@O-LNP) elicited greater gene silencing than those with the benchmark Onpattro lipid DLin-MC3-DMA (MC3) due to its stronger endosomal escape. Moreover, Fc-siRNA@O-LNPs encapsulated with ferrocene (Fc) and SLC7A11/Nrf2-targeted siRNA is formulated. The outcomes demonstrate optimal safety profiles and a significant anti-tumor effect by inducing long-lasting and efficient ferroptosis through a synergistic action in vivo. In summary, this work shows that imidazolyl lipid-prepared LNPs are efficient delivery vehicles for cancer therapy and ferroptosis-targeting siRNA administration, both of which have extensive clinical application potential.

Effect of a novel siRNA delivery system, siRNA ternary complex, on melanoma lung metastasis

In this study, we determined effects of an anionic siRNA delivery vector, siRNA ternary complex, which is constructed with biodegradable dendrigraft poly-L-lysine (DGL) and γ-polyglutamic acid (γ-PGA) on the melanoma cells and melanoma lung metastasis. The siRNA ternary complex showed high cellular uptake and silencing effect in melanoma cell line B16-F10/Luc cells. After intravenous administration of the siRNA ternary complex, high silencing effect was also observed in the lung of B16-F10/Luc melanoma metastasis model mice. Therefore, we applied vascular endothelial growth factor (VEGF)-siRNA on the siRNA ternary complex and determined the effect on the melanoma lung metastasis. The siRNA ternary complex containing VEGF-siRNA reduced VEGF protein levels significantly in in vitro and in vivo, and the complex successfully inhibited melanoma lung metastasis. This biodegradable and effective siRNA delivery vector, siRNA ternary complex, could be available for clinical trials.