Expanding RNAi to Kidneys, Lungs, and Spleen via Selective ORgan Targeting (SORT) siRNA Lipid Nanoparticles.

Inhibition of disease-causing mutations using RNA interference (RNAi) has resulted in clinically approved medicines with additional candidates in late stage trials. However, targetable tissues currently in preclinical development are limited to liver following systemic intravenous (IV) administration because predictable delivery of siRNA to non-liver tissues remains an unsolved challenge. Here, evidence of durable extrahepatic gene silencing enabled by siRNA Selective ORgan Targeting lipid nanoparticles (siRNA SORT LNPs) to the kidneys, lungs, and spleen is provided. LNPs excel at dose-dependent silencing of tissue-enriched endogenous targets resulting in 60%-80% maximal knockdown after a single IV injection and up to 88% downregulation of protein expression in mouse lungs after two doses. To examine knockdown potency and unbiased organ targeting, B6.129TdTom/EGFP mice that constitutively express the TdTomato transgene across all cell types are utilized to demonstrate 58%, 45%, and 15% reduction in TdTomato fluorescence in lungs, spleen, and kidneys, respectively. Finally, physiological relevance of siRNA SORT LNP-mediated gene silencing is established via acute suppression of endogenous Tie2 which induces lung-specific phenotypic alteration of vascular endothelial barrier. Due to plethora of extrahepatic diseases that may benefit from RNAi interventions, it is anticipated that the findings will expand preclinical landscape of therapeutic targets beyond the liver.

siRNA Delivery from Cationic Nanocarriers Prepared by Diffusion-assisted Loading in the Presence and Absence of Electrostatic Interactions.

In this study, we use modified cationic nanocarriers as vehicles for the intracellular delivery of therapeutic siRNA. After developing nanocarrier formulations with appropriate pKa, size, swellability, and cytocompatibility, we investigated the importance of siRNA loading methods by studying the impact of the pH and time over which siRNA is loaded into the nanocarriers. We concentrate on diffusion-based loading in the presence and absence of electrostatic interactions. siRNA release kinetics were studied using samples prepared from nanocarriers loaded by both mechanisms. In addition, siRNA delivery was evaluated for two formulations. While previous studies were conducted with samples prepared by siRNA loading at low pH values, this research provides evidence that loading conditions of siRNA affect the release behavior. This study concludes that this concept could prove advantageous for eliciting prolonged intracellular release of nucleic acids and negatively charged molecules, effectively decreasing dose frequency and contributing to more effective therapies and improved patient outcomes. In addition, our findings could be leveraged for enhanced control over siRNA release kinetics, providing novel methods for the continued optimization of cationic nanoparticles in a wide array of RNA interference-based applications.

In Vivo Endothelial Cell Gene Silencing by siRNA-LNPs Tuned with Lipoamino Bundle Chemical and Ligand Targeting.

Although small-interfering RNAs (siRNAs) are specific silencers for numerous disease-related genes, their clinical applications still require safe and effective means of delivery into target cells. Highly efficient lipid nanoparticles (LNPs) are developed for siRNA delivery, showcasing the advantages of novel pH-responsive lipoamino xenopeptide (XP) carriers. These sequence-defined XPs are assembled by branched lysine linkages between cationizable polar succinoyl tetraethylene pentamine (Stp) units and apolar lipoamino fatty acids (LAFs) at various ratios into bundle or U-shape topologies. Formulation of siRNA-LNPs using LAF4-Stp1 XPs as ionizable compounds led to robust cellular uptake, high endosomal escape, and successful in vitro gene silencing activity at an extremely low (150 picogram) siRNA dose. Of significance is the functional in vivo endothelium tropism of siRNA-LNPs with bundle LAF4-Stp1 XP after intravenous injection into mice, demonstrated by superior knockdown of liver sinusoidal endothelial cell (LSEC)-derived factor VIII (FVIII) and moderate silencing of hepatocyte-derived FVII compared to DLin-MC3-DMA-based LNPs. Optimizing lipid composition following click-modification of siRNA-LNPs with ligand c(RGDfK) efficiently silenced vascular endothelial growth factor receptor-2 (VEGFR-2) in tumor endothelial cells (TECs). The findings shed light on the role of ionizable XPs in the LNP in vivo cell-type functional targeting, laying the groundwork for future therapeutic applications.

Membrane Fusion-Mediated Loading of Therapeutic siRNA into Exosome for Tissue-Specific Application.

Tissue-specific delivery of oligonucleotide therapeutics beyond the liver remains a key challenge in nucleic acid drug development. To address this issue, exploiting exosomes as a novel carrier has emerged as a promising approach for efficient nucleic acid drug delivery. However, current exosome-based delivery systems still face multiple hurdles in their clinical applications. Herein, this work presents a strategy for constructing a hybrid exosome vehicle (HEV) through a DNA zipper-mediated membrane fusion approach for tissue-specific siRNA delivery. As a proof-of-concept, this work successfully fuses a liposome encapsulating anti-NFKBIZ siRNAs with corneal epithelium cell (CEC)-derived exosomes to form a HEV construct for the treatment of dry eye disease (DED). With homing characteristics inherited from exosomes, the siRNA-bearing HEV can target its parent cells and efficiently deliver the siRNA payloads to the cornea. Subsequently, the NFKBIZ gene silencing significantly reduces pro-inflammatory cytokine secretions from the ocular surface, reshapes its inflammatory microenvironment, and ultimately achieves an excellent therapeutic outcome in a DED mouse model. As a versatile platform, this hybrid exosome with targeting capability and designed therapeutic siRNAs may hold great potential in various disease treatments.

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.

Regulation of Protein Conformation Enables Cell-Selective Targeting of Virus-Mimicking Nanoparticles for siRNA Therapy of Glioblastoma.

Orthotopic glioblastoma (GBM) has an aggressive growth pattern and complex pathogenesis, becoming one of the most common and deadly tumors of the central nervous system (CNS). The emergence of RNA therapies offers promise for the treatment of GBM. However, the efficient and precise delivery of RNA drugs to specific tumor cells in the brain with high cellular heterogeneity remains ongoing. Here, a strategy is proposed to regulate protein conformation through lipid nanoenvironments to custom-design virus-mimicking nanoparticles (VMNs) with excellent selective cell targeting capabilities, leading to efficient and precise delivery of small interfering RNA for effective treatment of GBM. The optimized VMNs not only retain the ability to cross the blood-brain barrier and release the RNA by lysosomal escape like natural viruses but also ensure precise enrichment in the GBM area. This study lays the conceptual foundation for the custom design of VMNs with superior cell-selective targeting capabilities and opens up the possibility of RNA therapies for the efficient treatment of GBM and CNS tumors.

Effects of Histidine Oligomers in Lipid Nanoparticles on siRNA Delivery.

In this study, we developed histidine oligomer (oHis; 10mer)-incorporating LNPs (H10LNPs) as a novel carrier for efficient siRNA delivery. Notably, the unmodified oHis (10mer) was greatly incorporated within LNPs through ionic interaction with siRNAs, which serves as an endosome escape enhancer. H10LNPs with a size of approximately 65 nm demonstrated a significantly enhanced extent of endosomal escape, as evidenced by calcein assay and confocal microscopy images of intracellular fluorescence, surpassing conventional LNPs. Furthermore, the half inhibitory concentration (IC50) of the human endogenous globotriaosylceramide synthase (Gb3 synthase) gene in H10LNPs-treated cells exhibited a significant three-fold decrease, compared to that in LNP-treated cells. Notably, H10LNPs maintained comparable biocompatibility and biodistribution both in vitro and in vivo. Considering that the fabricated siRNA H10LNPs exhibited excellent biocompatibility and superior gene silencing activity over conventional LNPs, these particles can be harnessed for the safe delivery of therapeutic siRNAs. Additionally, this study introduces promising, feasible, simple, and alternative formulation processes for integrating unmodified functional cationic peptides into LNPs to enhance the delivery efficiency of a wide range of nucleic acid-based drugs. This article is protected by copyright. All rights reserved.

Electrospun composite-coated endotracheal tubes with controlled siRNA and drug delivery to lubricate and minimize upper airway injury.

Endotracheal Tubes (ETTs) maintain and secure a patent airway; however, prolonged intubation often results in unintended injury to the mucosal epithelium and inflammatory sequelae which complicate recovery. ETT design and materials used have yet to adapt to address intubation associated complications. In this study, a composite coating of electrospun polycaprolactone (PCL) fibers embedded in a four-arm polyethylene glycol acrylate matrix (4APEGA) is developed to transform the ETT from a mechanical device to a dual-purpose device capable of delivering multiple therapeutics while preserving coating integrity. Further, the composite coating system (PCL-4APEGA) is capable of sustained delivery of dexamethasone from the PCL phase and small interfering RNA (siRNA) containing polyplexes from the 4APEGA phase. The siRNA is released rapidly and targets smad3 for immediate reduction in pro-fibrotic transforming growth factor-beta 1 (TGFϐ1) signaling in the upper airway mucosa as well as suppressing long-term sequelae in inflammation from prolonged intubation. A bioreactor was used to study mucosal adhesion to the composite PCL-4APEGA coated ETTs and investigate continued mucus secretory function in ex vivo epithelial samples. The addition of the 4APEGA coating and siRNA delivery to the dexamethasone delivery was then evaluated in a swine model of intubation injury and observed to restore mechanical function of the vocal folds and maintain epithelial thickness when observed over 14 days of intubation. This study demonstrated that increase in surface lubrication paired with surface stiffness reduction significantly decreased fibrotic behavior while reducing epithelial adhesion and abrasion.

MMP13-targeted siRNA-loaded micelles for diagnosis and treatment of posttraumatic osteoarthritis.

Posttraumatic osteoarthritis (PTOA) patients are often diagnosed by X-ray imaging at a middle-late stage when drug interventions are less effective. Early PTOA is characterized by overexpressed matrix metalloprotease 13 (MMP13). Herein, we constructed an integrated diagnosis and treatment micelle modified with MMP13 enzyme-detachable, cyanine 5 (Cy5)-containing PEG, black hole quencher-3 (BHQ3), and cRGD ligands and loaded with siRNA silencing MMP13 (siM13), namely ERMs@siM13. ERMs@siM13 could be cleaved by MMP13 in the diseased cartilage tissues to detach the PEG shell, causing cRGD exposure. Accordingly, the ligand exposure promoted micelle uptake by the diseased chondrocytes by binding to cell surface αvß3 integrin, increasing intracellular siM13 delivery for on-demand MMP13 downregulation. Meanwhile, the Cy5 fluorescence was restored by detaching from the BHQ3-containing micelle, precisely reflecting the diseased cartilage state. In particular, the intensity of Cy5 fluorescence generated by ERMs@siM13 that hinged on the MMP13 levels could reflect the PTOA severity, enabling the physicians to adjust the therapeutic regimen. Finally, in the murine PTOA model, ERMs@siM13 could diagnose the early-stage PTOA, perform timely interventions, and monitor the OA progression level during treatment through a real-time detection of MMP13. Therefore, ERMs@siM13 represents an appealing approach for early-stage PTOA theranostics.

Metal-organic framework-mediated siRNA delivery and sonodynamic therapy for precisely triggering ferroptosis and augmenting ICD in osteosarcoma.

The complex genomics, immunosuppressive tumor microenvironment (TME), and chemotherapeutic resistance of osteosarcoma (OS) have resulted in limited therapeutic effects in the clinic. Ferroptosis is involved in tumor progression and is regulated mainly by glutathione peroxidase 4 (GPX4). Small interfering RNA (siRNA)-based RNA interference (RNAi) can precisely target any gene. However, achieving effective siRNA delivery is highly challenging. Here, we fabricated a TME-responsive metal-organic framework (MOF)-based biomimetic nanosystem (mFeP@si) with siGPX4 delivery and sonodynamic therapy (SDT) to treat OS by targeting ferroptosis. Under ultrasound (US) irradiation, mFeP@si achieves lysosomal escape via singlet oxygen (1O2)-mediated lysosomal membrane disruption and then accelerates ROS generation and glutathione (GSH) depletion. Meanwhile, siGPX4 silences GPX4 expression by binding to GPX4 mRNA and leads to the accumulation of toxic phospholipid hydroperoxides (PL-OOH), further magnifying the ROS storm and triggering ferroptosis. Notably, synergistic therapy remarkably enhances antitumor effects, improves the immunosuppressive TME by inducing potent immunogenic cell death (ICD), and increases the sensitivity of chemotherapy-resistant OS cells to cisplatin. Overall, this novel nanosystem, which targets ferroptosis by integrating RNAi and SDT, exhibits strong antitumor effects both in vitro and in vivo, providing new insights for treating OS.

A potent bioreducible ionizable lipid nanoparticle enables siRNA delivery for retinal neovascularization inhibition.

Small interfering RNA (siRNA) is emerging as a promising treatment for retinal neovascularization due to its specific inhibition of the expression of target genes. However, the clinical translation of siRNA drugs is hindered by the efficiency and safety of delivery vectors. Here, we describe the properties of a new bioreducible ionizable lipid nanoparticle (LNP) 2N12H, which is based on a rationally designed novel ionizable lipid called 2N12B. 2N12H exhibited degradation in response to the mimic cytoplasmic glutathione condition and ionization with a pKa value of 6.5, which remaining neutral at pH 7.4. At a nitrogen to phosphorus ratio of 5, 2N12H efficiently encapsulated and protected siRNA from degradation. Compared to the commercial vehicle Lipofectamine 2000, 2N12H demonstrated similar silencing efficiency and improved safety in the in vitro cell experiments. 2N12H/siVEGFA reduced the expression of VEGFA in retinal pigment epithelium cells and mouse retina, consequently suppressing cell migration and retinal neovascularization. In the mouse model, the therapeutic effect of 2N12H/siVEGFA was comparable to that of the clinical drug ranibizumab. Together, these results suggest the potential of this novel ionizable LNP to facilitate the development of nonviral ocular gene delivery systems.

Microfluidics-enabled fluorinated assembly of EGCG-ligands-siTOX nanoparticles for synergetic tumor cells and exhausted t cells regulation in cancer immunotherapy.

Immune checkpoint inhibitor (ICI)-derived evolution offers a versatile means of developing novel immunotherapies that targets programmed death-ligand 1 (PD-L1)/programmed death-1 (PD-1) axis. However, one major challenge is T cell exhaustion, which contributes to low response rates in "cold" tumors. Herein, we introduce a fluorinated assembly system of LFNPs/siTOX complexes consisting of fluorinated EGCG (FEGCG), fluorinated aminolauric acid (LA), and fluorinated polyethylene glycol (PEG) to efficiently deliver small interfering RNA anti-TOX (thymus high mobility group box protein, TOX) for synergistic tumor cells and exhausted T cells regulation. Using a microfluidic approach, a library of LFNPs/siTOX complexes were prepared by altering the placement of the hydrophobe (LA), the surface PEGylation density, and the siTOX ratio. Among the different formulations tested, the lead formulation, LFNPs3-3/siTOX complexes, demonstrated enhanced siRNA complexation, sensitive drug release, improved stability and delivery efficacy, and acceptable biosafety. Upon administration by the intravenous injection, this formulation was able to evoke a robust immune response by inhibiting PD-L1 expression and mitigating T cell exhaustion. Overall, this study provides valuable insights into the fluorinated assembly and concomitant optimization of the EGCG-based delivery system. Furthermore, it offers a promising strategy for cancer immunotherapy, highlighting its potential in improving response rates in ''cold'' tumors.

Nontoxic, Biodegradable Hyperbranched Poly(ß-amino ester)s for Efficient siRNA Delivery and Gene Silencing.

RNA interference (RNAi)-mediated gene silencing is a promising therapeutic approach to treat various diseases, but safe and efficient delivery remains a major challenge to its clinical application. Non-viral gene vectors, such as poly(ß-amino esters) (pBAEs), have emerged as a potential candidate due to their biodegradability, low toxicity profile, ease of synthesis, and high gene transfection efficiency for both DNA and siRNA delivery. However, achieving significant gene silencing using pBAEs often requires a large amount of polymer carrier (with polymer/siRNA weight ratio >100) or high siRNA dose (>100 nM), which might potentially exacerbate toxicity concerns during delivery. To overcome these barriers, we designed and optimized a series of hyperbranched pBAEs capable of efficiently condensing siRNA and achieving excellent silencing efficiency at a lower polymer/siRNA weight ratio (w/w) and siRNA dose. Through modulation of monomer combinations and branching density, we identified the top-performing hyperbranched pBAEs, named as h(A2B3)-1, which possess good siRNA condensation ability, low cytotoxicity, and high cellular uptake efficiency. Compared with Lipofectamine 2000, h(A2B3)-1 achieved lower cytotoxicity and higher siRNA silencing efficiency in HeLa cells at a polymer/siRNA weight ratio of 30 and 30 nM siRNA dose. Notably, h(A2B3)-1 enhanced the gene uptake in primary neural cells and effectively silenced the target gene in hard-to-transfect primary cortical neurons and oligodendrocyte progenitor cells, with gene knockdown efficiencies of 34.8 and 53.4% respectively. By incorporating a bioreducible disulfide compartment into the polymer backbone, the cytocompatibility of the h(A2B3)-1 was greatly enhanced while maintaining their good transfection efficiency. Together, the low cytotoxicity and high siRNA transfection efficiency of hyperbranched h(A2B3)-1 in this study demonstrated their great potential as a non-viral gene vector for efficient siRNA delivery and RNAi-mediated gene silencing. This provides valuable insight into the future development of safe and efficient non-viral siRNA delivery systems as well as their translation into clinical applications.

Which Lipid Nanoparticle (LNP) Designs Work? A Simple Kinetic Model Linking LNP Chemical Structure to In Vivo Delivery Performance.

Although lipid nanoparticles (LNPs) are the predominant nanocarriers for short-interfering RNA (siRNA) delivery, most therapies use nearly identical formulations that have taken 30 years to design but lack the diverse property ranges necessary for versatile application. This dearth in variety and the extended timeline for implementation are attributed to a limited understanding of how LNP properties facilitate overcoming biological barriers. Herein, a simple kinetic model was developed by using major rate-limiting steps for siRNA delivery, and this model enabled the identification of a critical parameter to predict LNP efficacy without extensive experimental testing. A volume-averaged log D, the "solubility" of charged molecules as a function of pH weighted by component volume fractions, resulted in a good correlation between LNP composition and siRNA delivery. Both the effects of modifying the structures of ionizable lipids and LNP composition on gene silencing were easily captured in the model predictions. Thus, this approach provides a robust LNP structure-activity relationship to dramatically accelerate the realization of effective LNP formulations.

Reversal of Chemoresistance via Staged Liberation of Chemodrug and siRNA in Hierarchical Response to ROS Gradient.

P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) often leads to the failure of antitumor chemotherapy, and codelivery of chemodrug with P-gp siRNA (siP-gp) represents a promising approach for treating chemoresistant tumors. To maximize the antitumor efficacy, it is desired that the chemodrug be latently released upon completion of siP-gp-mediated gene silencing, which however, largely remains an unmet demand. Herein, core-shell nanocomplexes (NCs) are developed to overcome MDR via staged liberation of siP-gp and chemodrug (doxorubicin, Dox) in hierarchical response to reactive oxygen species (ROS) concentration gradients. The NCs are constructed from mesoporous silica nanoparticles (MSNs) surface-decorated with cRGD-modified, PEGylated, ditellurium-crosslinked polyethylenimine (RPPT), wherein thioketal-linked dimeric doxorubicin (TK-Dox2) and photosensitizer are coencapsulated inside MSNs while siP-gp is embedded in the RPPT polymeric layer. RPPT with ultrahigh ROS-sensitivity can be efficiently degraded by the low-concentration ROS inside cancer cells to trigger siP-gp release. Upon siP-gp-mediated gene silencing and MDR reversal, light irradiation is performed to generate high-concentration, lethal amount of ROS, which cleaves thioketal with low ROS-sensitivity to liberate the monomeric Dox. Such a latent release profile greatly enhances Dox accumulation in Dox-resistant cancer cells (MCF-7/ADR) in vitro and in vivo, which cooperates with the generated ROS to efficiently eradicate MCF-7/ADR xenograft tumors.

Targeted delivery of polo-like kinase 1 siRNA nanoparticles using an EGFR-PEG bispecific antibody inhibits proliferation of high-risk neuroblastoma.

High-risk neuroblastoma has poor survival due to treatment failure and off-target side effects of therapy. Small molecule inhibitors have shown therapeutic efficacy at targeting oncogenic cell cycle dysregulators, such as polo-like kinase 1 (PLK1). However, their clinical success is limited by a lack of efficacy and specificity, causing off-target toxicity. Herein, we investigate a new treatment strategy whereby a bispecific antibody (BsAb) with dual recognition of methoxy polyethylene glycol (PEG) and a neuroblastoma cell-surface receptor, epidermal growth factor receptor (EGFR), is combined with a PEGylated small interfering RNA (siRNA) lipid nanoparticle, forming BsAb-nanoparticle RNA-interference complexes for targeted PLK1 inhibition against high-risk neuroblastoma. Therapeutic efficacy of this strategy was explored in neuroblastoma cell lines and a tumor xenograft model. Using ionizable lipid-based nanoparticles as a low-toxicity and clinically safe approach for siRNA delivery, we identified that their complexing with EGFR-PEG BsAb resulted in increases in cell targeting (1.2 to >4.5-fold) and PLK1 gene silencing (>2-fold) against EGFR+ high-risk neuroblastoma cells, and enhancements correlated with EGFR expression on the cells (r > 0.94). Through formulating nanoparticles with PEG-lipids ranging in diffusivity, we further identified a highly diffusible PEG-lipid which provided the most pronounced neuroblastoma cell binding, PLK1 silencing, and significantly reduced cancer growth in vitro in high-risk neuroblastoma cell cultures and in vivo in a tumor-xenograft mouse model of the disease. Together, this work provides an insight on the role of PEG-lipid diffusivity and EGFR targeting as potentially relevant variables influencing the therapeutic efficacy of siRNA nanoparticles in high-risk neuroblastoma.

Lipopolymer mediated siRNA delivery targeting aberrant oncogenes for effective therapy of myeloid leukemia in preclinical animal models.

The clinical development of tyrosine kinase inhibitors (TKI) has led to great strides in improving the survival of chronic myeloid leukemia (CML) and acute myeloid leukemia (AML) patients. But even the new generation TKIs are rendered futile in the face of evolving landscape of acquired mutations leading to drug resistance, necessitating the pursuit of alternative therapeutic approaches. In contrast to exploiting proteins as targets like most conventional drugs and TKIs, RNA Interference (RNAi) exerts its therapeutic action towards disease-driving aberrant genes. To realize the potential of RNAi, the major challenge is to efficiently deliver the therapeutic mediator of RNAi, small interfering RNA (siRNA) molecules. In this study, we explored the feasibility of using aliphatic lipid (linoleic acid and lauric acid)-grafted polymers (lipopolymers) for the delivery of siRNAs against the FLT3 oncogene in AML and BCR-ABL oncogene in CML. The lipopolymer delivered siRNA potently suppressed the proliferation AML and CML cells via silencing of the targeted oncogenes. In both AML and CML subcutaneous xenografts generated in NCG mice, intravenously administered lipopolymer/siRNA complexes displayed significant inhibitory effect on tumor growth. Combining siFLT3 complexes with gilteritinib allowed for reduction of effective drug dosage, longer duration of remission, and enhanced survival after relapse, compared to gilteritinib monotherapy. Anti-leukemic activity of siBCR-ABL complexes was similar in wild-type and TKI-resistant cells, and therapeutic efficacy was confirmed in vivo through prolonged survival of the NCG hosts systemically implanted with TKI-resistant cells. These results demonstrate the preclinical efficacy of lipopolymer facilitated siRNA delivery, providing a novel therapeutic platform for myeloid leukemias.

Exosome-based WTAP siRNA delivery ameliorates myocardial ischemia-reperfusion injury.

Myocardial ischemia/reperfusion (MI/R) injury is the primary cause of postischemicheartfailure. The increased expression of Thioredoxin-interacting protein (TXNIP) has been implicated in MI/R injury, although the detailed mechanism remains incompletely understood. In the present study, we observed the up-regulation of the m6A mRNA methylation complex component Wilms' tumor 1-associating protein (WTAP) in MI/R mice, which led to the m6A modification of TXNIP mRNA and an increase in mRNA abundance. Knock-down of WTAP resulted in a significant reduction in the m6A level of TXNIP mRNA and down-regulated TXNIP expression. Moreover, exosomes engineered with ischemic myocardium-targeting peptide (IMTP) were able to deliver WTAP siRNA into ischemic myocardial tissues, resulting in a specific gene knockdown and myocardial protection. In summary, our findings demonstrate that the WTAP-TXNIP regulatory axis plays a significant role in postischemicheartfailure, and the use of engineered exosomes targeting the ischemic heart shows promise as a strategy for siRNA therapy to protect the heart from injury.

Enhancing Gene Therapy through Ultradeformable Vesicles for Efficient siRNA Delivery.

Gene therapy is a revolutionary approach aimed at treating various diseases by manipulating the expression of specific genes. The composition and formulation of ultra-deformable vesicles play a crucial role in determining their properties and performance as siRNA delivery vectors. In the development of ultra-deformable vesicles for siRNA delivery, careful lipid selection and optimization are crucial for achieving desirable vesicle characteristics and efficient siRNA encapsulation and delivery. The stratum corneum acts as a protective barrier, limiting the penetration of molecules, including siRNA, into the deeper layers of the skin. Ultradeformable vesicles offer a promising solution to overcome this barrier and facilitate efficient siRNA delivery to target cells in the skin. The stratum corneum, the outermost layer of the skin, acts as a significant barrier to the penetration of siRNA.These engineering approaches enable the production of uniform and well-defined vesicles with enhanced deformability and improved siRNA encapsulation efficiency. Looking ahead, advancements in ultra-deformable vesicle design and optimization, along with continued exploration of combination strategies and regulatory frameworks, will further drive the field of ultra-deformable vesicle-based siRNA delivery.

Tet1 peptide and zinc (II)-adenine multifunctional module functionalized polycations as efficient siRNA carriers for Parkinson's disease.

A bioreducible Zn (II)-adenine multifunctional module (BS) and Tet1 peptide were used to modify low-molecular-weight PEI3.5k (polyethyleneimine with molecular weight of 3.5 kDa)into a siRNA vector Zn-PB-T with high transfection efficiency in neurons. A GSH-responsive breakable disulfide spacer was introduced into BS to realize the controlled release of siRNA from the polyplexes in cytoplasm. Zn-PB showed >90% transfection rates in multiple cell lines (3 T3, HK-2, HepG2, 293 T, HeLa, PANC-1)，and 1.8-folds higher EGFP knockdown rates than commercial Lipo2k in normal cell line 293 T and cancer cell line HepG2. And Zn-PB-T1 showed 4.7-4.9- and 8.0-8.1-folds higher transfection efficiency comparing to commercial Lipo2k and PEI25k (polyethyleneimine with molecular weight of 25 kDa) in PC12 cells respectively, 2.1-fold EGFP gene silencing efficiency (96.6% EGFP knockdown rates) superior to commercial Lipo2k in neurons. In Parkinson's model, Zn-PB-T1/SNCA-siRNA can effectively protect neurons against MPP+-induced cell death and apoptosis, increasing the cell survival rate to 84.6% and reducing the cell apoptosis rate to 10.8%. This work demonstrated the promising application prospects of the resulting efficient siRNA carriers in siRNA-mediated gene therapy of Parkinson's disease.