Rekindling RNAi Therapy: Materials Design Requirements for In Vivo siRNA Delivery

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-Based Nanoparticles for Twist1 Knockdown in 4T1 Cells

Bone metastasized breast cancer reduces the quality of life and median survival. Targeted delivery of twist1-siRNA using nanoparticles (NPs) is a promising strategy to overcome current limitations in treating such metastatic breast cancers. This research evaluates two types of chitosan (CHI)-based NPs for the delivery of twist1-siRNA. Alendronate conjugated PEG functionalized chitosan (ALD-PEG-CHI) NPs are developed for active targeting while PEG functionalized CHI (mPEG-CHI) NPs are fabricated for passive targeting. The size of twist1-siRNA-loaded NPs is below 70 nm and the zeta potential is near neutral for both types of NPs. Based on gel retardation assay, complete encapsulation of twist1-siRNA is achieved in both NP systems. The ALD-PEG-CHI-siRNA and mPEG-CHI-siRNA NPs display serum protection for 6 and 4 h, respectively, compared to the immediate degradation of naked twist1-siRNA. The NPs can knockdown twist1 in 4T1 cells as demonstrated through protein expression as well as by phenotypic change in directional cell migration by wound healing assay. Overall, these in vitro results illustrate the potential of the NPs as an effective therapeutic system for bone metastasized breast cancer.

A Metformin-Based Multifunctional Nanoplatform as a DNA Damage Amplifier for Maximized Radio-Immunotherapy to Overcome Radiotherapy Resistance

Radiotherapy (RT) has been highlighted to be an effective strategy for antitumor immunity activation by causing direct DNA damages, but it generally suffers from low response rates due to the compromised cytosolic DNA (cDNA) recognition by cyclic GMP-AMP synthase (cGAS). Simultaneous DNA repair and clearance system regulation for enhanced cDNA accumulation is a useful approach to improve immune response rates, which remains seldom reported to our knowledge. Here, we report the construction of a metformin (MET)-based multifunctional nanocomplex, CS-MET/siTREX1 (CSMT), consisting of biguanide-decorated CS (CS-MET) as the vector and 3'-5' DNA exonuclease TREX1 siRNA (siTREX1) as the therapeutic gene for RT-induced antitumor immunity enhancement by amplifying the initial DNA damage signals. The uniqueness of this study is the development of CSMT as a specific DNA damage amplifier to promote cDNA accumulation for maximizing radio-immunotherapy and circumventing RT resistance. Specifically, the CSMT nanocomplexes show not only enhanced gene transfection efficiency by MET modification but also synergistic therapeutic effects including MET's inhibition on DNA repair and siTREX1's attenuation on cDNA clearance, which leads to the greatest inhibitory effect in a Hepa1-6 proximal/distal tumor model with a high tumor growth inhibition (TGI) value of 99.1% for the primary tumor and significantly compromised distal tumor growth by inducing immunogenic cell death (ICD), promoting tumor-associated neutrophil (TAN) polarization, and stimulating tumor-specific memory T-cell generation. Overall, the CSMT nanocomplexes developed herein hold great translatable promises for overcoming RT resistance in clinics.

Overcoming matrix barriers for enhanced immune infiltration using siRNA-coated metal-organic frameworks

The extracellular matrix (ECM) of solid tumor constitutes a formidable physical barrier that impedes immune cell infiltration, contributing to immunotherapy resistance. Breast cancer, particularly triple-negative breast cancer (TNBC), is characterized by a collagen-rich tumor microenvironment, which is associated with T cell exclusion and poor therapeutic outcomes. Discoidin domain receptor 2 (DDR2) and integrins, key ECM regulatory receptors on cancer cells, play pivotal role in maintaining this barrier. In this study, we developed a dual-receptor-targeted strategy using metal-organic frameworks (MOFs) to deliver DDR2-specific siRNA (siDDR2) and ITGAV-specific siRNA (siITGAV) to disrupt the ECM barrier. siDDR2 modulates immune infiltration by regulating collagen-cell interactions, while siITGAV suppresses TGF-β1 activation. The MOF@siDDR2+siITGAV complex significantly reduced collagen deposition, enhanced CD8+ T cell infiltration, and downregulated programmed cell death ligand 1 (PD-L1) expression in TNBC. Consequently, this approach markedly inhibited tumor growth. Our findings demonstrate that dual-receptor-targeted MOF-based nanocarriers (MOF@siDDR2+siITGAV) can effectively reprogram the tumor ECM to enhance immune cell access, offering a promising prospect for synergistic cancer immunotherapy. STATEMENT OF SIGNIFICANCE: A dual-receptor-targeted MOF nanocarrier is developed to improve immune accessibility in tumors. Concurrent blockade of DDR2 and ITGAV effectively decreases collagen deposition, increases CD8+ T cell infiltration, and suppresses PD-L1 expression. Modulating the mechanical properties of the extracellular matrix (ECM) to enhance immune accessibility offers an innovative strategy for cancer treatment.

ZIF-8-Modified Multifunctional Hydrogel Loading siRNA and DOX for Postoperative Therapy of Maxillofacial Osteosarcoma and Bone Repair

The primary clinical challenges associated with postoperative maxillofacial osteosarcoma include high mortality rates and significant local recurrence. Additionally, patients often exhibit substantial bone defects that are incapable of self-healing, necessitating the implantation of scaffolds. Multifunctional hydrogels, which enable sustained local release of therapeutic agents and enhance scaffold surface properties, demonstrate significant potential for the postoperative management of maxillofacial osteosarcoma. In this study, doxorubicin (DOX) and PD-L1 siRNA were initially loaded into ZIF-8 to synthesize highly stable nanocomplex RNA-DOX@ZIF-8 (RDZ). Subsequently, a multifunctional hydrogel (Gel@RDZ) was fabricated by uniformly mixing RDZ with catechol-modified chitosan. Gel@RDZ exhibits a high drug-loading capacity, excellent viscoelasticity, and strong scaffold adhesion. In a rat femoral defect model, the Gel@RDZ-coated scaffold group demonstrated superior bone regeneration capabilities. Furthermore, in a murine osteosarcoma recurrence model, Gel@RDZ exhibited optimal immune cell infiltration, substantially reduced tumor recurrence, and markedly enhanced the tumor-killing efficacy of CD8+ T cells. Therefore, the development of a multifunctional hydrogel system (Gel@RDZ) provides a comprehensive treatment for postoperative maxillofacial osteosarcoma.

ATP-responsive tumor targeted lipid nanoparticle for enhanced siRNA delivery and improved treatment efficacy in melanoma

Small interfering RNA (siRNA) plays a crucial role in tumor therapy, especially for non-druggable targets with obvious advantages. Nevertheless, its molecular weight, negative charge, and susceptibility to degradation hinder effective delivery to tumor cells for therapeutic action. Lipid nanoparticles (LNPs) serve as an excellent delivery mechanism for siRNA but still face problems such as suboptimal tumor targeting and inefficient intracellular release. To enhance melanoma treatment, we designed lipid nanoparticles modified with phenylboronic acid (PBA) for efficient delivery of siRNA targeting "undruggable" microphthalmia-associated transcription factor (MITF). This nanocarrier successfully encapsulated siRNA and improved tumor targeting by allowing phenylboronic acid to interact with sialic acid residues overexpressed in tumor cells. Furthermore, PBA-modified lipid nanoparticles facilitated the ATP-responsive release of siRNA intracellular. These two aspects enhance gene silencing efficiency. The in vivo targeting and gene silencing capabilities of PBA-modified lipid nanoparticles significantly surpassed those of unmodified LNP. Additionally, PBA-modified nanoparticles exhibited considerable anti-tumor and anti-metastatic effects in animal models, offering an alternative approach for siRNA therapy.

Current landscape of metal-organic framework-mediated nucleic acid delivery and therapeutics

Nucleic acid drugs utilize DNA or RNA molecules to modulate abnormal gene expression or protein translation in cells, enabling precise treatment for specific conditions. In recent years, nucleic acid drugs have demonstrated tremendous potential in vaccine development and treating genetic disorders. Currently, the primary carriers for clinically approved nucleic acid therapies include lipid nanoparticles and viral vectors. Beyond that, metal-organic frameworks (MOFs) are highly ordered, porous nanomaterials formed through the self-assembly of metal ions and organic ligands via coordination bonds. Their porosity structure offers great loading efficiency, stability, tunability, and biocompatibility, making them an attractive option for nucleic acid delivery. Given the research on MOFs as nucleic acid carriers has garnered significant attention in recent years, this review provides an overview of the therapeutic strategies and advancements in MOF-mediated nucleic acid delivery. The unique properties of various MOF carriers are introduced, and different approaches for nucleic acid loading are parallelly compared. Moreover, a systematic classification based on the type of nucleic acid cargo loaded in MOFs and corresponding applications is thoroughly described. This summary outlines the unique mechanisms through MOFs enhance nucleic acid delivery and emphasizes their substantial impact on therapeutic efficacy. In addition, the utilization of MOF-mediated nucleic acid treatment in combination with other therapies against malignant tumors is discussed in particular. Finally, an outlook on the challenges and potential opportunities of this technology in future translational production and clinical implementation is presented and explored.

A Smart mRNA-Initiated Theranostic Multi-shRNA Nanofactory for Precise and Efficient Cancer Gene Therapy

Despite the significant potential of short hairpin RNA (shRNA)-mediated gene therapy for various diseases, the clinical success of cancer treatment remains poor, partly because of low selectivity and low efficiency. In this study, an mRNA-initiated autonomous multi-shRNA nanofactory (RNF@CM) is designed for in vivo amplification imaging and precise cancer treatment. The RNF@CM consists of a gold nanoparticle core, an interlayer of two types of three-stranded DNA/RNA hybrid probes, one of which is bound to aptamer-inhibited DNA polymerases, and an outer layer of the cancer cell membrane. After the specific delivery of RNF@CM into target cancer cells, an intracellular tumour-related mRNA target can initiate the RNF@CM with a circular strand-displacement polymerisation reaction, resulting in the release of significantly amplified fluorescence and continuous production of three types of shRNAs. The RNF@CM effectively distinguished cancer cells from normal cells, exclusively produced multiple shRNAs in response to a specific mRNA target in cancer cells, accurately diagnosed tumours in vivo, and significantly inhibited tumour growth with negligible toxicity, expanding the toolbox for on-demand gene delivery and precision theranostics.

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.

Multi-functional near-infrared fluorescent polymer dot-siRNA for gene expression regulation

Regulation of gene expression in eukaryotic cells is critical for cell survival, proliferation, and cell fate determination. Misregulation of gene expression can have substantial, negative consequences that result in disease or tissue dysfunction that can be targeted for therapeutic intervention. Several strategies to inhibit gene expression at the level of mRNA transcription and translation have been developed, such as anti-sense inhibition and CRISPR-Cas9 gene editing. However, these strategies have some limitations in terms of specificity, toxicity, and ease of use. We have designed a nanomaterials-based tool to inhibit gene expression in eukaryotic cells with a potential application in basic and biomedical research. At the heart of our rational design approach is a polymer dots (Pdots)-based nanoplatform that can provide a means to deliver gene-specific small interfering (siRNA) into cells while at the same time providing a visualization mechanism to determine which cells have taken up the siRNA. The Pdots that we designed and synthesized had an average size 64.25 ± 0.60 nm and a zeta potential that was +37.40 ± 8.28 mV. The Pdot-1 nmole Gapdh siRNA showed an average size of 82.27 ± 9.83 nm, with the zeta potential values determined to be -52.00 ± 6.05 mV in the HEPES buffer. Both Pdots and Pdot-siRNA displayed two emission peaks in the visible (588 nm) and near-infrared (NIR) emission range (775 nm). We treated primary cultures of mouse brain-derived microvascular cells with Pdot-Gapdh siRNA and observed uniform cellular uptake of the nanomaterial in the cells and reduced intensity of Gapdh immunolabeling. Our results highlight the potential application of Pdot-siRNA for gene expression targeting with simultaneous visual monitoring of Pdot-siRNA delivery. The simple design offers a flexible and novel strategy to inhibit a wide range of mRNA targets with minimal toxicity, high efficiency, and focused cell visualization.

A Manual for Genome and Transcriptome Engineering

Genome and transcriptome engineering have emerged as powerful tools in modern biotechnology, driving advancements in precision medicine and novel therapeutics. In this review, we provide a comprehensive overview of the current methodologies, applications, and future directions in genome and transcriptome engineering. Through this, we aim to provide a guide for tool selection, critically analyzing the strengths, weaknesses, and best use cases of these tools to provide context on their suitability for various applications. We explore standard and recent developments in genome engineering, such as base editors and prime editing, and provide insight into tool selection for change of function (knockout, deletion, insertion, substitution) and change of expression (repression, activation) contexts. Advancements in transcriptome engineering are also explored, focusing on established technologies like antisense oligonucleotides (ASOs) and RNA interference (RNAi), as well as recent developments such as CRISPR-Cas13 and adenosine deaminases acting on RNA (ADAR). This review offers a comparison of different approaches to achieve similar biological goals, and consideration of high-throughput applications that enable the probing of a variety of targets. This review elucidates the transformative impact of genome and transcriptome engineering on biological research and clinical applications that will pave the way for future innovations in the field.

Tetrahedral DNA Framework-Based Spherical Nucleic Acids for Efficient siRNA Delivery

Spherical nucleic acids (SNAs) hold substantial therapeutic potential for the delivery of small interfering RNAs (siRNAs). Nevertheless, their potential remains largely untapped due to the challenges of cytosolic delivery. Inspired by the dynamic, spiky architecture of coronavirus, an interface engineering approach based on a tetrahedral DNA framework (tDF) is demonstrated for the development of coronavirus-mimicking SNAs. By exploiting their robustness and precise construction, tDFs are evenly arranged on the surface of core nanoparticles (NPs) with flexible conformations, generating a dynamic, spiky architecture. This spiky architecture in tetrahedral DNA framework-based SNAs (tDF-SNAs) substantially improve siRNAs duplex efficiency from 20 % to 95 %. Meanwhile, tDF-SNAs changed the endocytosis pathway to clathrin-independent cellular engulfment pathway and enhanced the cellular uptake efficiency. Due to these advances, the delivery efficiency of siRNA molecules by tDF-SNAs is 1-2 orders of magnitude higher than that of SNAs, resulting in a 2-fold increase in gene silencing efficacy. These results show promise in the development of bioinspired siRNAs delivery systems for intracellular applications.

A prodrug nanodevice co-delivering docetaxel and ROR1 siRNA for enhanced triple negative breast cancer therapy

Triple-negative breast cancer (TNBC) has been a clinical challenge due to its high recurrence and metastasis rates. Chemotherapy remains the primary treatment for TNBC after surgery ablation, but it lacks targeted specificity and causes side effects in normal tissues. Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is significantly expressed in TNBC cells, and small interference RNA (siRNA) targeting ROR1 can effectively suppress ROR1 gene expression, thereby inhibiting proliferation and metastasis. However, clinical application of ROR1 siRNA is limited by susceptibility to clearance and difficulty in endosomal escape. In this study, the docetaxel (DTX) prodrug nanoparticle BBRM delivering ROR1 siRNA was constructed. The BBRM could be effectively internalized by tumor cells and endosomal escape to release DTX and ROR1 siRNA. In 4T1 tumor-bearing mice, BBRM could be targeting delivered to tumor and lung tissues, with good biosafety, achieving a tumor inhibition rate of 74.1 % and inhibiting lung metastasis. By integrating chemotherapy and RNA interference therapy, BBRM successfully co-delivered chemotherapeutic agents and siRNA to improve the therapeutic efficacy of triple-negative breast cancer and provided a promising strategy for clinical transformation. STATEMENT OF SIGNIFICANCE: Chemotherapy is still the primary treatment for triple-negative breast cancer (TNBC) after surgery ablation, but it causes side effects without targeting capacity. ROR1 is significantly expressed in TNBC cells, and RNA interference for ROR1 can suppress ROR1 gene expression to inhibit tumor proliferation. However, as oligonucleotides, effect of ROR1 siRNA is limited by susceptibility to clearance and difficulty in endosomal escape. In this work, we designed a nanodevice based on a docetaxel (DTX) prodrug that targets ROR1 for the synergistic therapy of TNBC. We constructed a nanoparticle (BBRM) for co-delivery of the DTX and ROR1 siRNA. The BBRM could be effectively internalized by tumor cells and endosomal escape. The ROR1 siRNA downregulated ROR1 protein expression and improved the anti-proliferative and anti-metastatic effects. In addition, BBRM reversed the immunosuppressive tumor microenvironment, thus improving breast cancer therapeutic efficacy. It was a pioneering investigation in synergistic chemo-gene therapy by co-delivering DTX and ROR1 siRNA for TNBC treatment.

T14diLys/DOPE Liposomes: An Innovative Option for siRNA-Based Gene Knockdown?

BACKGROUND/OBJECTIVES

Bringing small interfering RNA (siRNA) into the cell cytosol to achieve specific gene silencing is an attractive but also very challenging option for improved therapies. The first step for successful siRNA delivery is the complexation with a permanent cationic or ionizable compound. This protects the negatively charged siRNA and enables transfection through the cell membrane. The current study explores the performance of the innovative, ionizable lipid 2-Tetradecylhexadecanoic acid-(2-bis{[2-(2,6-diamino-1-oxohexyl)amino]ethyl}aminoethyl)-amide (T14diLys), in combination with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), for siRNA delivery and the impact of the production method (sonication vs. extrusion) on the particle properties.

METHODS

Liposomes were produced either with sonication or extrusion and characterized. The extruded liposomes were combined with siRNA at different N/P ratios and investigated in terms of size zeta potential, encapsulation efficiency, lipoplex stability against RNase A, and knockdown efficiency using enhanced green fluorescent protein (eGFP)-marked colon adenocarcinoma cells.

RESULTS

The liposomes prepared by extrusion were smaller and had a narrower size distribution than the sonicated ones. The combination of siRNA and liposomes at a nitrogen-to-phosphate (N/P) ratio of 5 had optimal particle properties, high encapsulation efficiency, and lipoplex stability. Gene knockdown tests confirmed this assumption.

CONCLUSIONS

Liposomes produced with extrusion were more reproducible and provided enhanced particle properties. The physicochemical characterization and in vitro experiments showed that an N/P ratio of 5 was the most promising ratio for siRNA delivery.

Direct cytosolic delivery of siRNA via cell membrane fusion using cholesterol-enriched exosomes

Efficient cytosolic delivery is a significant hurdle when using short interfering RNA (siRNA) in therapeutic applications. Here we show that cholesterol-rich exosomes are prone to entering cancer cells through membrane fusion, achieving direct cytosolic delivery of siRNA. Molecular dynamics simulations suggest that deformation and increased contact with the target cell membrane facilitate membrane fusion. In vitro we show that cholesterol-enriched milk-derived exosomes (MEs) achieve a significantly higher gene silencing effect of siRNA, inducing superior cancer cell apoptosis compared with the native and cholesterol-depleted MEs, as well as conventional transfection agents. When administered orally or intravenously to mice bearing orthotopic or subcutaneous tumours, the cholesterol-enriched MEs/siRNA exhibit antitumour activity superior to that of lipid nanoparticles. Collectively, by modulating the cholesterol content of exosome membranes to facilitate cell entry via membrane fusion, we provide a promising approach for siRNA-based gene therapy, paving the way for effective, safe and simple gene therapy strategies.

Sele-targeted siRNA liposome nanoparticles inhibit pathological scars formation via blocking the cross-talk between monocyte and endothelial cells: a preclinical study based on a novel mice scar model

BACKGROUND

Pathological scars (PS) are one of the most common complications in patients with trauma and burns, leading to functional impairments and aesthetic concerns. Mechanical tension at injury sites is a crucial factor in PS formation. However, the precise mechanisms remain unclear due to the lack of reliable animal models.

RESULTS

We developed a novel mouse model, the Retroflex Scar Model (RSM), which induces PS by applying controlled tension to wounds in vivo. RNA sequencing identified significant transcriptome changes in RSM-induced scars. Elevated expression of E-Selectin (Sele) was observed in endothelial cells from both the RSM model and human PS (Keloid) samples. In vitro studies demonstrated that cyclic mechanical stretching (CMS) increased Sele expression, promoting monocyte adhesion and the release of pro-inflammatory factors. Single-cell sequencing analysis from the GEO database, complemented by Western blotting, immunofluorescence, and co-immunoprecipitation, confirmed the role of Sele-mediated monocyte adhesion in PS formation. Additionally, we developed Sele-targeted siRNA liposome nanoparticles (LNPs) to inhibit monocyte adhesion. Intradermal administration of these LNPs effectively reduced PS formation in both in vivo and in vitro studies.

CONCLUSIONS

This study successfully established a reliable mouse model for PS, highlighting the significant roles of mechanical tension and chronic inflammation in PS formation. We identified Sele as a key therapeutic target and developed Sele-targeted siRNA LNPs, which demonstrated potential as a preventive strategy for PS. These findings provide valuable insights into PS pathogenesis and open new avenues for developing effective treatments for pathological scars.

Facile Alkyne Assembly-Enabled Functional Au Nanosheets for Photoacoustic Imaging-Guided Photothermal/Gene Therapy of Orthotopic Glioblastoma

Treatment of glioblastoma (GBM) remains challenging due to the presence of blood-brain barrier (BBB) and tumor heterogeneity. Herein, Au nanosheets (AuNSs) functionalized with RGD peptides and small interfering RNA (siRNA), referred to as AuNSs-RGD-C≡C-siRNA (ARCR), are prepared to achieve multimodal therapy for GBM. The AuNSs with a large modifiable surface area, intriguing photothermal conversion efficiency (50.26%), and remarkable photothermal stability (44 cycles over 7 h) are created using a well-designed amphiphilic surfactant. Furthermore, alkynyl groups are assembled onto the Au surface within 1 min, enabling strong covalent binding of siRNA to AuNSs and thereby avoiding the interference from biological thiols. Owing to the lipophilicity of the surfactant and the targeting property of RGD, ARCR effectively passes through the BBB and accumulates in GBM tumor regions, allowing near-infrared photoacoustic imaging-guided photothermal/gene therapy. This work proposes a facile strategy to construct theranostic Au-based materials, highlighting the potential of multifunctional nanoagents for GBM therapy.

Regulating copper homeostasis of tumor cells to promote cuproptosis for enhancing breast cancer immunotherapy

Cuproptosis is an emerging mode of programmed cell death for tumor suppression but sometimes gets resisted by tumor cells resist under specific mechanisms. Inhibiting copper transporter ATPase (ATP7A) was found to disrupt copper ion homeostasis, thereby enhancing the effect of cuproptosis and eventually inhibiting tumor invasion and metastasis. In this study, we develop a multifunctional nanoplatfrom based on Cu9S8 (CAPSH), designed to enhance cuproptosis in tumor cells by specifically targeting ATP7A interference, while combining thermodynamic therapy with immune effects. The release of copper ions from CAPSH and the copper homeostasis interference by siRNA cooperatively increases the concentration of copper ions in tumor cells, which induces effectively cuproptosis and activates immune responses for suppressing development and metastasis of tumor. This nanoplatform simultaneously regulates cuproptosis from both principles of onset and development, facilitating the application of cuproptosis in tumor therapy.

PEGylation Can Effectively Strike a Balance in siRNA Delivery Performances of Guanidinylated Linear Synthetic Polypeptides with Potential Use for Transcriptional Gene Silencing

The prevailing design philosophy for polymeric vectors delivering siRNA is rooted in the post-transcriptional gene silencing (PTGS) mechanism. Yet, the transcriptional gene silencing (TGS) mechanism offers a potentially more durable silencing effect, which necessitates efficient siRNA delivery into the nucleus. However, it remains a challenge for the polymeric vectors to efficiently deliver siRNA into the nucleus. We have explored guanidinylated cyclic synthetic polypeptides (GCSPs) to enhance the nuclear delivery of siRNA, but an increased cytotoxicity and difficulty in producing the GCSPs on a large scale limit their utility. Herein, we simply prepare PEGylated guanidinylated linear synthetic polypeptides (PGLSPs) exhibiting improved membrane penetration, direct siRNA transport to the nucleus, reduced toxicity, high cellular uptake, and mitigation of protein corona formation. The PEGylation can effectively balance the vector's nuclear delivery capacity with other critical aspects of performances for siRNA delivery. Therefore, the PGLSPs hold promise as TGS-based delivery vectors, offering potential for future therapeutic applications.

Deciphering the role of siRNA in anxiety and depression

Anxiety and depression are central nervous system illnesses that are among the most prevalent medical concerns of the twenty-first century. Patients with this condition and their families bear psychological, financial, and societal hardship. There are currently restrictions when utilizing the conventional course of treatment. RNA interference is expected to become an essential approach in anxiety and depression due to its potent and targeted gene silencing. Silencing of genes by post-transcriptional modification is the mechanism of action of small interfering RNA (siRNA). The suppression of genes linked to disease is typically accomplished by siRNA molecules in an efficient and targeted manner. Unfavourable immune responses, off-target effects, naked siRNA instability, nuclease vulnerability, and the requirement to create an appropriate delivery method are some of the challenges facing the clinical application of siRNA. This review focuses on the use of siRNA in the treatment of anxiety and depression.

Construction of charge-reversible coordination-crosslinked spherical nucleic acids to deliver dual anti-cancer genes and ferroptosis payloads

Spherical nucleic acids (SNAs) are nanostructures with the DNA arranged radially on the surface, thus allowing specific binding with cancer cells expressing high levels of scavenger receptor-A to enhance cellular uptake. However, conventional carriers for SNAs are cytotoxic, not degradable and difficult to deliver multiple payloads. In this study, we developed charge-reversible coordination-crosslinked SNAs to deliver dual anti-cancer genes and ferroptosis payload for anti-cancer purposes. To this end, we modified poly(lactic acid) (PLA) with functionalized side chains to allow its binding with antisense oligonucleotides (ASOs) and siRNA, annealed two single-stranded RNAs to obtain double-stranded RNA, and introduced a polyethylene glycol (PEG) shell to enhance the circulation time. Additionally, the ferroptosis payload imidazole was coordinated with iron ions as a core-crosslinked group to enhance the stability of SNAs and efficiency to kill cancer cells. We demonstrated that this novel nanocomplex efficiently internalized and killed CT-26 cells in vitro. In vivo data confirmed that the dual gene delivery system successfully targeted CT-26 tumors in tumor-bearing BALB/c mice, and exhibited strong tumor suppression ability, without inducing adverse toxic effects. Taken together, our dual gene therapy system offered an enhanced anti-tumor solution by simultaneously delivering dual anti-cancer genes and ferroptosis payload in tumor microenvironment.

Gelatin and lipidoid integrate to create gelasomes to enhance siRNA delivery with low toxicity

RNAi therapeutics possess the potential to cure many uncurable human diseases. For instance, RNAi therapeutics using liposomes showed remarkable survival benefits in patients with liver diseases. However, the extension of liposomes to deliver RNA to cure other ailments has largely been unsuccessful. Therefore, researchers are focusing on designing and testing different combinations of materials for versatile RNA delivery applications. Yet, an efficient and safe RNA delivery platform has not been identified. In this work, we have developed a new class of RNA-delivery vehicle called "Gelasomes," using an incongruous combination of gelatin and lipidoid to exploit each material's unique properties while overcoming their inherent limitations. The low in vivo toxicity of Gelasomes is attributed to the exterior gelatin layers that shield the exposure of cationic lipidoid-siRNA clusters and yet present a biocompatible surface. Indeed, toxicity studies in mice indicate that repeated administration of Gelasomes (up to 48 mg/kg BW) is well-tolerated with no notable changes in body weight, hematology, or serum chemistry. Interestingly, the gelatin outer layer efficiently protects siRNA from serum degradation (48 h), preserving its functionality beyond two months of storage. Notably, Gelasomes possess dual siRNA conjugation modes, i.e., electrostatic binding with lipidoid core and covalent attachment to gelatin surface. The bivalency coupled with lipidoids' high transfection efficiency rendered Gelasomes with remarkably high gene silencing efficiency (>90 %) at very low treatment doses in vitro (40 μg/mL). In vivo studies further confirmed the high gene silencing ability of Gelasomes in non-small cell lung tumor mouse models. This new platform is tunable on all fronts: size, degree of surface coating, and biomolecule functionalization. Truncating the lipidoid C14-tail to a C8-tail yielded Gelasomes of reduced size. As lipidoids with different carbon lengths are synthesizable, we can develop a library of Gelasomes with different sizes. The surface coating with less gelatin resulted in high transfection efficiency at low doses of Gelasomes. The structure of Gelasomes offers chemical handles to couple target-specific molecules like antibodies to tune their properties for efficient biological application.

Polymers as Efficient Non-Viral Gene Delivery Vectors: The Role of the Chemical and Physical Architecture of Macromolecules

Gene therapy is the technique of inserting foreign genetic elements into host cells to achieve a therapeutic effect. Although gene therapy was initially formulated as a potential remedy for specific genetic problems, it currently offers solutions for many diseases with varying inheritance patterns and acquired diseases. There are two major groups of vectors for gene therapy: viral vector gene therapy and non-viral vector gene therapy. This review examines the role of a macromolecule's chemical and physical architecture in non-viral gene delivery, including their design and synthesis. Polymers can boost circulation, improve delivery, and control cargo release through various methods. The prominent examples discussed include poly-L-lysine, polyethyleneimine, comb polymers, brush polymers, and star polymers, as well as hydrogels and natural polymers and their modifications. While significant progress has been made, challenges still exist in gene stabilization, targeting specificity, and cellular uptake. Overcoming cytotoxicity, improving delivery efficiency, and utilizing natural polymers and hybrid systems are vital factors for prospects. This comprehensive review provides an illuminating overview of the field, guiding the way toward innovative non-viral-based gene delivery solutions.

DNA/RNA heteroduplex technology with cationic oligopeptide reduces class-related adverse effects of nucleic acid drugs

Antisense oligonucleotides (ASOs) are a therapeutic modality for incurable diseases. However, systemic injection of gapmer-type ASOs causes class-related toxicities, including prolongation of activated partial thromboplastin time (aPTT) and thrombocytopenia. We previously reported that cholesterol-conjugated DNA/RNA heteroduplex oligonucleotides (Chol-HDOs) exhibit significantly enhanced gene-silencing effects compared to ASOs, even in the central nervous system, by crossing the blood-brain barrier. In the present study, we initially evaluated the effect of the HDO structure on class-related toxicities. The HDO structure ameliorated the class-related toxicities associated with ASOs, but they remained to some extent. As a further antidote, we have developed artificial cationic oligopeptides, L-2,4-diaminobutanoic acid oligomers (DabOs), which bind to the phosphates in the major groove of the A-type double-helical structure of HDOs. The DabO/Chol-HDO complex showed significantly improved aPTT prolongation and thrombocytopenia in mice while maintaining gene-silencing efficacy. Moreover, the conjugation with DabOs effectively prevented cerebral infarction, a condition frequently observed in mice intravenously injected with high-dose Chol-HDO. These approaches, combining HDO technology with DabOs, offer distinct advantages over conventional strategies in reducing toxicities. Consequently, the DabO/HDO complex represents a promising platform for overcoming the class-related toxicities associated with therapeutic ASOs.

Non-viral vectors combined delivery of siRNA and anti-cancer drugs to reverse tumor multidrug resistance

Multidrug resistance (MDR) of tumors is one of the main reasons for the failure of chemotherapy. Multidrug resistance refers to the cross-resistance of tumor cells to multiple antitumor drugs with different structures and mechanisms of action. Current strategies to reverse multidrug resistance in tumors include MDR inhibitors and RNAi technology. siRNA is a small molecule RNA that is widely used in RNAi technology and has the characteristics of being prepared in large quantities and chemically modified. However, siRNA is susceptible to degradation in vivo. The effect of siRNA therapy alone is not ideal, so siRNA and anticancer drugs are administered in combination to reverse the MDR of tumors. Non-viral vectors are now commonly used to deliver siRNA and anticancer drugs to tumor sites. This article will review the progress of siRNA and chemotherapeutic drug delivery systems and their mechanisms for reversing multidrug resistance.

Advanced gene therapy system for the treatment of solid tumour: A review

In contrast to conventional therapies that require repeated dosing, gene therapy can treat diseases by correcting defective genes after a single transfection and achieving cascade amplification, and has been widely studied in clinical settings. However, nucleic acid drugs are prone to catabolism and inactivation. A variety of nucleic acid drug vectors have been developed to protect the target gene against nuclease degradation and increase the transformation efficiency and safety of gene therapy. In addition, gene therapy is often combined with chemotherapy, phototherapy, magnetic therapy, ultrasound, and other therapeutic modalities to improve the therapeutic effect. This review systematically introduces ribonucleic acid (RNA) interference technology, antisense oligonucleotides, and clustered regularly interspaced short palindromic repeat/CRISPR-associated nuclease 9 (CRISPR/Cas9) genome editing. It also introduces the commonly used nucleic acid drug vectors, including viral vectors (adenovirus, retrovirus, etc.), organic vectors (lipids, polymers, etc.), and inorganic vectors (MOFs, carbon nanotubes, mesoporous silica, etc.). Then, we describe the combined gene therapy modalities and the pathways of action and report the recent applications in solid tumors of the combined gene therapy. Finally, the challenges of gene therapy in solid tumor treatment are introduced, and the prospect of application in this field is presented.

Polymer-DNA Carriers Co-Deliver Photosensitizer and siRNA for Light-Promoted Gene Transfection and Hypoxia-Relieved Photodynamic Therapy

Photochemical internalization is an efficient strategy relying on photodynamic reactions to promote siRNA endosomal escape for the success of RNA-interference gene regulation, which makes gene-photodynamic combined therapy highly synergistic and efficient. However, it is still desired to explore capable carriers to improve the delivery efficiency of the immiscible siRNA and organic photosensitizers simultaneously. Herein, we employ a micellar nanostructure (PSNA) self-assembled from polymer-DNA molecular chimeras to fulfill this task. PSNA can plentifully load photosensitizers in its hydrophobic core simply by the nanoprecipitation method. Moreover, it can organize siRNA self-assembly by the densely packed DNA shell, which leads to a higher loading capacity than the typical electrostatic condensation method. The experimental results prove that this PSNA carrier can greatly facilitate siRNA escape from the endosome/lysosome and enhance transfection. Accordingly, the PSNA-administrated therapy exhibits a significantly improved anti-tumor efficacy owing to the highly efficient co-delivery capability.

Unveiling the PDK4-centered rituximab-resistant mechanism in DLBCL: the potential of the "Smart" exosome nanoparticle therapy

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) represents a prevalent malignant tumor, with approximately 40% of patients encountering treatment challenges or relapse attributed to rituximab resistance, primarily due to diminished or absent CD20 expression. Our prior research identified PDK4 as a key driver of rituximab resistance through its negative regulation of CD20 expression. Further investigation into PDK4's resistance mechanism and the development of advanced exosome nanoparticle complexes may unveil novel resistance targets and pave the way for innovative, effective treatment modalities for DLBCL.

METHODS

We utilized a DLBCL-resistant cell line with high PDK4 expression (SU-DHL-2/R). We infected it with short hairpin RNA (shRNA) lentivirus for RNA sequencing, aiming to identify significantly downregulated mRNA in resistant cells. Techniques including immunofluorescence, immunohistochemistry, and Western blotting were employed to determine PDK4's localization and expression in resistant cells and its regulatory role in phosphorylation of Histone deacetylase 8 (HDAC8). Furthermore, we engineered advanced exosome nanoparticle complexes, aCD20@ExoCTX/siPDK4, through cellular, genetic, and chemical engineering methods. These nanoparticles underwent characterization via Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM), and their cellular uptake was assessed through flow cytometry. We evaluated the nanoparticles' effects on apoptosis in DLBCL-resistant cells and immune cells using CCK-8 assays and flow cytometry. Additionally, their capacity to counteract resistance and exert anti-tumor effects was tested in a resistant DLBCL mouse model.

RESULTS

We found that PDK4 initiates HDAC8 activation by phosphorylating the Ser-39 site, suppressing CD20 protein expression through deacetylation. The aCD20@ExoCTX/siPDK4 nanoparticles served as effective intracellular delivery mechanisms for gene therapy and monoclonal antibodies, simultaneously inducing apoptosis in resistant DLBCL cells and triggering immunogenic cell death in tumor cells. This dual action effectively reversed the immunosuppressive tumor microenvironment, showcasing a synergistic therapeutic effect in a subcutaneous mouse tumor resistance model.

CONCLUSIONS

This study demonstrates that PDK4 contributes to rituximab resistance in DLBCL by modulating CD20 expression via HDAC8 phosphorylation. The designed exosome nanoparticles effectively overcome this resistance by targeting the PDK4/HDAC8/CD20 pathway, representing a promising approach for drug delivery and treating patients with Rituximab-resistant DLBCL.

Bacteria extracellular vesicle as nanopharmaceuticals for versatile biomedical potential

Bacteria extracellular vesicles (BEVs), characterized as the lipid bilayer membrane-surrounded nanoparticles filled with molecular cargo from parent cells, play fundamental roles in the bacteria growth and pathogenesis, as well as facilitating essential interaction between bacteria and host systems. Notably, benefiting from their unique biological functions, BEVs hold great promise as novel nanopharmaceuticals for diverse biomedical potential, attracting significant interest from both industry and academia. Typically, BEVs are evaluated as promising drug delivery platforms, on account of their intrinsic cell-targeting capability, ease of versatile cargo engineering, and capability to penetrate physiological barriers. Moreover, attributing to considerable intrinsic immunogenicity, BEVs are able to interact with the host immune system to boost immunotherapy as the novel nanovaccine against a wide range of diseases. Towards these significant directions, in this review, we elucidate the nature of BEVs and their role in activating host immune response for a better understanding of BEV-based nanopharmaceuticals' development. Additionally, we also systematically summarize recent advances in BEVs for achieving the target delivery of genetic material, therapeutic agents, and functional materials. Furthermore, vaccination strategies using BEVs are carefully covered, illustrating their flexible therapeutic potential in combating bacterial infections, viral infections, and cancer. Finally, the current hurdles and further outlook of these BEV-based nanopharmaceuticals will also be provided.

Inhibition of SARS-CoV-2 Replication by Self-Assembled siRNA Nanoparticles Targeting Multiple Highly Conserved Viral Sequences

Coronavirus infectious disease 2019 (COVID-19), caused by severe acute respiratory virus type 2 (SARS-CoV-2), has caused a global public health crisis. As an RNA virus, the high gene mutability of SARS-CoV-2 poses significant challenges to the development of broad-spectrum vaccines and antiviral therapeutics. There remains a lack of specific therapeutics directly targeting SARS-CoV-2. With the ability to efficiently inhibit the expression of target genes in a sequence-specific way, small interfering RNA (siRNA) therapy has exhibited significant potential in antiviral and other disease treatments. In this work, we presented a highly effective self-assembled siRNA nanoparticle targeting multiple highly conserved regions of SARS-CoV-2. The siRNA sequences targeting viral conserved regions were first screened and evaluated by their thermodynamic features, off-target effects, and secondary structure toxicities. RNA motifs including siRNA sequences were then designed and self-assembled into siRNA nanoparticles. These siRNA nanoparticles demonstrated remarkable uniformity and stability and efficiently entered cells directly through cellular endocytic pathways. Moreover, these nanoparticles effectively inhibited the replication of SARS-CoV-2, exhibiting a superior inhibitory effect compared to free siRNA. These results demonstrated that these self-assembled siRNA nanoparticles targeting highly conserved regions of SARS-CoV-2 represent highly effective antiviral candidates for the treatment of infections, and are promisingly effective against current and future viral variants.

Dual-Targeted Novel Temozolomide Nanocapsules Encapsulating siPKM2 Inhibit Aerobic Glycolysis to Sensitize Glioblastoma to Chemotherapy

Chemotherapy of glioblastoma (GBM) has not yielded success due to inefficient blood-brain barrier (BBB) penetration and poor glioma tissue accumulation. Aerobic glycolysis, as the main mode of energy supply for GBM, safeguards the rapid growth of GBM while affecting the efficacy of radiotherapy and chemotherapy. Therefore, to effectively inhibit aerobic glycolysis, increase drug delivery efficiency and sensitivity, a novel temozolomide (TMZ) nanocapsule (ApoE-MT/siPKM2 NC) is successfully designed and prepared for the combined delivery of pyruvate kinase M2 siRNA (siPKM2) and TMZ. This drug delivery platform uses siPKM2 as the inner core and methacrylate-TMZ (MT) as the shell component to achieve inhibition of glioma energy metabolism while enhancing the killing effect of TMZ. By modifying apolipoprotein E (ApoE), dual targeting of the BBB and GBM is achieved in a "two birds with one stone" style. The glutathione (GSH) responsive crosslinker containing disulfide bonds ensures "directional blasting" cleavage of the nanocapsules to release MT and siPKM2 in the high GSH environment of glioma cells. In addition, in vivo experiments verify that ApoE-MT/siPKM2 NC has good targeting ability and prolongs the survival of tumor-bearing nude mice. In summary, this drug delivery system provides a new strategy for metabolic therapy sensitization chemotherapy.

Principle, application and challenges of development siRNA-based therapeutics against bacterial and viral infections: a comprehensive review

While significant progress has been made in understanding and applying gene silencing mechanisms and the treatment of human diseases, there have been still several obstacles in therapeutic use. For the first time, ONPATTRO, as the first small interfering RNA (siRNA) based drug was invented in 2018 for treatment of hTTR with polyneuropathy. Additionally, four other siRNA based drugs naming Givosiran, Inclisiran, Lumasiran, and Vutrisiran have been approved by the US Food and Drug Administration and the European Medicines Agency for clinical use by hitherto. In this review, we have discussed the key and promising advances in the development of siRNA-based drugs in preclinical and clinical stages, the impact of these molecules in bacterial and viral infection diseases, delivery system issues, the impact of administration methods, limitations of siRNA application and how to overcome them and a glimpse into future developments.

Recent Progress in Nucleic Acid Pulmonary Delivery toward Overcoming Physiological Barriers and Improving Transfection Efficiency

Pulmonary delivery of therapeutic agents has been considered the desirable administration route for local lung disease treatment. As the latest generation of therapeutic agents, nucleic acid has been gradually developed as gene therapy for local diseases such as asthma, chronic obstructive pulmonary diseases, and lung fibrosis. The features of nucleic acid, specific physiological structure, and pathophysiological barriers of the respiratory tract have strongly affected the delivery efficiency and pulmonary bioavailability of nucleic acid, directly related to the treatment outcomes. The development of pharmaceutics and material science provides the potential for highly effective pulmonary medicine delivery. In this review, the key factors and barriers are first introduced that affect the pulmonary delivery and bioavailability of nucleic acids. The advanced inhaled materials for nucleic acid delivery are further summarized. The recent progress of platform designs for improving the pulmonary delivery efficiency of nucleic acids and their therapeutic outcomes have been systematically analyzed, with the application and the perspectives of advanced vectors for pulmonary gene delivery.

Co-Delivery of siNRF2 and Sorafenib by a "Click" Dual Functioned Hyperbranched Nanocarrier for Synergistically Inducing Ferroptosis in Hepatocellular Carcinoma

In the course of antitumor therapy, the complex tumor microenvironment and drug-mediated changes in cell signaling and biological processes lead to drug resistance. The effect of sorafenib is greatly limited by the specific tumor microenvironment induced by antiangiogenic therapy and ferroptosis resistance induced by the upregulation of nuclear factor erythroid-2 related factor 2 (NRF2). In this study, a pH responsive and amphiphilic hyperbranched polyglycerol, HDP, is synthesized based on a co-graft click chemistry pathway. This nano-scale carrier provides excellent drug-loading capacity, storing stability and pH responsibility, and effectively co-delivery of sorafenib and siRNA. Sorafenib and siNRF2 plays a greatly synergistic effect in inducing reactive oxygen species (ROS), iron overloading, depleting glutathione (GSH), and promoting lipid peroxidation. Importantly, verified in two different animal experiments, HDP-ss (HDP loaded with both siNRF2 and sorafenib) presents a superior anti-tumor effect, by achieving a tumor inhibition rate of ≈94%. Thus, HDP can serve as an excellent targeted delivery nanocarrier with good biocompatibility in antitumor therapy, and combined application of siNRF2 effectively improves the antitumor effect of sorafenib by overcoming NRF2-mediated ferroptosis resistance. Taken together, this study provides a novel therapeutic strategy to combat the drug resistance in antiangiogenic therapy and ferroptosis.

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.

Selenium-Containing Nanocomplexes Achieve Dual Immune Checkpoint Blockade for NK Cell Reinvigoration

The blockade of immune checkpoints has emerged as a promising strategy for cancer immunotherapy. However, most of the current approaches focus on T cells, leaving natural killer (NK) cell-mediated therapeutic strategies rarely explored. Here, a selenium-containing nanocomplex is developed that acts as a dual immune checkpoint inhibitor to reinvigorate NK cell-based cancer immunotherapy. The Se nanocomplex can deliver and release siRNA that targets programmed death ligand-1 (PD-L1) in tumor cells, thereby silencing the checkpoint receptor PD-L1. The intracellular reactive oxygen species generated by porphyrin derivatives in the nanocomplexes can oxidize the diselenide bond into seleninic acid, which blocks the expression of another checkpoint receptor, human leukocyte antigen E. The blockade of dual immune checkpoints shows synergistic effects on promoting NK cell-mediated antitumoral activity. This study provides a new strategy to reinvigorate NK cell immunity for the development of combined cancer immunotherapy.

LDLR-Mediated Targeting and Productive Uptake of siRNA-Peptide Ligand Conjugates In Vitro and In Vivo

Small RNA molecules such as microRNA and small interfering RNA (siRNA) have become promising therapeutic agents because of their specificity and their potential to modulate gene expression. Any gene of interest can be potentially up- or down-regulated, making RNA-based technology the healthcare breakthrough of our era. However, the functional and specific delivery of siRNAs into tissues of interest and into the cytosol of target cells remains highly challenging, mainly due to the lack of efficient and selective delivery systems. Among the variety of carriers for siRNA delivery, peptides have become essential candidates because of their high selectivity, stability, and conjugation versatility. Here, we describe the development of molecules encompassing siRNAs against SOD1, conjugated to peptides that target the low-density lipoprotein receptor (LDLR), and their biological evaluation both in vitro and in vivo.

Recent Advances in Engineering Carriers for siRNA Delivery

RNA interference (RNAi) technology has been a promising treatment strategy for combating intractable diseases. However, the applications of RNAi in clinical are hampered by extracellular and intracellular barriers. To overcome these barriers, various siRNA delivery systems have been developed in the past two decades. The first approved RNAi therapeutic, Patisiran (ONPATTRO) using lipids as the carrier, for the treatment of amyloidosis is one of the most important milestones. This has greatly encouraged researchers to work on creating new functional siRNA carriers. In this review, the recent advances in siRNA carriers consisting of lipids, polymers, and polymer-modified inorganic particles for cancer therapy are summarized. Representative examples are presented to show the structural design of the carriers in order to overcome the delivery hurdles associated with RNAi therapies. Finally, the existing challenges and future perspective for developing RNAi as a clinical modality will be discussed and proposed. It is believed that the addressed contributions in this review will promote the development of siRNA delivery systems for future clinical applications.

Nanotechnology strategies to address challenges in topical and cellular delivery of siRNAs in skin disease therapy

Gene therapy is one of the most advanced therapies in current medicine. In particular, interference RNA-based therapy by small interfering RNA (siRNA) has gained attention in recent years as it is a highly versatile, selective and specific therapy. In dermatological conditions, topical delivery of siRNA offers numerous therapeutic advantages, mainly by inhibiting the expression of target transcripts directly in the skin. However, crossing the stratum corneum and overcoming intracellular barriers is an inherent challenge. Substantial efforts by scientists have moved towards the use of multimodal and multifunctional nanoparticles to overcome these barriers and achieve greater bioavailability in their site of action, the cytoplasm. In this review the most innovative strategies based on nanoparticle and physical methods are presented, as well as the design principles and the main factors that contribute to the performance of these systems. This review also highlights the synergistic contributions of medicine, nanotechnology, and molecular biology to advancing translational research into siRNA-based therapeutics for skin diseases.

Chemically Modified Platforms for Better RNA Therapeutics

RNA-based therapies have catalyzed a revolutionary transformation in the biomedical landscape, offering unprecedented potential in disease prevention and treatment. However, despite their remarkable achievements, these therapies encounter substantial challenges including low stability, susceptibility to degradation by nucleases, and a prominent negative charge, thereby hindering further development. Chemically modified platforms have emerged as a strategic innovation, focusing on precise alterations either on the RNA moieties or their associated delivery vectors. This comprehensive review delves into these platforms, underscoring their significance in augmenting the performance and translational prospects of RNA-based therapeutics. It encompasses an in-depth analysis of various chemically modified delivery platforms that have been instrumental in propelling RNA therapeutics toward clinical utility. Moreover, the review scrutinizes the rationale behind diverse chemical modification techniques aiming at optimizing the therapeutic efficacy of RNA molecules, thereby facilitating robust disease management. Recent empirical studies corroborating the efficacy enhancement of RNA therapeutics through chemical modifications are highlighted. Conclusively, we offer profound insights into the transformative impact of chemical modifications on RNA drugs and delineates prospective trajectories for their future development and clinical integration.

Synthesis and biophysical evaluation of carbosilane dendrimers as therapeutic siRNA carriers

Gene therapy presents an innovative approach to the treatment of previously incurable diseases. The advancement of research in the field of nanotechnology has the potential to overcome the current limitations and challenges of conventional therapy methods, and therefore to unlocking the full potential of dendrimers for use in the gene therapy of neurodegenerative disorders. The blood-brain barrier (BBB) poses a significant challenge when delivering therapeutic agents to the central nervous system. In this study, we investigated the biophysical properties of dendrimers and their complexes with siRNA directed against the apolipoprotein E (APOE) gene to identify an appropriate nanocarrier capable of safely delivering the cargo across the BBB. Our study yielded valuable insights into the complexation process, stability over time, the mechanisms of interaction, the influence of dendrimers on the oligonucleotide's spatial structure, and the potential cytotoxic effects on human cerebral microvascular endothelium cells. Based on our findings, we identified that the dendrimer G3Si PEG6000 was an optimal candidate for further research, potentially serving as a nanocarrier capable of safely delivering therapeutic agents across the BBB for the treatment of neurodegenerative disorders.

An innovative gene expression modulating strategy by converting nucleic acids into HNC therapeutics using carrier-free nanoparticles

Background

Cell fate and microenvironmental changes resulting from aberrant expression of specific proteins in tumors are one of the major causes of inadequate anti-tumor immune response and poor prognosis in head and neck cancer (HNC). Eukaryotic initiation factor 3C (eIF3c) has emerged as a promising therapeutic target for HNC due to its ability to regulate protein expression levels in tumor cells, but its drug development is difficult to achieve by targeting traditional protein-protein interactions. siRNA has emerged as a highly promising modality for drug development targeting eIF3c, while its application is hindered by challenges pertaining to inadequate stability and insufficient concentration specifically within tumor sites.

Method

We employed a method to convert flexible siRNAs into stable and biologically active infinite Auric-sulfhydryl coordination supramolecular siRNAs (IacsRNAs). Through coordinated self-assembly, we successfully transformed eIF3C siRNAs into the carrier-free HNC nanotherapeutic agent Iacs-eif3c-RNA. The efficacy of this agent was evaluated in vivo using HNC xenograft models, demonstrating promising antitumor effects.

Results

Iacs-eif3c-RNA demonstrated the ability to overcome the pharmacological obstacle associated with targeting eIF3C, resulting in a significant reduction in eIF3C expression within tumor tissues, as well as effective tumor cell proliferating suppression and apoptosis promotion. In comparison to monotherapy utilizing the chemotherapeutic agent cisplatin, Iacs-eif3c-RNA exhibited superior anti-tumor efficacy and favorable biosafety.

Conclusion

The utilization of Iacs-eif3c-RNA as a carrier-free nanotherapeutic agent presents a promising and innovative approach for addressing HNC treating challenges. Moreover, this strategy demonstrates potential for the translation of therapeutic siRNAs into clinical drugs, extending its applicability to the treatment of other cancers and various diseases.

An update on the therapeutic role of RNAi in NAFLD/NASH

Unhealthy lifestyles have given rise to a growing epidemic of metabolic liver diseases, including nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). NAFLD often occurs as a consequence of obesity, and currently, there is no FDA-approved drug for its treatment. However, therapeutic oligonucleotides, such as RNA interference (RNAi), represent a promising class of pharmacotherapy that can target previously untreatable conditions. The potential significance of RNAi in maintaining physiological homeostasis, understanding pathogenesis, and improving metabolic liver diseases, including NAFLD, is discussed in this article. We explore why NAFLD/NASH is an ideal target for therapeutic oligonucleotides and provide insights into the delivery platforms of RNAi and its therapeutic role in addressing NAFLD/NASH.

Liver-Specific Ionizable Lipid Nanoparticles Mediated Efficient RNA Interference to Clear "Bad Cholesterol"

Background

High-level low-density lipoprotein cholesterol (LDL-C) plays a vital role in the development of atherosclerotic cardiovascular disease. Low-density lipoprotein receptors (LDLRs) are scavengers that bind to LDL-C in the liver. LDLR proteins are regulated by proprotein convertase subtilisin/kexin type 9 (PCSK9), which mediates the degradation of LDLR and adjusts the level of the plasma LDL-C. The low expression of PCSK9 leads to the up-regulation of liver LDLRs and the reduction of plasma LDL-C. Hepatocytes are attractive targets for small interfering RNA (siRNA) delivery to silence Pcsk9 gene, due to their significant role in LDL-C regulation.

Methods

Here, a type of liver-specific ionizable lipid nanoparticles is developed for efficient siRNA delivery. This type of nanoparticles shows high stability, enabling efficient cargo delivery specifically to hepatocytes, and a membrane-active polymer that reversibly masks activity until an acidic environment is reached.

Results

Significantly, the siPcsk9 (siRNA targeting to Pcsk9)-loaded nanoparticles (GLP) could silence 90% of the Pcsk9 mRNA in vitro. In vivo study showed that the improved accumulation of GLP in the liver increased LDLR level by 3.35-fold and decreased plasma LDL-C by 35%.

Conclusion

GLP has shown a powerful effect on reducing LDL-C, thus providing a potential therapy for atherosclerotic cardiovascular disease.

Nano-scale delivery systems for siRNA delivery in cancer therapy: New era of gene therapy empowered by nanotechnology

RNA interference (RNAi) is a unique treatment approach used to decrease a disease's excessive gene expression, including cancer. SiRNAs may find and destroy homologous mRNA sequences within the cell thanks to RNAi processes. However, difficulties such poor cellular uptake, off-target effects, and susceptibility to destruction by serum nucleases in the bloodstream restrict the therapeutic potential of siRNAs. Since some years ago, siRNA-based therapies have been in the process of being translated into the clinic. Therefore, the primary emphasis of this work is on sophisticated nanocarriers that aid in the transport of siRNA payloads, their administration in combination with anticancer medications, and their use in the treatment of cancer. The research looks into molecular manifestations, difficulties with siRNA transport, the design and development of siRNA-based delivery methods, and the benefits and drawbacks of various nanocarriers. The trapping of siRNA in endosomes is a challenge for the majority of delivery methods, which affects the therapeutic effectiveness. Numerous techniques for siRNA release, including as pH-responsive release, membrane fusion, the proton sponge effect, and photochemical disruption, have been studied to overcome this problem. The present state of siRNA treatments in clinical trials is also looked at in order to give a thorough and systematic evaluation of siRNA-based medicines for efficient cancer therapy.

Impact of Peptide Sequence on Functional siRNA Delivery and Gene Knockdown with Cyclic Amphipathic Peptide Delivery Agents

Short-interfering RNA (siRNA) oligonucleotide therapeutics that modify gene expression by accessing RNA-interference (RNAi) pathways have great promise for the treatment of a range of disorders; however, their application in clinical settings has been limited by significant challenges in cellular delivery. Herein, we report a structure-function study using a series of modified cyclic amphipathic cell-penetrating peptides (CAPs) to determine the impact of peptide sequence on (1) siRNA-binding efficiency, (2) cellular delivery and knockdown efficiency, and (3) the endocytic uptake mechanism. Nine cyclic peptides of the general sequence Ac-C[XZ]4CG-NH2 in which X residues are hydrophobic/aromatic (Phe, Tyr, Trp, or Leu) and Z residues are charged/hydrophilic (Arg, Lys, Ser, or Glu) are assessed along with one acyclic peptide, Ac-(WR)4G-NH2. Cyclization is enforced by intramolecular disulfide bond formation between the flanking Cys residues. Binding analyses indicate that strong cationic character and the presence of aromatic residues that are competent to participate in CH-π interactions lead to CAP sequences that most effectively interact with siRNA. CAP-siRNA binding increases in the following order as a function of CAP hydrophobic/aromatic content: His < Phe < Tyr < Trp. Both cationic charge and disulfide-constrained cyclization of CAPs improve uptake of siRNA in vitro. Net neutral CAPs and an acyclic peptide demonstrate less-efficient siRNA translocation compared to the cyclic, cationic CAPs tested. All CAPs tested facilitated efficient siRNA target gene knockdown of at least 50% (as effective as a lipofectamine control), with the best CAPs enabling >80% knockdown. Significantly, gene knockdown efficiency does not strongly correlate with CAP-siRNA internalization efficiency but moderately correlates with CAP-siRNA-binding affinity. Finally, utilization of small-molecule inhibitors and targeted knockdown of essential endocytic pathway proteins indicate that most CAP-siRNA nanoparticles facilitate siRNA delivery through clathrin- and caveolin-mediated endocytosis. These results provide insight into the design principles for CAPs to facilitate siRNA delivery and the mechanisms by which these peptides translocate siRNA into cells. These studies also demonstrate the nature of the relationships between peptide-siRNA binding, cellular delivery of siRNA cargo, and functional gene knockdown. Strong correlations between these properties are not always observed, which illustrates the complexity in the design of optimal next-generation materials for oligonucleotide delivery.

Delivery of SAV-siRNA via Exosomes from Adipose-Derived Stem Cells for the Treatment of Myocardial Infarction

BACKGROUND

Myocardial infarction (MI) leads to cardiomyocyte death, poor cardiac remodeling, and heart failure, making it a major cause of mortality and morbidity. To restore cardiac pumping function, induction of cardiomyocyte regeneration has become a focus of academic interest. The Hippo pathway is known to regulate cardiomyocyte proliferation and heart size, and its inactivation allows adult cardiomyocytes to re-enter the cell cycle.

METHODS

In this study, we investigated whether exosomes from adipose-derived stem cells (ADSCs) could effectively transfer siRNA for the Hippo pathway regulator Salvador (SAV) into cardiomyocytes to induce cardiomyocyte regeneration in a mouse model of MI.

RESULTS

Our results showed that exosomes loaded with SAV-siRNA effectively transferred siRNA into cardiomyocytes and induced cardiomyocyte re-entry into the cell cycle, while retaining the previously demonstrated therapeutic efficacy of ADSC-derived exosomes to improve post-infarction cardiac function through anti-fibrotic, pro-angiogenic, and other effects.

CONCLUSIONS

Our findings suggest that siRNA delivery via ADSC-derived exosomes may be a promising approach for the treatment of MI.

Stimuli-Responsive Nanotechnology for RNA Delivery

Ribonucleic acid (RNA) drugs have shown promising therapeutic effects for various diseases in clinical and preclinical studies, owing to their capability to regulate the expression of genes of interest or control protein synthesis. Different strategies, such as chemical modification, ligand conjugation, and nanotechnology, have contributed to the successful clinical translation of RNA medicine, including small interfering RNA (siRNA) for gene silencing and messenger RNA (mRNA) for vaccine development. Among these, nanotechnology can protect RNAs from enzymatic degradation, increase cellular uptake and cytosolic transportation, prolong systemic circulation, and improve tissue/cell targeting. Here, a focused overview of stimuli-responsive nanotechnologies for RNA delivery, which have shown unique benefits in promoting RNA bioactivity and cell/organ selectivity, is provided. Many tissue/cell-specific microenvironmental features, such as pH, enzyme, hypoxia, and redox, are utilized in designing internal stimuli-responsive RNA nanoparticles (NPs). In addition, external stimuli, such as light, magnetic field, and ultrasound, have also been used for controlling RNA release and transportation. This review summarizes a wide range of stimuli-responsive NP systems for RNA delivery, which may facilitate the development of next-generation RNA medicines.

Research Status of Dendrimer Micelles in Tumor Therapy for Drug Delivery

Dendrimers are a family of polymers with highly branched structure, well-defined composition, and extensive functional groups, which have attracted great attention in biomedical applications. Micelles formed by dendrimers are ideal nanocarriers for delivering anticancer agents due to the explicit study of their characteristics of particle size, charge, and biological properties such as toxicity, blood circulation time, biodistribution, and cellular internalization. Here, the classification, preparation, and structure of dendrimer micelles are reviewed, and the specific functional groups modified on the surface of dendrimers for tumor active targeting, stimuli-responsive drug release, reduced toxicity, and prolonged blood circulation time are discussed. In addition, their applications are summarized as various platforms for biomedical applications related to cancer therapy including drug delivery, gene transfection, nano-contrast for imaging, and combined therapy. Other applications such as tissue engineering and biosensor are also involved. Finally, the possible challenges and perspectives of dendrimer micelles for their further applications are discussed.

Transcutaneous Immunotherapy for RNAi: A Cascade-Responsive Decomposable Nanocomplex Based on Polyphenol-Mediated Framework Nucleic Acid in Psoriasis

Skin is the first barrier against external threats, and skin immune dysfunction leads to multiple diseases. Psoriasis is an inflammatory, chronic, common, immune-related skin disease that affects more than 125 million people worldwide. RNA interference (RNAi) therapy is superior to traditional therapies, but rapid degradation and poor cell uptake are the greatest obstacles to its clinical transformation. The transdermal delivery of siRNA and controllable assembly/disassembly of nanodrug delivery systems can maximize the therapeutic effect. Tetrahedral framework nucleic acid (tFNA) is undoubtedly the best carrier for the transdermal transport of genes due to its excellent noninvasive transdermal effect and editability. The authors combine acid-responsive tannic acid (TA), RNase H-responsive sequences, siRNA, and tFNA into a novel transdermal RNAi drug with controllable assembly and disassembly: STT. STT has heightened resistance to enzyme, serum, and lysosomal degradation, and its size is similar to that of tFNA, enabling easy transdermal transport. After transdermal administration, STT can specifically silence nuclear factor kappa-B (NF-κB) p65, thereby maintaining the stability of the skin's microenvironment and reshaping normal skin immune defense. This work demonstrates the advantages of STT in RNAi therapy and the potential for future treatment of skin-related diseases.