In vivo self-assembled siRNA as a modality for combination therapy of ulcerative colitis

Treatment of neurological pathology and inflammation in Machado-Joseph disease through in vivo self-assembled siRNA

Machado-Joseph disease, also known as spinocerebellar ataxia type 3 (MJD/SCA3), is a fatal autosomal dominant hereditary ataxia characterized by cerebellar ataxia resulting from the abnormal expansion of CAG repeats in exon 10 of the ATXN3 gene. At present, there is no effective treatment for SCA3. Small interfering RNAs (siRNAs) are emerging as potential therapeutic strategies to target the disease-causing mutant ATXN3 (mATXN3) protein specifically. However, the efficiency of delivery of siRNAs remains a major obstacle for clinical application, particularly in brain disorders. The aim of this study was to develop a synthetic biology strategy to reprogram the host liver as a tissue chassis to induce and deliver in vivo self-assembled siRNAs to target the ATXN3 gene. A synthetic construct directed by a cytomegalovirus promoter was designed to encode a neuron-targeting rabies virus glycoprotein tag and mATXN3-siRNA. After intravenous injection, the synthetic construct was taken up by mouse livers, which were then reprogrammed to enable the self-assembly, production and secretion of small extracellular vesicles encapsulating mATXN3-siRNA. The small extracellular vesicle-encapsulated mATXN3-siRNA was transported through the endogenous circulating system of small extracellular vesicles, crossing the blood-brain barrier and reaching the cerebellar cortex and spinal cerebellar tract, where they silenced the ATXN3 gene. Treatment with the synthetic construct for 8 or 12 weeks led to significant improvements in motor balance ability and reduction of cerebellar atrophy in YACMJD84.2 transgenic mice. The number of Purkinje cells in the cerebellar cortex was significantly increased, and the loss of myelin basic protein was reduced. Moreover, the quantity of neurotoxic nuclear inclusion bodies and the expression of glial fibrillary acidic protein, which promotes neuroinflammation in activated astrocytes, were decreased significantly. The synthetic construct facilitated the generation and delivery of in vivo self-assembled siRNA to the cerebellar cortex and spinal cerebellar tract, thereby inhibiting the expression of mATXN3 protein. This treatment successfully addressed motor impairments, alleviated neuropathological phenotypes and mitigated neuroinflammation in YACMJD84.2 transgenic mice. Our strategy effectively overcomes the primary challenges associated with siRNA therapy for cerebellar ataxia, offering a promising avenue for future clinical treatments.

Classification of Nanomaterial Drug Delivery Systems for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, primarily arises from defects in the colonic barrier, imbalances of the gut microbiota, and immune response issues. These complex causes make it difficult to achieve a complete cure. Patients with IBD frequently experience recurrent abdominal pain and bloody diarrhea, while severe cases may result in intestinal obstruction, perforation, and cancer. Lifelong maintenance therapy may thus be needed to manage these symptoms; however, traditional IBD drugs, such as 5-aminosalicylic acid, glucocorticoids, immunosuppressants, and biological agents, are often associated with problems including poor solubility, instability, and ineffective targeting, as well as causing serious side effects in non-target tissues. Nanomaterial drug delivery systems (NDDS) have recently shown great promise in optimizing drug distribution, solubility through biocompatible coatings, enhancing bioavailability via PEGylation and reducing side effects. These formulations can enhance a drug's pharmacokinetics by modifying its properties, improve its ability to cross barriers, and boost bioavailability. In addition, NDDS can enable targeted delivery, increase local drug concentrations, improve efficacy, and reduce side effects, as well as protecting active drug molecules from immune recognition and protease degradation. The clinical use of these systems for treating IBD, however, requires further research. This review summarizes the classification of NDDS for IBD, and concludes that, despite ongoing challenges, NDDS may represent an effective treatment approach for IBD. In summary, NDDS enhance the targeted delivery of therapeutic agents to specific cells or tissues, thereby improving drug bioavailability and therapeutic efficacy. These systems effectively surmount biological barriers, facilitating efficient drug delivery to targeted sites, which is crucial for attaining optimal therapeutic outcomes. This review contributes to a deeper understanding of how the physicochemical properties of NDDS influence pharmacological behavior in vivo and can expedite their clinical translation.

Nanotechnology used for siRNA delivery for the treatment of neurodegenerative diseases: Focusing on Alzheimer's disease and Parkinson's disease

Neurodegenerative diseases (ND) are often accompanied by dementia, motor dysfunction, or disability. Caring for these patients imposes a significant psychological and financial burden on families. Until now, there are no effective methods for the treatment of NDs. Among them, Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common. Recently, studies have revealed that the overexpression of certain genes may be linked to the occurrence of AD and PD. Small interfering RNAs (siRNAs) are a powerful tool for gene silencing because they can specifically bind to and cleave target mRNA. However, the intrinsic properties of naked siRNA and various physiological barriers limit the application of siRNA in the brain. Nanotechnology is a promising option for addressing these issues. Nanoparticles are not only able to protect siRNA from degradation but also have the advantage of crossing various physiological barriers to reach the brain target of siRNA. In this review, we aim to introduce diverse nanotechnology used for delivering siRNA to treat AD and PD. Finally, we will briefly discuss our perspectives on this promising field.

Functional Ginger-Derived Extracellular Vesicles-Coated ZIF-8 Containing TNF-α siRNA for Ulcerative Colitis Therapy by Modulating Gut Microbiota

Tumor necrosis factor-α (TNF-α) plays a causal role in the pathogenesis of ulcerative colitis (UC), and anti-TNF-α siRNA shows great promise in UC therapy. However, delivering siRNA with site-targeted stability and therapeutic efficacy is still challenging due to the complex and dynamic intestinal microenvironment. Here, based on the functional plant-derived ginger extracellular vesicles (EVs) and porous ZIF-8 nanoparticles, we propose a novel TNF-α siRNA delivery strategy (EVs@ZIF-8@siRNA) for UC targeted therapy. Ginger EVs show strong colon and macrophage targeting, as well as robust resistance to acidic degradation in the stomach. Moreover, 6-shogaol in ginger-derived EVs displays anti-inflammatory effects, which enhance the treatment efficiency by cooperation with TNF-α siRNA. In vitro experiments reveal that ZIF-8 nanoparticles have high TNF-α siRNA loading capacity and promote siRNA escape from cellular lysosomes. In vivo experiments show that the TNF-α level is reduced more significantly in colonic tissue than other nontargeted inflammation related factors, showing a good targeting of this composite nanoparticle. Furthermore, gut microbiota sequencing results demonstrate that the nanoparticles can promote intestinal barrier repair by regulating the intestinal microbial balance and restoring the intestinal health of UC mice. Therefore, the developed EVs@ZIF-8@siRNA nanoparticles may represent a novel colon-targeted oral drug, providing a promising therapeutic strategy for UC therapy.

Spatiotemporally Controllable Covalent Bonding of RNA for Multi-Protein Interference

Many diseases are associated with genetic mutation and expression of mutated proteins, such as cancers. Therapeutic approaches that selectively target the synthesis process of multiple proteins show greater potential compared to single-protein approaches in oncological diseases. However, conventional agents to regulate the synthesis of multiple protein still suffer from poor spatiotemporal selectivity and stability. Here, a new method using a dye-peptide conjugate, PRFK, for multi-protein interference with spatiotemporal selectivity and reliable stability, is reported. By using the peptide sequence that targets tumor cells, PRFK can be efficiently taken up, followed by specific binding to the KDELR (KDEL receptor) protein located in the endoplasmic reticulum (ER). The dye generates 1O2 under light irradiation, enabling photodynamic therapy. This process converts the furan group into a cytidine-reactive intermediate, which covalently binds to mRNA, thereby blocking protein synthesis. Upon treating 4T1 cells, the proteomics data show alterations in apoptosis, ferroptosis, proliferation, migration, invasion, and immune infiltration, suggesting that multi-protein interference leads to the disruption of cellular physiological activities, ultimately achieving tumor treatment. This study presents a multi-protein interference probe with the potential for protein interference within various subcellular organelles in the future.

Inhibiting the cGAS-STING Pathway in Ulcerative Colitis with Programmable Micelles

Ulcerative colitis is a chronic condition in which a dysregulated immune response contributes to the acute intestinal inflammation of the colon. Current clinical therapies often exhibit limited efficacy and undesirable side effects. Here, programmable nanomicelles were designed for colitis treatment and loaded with RU.521, an inhibitor of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. STING-inhibiting micelles (SIMs) comprise hyaluronic acid-stearic acid conjugates and include a reactive oxygen species (ROS)-responsive thioketal linker. SIMs were designed to selectively accumulate at the site of inflammation and trigger drug release in the presence of ROS. Our in vitro studies in macrophages and in vivo studies in a murine model of colitis demonstrated that SIMs leverage HA-CD44 binding to target sites of inflammation. Oral delivery of SIMs to mice in both preventive and delayed therapeutic models ameliorated colitis's severity by reducing STING expression, suppressing the secretion of proinflammatory cytokines, enabling bodyweight recovery, protecting mice from colon shortening, and restoring colonic epithelium. In vivo end points combined with metabolomics identified key metabolites with a therapeutic role in reducing intestinal and mucosal inflammation. Our findings highlight the significance of programmable delivery platforms that downregulate inflammatory pathways at the intestinal mucosa for managing inflammatory bowel diseases.

Bioinspired and biomimetic strategies for inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease with high morbidity and an increased risk of cancer or death, resulting in a heavy societal medical burden. While current treatment modalities have been successful in achieving long-term remission and reducing the risk of complications, IBD remains incurable. Nanomedicine has the potential to address the high toxic side effects and low efficacy in IBD treatment. However, synthesized nanomedicines typically exhibit some degree of immune rejection, off-target effects, and a poor ability to cross biological barriers, limiting the development of clinical applications. The emergence of bionic materials and bionic technologies has reshaped the landscape in novel pharmaceutical fields. Biomimetic drug-delivery systems can effectively improve biocompatibility and reduce immunogenicity. Some bioinspired strategies can mimic specific components, targets or immune mechanisms in pathological processes to produce targeting effects for precise disease control. This article highlights recent research on bioinspired and biomimetic strategies for the treatment of IBD and discusses the challenges and future directions in the field to advance the treatment of IBD.

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.

Attenuation of Chronic Inflammation in Intestinal Organoids with Graphene Oxide-Mediated Tumor Necrosis Factor-α_Small Interfering RNA Delivery

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract with a complex and multifactorial etiology, making it challenging to treat. While recent advances in immunomodulatory biologics, such as antitumor necrosis factor-α (TNF-α) antibodies, have shown moderate success, systemic administration of antibody therapeutics may lead to several adverse effects, including the risk of autoimmune disorders due to systemic cytokine depletion. Transient RNA interference using exogenous short interfering RNA (siRNA) to regulate target gene expression at the transcript level offers an alternative to systemic immunomodulation. However, siRNAs are susceptible to premature degradation and have poor cellular uptake. Graphene oxide (GO) nanoparticles have been shown to be effective nanocarriers for biologics due to their reduced cytotoxicity and enhanced bioavailability. In this study, we evaluate the therapeutic efficacy of GO mediated TNF-α_siRNA using in vitro models of chronic inflammation generated by treating murine small intestines (enteroids) and large intestines (colonoids) with inflammatory agents IL-1β, TNF-α, and LPS. The organotypic mouse enteroids and colonoids developed an inflammatory phenotype similar to that of IBD, characterized by impaired epithelial homeostasis and an increased production of inflammatory cytokines such as TNF-α, IL-1β, and IL-6. We assessed siRNA delivery to these inflamed organoids using three different GO formulations. Out of the three, small-sized GO with polymer and dendrimer modifications (smGO) demonstrated the highest transfection efficiency, which led to the downregulation of inflammatory cytokines, indicating an attenuation of the inflammatory phenotype. Moreover, the transfection efficiency and inflammation-ameliorating effects could be further enhanced by increasing the TNF-α_siRNA/smGO ratio from 1:1 to 3:1. Overall, the results of this study demonstrate that ex vivo organoids with disease-specific phenotypes are invaluable models for assessing the therapeutic potential of nanocarrier-mediated drug and biologic delivery systems.

Synthesizing biomaterials in living organisms

Living organisms fabricate biomacromolecules such as DNA, RNA, and proteins by the self-assembly process. The research on the mechanism of biomacromolecule formation also inspires the exploration of in vivo synthesized biomaterials. By elaborate design, artificial building blocks or precursors can self-assemble or polymerize into functional biomaterials within living organisms. In recent decades, these so-called in vivo synthesized biomaterials have achieved extensive applications in cell-fate manipulation, disease theranostics, bioanalysis, cellular surface engineering, and tissue regeneration. In this review, we classify strategies for in vivo synthesis into non-covalent, covalent, and genetic types. The development of these approaches is based on the chemical principles of supramolecular chemistry and synthetic chemistry, biological cues such as enzymes and microenvironments, and the means of synthetic biology. By summarizing the design principles in detail, some insights into the challenges and opportunities in this field are provided to  enlighten further research.

Engineered Extracellular Vesicles: A potential treatment for regeneration

Extracellular vesicles (EVs) play a critical role in various physiological and pathological processes. EVs have gained recognition in regenerative medicine due to their biocompatibility and low immunogenicity. However, the practical application of EVs faces challenges such as limited targeting ability, low yield, and inadequate therapeutic effects. To overcome these limitations, engineered EVs have emerged. This review aims to comprehensively analyze the engineering methods utilized for modifying donor cells and EVs, with a focus on comparing the therapeutic potential between engineered and natural EVs. Additionally, it aims to investigate the specific cell effects that play a crucial role in promoting repair and regeneration, while also exploring the underlying mechanisms involved in the field of regenerative medicine.

Remodeling the tumor immune microenvironment via siRNA therapy for precision cancer treatment

How to effectively transform the pro-oncogenic tumor microenvironments (TME) surrounding a tumor into an anti-tumoral never fails to attract people to study. Small interfering RNA (siRNA) is considered one of the most noteworthy research directions that can regulate gene expression following a process known as RNA interference (RNAi). The research about siRNA delivery targeting tumor cells and TME has been on the rise in recent years. Using siRNA drugs to silence critical proteins in TME was one of the most efficient solutions. However, the manufacture of a siRNA delivery system faces three major obstacles, i.e., appropriate cargo protection, accurately targeted delivery, and site-specific cargo release. In the following review, we summarized the pharmacological actions of siRNA drugs in remolding TME. In addition, the delivery strategies of siRNA drugs and combination therapy with siRNA drugs to remodel TME are thoroughly discussed. In the meanwhile, the most recent advancements in the development of all clinically investigated and commercialized siRNA delivery technologies are also presented. Ultimately, we propose that nanoparticle drug delivery siRNA may be the future research focus of oncogene therapy. This summary offers a thorough analysis and roadmap for general readers working in the field.

Engineered NF-κB siRNA-encapsulating exosomes as a modality for therapy of skin lesions

Introduction

Despite the protection and management of skin has been paid more and more attention, effective countermeasures are still lacking for patients suffering from UV or chemotherapy with damaged skin. Recently, gene therapy by small interfering RNA (siRNA) has emerged as a new therapeutic strategy for skin lesions. However, siRNA therapy has not been applied to skin therapy due to lack of effective delivery vector.

Methods

Here, we develop a synthetic biology strategy that integrates the exosomes with artificial genetic circuits to reprogram the adipose mesenchymal stem cell to express and assemble siRNAs into exosomes and facilitate in vivo delivery siRNAs for therapy of mouse models of skin lesions.

Results

Particularly, siRNA enriched exosomes (si-ADMSC-EXOs) could be directly taken up by the skin cells to inhibit the expression of skin injury related genes. When mice with skin lesions were smeared with si-ADMSC-EXOs, the repair of lesioned skin became faster and the expression of inflammatory cytokines were decreased.

Discussion

Overall, this study establishes a feasible therapeutic strategy for skin injury, which may offer an alternative to conventional biological therapies requiring two or more independent compounds.