Exploring precision treatments in immune-mediated inflammatory diseases: Harnessing the infinite potential of nucleic acid delivery

Drug-loaded microneedle patches containing regulatory T cell-derived exosomes for psoriasis treatment

Psoriasis is a chronic inflammatory skin disease characterized by epidermal hyperplasia, skin inflammation, and immune dysregulation. These factors contribute to the persistent progression of the disease. While addressing excessive keratinocyte proliferation or inhibiting inflammation may provide temporary therapeutic relief, unresolved immune dysregulation often exacerbates the condition. Therefore, comprehensive treatments that alleviate skin symptoms and regulate immune tolerance are urgently required. An ideal treatment would target multiple factors, including keratinocyte proliferation, inflammation, and immune tolerance, while minimizing systemic side effects. In this study, we developed a dissolvable hyaluronic acid microneedle patch containing regulatory T cell (Treg) exosomes loaded with dimethyl fumarate (DMF) (rExo@DMF MNs). DMF acts as an inhibitor of keratinocyte proliferation and an anti-inflammatory agent through NF-κB suppression and Nrf2 activation, inhibiting the production of pro-inflammatory cytokines and the activation of inflammatory cells. Delivering DMF via Treg exosomes enhances its retention at the lesion site. This system inhibits keratinocyte proliferation and migration, reduces pro-inflammatory cytokine release, and alleviates epidermal hyperplasia and inflammation in an imiquimod-induced psoriasis mouse model. Additionally, Treg exosomes modulate immune responses to promote tolerance. rExo@DMF MNs demonstrate immunomodulatory effects by inhibiting T helper 17 (Th17) cells and inducing regulatory immune cells such as Tregs and tolerogenic dendritic cells (tDCs) differentiation. rExo@DMF MNs alleviate skin symptoms and regulate immune cells in the skin, spleen, and lymph nodes, demonstrating both local and systemic immunoregulation with promising therapeutic potential for psoriasis. STATEMENT OF SIGNIFICANCE: Novel therapies are urgently needed to alleviate skin symptoms and regulate immunity, as current psoriasis treatments focus on symptom relief while neglecting the underlying immune dysfunction, resulting in limited efficacy. Moreover, systemic immunosuppression often leads to severe side effects. This study introduces a hybrid microneedle system (rExo@DMF MNs) that alleviates psoriasis symptoms and modulates immune responses locally and systemically. In addition, rExo@DMF MNs penetrate hyperkeratotic skin, ensuring targeted rExo@DMF release while minimizing systemic exposure and side effects. All components of the system, including hyaluronic acid (a key component of the skin matrix), regulatory T cell-derived exosomes, and DMF (a clinically validated drug), exhibit biocompatibility. This comprehensive approach addresses multiple pathogenic factors, promising an effective and safe psoriasis treatment.

Compensatory effect-based oxidative stress management microneedle for psoriasis treatment

Reactive oxygen species (ROS) at elevated levels trigger oxidative DNA damage, which is a significant factor in psoriasis exacerbation. However, normal ROS levels are essential for cell signaling, cell growth regulation, differentiation, and immune responses. To address this, we developed ROS control strategies inspired by compensatory effects. DNA nanostructures with the advantage of being more stable than linear nucleic acid molecules in physiological environments were exquisitely fabricated and incorporated into microneedles (MN). These nanostructures regulate ROS levels and facilitate the delivery of IL-17A siRNA to psoriatic lesions. Our findings demonstrate that this transdermal drug delivery system effectively manages ROS levels in the psoriatic microenvironment, inhibiting pyroptosis and abnormal immune activation. Moreover, modulating ROS levels enhances the therapeutic impact of IL-17A siRNA, offering a promising in situ treatment approach for psoriasis.

Landscape of small nucleic acid therapeutics: moving from the bench to the clinic as next-generation medicines

The ability of small nucleic acids to modulate gene expression via a range of processes has been widely explored. Compared with conventional treatments, small nucleic acid therapeutics have the potential to achieve long-lasting or even curative effects via gene editing. As a result of recent technological advances, efficient small nucleic acid delivery for therapeutic and biomedical applications has been achieved, accelerating their clinical translation. Here, we review the increasing number of small nucleic acid therapeutic classes and the most common chemical modifications and delivery platforms. We also discuss the key advances in the design, development and therapeutic application of each delivery platform. Furthermore, this review presents comprehensive profiles of currently approved small nucleic acid drugs, including 11 antisense oligonucleotides (ASOs), 2 aptamers and 6 siRNA drugs, summarizing their modifications, disease-specific mechanisms of action and delivery strategies. Other candidates whose clinical trial status has been recorded and updated are also discussed. We also consider strategic issues such as important safety considerations, novel vectors and hurdles for translating academic breakthroughs to the clinic. Small nucleic acid therapeutics have produced favorable results in clinical trials and have the potential to address previously "undruggable" targets, suggesting that they could be useful for guiding the development of additional clinical candidates.

Recent advances in poly(amino acids), polypeptides, and their derivatives in drug delivery

Poly(amino acids), polypeptides, and their derivatives have demonstrated significant potential as biodegradable biomaterials in the field of drug delivery. As degradable drug carriers, they can effectively load or conjugate drug molecules including small molecule drugs, nucleic acids, peptides, and protein-based drugs, enhancing the stability and targeting of the drugs in vivo. This strategy ultimately facilitates precise drug delivery and controlled release, thereby improving therapeutic efficacy and reducing side effects within the body. This review systematically describes the structural characteristics and preparation methods of poly(amino acids) and polypeptides, summarizes the advantages of poly(amino acids), polypeptides, and their derivatives in drug delivery, and detailedly introduces the latest advancements in this area. The review also discusses current challenges and opportunities associated with poly(amino acids), peptides, and their derivatives, and offers insights into the future directions for these biodegradable materials. This review aims to provide valuable references for scientific research and clinical translation of biodegradable biomaterials based on poly(amino acids) and peptides.

Microneedle-Based Approaches for Skin Disease Treatment

The use of microneedles (MNs) has been established as an effective transdermal drug delivery strategy that has been extensively deployed for treating various diseases, including skin diseases. MNs can surpass the constraints of conventional drug delivery methods by their superior safety and efficacy through precise targeting, while simultaneously enabling painless delivery. Currently, MNs are increasingly used as carriers for drug delivery, with the loading of insoluble drugs to improve their treatment efficiency or combining with bioactive substances for the construction of an efficient drug delivery system to maximize the effects of bioactive substances. The methods used for preparation MNs are diverse, enabling them to meet the requirements of most applications. The emergence of MNs has addressed the shortcomings associated with insoluble drugs, expanded the applications of bioactive substances, and improved their use in clinical practice. This review summarizes current information on the application of MNs in a variety of skin diseases, such as psoriasis, vitiligo, alopecia, hypertrophic scarring, atopic dermatitis, melanoma, acne, and skin infections. The current clinical applications and future opportunities for MNs in the treatment of skin diseases are also discussed. Despite substantial progress in the clinical application of MNs as delivery vectors, issues such as low drug loading and poor mechanical strength during MNs preparation remain the main challenges. Therefore, clinical implementation of MNs-based therapies remains limited, highlighting key opportunities for future research.

Oral Lactoferrin-Responsive Formulation Anchoring around Inflammatory Bowel Region for IBD Therapy

Oral formulation is the ideal treatment method for inflammatory bowel disease (IBD) therapy, but the mucosal damage and diarrhea symptoms impede the drug retention around the inflammatory region, severely limiting IBD therapeutic efficacy. To address this, an oral astaxanthin (Ast) precise delivery formulation is developed with the selective Ast anchoring around the inflammatory region by the novel lactoferrin (LF)-responsive flocculation. This formulation also heightens the apparent solubility of Ast with the minimized edible safety risks for the edible raw materials. For in vivo IBD therapy, the precise delivery formulation exhibits remarkable outcomes, including a significant increase in colon length and a 100% survival rate. Furthermore, it is verified that the mechanism of treatment is primarily attributed to the improved immunoregulation, epithelial repair, and gut microbiota remodeling after the LF-responsive flocculation. This effective inflammatory-responsive delivery design is instructive and valuable to develop more precise delivery systems for IBD therapy.

Fully Bioactive Nanodrugs: Stem Cell-Derived Exosomes Engineered with Biomacromolecules to Treat CCl4- and Extreme Hepatectomy-Induced Acute Liver Failure

Acute liver failure (ALF) is a serious global disease characterized by rapid onset and high mortality. Currently, the clinical treatment of ALF faces considerable hurdles due to limited medication options and the scarcity of liver transplants. Despite biomacromolecules such as hepatocyte growth factor (HGF) and glutathione (GSH) having been applied for ALF symptom relief in the clinic, they still face substantial challenges including poor stability, difficulty in acting on intracellular targets, and inadequate therapeutic outcome. In this work, by taking advantage of the innate targeting and regenerative capabilities of mesenchymal stem cells (MSCs), we harnessed MSC-derived exosomes as natural bioactive carriers for the simultaneous delivery of HGF and GSH, forming a fully bioactive nanodrug termed HG@Exo. Impressively, the HG@Exo demonstrated potent therapeutic effects against both carbon tetrachloride (CCl4)- and extreme hepatectomy-induced ALF through multiple mechanisms, including regulation of oxidative stress, reduction of inflammation, and promotion of hepatocyte regeneration, which were facilitated by its inflammation-targeting to damaged liver tissues. Furthermore, an FDA-approved near-infrared fluorescent dye, indocyanine green (ICG), has been incorporated into the exosomes (HGI@Exo) to endow them with real-time in vivo tracking capability, which showed favorable liver accumulation of the HGI@Exo in both CCl4- and surgery-induced ALF animal models, providing crucial insights into their biodistribution and therapeutic efficacy. Overall, the presented fully bioactive nanodrugs with targeting and theranostic abilities hold significant promise for potentiating the therapeutic efficacy of biomacromolecules for the improved treatment of ALF and other inflammatory diseases.

Nrf2-mediated ferroptosis inhibition: a novel approach for managing inflammatory diseases

Inflammatory diseases, including psoriasis, atherosclerosis, rheumatoid arthritis, and ulcerative colitis, are characterized by persistent inflammation. Moreover, the existing treatments for inflammatory diseases only provide temporary relief by controlling symptoms, and treatments of unstable and expensive. Therefore, new therapeutic solutions are urgently needed to address the underlying causes or symptoms of inflammatory diseases. Inflammation frequently coincides with a high level of (reactive oxygen species) ROS activation, serving as a fundamental element in numerous physiological and pathological phenotypes that can result in serious harm to the organism. Given its pivotal role in inflammation, oxidative stress, and ferroptosis, ROS represents a focal node for investigating the (nuclear factor E2-related factor 2) Nrf2 pathway and ferroptosis, both of which are intricately linked to ROS. Ferroptosis is mainly triggered by oxidative stress and involves iron-dependent lipid peroxidation. The transcription factor Nrf2 targets several genes within the ferroptosis pathway. Recent studies have shown that Nrf2 plays a significant role in three key ferroptosis-related routes, including the synthesis and metabolism of glutathione/glutathione peroxidase 4, iron metabolism, and lipid processes. As a result, ferroptosis-related treatments for inflammatory diseases have attracted much attention. Moreover, drugs targeting Nrf2 can be used to manage inflammatory conditions. This review aimed to assess ferroptosis regulation mechanism and the role of Nrf2 in ferroptosis inhibition. Therefore, this review article may provide the basis for more research regarding the treatment of inflammatory diseases through Nrf2-inhibited ferroptosis.

Atavistic strategy for the treatment of hyperuricemia via ionizable liposomal mRNA

Hyperuricemia is associated with an increased risk of gout, hypertension, diabetes, and cardiovascular diseases. Most mammals maintain normal serum uric acid (SUA) via urate oxidase (Uox), an enzyme that metabolizes poorly-soluble UA to highly-soluble allantoin. In contrast, Uox became a pseudogene in humans and apes over the long course of evolution. Here we demonstrate an atavistic strategy for treating hyperuricemia based on endogenous expression of Uox in hepatocytes mediated by mRNA (mUox) loaded with an ionizable lipid nanoparticle termed iLAND. mUox@iLAND allows effective transfection and protein expression in vitro. A single dose of mUox@iLAND lowers SUA levels for several weeks in two female murine models, including a novel long-lasting model, which is also confirmed by metabolomics analysis. Together with the excellent safety profiles observed in vivo, the proposed mRNA agent demonstrates substantial potential for hyperuricemia therapy and the prevention of associated conditions.