Development of Spleen Targeting H2S Donor Loaded Liposome for the Effective Systemic Immunomodulation and Treatment of Inflammatory Bowel Disease

Multicomponent Synthesis of Imidazole-Based Ionizable Lipids for Highly Efficient and Spleen-Selective Messenger RNA Delivery

The spleen emerges as a pivotal target for mRNA delivery, prompting a continual quest for specialized and efficient lipid nanoparticles (LNPs) designed to enhance spleen-selective transfection efficiency. Here we report imidazole-containing ionizable lipids (IMILs) that demonstrate a pronounced preference for mRNA delivery into the spleen with exceptional transfection efficiency. We optimized IMIL structures by constructing and screening a multidimensional IMIL library containing multiple heads, tails, and linkers to perform a structure-activity correlation analysis. Following high-throughput in vivo screening, we identified A3B7C2 as a top-performing IMIL in spleen-specific mRNA delivery via the formulated LNPs, achieving a remarkable 98% proportion of splenic transfection. Moreover, A3B7C2-based LNPs are particularly potent in splenic dendritic cell transfection. Comparative analyses revealed that A3B7C2-based LNPs achieved a notable 2.8-fold and 12.9-fold increase in splenic mRNA transfection compared to SM102 and DLin-MC3-DMA lipid formulations, respectively. Additionally, our approach yielded an 18.3-fold enhancement in splenic mRNA expression compared to the SORT method without introducing additional anionic lipids. Collectively, these IMILs highlight promising avenues for further research in spleen-selective mRNA delivery. This work offers valuable insights for the swift discovery and rational design of ionizable lipid candidates tailored for spleen-selective transfection, thereby facilitating the application of mRNA therapeutics in spleen-related interventions.

A fluorescent probe for detecting H2O2 and delivering H2S in lysosomes and its application in maintaining the redox environments

Hydrogen peroxide (H2O2) is a reactive oxygen species (ROS) that can be used as a marker for the occurrence of oxidative stress in the organism. Lysosomes serve as intracellular digestive sites, and when the concentration of H2O2 in them is abnormal, lysosomal function is often impaired, leading to the development of diseases. Hydrogen sulfide (H2S) acts as a gaseous signaling molecule that scavenges H2O2 from cells and tissues, thereby maintaining the redox environment of the body. However, most of the reported hydrogen peroxide fluorescent probes so far can only detect H2O2, but cannot maintain the intracellular redox environment. In this paper, an H2O2 fluorescent probe LN-HOD with lysosomal targeting properties was designed and synthesized by combining the H2O2 recognition site with a naphthylamine fluorophore via a thiocarbamate moiety. The probe has the advantages of large Stokes shift (110 nm), high sensitivity and good H2S release capability. The probe LN-HOD can be used to detect H2O2 in cells, zebrafish and plant roots. In addition, LN-HOD detects changes in the concentration of H2O2 in plant roots when Arabidopsis is stressed by cadmium ion (Cd2+). And through its ability to release H2S, it can help to remove excess H2O2 and maintain the redox environment in cells, zebrafish and plant roots. The present work provides new ideas for the detection and assisted removal of H2O2, which contributes to the in-depth study of the cellular microenvironment in organisms.

Spleen-targeted delivery systems and strategies for spleen-related diseases

The spleen, body's largest secondary lymphoid organ, is also a vital hematopoietic and immunological organ. It is regarded as one of the most significant organs in humans. As more researchers recognize the functions of the spleen, clinical methods for treating splenic diseases and spleen-targeted drug delivery systems to improve the efficacy of spleen-related therapies have gradually developed. Many modification strategies (size, charge, ligand, protein corona) and hitchhiking strategies (erythrocytes, neutrophils) of nanoparticles (NPs) have shown a significant increase in spleen targeting efficiency. However, most of the targeted drug therapy strategies for the spleen are to enhance or inhibit the immune function of the spleen to achieve therapeutic effects, and there are few studies on spleen-related diseases. In this review, we not only provide a detailed summary of the design rules for spleen-targeted drug delivery systems in recent years, but also introduce common spleen diseases (splenic tumors, splenic injuries, and splenomegaly) with the hopes of generating more ideas for future spleen research.

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.

Effect of bovine colostrum liposomes on the bioavailability of immunoglobulin G and their immunoregulatory function in immunosuppressed BALB/c mice

Bovine colostrum (BC) has high nutritional value; however, the low bioavailability of immune active substances in BC may affect their immunoregulatory function. Our previous studies indicated that encapsulating bovine colostrum with liposomes could enable the sustained release of immunoglobulin G in vitro; however, the effect of bovine colostrum liposomes (BCLs) on the bioavailability of immunoglobulins in vivo is still unknown. In addition, the immunoregulatory function of BCLs on immunosuppressed mice is still unclear. Therefore, our current study aimed to explore the effect of BCLs on the bioavailability of immunoglobulins, and further explore their immunoregulatory effect on immunosuppressed BALB/c mice. Through metabolic cage experiments, it was shown that BCLs decreased the urine and fecal concentrations of IgG and exhibited a higher bioavailability of IgG in mice than BC (about 2-fold). In addition, by establishing an immunosuppressed animal model, it was found that BCLs could increase the body weight, spleen weight, and thymus weight in immunosuppressed BALB/c mice, which further restored the serum levels of interleukin-4 (IL-4), interleukin-10 (IL-10), tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ). Through histology analysis, it was suggested that BCLs restored the structure of jejunal epithelial cells, which was accompanied by an improvement in intestinal cytokine levels (IL-4, IL-10, TNF-α, and IFN-γ). Finally, BCLs increased serum and intestine concentrations of immunoglobulin G (IgG) and immunoglobulin A (IgA) in immunosuppressed BALB/c mice, which further indicated that BCLs had a sustained-release effect for immunoglobulin G in vivo. Our current research will provide a basis for understanding the role of BCLs on the bioavailability of IgG and their immunoregulatory effect on immunosuppressed mice, which might further provide some reference for the application of BCLs.

A H2 S-Generated Supramolecular Photosensitizer for Enhanced Photodynamic Antibacterial Infection and Relieving Inflammation

Photodynamic therapy (PDT) is a promising treatment against bacteria-caused infections. By producing large amounts of reactive oxygen species (ROS), PDT can effectively eliminate pathogenic bacteria, without causing drug resistance. However, excessive ROS may also impose an oxidative stress on surrounding tissues, resulting in local inflammation. To avoid this major drawback and limit pro-inflammation during PDT, this work prepared a supramolecular photosensitizer (TPP-CN/CP5) based on host-guest interactions between a cysteine-responsive cyano-tetraphenylporphyrin (TPP-CN) and a water-soluble carboxylatopillar[5]arene (CP5). TPP-CN/CP5 not only possesses excellent photodynamic antibacterial properties, but also shows good anti-inflammatory and cell protection capabilities. Under 660 nm light irradiation, TPP-CN/CP5 could rapidly produce abundant ROS for sterilization. After the PDT process, the addition of cysteine (Cys) triggers the release of H2 S from TPP-CN. H2 S then stops the induced inflammation by inhibiting the production of related inflammatory factors. Both in vitro and in vivo experiments show the excellent antibacterial effects and anti-inflammatory abilities of TPP-CN/CP5. These results will certainly promote the clinical application of PDT in the treatment of bacterial infectious diseases.

Advancements in hydrogel-based drug delivery systems for the treatment of inflammatory bowel disease: a review

Inflammatory bowel disease (IBD) is a chronic disorder that affects millions of individuals worldwide. However, current drug therapies for IBD are plagued by significant side effects, low efficacy, and poor patient compliance. Consequently, there is an urgent need for novel therapeutic approaches to alleviate IBD. Hydrogels, three-dimensional networks of hydrophilic polymers with the ability to swell and retain water, have emerged as promising materials for drug delivery in the treatment of IBD due to their biocompatibility, tunability, and responsiveness to various stimuli. In this review, we summarize recent advancements in hydrogel-based drug delivery systems for the treatment of IBD. We first identify three pathophysiological alterations that need to be addressed in the current treatment of IBD: damage to the intestinal mucosal barrier, dysbiosis of intestinal flora, and activation of inflammatory signaling pathways leading to disequilibrium within the intestines. Subsequently, we discuss in depth the processes required to prepare hydrogel drug delivery systems, from the selection of hydrogel materials, types of drugs to be loaded, methods of drug loading and drug release mechanisms to key points in the preparation of hydrogel drug delivery systems. Additionally, we highlight the progress and impact of the hydrogel-based drug delivery system in IBD treatment through regulation of physical barrier immune responses, promotion of mucosal repair, and improvement of gut microbiota. In conclusion, we analyze the challenges of hydrogel-based drug delivery systems in clinical applications for IBD treatment, and propose potential solutions from our perspective.

Evidence for the gut-skin axis: Common genetic structures in inflammatory bowel disease and psoriasis

BACKGROUND

Inflammatory bowel disease (IBD) and psoriasis (Ps) are common immune-mediated diseases that exhibit clinical comorbidity, possibly due to a common genetic structure. However, the exact mechanism remains unknown.

METHODS

The study population consisted of IBD and Ps genome-wide association study (GWAS) data. Genetic correlations were first evaluated. Then, the overall evaluation employed LD score regression (LDSC), while the local assessment utilized heritability estimation from summary statistics (HESS). Causality assessment was conducted through two-sample Mendelian randomization (2SMR), and genetic overlap analysis utilized the conditional false discovery rate/conjunctional FDR (cond/conjFDR) method. Finally, LDSC applied to specifically expressed genes (LDSC-SEG) was performed at the tissue level. For IBD and Ps-specific expressed genes, genetic correlation, causality, shared genetics, and trait-specific associated tissues were methodically examined.

RESULTS

At the genomic level, both overall and local genetic correlations were found between IBD and Ps. MR analysis indicated a positive causal relationship between Ps and IBD. The conjFDR analysis with a threshold of < 0.01 identified 43 loci shared between IBD and Ps. Subsequent investigations into disease-associated tissues indicated a close association of IBD and Ps with whole blood, lung, spleen, and EBV-transformed lymphocytes.

CONCLUSION

The current research offers a novel perspective on the association between IBD and Ps. It contributes to an enhanced comprehension of the genetic structure and mechanisms of comorbidities in both diseases.

Size-Dependent In Vivo Transport of Nanoparticles: Implications for Delivery, Targeting, and Clearance

Understanding the in vivo transport of nanoparticles provides guidelines for designing nanomedicines with higher efficacy and fewer side effects. Among many factors, the size of nanoparticles plays a key role in controlling their in vivo transport behaviors due to the existence of various physiological size thresholds within the body and size-dependent nano-bio interactions. Encouraged by the evolving discoveries of nanoparticle-size-dependent biological effects, we believe that it is necessary to systematically summarize the size-scaling laws of nanoparticle transport in vivo. In this review, we summarized the size effect of nanoparticles on their in vivo transport along their journey in the body: begin with the administration of nanoparticles via different delivery routes, followed by the targeting of nanoparticles to intended tissues including tumors and other organs, and eventually clearance of nanoparticles through the liver or kidneys. We outlined the tools for investigating the in vivo transport of nanoparticles as well. Finally, we discussed how we may leverage the size-dependent transport to tackle some of the key challenges in nanomedicine translation and also raised important size-related questions that remain to be answered in the future.

Recent advances on emerging nanomaterials for diagnosis and treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic idiopathic inflammatory disorder that affects the entire gastrointestinal tract and is associated with an increased risk of colorectal cancer. Mainstream clinical testing methods are time-consuming, painful for patients, and insufficiently sensitive to detect early symptoms. Currently, there is no definitive cure for IBD, and frequent doses of medications with potentially severe side effects may affect patient response. In recent years, nanomaterials have demonstrated considerable potential for IBD management due to their diverse structures, composition, and physical and chemical properties. In this review, we provide an overview of the advances in nanomaterial-based diagnosis and treatment of IBD in recent five years. Multi-functional bio-nano platforms, including contrast agents, near-infrared (NIR) fluorescent probes, and bioactive substance detection agents have been developed for IBD diagnosis. Based on a series of pathogenic characteristics of IBD, the therapeutic strategies of antioxidant, anti-inflammatory, and intestinal microbiome regulation of IBD based on nanomaterials are systematically introduced. Finally, the future challenges and prospects in this field are presented to facilitate the development of diagnosis and treatment of IBD.

H2S-Reactivating Antitumor Immune Response after Microwave Thermal Therapy for Long-Term Tumor Suppression

Microwave thermal therapy (MWTT) is one of the most potent ablative treatments known, with advantages like deep penetration, minimal invasion, repeatable operation, and low interference from bone and gas. However, microwave (MW) is not selective against tumors, and residual tumors after incomplete ablation will generate immunosuppression, ultimately making tumors prone to recurrence and metastasis. Herein, a nano-immunomodulator (Bi-MOF-l-Cys@PEG@HA, BMCPH) is proposed to reverse the immunosuppression and reactivate the antitumor immune effect through responsively releasing H2S in tumor cells for improving MWTT. Under MW irradiation, BMCPH will mediate MWTT to ablate tumors and release l-cysteine (l-Cys) to react with the highly expressed cystathionine β-synthase in tumor to generate H2S. The generated H2S can inhibit the accumulation of myeloid-derived suppressor cells (MDSCs) and promote the expression of cytotoxic T lymphocytes (CTLs). Moreover, Bi-MOF can also scavenge reactive oxygen species (ROS), a major means of MDSCs-mediated immunosuppression, to further weaken the immunosuppressive effect. Simultaneously, the surface-covered HA will gather CTLs around the tumor to enhance the immune response. This nano gas immunomodulator provides an idea for the sensitive and tunable release of unstable gas molecules at tumor sites. The strategy of H2S gas to reverse immunosuppression and reactivate antitumor immune response introduces a direction to reduce the risk of tumor recurrence and metastasis after thermal ablation.

Anti-Inflammatory Effects of Dietary Polyphenols through Inhibitory Activity against Metalloproteinases

Matrix metalloproteinases (MMPs) are zinc-dependent metalloproteinases that play important roles in a variety of diseases, including cancer, cardiovascular disease, diabetes, obesity, and brain diseases. Dietary polyphenols are thought to have a variety of beneficial effects on these diseases characterized by inflammation. Clinical studies have demonstrated that MMPs are in most cases upregulated in various inflammatory diseases, including osteoarthritis, rheumatoid arthritis, inflammatory bowel disease, and Alzheimer's disease. Studies using patient-derived human samples, animal studies, and cellular experiments have suggested that polyphenols may be beneficial against inflammatory diseases by suppressing MMP gene expression and enzyme activity. One important mechanism by which polyphenols exert their activity is the downregulation of reactive oxygen species that promote MMP expression. Another important mechanism is the direct binding of polyphenols to MMPs and their inhibition of enzyme activity. Molecular docking analyses have provided a structural basis for the interaction between polyphenols and MMPs and will help to explore new polyphenol-based drugs with anti-inflammatory properties.