Wei Wu

Oral delivery of small interfering RNA (siRNA) for inflammatory bowel disease (IBD) remains a major challenge due to nuclease degradation in the gastrointestinal tract and low cellular uptake. Herein, we developed a bovine milk-derived exosome-based nanoplatform (Exos@siR) loaded with IL-23p19 siRNA for oral IBD therapy. Bovine milk exosomes were isolated and purified via acid precipitation, ultrafiltration and size exclusion chromatography, and IL-23p19 siRNA was efficiently encapsulated through electroporation. The resulting Exos@siR exhibited uniform particle size, good colloidal stability and protected siRNA from serum degradation. Compared with free siRNA, Exos@siR showed 3.7-fold higher cellular uptake in RAW 264.7 macrophages. In vivo imaging further confirmed prolonged gastrointestinal retention of the exosomal delivery system after oral administration. In the DSS-induced murine colitis model, oral administration of Exos@siR significantly alleviated body weight loss, elevated disease activity index, colon shortening, splenomegaly, myeloperoxidase (MPO) overactivation and histopathological damage. Mechanistically, Exos@siR effectively silenced IL-23p19 expression in colon tissues, which downregulated pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) and upregulated the anti-inflammatory cytokine IL-10, meanwhile restored the expression of tight junction proteins ZO-1 and Occludin to repair intestinal barrier integrity. Collectively, bovine milk-derived exosomes serve as a biocompatible and effective platform for oral siRNA delivery, providing a promising therapeutic strategy for IL-23p19-targeted IBD treatment.

The disadvantage of a traditional dosage regimen is the inability to deliver a sufficient drug concentration to the lesion site, which can result in adverse side effects due to nonspecific drug delivery. Actively targeting hepatic cells is a promising therapeutic strategy for liver disease. In this study, l-carnitine and a targeting peptide derived from the hepatitis B virus large envelope protein were used to modify liposomes for drug delivery to the liver through the sodium taurocholate cotransporting polypeptide (NTCP) and the organic cation/carnitine transporter 2 (OCTN2) receptors. Silybin was selected as the model drug. The solubility of silybin can reach 0.3 mg/mL after encapsulation in liposomes. The NTCP-specific and OCTN2-accelerated Myrcludex B and l-carnitine dual-modified liposomes were validated in vitro. The uptake of coumarin-6 in dual ligand-modified liposomes by hepatocytes was up to 2.36 μg/mg compared with unmodified liposomes (1.05 μg/mg). The pharmacokinetics and targeting abilities of various liposome formulations were evaluated in Kunming mice. Targeted liposomes increased the concentration of silybin and prolonged the drug's retention time in the liver. The area under the liver's pharmacokinetic curve of targeted liposomes was twice that of silybin injection, suggesting the promising application potential of silybin-loaded hepatotropic nanovesicles.

Japanese Ardisia is widely used as a hepatoprotective and anti-inflammatory agent in China. However, the active ingredients in Japanese Ardisia and their potential mechanisms of action in the treatment of autoimmune hepatitis (AIH) are unknown. The pharmacodynamic substance and mechanism of action of Japanese Ardisia in the treatment of AIH were investigated using network pharmacology and molecular docking technology in this study. Following that, the effects of Japanese Ardisia were evaluated using the concanavalin A (Con A)-induced acute liver injury rat model. The active ingredients and targets of Japanese Ardisia were searched using the Traditional Chinese Medicine Systems Pharmacology database, and hepatitis-related therapeutic targets were identified through GeneCards and Online Mendelian Inheritance in Man databases. A compound–target network was then constructed using Cytoscape software, and enrichment analysis was performed using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Molecular docking technology was used to simulate the docking of key targets, and the AIH rat model was used to validate the expression of key targets. Nineteen active chemical components and 143 key target genes were identified. GO enrichment analysis revealed that the treatment of AIH with Japanese Ardisia mainly involved DNA–binding transcription factor binding, RNA polymerase II-specific DNA transcription factor binding, cytokine receptor binding, receptor-ligand activity, ubiquitin-like protein ligase binding, and cytokine activity. In the KEGG enrichment analysis, 165 pathways were identified, including the lipid and atherosclerotic pathway, IL-17 signaling pathway, TNF signaling pathway, hepatitis B pathway, and the AGE–RAGE signaling pathway in diabetic complications. These pathways may be the key to effective AIH treatment with Japanese Ardisia. Molecular docking showed that quercetin and kaempferol have good binding to AKT1, IL6, VEGFA, and CASP3. Animal experiments demonstrated that Japanese Ardisia could increase the expression of AKT1 and decrease the expression of CASP3 protein, as well as IL-6, in rat liver tissues. This study identified multiple molecular targets and pathways for Japanese Ardisia in the treatment of AIH. At the same time, the effectiveness of Japanese Ardisia in treating AIH was verified by animal experiments.

The mechanism of action of Ardisia japonica in the treatment of immune liver injury was systematically analyzed from the perspective of the biological metabolic network by using non-targeted metabolomics combined with biological network analysis tools. A rat model of acute immune hepatic injury was established by Concanavalin A (Con A) and the efficacy of the treatment of acute immune liver injury was judged by gavage of A. japonica. Liquid chromatography-mass spectrometry (LC-MS)-based plasma metabolomics was used to identify the key metabolites and metabolic pathways for the hepatoprotective effects of A. japonica. The results demonstrated that A. japonica reduced the levels of inflammatory parameters, decreased hepatic malondialdehyde levels, and enhanced hepatic antioxidant enzyme activity in animal experiments. The clustering of metabolomic samples showed significant separation in principal component analysis plots and the three groups in PLS-DA and OPLS-DA models could be clearly distinguished in multivariate statistical analysis. Among the 937 total metabolites, 445 metabolites were significantly different between the control and model groups, while 144 metabolites were identified as metabolites with differences between the model and administration groups, and a total of 39 differential metabolites were identified to affect the metabolic levels of the three groups. The differential metabolites were principally involved in the citric acid cycle, glutathione metabolism, vitamin B6 metabolism, and steroid hormone biosynthesis. This study found that A. japonica can significantly inhibit acute liver injury in rats, and exert a hepatoprotective effect through anti-inflammatory effect, inhibition of lipid peroxidation, improvement of the antioxidant defense system, and regulation of metabolites and related metabolic pathways. This study will provide a theoretical basis for the application of A. japonica in the treatment of the liver injury.

To increase the antitumor drug concentration in the liver tumor site and improve the therapeutic effects, a functionalized liposome (PPP-LIP) with tumor targetability and enhanced internalization after matrix metalloproteinase-2 (MMP2)-triggered cell-penetrating peptide (TATp) exposure was modified with myrcludex B (a synthetic HBV preS-derived lipopeptide endowed with compelling liver tropism) for liver tumor-specific delivery. After intravenous administration, PPP-LIP was mediated by myrcludex B to reach the hepatocyte surface. The MMP2-overexpressing tumor microenvironment deprotected PEG, exposing it to TATp, facilitating tumor penetration and subsequent efficient destruction of tumor cells. In live imaging of small animals and cellular uptake, PPP-LIP was taken up much more than typical unmodified liposomes in the ICR mouse liver and liver tumor cells. Hydroxycamptothecin (HCPT)-loaded PPP-LIP showed a better antitumor effect than commercially available HCPT injections among MTT, three-dimensional (3 D) tumor ball, and tumor-bearing nude mouse experiments. Our findings indicated that PPP-LIP nanocarriers could be a promising tumor-targeted medication delivery strategy for treating liver cancers with elevated MMP2 expression.

The high physiology and low toxicity of therapeutic peptides and proteins have made them a hot spot for drug development in recent years. However, their poor oral bioavailability and unstable metabolism make their clinical application difficult. The bilayer membrane of liposomes provides protection for the drug within the compartment, and their high biocompatibility makes the drug more easily absorbed by the body. However, phospholipids—which form the membranes—are subjected to various digestive enzymes and mucosal adhesion in the digestive tract and disintegrate before absorption. Improvements in the composition of liposomes or modifying their surface can enhance the stability of the liposomes in the gastrointestinal tract. This article reviews the basic strategies for liposome preparation and surface modification that promote the oral administration of therapeutic polypeptides.