Ulcerative colitis (UC) results in inflammation and ulceration of the colon and the rectum’s inner lining. The application of herbal therapy in UC is increasing worldwide. As natural macromolecular compounds, polysaccharides have a significant role in the treatment of UC due to advantages of better biodegradation, good biocompatibility, immunomodulatory activity, and low reactogenicity. Therefore, polysaccharide drug formulation is becoming a potential candidate for UC treatment. In this review, we summarize the etiology and pathogenesis of UC and the therapeutic effects of polysaccharides on UC, such as regulating the expression of cytokines and tight junction proteins and modulating the balance of immune cells and intestinal microbiota. Polysaccharides can also serve as drug delivery carriers to enhance drug targeting and reduce side effects. This review provides a theoretical basis for applying natural plant polysaccharides in the prevention and treatment of UC.

Clinical drug administration aims to deliver drugs efficiently and safely to target tissues, organs, and cells, with the objective of enabling their therapeutic effects. Currently, the main approach to enhance a drug’s effectiveness is ensuring its efficient delivery to the intended site. Due to the fact that there are still various drawbacks of traditional drug delivery methods, such as high toxicity and side effects, insufficient drug specificity, poor targeting, and poor pharmacokinetic performance, nanocarriers have emerged as a promising alternative. Nanocarriers possess significant advantages in drug delivery due to their size tunability and surface modifiability. Moreover, nano-drug delivery systems have demonstrated strong potential in terms of prolonging drug circulation time, improving bioavailability, increasing drug retention at the tumor site, decreasing drug resistance, as well as reducing the undesirable side effects of anticancer drugs. Numerous studies have focused on utilizing polysaccharides as nanodelivery carriers, developing delivery systems based on polysaccharides, or exploiting polysaccharides as tumor-targeting ligands to enhance the precision of nanoparticle delivery. These types of investigations have become commonplace in the academic literature. This review aims to elucidate the preparation methods and principles of polysaccharide gold nanocarriers. It also provides an overview of the factors that affect the loading of polysaccharide gold nanocarriers with different kinds of drugs. Additionally, it outlines the strategies employed by polysaccharide gold nanocarriers to improve the delivery efficiency of various drugs. The objective is to provide a reference for further development of research on polysaccharide gold nanodelivery systems.

Dendritic cells (DCs) play a central role in inducing both immunity and tolerance as specialized antigen-presenting cells (APCs). The immunometabolic firestorm in recent years has focused our attention on how DCs use energy and respond to nutritional changes that affect immune functions. Like in every other cell, such metabolic events as the concentration of free amino acids, membrane-bound transporter proteins, key metabolic enzymes, and sensors (e.g., mTOR and GCN2), also profoundly affect the function and fate of DCs. Therefore, dysregulation of amino acid metabolism can cause metabolic reprogramming of DCs, leading to or accelerating the occurrence of various immunological disorders, like type 1 diabetes, rheumatoid arthritis, and cancer. Since amino acids cannot directly enter the cell to participate in metabolic activities, their transporters act as critical metabolic gatekeepers. To catch up with the rapid development in the immune metabolism field, this review summarized recent studies on the potential roles of different amino acids and their transporters in the regulation of DCs biology to offer new insights for immune-dysregulated diseases and explore new therapeutic targets.

Background: Cervical cancer is the fourth leading cause of death among women worldwide, with human papillomavirus (HPV) identified as a major contributing factor. This study investigates the immunostimulatory activity and antigen delivery efficiency of Glycyrrhiza uralensis polysaccharide gold nanoparticles (GUPS-AuNPs) and assesses the antitumor efficacy of an HPV dendritic cell (DC) vaccine using GUPS-AuNPs as a delivery system. Methods: GUPS-AuNPs were synthesized via a green reduction method and characterized using advanced techniques, including SEM, EDS, TEM, UV, and FT-IR spectroscopy. DCs served as the primary experimental model, with flow cytometry employed to evaluate the immunostimulatory activity and antigen delivery effectiveness of GUPS-AuNPs. Additionally, a TC-1 tumor-bearing mouse model was established to assess the immunostimulatory and antitumor effects of the HPV-DC vaccine facilitated by GUPS-AuNPs. Results: The synthesized GUPS-AuNPs exhibited a particle size of 120.77 ± 3.13 nm, a surface charge of −11.9 ± 2.1 mV, and excellent stability. Flow cytometry analysis demonstrated that GUPS-AuNPs significantly enhanced DC maturation and promoted T cell proliferation. Furthermore, antigen delivery experiments revealed that GUPS-AuNPs improved the antigen capture capabilities of DCs. Confocal imaging confirmed that GUPS-AuNPs extended the intracellular retention time of antigens. In vivo studies showed that the HPV-DC vaccine formulated with GUPS-AuNPs as carriers effectively suppressed tumor growth, elevated the populations of CD4⁺ T and CD8⁺ T cells in the spleen, and induced a robust antigen-specific immune response. Conclusions: GUPS-AuNPs effectively enhance DC maturation and antigen delivery, significantly boosting the adaptive immune response triggered by HPV vaccines and leading to the inhibition of tumor progression. This research introduces GUPS-AuNPs as a novel, safe, and efficient antigen delivery platform with promising potential for vaccine development.

Glycyrrhiza uralensis polysaccharides (GUPS) are considered safe and effective natural medicine due to their extensive pharmacological activity and low toxicity. However, their large molecular weight (approximately 29 kDa) and high polarity restrict intestinal absorption, resulting in poor oral bioavailability. Here, GUPS-PLGA nanoparticles (GUPS-PLGA NPs, GPN) were prepared and their intestinal absorption characteristics and immunostimulatory activity were evaluated both in vitro and in vivo. Notably, GPN with a high encapsulation rate (63.18%) was prepared by response surface methodology. Furthermore, GPN exhibited a uniform spherical shape with a 242.4 ± 3.18 nm particle size, good stability, and sustained-release properties. Oral administration of GPN enhanced the intestinal retention of GUPS and improved its transport capacity in a Caco-2 cell monolayer model (0.66 vs. 1.36 Papp×10⁶ cm/s). More importantly, GPN markedly promoted dendritic cell (DC) maturation through direct interactions and indirect effects across the Caco-2 cell monolayer. Furthermore, GPN significantly increased the number and activation state of T cells, DC, and macrophages in mice's spleen and mesenteric lymph nodes (MLN), demonstrating superior immune-enhancing effects. In summary, the PLGA-based oral drug delivery system markedly improved GUPS's intestinal absorption and efficacy, providing a theoretical foundation for developing GUPS as an oral medication and functional food.

Dendritic cells (DCs) can activate T cells to trigger sustained antitumor immune responses, a process in which the continuous migration of antigen-loaded DCs from the tumor microenvironment to tumor-draining lymph nodes is critical. DCs have evolved a complex and dynamic regulatory network to mediate their migration to specific locations, with multiple transporters including amino acid transporters reported to participate in this process. Slc1a2 is highly expressed in the nervous system, where it mediates the clearance of extracellular glutamate, primarily in astrocytes; however, its role in the immune system remains unclear. In this study, we showed that activated DCs upregulated Slc1a2 to boost glutamate uptake, which in turn promoted DC functionality and antitumor vaccine potency. Furthermore, glutamate signaling induced Sema3A, which elevated small GTPase signaling pathways (e.g., RhoA/Rac1/Cdc42) and drove dynamic cytoskeletal remodeling, thereby providing the necessary molecular machinery for DC migration during antitumor immunity in vivo. We first demonstrated that Slc1a2-mediated glutamate metabolism functioned as a metabolic checkpoint for DC migration and antigen-specific immunity in vivo, with the Sema3A/small GTPase axis serving as the core mechanism linking glutamate signaling to cytoskeletal reorganization.