Covalent modification of therapeutic compounds is a clinically proven strategy to devise prodrugs with enhanced treatment efficacies. Self-assembly of prodrugs expands the functional space of conventional prodrug design, providing a possible pathway to more effective therapies.

Lung cancer (LC) is the leading cause of cancer-related death worldwide due to its late diagnosis and poor outcomes. As has been found for other types of tumors, there is increasing evidence that myeloid-derived suppressor cells (MDSCs) play important roles in the promotion and progression of LC. Here, we briefly introduce the definition of MDSCs and their immunosuppressive functions. We next specifically discuss the multiple roles of MDSCs in the lung tumor microenvironment, including those in tumor growth and progression mediated by inhibiting antitumor immunity, and the associations of MDSCs with a poor prognosis and increased resistance to chemotherapy and immunotherapy. Finally, we also discuss preclinical and clinical treatment strategies targeting MDSCs, which may have the potential to enhance the efficacy of immunotherapy.

The dysfunction of the intestinal epithelial barrier contributes to local or systemic infection and inflammation. Some lactic acid bacteria (LAB) strains had been shown to improve the conditions of barrier function and, for this reason, are recognized as probiotics. Weissella cibaria, a species belonging to the LAB group, is known to promote several health benefits. However, the role of W. cibaria in regulating the integrity of the intestinal epithelial barrier has not yet been investigated. In this study, W. cibaria MW01 was isolated from Chinese sauerkraut and was selected based on its functional features, such as gastric juice and bile salt tolerance, besides antagonistic activity against pathogenic bacteria. In a cellular model of the intestinal barrier, it was observed that W. cibaria was able to adhere more efficiently than Lactobacillus rhamnosus GG in Caco-2 cells. Moreover, the LPS-induced inflammation in Caco-2 cells was attenuated by the treatment with W. cibaria MW01, which reduced the synthesis of TNF-α, IL-6, and IL-8. In addition, it was noted that the treatment with W. cibaria MW01 recovered the integrity of the Caco-2 cell monolayer exposed to LPS. Furthermore, W. cibaria MW01 significantly alleviated LPS-induced downregulation of tight junction proteins (TJP) (claudin, occludin, and tight junction protein-1). Mechanistically, W. cibaria MW01 inhibited the translocation of NF-κB to the nucleus and deactivated the MLCK-pMLC pathway during LPS exposure. Thus, W. cibaria MW01, as a potential probiotic, can protect intestinal epithelial barrier function by regulating inflammation and expression of TJP via the NF-κB-mediated MLCK-pMLC pathway.

Probiotic-based therapy for ulcerative colitis (UC) is a novel and promising approach that has gained much popularity in recent years. However, probiotics may be easily captured and destroyed by the harsh in vivo environment, which limits their application prospects to a large extent. This work introduces a versatile facile approach for decorating individual probiotics with nanozyme coatings, named Pt-Lipid@EcN. A bimolecular lipid coating is deposited on the surface of probiotics used in the oral treatment of UC using simple self-assembly with a liposome under cytocompatible conditions, and it acts as armor to effectively protect the probiotics from strong digestive acids and enzymes. The obtained results indicated that the liposome-coated Escherichia coli Nissle (EcN) 1917 could significantly improve the colonization rate of the microorganisms in the intestinal tract. We also explored the specific mechanism of Pt-Lipid@EcN to improve the behavior of murine UC models, including reduction of inflammatory effects and histological injury, and regulation of epithelial barrier homeostasis in the intestine. The nanozyme-shielded probiotic exhibited enhanced anti-inflammatory ability in vivo, introducing novel strategies for the application of nanozyme biomedicine in the treatment of colonic inflammatory diseases.

Chemodynamic therapy (CDT) has been critically challenged by insufficient H ₂ O ₂ in cancer tissues and inefficient reactive oxygen species (ROS) production.