Tumor immunotherapy as a promising method for tumor treatment received tremendous attention. However, the problem of low clinical response rate still needs to be solved, especially in the poorly immunogenic tumors. The enhancement of tumor antigens presentation can effectively activate dendritic cells (DCs) and improve the tumor immunotherapy. In this work, TAK-243 as an inhibitor of the ubiquitin activating enzyme (UAE), was fabricated into cationic lipid-assisted nanoparticle (CLAN_TAK-243). The obtained CLAN_TAK-243 could act as an effective tumor immunotherapy enhancer to promote the maturation of DCs as well as antigen presentation, which obviously stimulated the T cells activation and proliferation. Such CLAN_TAK-243 injected intravenously could well trigger immune response to tumor cells in vivo. Importantly, mice treated with CLAN_TAK-243 could obtain a long immune memory effect to protect themselves from re-challenged tumor cells. Therefore, this work presented an effective immunotherapy strategy for poorly immunogenic tumor.

Nanoparticle (NP) drug delivery systems have been successfully designed and implemented to orally deliver siRNAs for inflammatory disorders. However, the influence of surface charge on orally administered siRNA nanocarriers has not been investigated. In this study, we prepared structurally related poly(ethylene glycol)-block-poly(lactic-co-glycolic acid) (PEG_5K-b-PLGA_10K) NPs with the assistance of a synthesized lipid featuring surface amine groups for subsequent charge tuning. NPs were prepared by a double emulsion method, and their surface charge could be tuned and controlled by a succinylation reaction to yield NPs with different surface charges, while maintaining their size and composition. The prepared NPs were termed as aminated NPs (ANPs), plain NPs (PNPs), or carboxylated NPs (CNPs) based on their surface charge. All NPs exhibited the desired structural stability and siRNA integrity after enzymatic degradation. In vivo studies showed that ANPs significantly accumulated in inflamed colons, and they were successful in decreasing TNF-α secretion and mRNA expression levels while maintaining colonic histology in a murine model of acute ulcerative colitis (UC). This study described a methodology to modify the surface charge of siRNA-encapsulating polymeric NPs and highlighted the influence of surface charge on oral delivery of siRNA for localized inflammatory disorders.