Breast cancer is the primary reason for cancer-related death in women worldwide and the development of new formulations to treat breast cancer patients is crucial. Curcumin (Cur), a natural product, exerts promising anticancer activities against various cancer types. However, its therapeutic efficacy is hindered as a result of poor water solubility, instability, and low bioavailability. The aim of this work is to assess the curative effect of a novel nanoformulation, i.e., Cur-loaded and calcium-doped dendritic mesoporous silica nanoparticles modified with folic acid (Cur-Ca@DMSNs-FA) for breast cancer therapy. The results manifested that Cur-Ca@DMSNs-FA dispersed very well in aqueous solution, released Cur with a pH-responsible profile, and targeted efficiently to human breast cancer MCF-7 cells. Further investigations indicated that Cur-Ca@DMSNs-FA effectively inhibited cell proliferation, increased intracellular ROS generation, decreased mitochondrial membrane potential, and enhanced cell cycle retardation at G2/M phase, leading to a higher apoptosis rate in MCF-7 compared to free Cur. Moreover, the Western blotting analysis demonstrated that Cur-Ca@DMSNs-FA were more active than free Cur through suppression of PI3K/AKT/mTOR and Wnt/β-catenin signaling, and activation of the mitochondria-mediated apoptosis pathway. In addition, hemolysis assay showed that the Ca@DMSNs-FA exhibited good biocompatibility. Last, in vivo studies indicated that when Cur was encapsulated in Ca@DMSNs-FA, the Cur concentration in blood serum and tumor tissues was increased after 1 h intraperitoneal injection. In conclusion, Cur-Ca@DMSNs-FA might act as a potential anticancer drug formulation for breast cancer therapy.

Checkpoint blockade immunotherapy has demonstrated significant clinical success in various malignant tumors. However, the therapeutic response is limited due to the immunosuppressive tumor microenvironment (ITM). In this study, a functional nanomaterial, layered double hydroxides (LDHs), carrying specific functional miR155 is developed to modulate ITM by synergistically repolarizing tumor associated macrophages (TAMs) to M1 subtype. LDH nanoparticles loaded with miR155 (LDH@155) exhibit superior ability in cellular uptake by murine macrophages, miR escape into the cytoplasm and TAMs specific delivery when introtumoral administration. Meanwhile, upon exposure to LDH@155, TAMs are significantly skewed to M1 subtype, which markedly inhibits myeloid‐derived suppressor cells (MDSCs) formation and stimulates T‐lymphocytes to secrete more interferon‐γ (IFN‐γ) cytokines in vitro. Introtumoral administration of LDH@155 reduces the percentage of TAMs and MDSCs in the tumor and elevates CD4 + and CD8 + T cell infiltration and activation, which can promote therapeutic efficiency of α‐PD‐1 antibody immunotherapy. Furthermore, it is found that LDH@155 significantly decreases the expression level of phosphorylated STAT3 and ERK1/2 and activates NF‐κB expression in TAMs, indicating that the STAT3, ERK1/2, and NF‐κB signaling pathways may involve in LDH@155‐induced macrophage polarization. Overall, the results suggest that LDH@155 nanoparticles may, in the future, function as a promising agent for cancer combinational immunotherapy.

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The tumor immune microenvironment (TIME) has been demonstrated to be the main cause of cancer immunotherapy failure in various malignant tumors, due to poor immunogenicity and existence of immunosuppressive factors. Thus, establishing effective treatments for hostile TIME remodeling has considerable potential to enhance immune response rates for durable tumor growth retardation. This study aims to develop a novel nanocomposite, polyethyleneimine-modified dendritic mesoporous silica nanoparticles loaded with microRNA-125a (DMSN-PEI@125a) to synergistically enhance immune response and immunosuppression reversion, ultimately generating a tumoricidal environment. Our results showed that DMSN-PEI@125a exhibited excellent ability in cellular uptake by murine macrophages and the cervical cancer cell line TC-1, repolarization of tumor associated macrophages (TAMs) to M1 type in a synergistic manner, and promotion of TC-1 immunogenic death. Intratumor injection of DMSN-PEI@125a facilitated the release of more damage-related molecular patterns and enhanced the infiltration of natural killer and CD8+ T cells. Meanwhile, repolarized TAMs could function as a helper to promote antitumor immunity, thus inhibiting tumor growth in TC-1 mouse models in a collaborative manner. Collectively, this work highlights the multifunctional roles of DMSN-PEI@125a in generating an inflammatory TIME and provoking antitumor immunity, which may serve as a potential agent for cancer immunotherapy.