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Screening Bioactive Nanoparticles in Phagocytic Immune Cells for Inhibitors of Toll-like Receptor Signaling
Published on: July 26, 2017
Tumor pH-triggered PEG detachable nanoparticles for TLR7/8 agonist delivery to improve cancer immunotherapy
Jia-Qi Luo1,2, Yong-Cong Huang3, Jing-Yang Zhang3
1Laboratory of Stem Cells and Translational Medicine, Institute for Clinical Medicine, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou 510006, China. yuyouduan@scut.edu.cn.
Antigen-presenting cells (APCs), such as macrophages and dendritic cells (DCs) are key players in modulating the immune responses of cytotoxic T lymphocytes (CTLs). Resiquimod (R848), a toll-like receptor (TLR) agonist, has demonstrated the capacity to enhance APC function and reprogram the phenotype of macrophages; however, the unfavorable in vivo performance constrains its therapeutic potential. Here, we developed R848-loaded mesoporous silica nanoparticles (denoted as R848@MSN-bi-PEG) with pH-responsive surface polyethylene glycol (PEG) detachment to effectively modulate APCs. The acidic tumor pH triggered PEG detachment when R848@MSN-bi-PEG accumulated at the tumor site, thereby promoting APC uptake and R848 release, which facilitated DCs maturation and macrophage repolarization to a pro-inflammatory phenotype. The in vivo antitumor study indicated that R848@MSN-bi-PEG led to potent anti-tumor immunity by modulating the immunosuppressive tumor microenvironment. This approach offers a novel strategy to improve the effectiveness of cancer immunotherapy.
Antigen-presenting cells (APCs), such as macrophages and dendritic cells (DCs) are key players in modulating the immune responses of cytotoxic T lymphocytes (CTLs). Resiquimod (R848), a toll-like receptor (TLR) agonist, has demonstrated the capacity to enhance APC function and reprogram the phenotype of macrophages; however, the unfavorable in vivo performance constrains its therapeutic potential. Here, we developed R848-loaded mesoporous silica nanoparticles (denoted as R848@MSN-bi-PEG) with pH-responsive surface polyethylene glycol (PEG) detachment to effectively modulate APCs. The acidic tumor pH triggered PEG detachment when R848@MSN-bi-PEG accumulated at the tumor site, thereby promoting APC uptake and R848 release, which facilitated DCs maturation and macrophage repolarization to a pro-inflammatory phenotype. The in vivo antitumor study indicated that R848@MSN-bi-PEG led to potent anti-tumor immunity by modulating the immunosuppressive tumor microenvironment. This approach offers a novel strategy to improve the effectiveness of cancer immunotherapy.
