MMP-2/GSH-responsive nanobomb for tumor chemo-immunotherapy with hierarchical delivery and TAMs re-education by regulating hbegf-activated ERK/MAPK signal pathway

The low targeting of immunity regulators & chemotherapy drugs and immune tolerance in the tumor microenvironment significantly hindered the chemo-immunotherapy effect. In this work, an MMP-2/GSH-responsive nanobomb loading Resiquimod (R848) and prodrug Cisplatin (Pt) with hierarchical drug delivery and tumor associated macrophages (TAMs) polarization traits was designed for improved chemo-immunotherapy. The Pt-carrying dendrimers penetrate the depth of tumor tissues under MMP-2 and activate the cytotoxicity of Pt prodrug in response to GSH, causing effective tumor damage and enhancing immunogenicity. Meanwhile, R848 is effectively uptake by TAMs, which were re-educated and then greatly relieved immune resistance. In vitro and in vivo results collectively revealed that the nanosystem could not only overcome the barrier of tumor penetration and the heterogeneity action sites of drugs but also re-educate TAMs and suppress immune evasion via activating extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signal pathway regulated by heparin binding EGF like growth factor (Hbegf) gene. The gene silencing or knockout in vitro and in vivo demonstrated that Hbegf could regulate the re-education of TAMs and the progression of tumors.