Tumor Microenvironment Responsive Nanogel for the Combinatorial Antitumor Effect of Chemotherapy and Immunotherapy.

A biomimetic nanogel with tumor microenvironment responsive property is developed for the combinatorial antitumor effects of chemotherapy and immunotherapy. Nanogels are formulated with hydroxypropyl-β-cyclodextrin acrylate and two opposite charged chitosan derivatives for entrapping anticancer drug paclitaxel and precisely controlling the pH responsive capability, respectively. The nanogel supported erythrocyte membrane can achieve "nanosponge" property for delivering immunotherapeutic agent interleukin-2 without reducing the bioactivity. By responsively releasing drugs in tumor microenvironment, the nanogels significantly enhanced antitumor activity with improved drug penetration, induction of calreticulin exposure, and increased antitumor immunity. The tumor microenvironment is remodeled by the combination of these drugs in low dosage, as evidenced by the promoted infiltration of immune effector cells and reduction of immunosuppressive factors.