In situ repolarization of Tumor-Associated Macrophages with synergic nanoformulation to reverse immunosuppressive TME in mouse breast cancer for cancer therapy

The conversion of tumor-associated macrophages (TAMs) from M2 phenotype to M1 phenotype could reverse the immunosuppression associated with the tumor microenvironment. Here, we constructed M2 phenotype macrophage-targeted Lipo@CpG-FA by encapsulating CpG ODNs. The combination of Lipo@CpG-FA with FA-Lipo@Ele-AS1411 caused regression and inhibition of 4T1 breast cancers by reversing the M2-TAMs mediated immunosuppression and efficiently inducing effector T cell activation in the tumor microenvironment. In addition to antitumor effects, Elemene (Ele) could inhibit the effect M2 macrophage proliferation by enhancing the therapeutic effects. The application of this strategy may be potentially expanded for cancer therapy in combination with other therapeutics.