A hybrid bacterium with tumor-associated macrophage polarization for enhanced photothermal-immunotherapy

(B.b) through electrostatic interactions. The hybrid bacteria with hypoxia targeting ability can effectively accumulate and penetrate the tumor tissues, enabling the B.b to fully contact with the TAMs and mediate their polarization toward M1 phenotype to reverse the immunosuppressive tumor microenvironment. It also enables to overcome the intratumoral heterogeneity and obtain abundant tumor-associated antigens by coupling tumor penetration of the B.b with photothermal effect of the QDs, resulting in an enhanced immune effect. This strategy that combines B.b-triggered TAM polarization and QD-induced ICD achieved a remarkable inhibition of tumor growth in orthotopic breast cancer.