Bacterial membrane-coated bacteriform manganese dioxide platforms amplify phototherapeutic efficacy through the cGAS-STING pathway

Natural bacteria and bacterial bionics offer significant advantages in the synergistic approach to cancer treatments, while the development of such platforms remains challenging. Herein, bacterial membrane-coated chlorin e6-conjugated bacteriform manganese dioxide platform (BCBM) has been developed for amplifying phototherapeutic efficacy of tumors. The BCBM platform has been prepared by the in-situ growth of manganese dioxide on the surface of silica nanorods and subsequent etching process, photosensitizer conjugation, and bacterial membrane encapsulation. The manganese dioxide and bacterial membrane endow the BCBM with bacteria-like characteristics, enabling a specific response to the tumor microenvironment (TME). The manganese dioxide can react with hydrogen peroxide to produce large amounts of oxygen and manganese ions under acidic conditions. Upon near-infrared irradiation, the BCBM exhibits an excellent ability to generate reactive oxygen species because of sufficient oxygen supply. Furthermore, the released manganese ions activate cGAS-STING pathway, leading to the efficient apoptosis of cancer cells. The process of apoptosis is accompanied by the release of tumor-associated signaling molecules, which enhances therapeutic efficacy. Therefore, this work offers insights into designing biomimetic multifunctional nanoagents against cancers.