ATP-Responsive Manganese-Based Bacterial Materials Synergistically Activate the cGAS-STING Pathway for Tumor Immunotherapy.

Stimulating the cyclic guanosine monophophate(GMP)-adenosine monophosphate (AMP) synthase (cGAS)-stimulator of interferon genes (STING) pathway is a crucial strategy by which bacteria activate the tumor immune system. However, the limited stimulation capability poses significant challenges in advancing bacterial immunotherapy. Here, an adenosine 5'-triphosphate (ATP)-responsive manganese (Mn)-based bacterial material (E. coli@PDMC-PEG (polyethylene glycol)) is engineered successfully, which exhibits an exceptional ability to synergistically activate the cGAS-STING pathway. In the tumor microenvironment, which is characterized by elevated ATP levels, this biohybrid material degrades, resulting in the release of divalent manganese ions (Mn2+) and subsequent bacteria exposure. This combination synergistically activates the cGAS-STING pathway, as Mn2+ enhances the sensitivity of cGAS to the extracellular DNA (eDNA) secreted by the bacteria. The results of the in vivo experiments demonstrate that the biohybrid materials E. coli@PDMC-PEG and VNP20009@PDMC-PEG effectively inhibit the growth of subcutaneous melanoma in mice and in situ liver cancer in rabbits. Valuable insights for the development of bacteria-based tumor immunotherapy are provided here.

Thin film nanoarchitectonics of layer-by-layer assembly with reduced graphene oxide on intraocular lens for photothermal therapy of posterior capsular opacification.

Due to development of surgical techniques and intraocular lens (IOL) implants, vision can often be restored in cataracts patients. However, posterior capsular opacification (PCO) has become the most common and challenging complication in cataracts surgery. While various approaches such as surface modification and drug prophylaxis have been investigated to prevent PCO development, there is no standard treatment that is sufficiently safe and effective to meet clinical demands. Near-infrared (NIR) light-triggered photothermal therapy is an attractive noninvasive treatment for PCO prophylaxis. We fabricated a new type of IOL with excellent biocompatibility, stability, and photothermal conversion property. Polyethyleneimine (PEI) and graphene oxide (GO) were layer-by-layer assembled on model polymethylmethacrylate and IOL substrates, and the thickness, surface roughness, and wettability of the substrates with different numbers of bilayers were evaluated. After the reduction of GO to reduced GO (rGO), a rGO/PEI multilayer thin film with good stability and photothermal conversion capability was obtained. The rGO/PEI multilayer coating was able to induce apoptosis in lens epithelium cells under 808-nm NIR laser irradiation in vitro. Finally, rGO@IOL was implanted into rabbit eyes, and the biocompatibility and ability to prevent PCO were evaluated for 5 weeks. The rGO@IOL implant exhibited excellent PCO prevention ability with the assistance of NIR irradiation and did not induce obvious pathological effects in surrounding healthy tissues. The rGO@IOL implant with good biocompatibility, good physicochemical stability, and excellent photothermal conversion property shows promise for clinical application in PCO prophylaxis.