Bacterially Synthesized Tellurium Nanorods for Elimination of Advanced Malignant Tumor by Photothermal Immunotherapy

Abstract

Probiotic Escherichia coli Nissle 1917 (EcN) are employed as a bioreactor for intracellularly synthesizing tellurium nanorods (TeNRs) providing a biohybrid therapeutic platform (Te@EcN) for the elimination of advanced malignant tumor by photothermal immunotherapy. Te@EcN is found to possess superior photothermal property upon near‐infrared irradiation, and can efficiently accumulate and retain in tumors, although EcN loses proliferation ability after the synthesis of TeNRs, thus inducing considerable immunogenic tumor cell death. Under co‐stimulation by EcN acting as immunoadjuvants, maturation of dendritic cells and priming of cytotoxic T cells are largely promoted. In addition, Te@EcN can reprogram tumor‐associated macrophages to ameliorate the immunosuppressive tumor microenvironment. Thus, tumor metastasis and recurrence can be efficiently suppressed. Most importantly, owing to the non‐pathogenicity of probiotic EcN and their non‐proliferative characteristics after TeNRs synthesis, Te@EcN is found to be rapidly metabolized and cleared from the normal tissues, showing very slight acute side effects in healthy mice even at a relatively high administration dose. Therefore, the proposed combined therapeutic strategy based on bacteria‐synthesized TeNRs may find great potential in improving bacteria‐mediated tumor therapy with increased antitumor efficacy and reduced toxicity.

Rational Design of Biomaterials to Potentiate Cancer Thermal Therapy

“…A similar phenomenon has also been observed in preclinical animal experiments with outer membrane vesicles (OMVs) isolated from diverse bacteria as bifunctional biomaterials to induce tumor-localized photothermal ablation and immunostimulation . More recently, diverse immunostimulatory biomaterials, including both live bacteria and their derived OMVs as well as noninfectious virus-like particles, have been genetically or chemically modified with NIR-absorbing agents (e.g., melanin, ICG, croconium dyes, tellurium nanorods, palladium nanoparticles) to boost highly efficient photoimmunotherapy. − …”

Decorating Bacteria with Triple Immune Nanoactivators Generates Tumor‐Resident Living Immunotherapeutics

“…We noted that EcN alone was incapable of polarizing macrophages, which could be ascribed to the relatively low feed ratio of bacteria to cells and the short incubation time. [37,38] These data illustrated the potential of PDA nanoparticles attached to the EcN surface to repolarize TAMs into pro-inflammatory M1 profile, which is characterized by improved phagocytic and T cell activation capabilities.…”

Tellurium/polymers for flexible thermoelectrics: status and challenges

“…Various strategies were implemented to form Te nanostructures, such as solution-based approaches, liquid-phase exfoliation and vapor deposition. In the past decade, Te nanocrystals with a variety of dimensions, including zero dimension (0D), 52–55 one dimension (1D) 56–62 and two dimension (2D) 63–69 nanostructures have been successfully synthesized.…”