Magnetotactic Bacteria-Based Drug-Loaded Micromotors for Highly Efficient Magnetic and Biological Double-Targeted Tumor Therapy

Abstract

Bacteria-mediated cancer therapy has attracted much attention in recent years. However, using magnetotactic bacteria as both a drug carrier and a drug for cancer therapy has never been reported. Herein, we incorporated a photosensitizer chlorin e6 (Ce6) into the M. magneticum strain AMB-1 through a chemical bond or physical blending. A chemical reaction was finally selected for fabricating AMB-1/Ce6 micromotors, as such micromotors exhibited high drug payload and normal bacterial activities. An interesting finding is that AMB-1 is not only an excellent drug carrier but also a unique drug that could inhibit mouse tumor growth. We also, for the first time, demonstrated that AMB-1 is a photosensitizer. Under laser irradiation, micromotors killed cancer cells with high efficiency due to the high-level reactive oxygen species generated by the micromotors. Micromotors could target the hypoxic and normoxic regions in vitro via both the active swimming of AMB-1 and external magnetic field guidance. Micromotors showed high tumor-homing ability owing to the above double targeting mechanisms. After injection with the micromotors followed by magnetic field guidance and laser irradiation, the growth of mouse tumors was significantly inhibited owing to the AMB-1-based biotherapy and phototoxicity of AMB-1 and Ce6. This micromotor-mediated tumor-targeted therapy strategy may be a great platform for treating many types of solid tumors.

Fabrication of Red Blood Cell-Mimicking Janus Microparticles with Enhanced Upconversion Luminescence and Drug Delivery Performance Using Double-Needle Electrospray

“…In vivo experiments showed that the hydrogel could respond to an external magnetic field and produce a synergistic effect on tumors under the external magnetic field. Wang et al also fabricated a micromotor with a saturation magnetization of approximately 0.5 emu/g based on M. magneticum strain AMB-1 (a kind of magnetotactic bacteria) and photosensitizer chlorin e6.…”

“…In vivo experiments showed that the hydrogel could respond to an external magnetic field and produce a synergistic effect on tumors under the external magnetic field. Wang et al 50 also fabricated a micromotor with a saturation magnetization of approximately 0.5 emu/g based on M. magneticum strain AMB-1 (a kind of magnetotactic bacteria) and photosensitizer chlorin e6. After injection with the micromotors followed by magnetic field guidance and laser irradiation, the growth of mouse tumors was significantly inhibited owing to the AMB-1based biotherapy and phototoxicity of AMB-1 and chlorin e6.…”

A drug co-delivery platform made of magnesium-based micromotors enhances combination therapy for hepatoma carcinoma cells

“…At present, micro/nanomotors are gradually being developed and employed in the mouse tumor environment, including the application of Mg micromotors to improve the survival rate of tumor mice. 24,52,53 Unlike in vitro cellular levels, it is difficult to maintain high concentrations of free drugs in and around cancer cells in the body. Therefore, the development of diverse drug delivery vehicles is necessary.…”

“…Therefore, the development of diverse drug delivery vehicles is necessary. 52,53 Compared to the passive phases of drug delivery, the active phases of drug administration, which rely on the autonomous motion capability and delicate functional design of micro/nanomotors, are expected to exert enhanced anti-tumor effects when further applied in in vivo therapy. 54 We envision that the proposed Mg-based micromotor drug delivery platform would have great potential in diverse biomedical applications.…”

Integration of CoAl-Layered Double Hydroxides on Commensal Bacteria to Enable Targeted Tumor Inhibition and Immunotherapy

“…Recently, some bacteria-based biohybrid systems show potential in synergistic cancer therapy. − Anaerobic or facultative anaerobic characteristics enable bacteria to possess hypoxia tropism for active tumor targeting. , In addition, the immunogenicity of bacteria facilitates it with immune activity. ,, Propionibacterium acnes (PA), as an anaerobic bacterium with oxygen tolerance, is a commensal organism in human skin . The hypoxic TME is preferential for PA to proliferate and metabolize.…”