Volbots: Volvox Microalgae-Based Robots for Multimode Precision Imaging and Therapy

摘要

Biohybrid microrobotics are exploited as a delivery approach to activelytransport therapeutic payload to tumors. However, the therapeutic utilityof this approach can be diminished by tumor hypoxia. Moreover, currentbiohybrid microrobotics design is mainly focused on the living organisms’motility and biocompatibility, yet the unique biological function ofthe natural organism is often overlooked. Here, an all-in-one self-propelledvolvox-based multifunctional robot, that is, Volbot, with built-in capabilitiesof fluid mixing, multimode imaging, and photosynthesis-mediated in situoxygen generation that can potentially relieve hypoxia is developed. Volbotscan follow a pre-specified route and directionality under the control of amagnetic field. Red-light irradiation (λ = 650 nm) can enhance the Volbot’slocomotive behavior, enhance the mixing of biofluids, and modulatethe oxygen production to improve the efficacy of photodynamic therapy.Moreover, Volbots can absorb near-infrared irradiation and produce localizedhyperthermia to treat tumors. Subcutaneous tumor suppression canbe achieved by this high-yield oxygen-producing biohybrid “microfactory”in a photodynamic/photothermal-synergistic therapy strategy. Furthermore,Volbots also offer imaging capabilities and exhibit considerable promise asa multifunctional microrobotics-based theranostic approach for a precisiontumor therapy strategy.