ReviewMEDICAL ROBOTS

Micro/nanorobots for biomedicine: Delivery, surgery, sensing, and detoxification

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Science Robotics  01 Mar 2017:
Vol. 2, Issue 4, eaam6431
DOI: 10.1126/scirobotics.aam6431

Figures

  • Fig. 1 Actuation mechanisms and potential biomedical applications of various types of micro/nanorobots.

    (A) Typical propulsion mechanisms of micro/nanoscale robots. (B) Chemically powered microrocket [adapted with permission from (30)]. Scale bar, 50 μm. (C) Magnetically actuated helical nanoswimmer [adapted with permission from (31); copyright 2009 American Chemical Society]. Scale bar, 200 nm. (D) Acoustically propelled nanowire motor [adapted with permission from (32); copyright 2013 American Chemical Society]. Scale bar, 200 nm. (E) Biologically propelled sperm hybrid microrobot [adapted with permission from (33)]. (F) Potential biomedical applications of nanorobots. (G) Magnetic helical microrobot for cargo delivery [adapted with permission from (38)]. Scale bar, 50 μm. (H) Microgrippers for high-precision surgery [adapted with permission from (39)]. Scale bar, 100 μm. (I) Antibody-immobilized microrobot for sensing and isolating cancer cells [adapted with permission from (40)]. Scale bar, 30 μm. (J) RBC membrane–coated nanomotor for biodetoxification [adapted with permission from (41)].

  • Fig. 2 Representative examples of micro/nanorobot-based in vivo delivery.

    (A) Acid-powered, zinc-based micromotors for enhanced retention in the mouse’s stomach (34). (B) Enteric micromotor, coated with a pH-sensitive polymer barrier (enteric coating) to bypass the acidic stomach environment and to selectively position and spontaneously propel in the GI tract [adapted with permission from (35); copyright 2016 American Chemical Society]. (C) Controlled in vivo swimming of a swarm of bacteria-like microrobotic flagella [adapted with permission from (36)]. (D) Magneto-aerotactic motor-like bacteria delivering drug-containing nanoliposomes to tumor hypoxic regions [reprinted with permission from Macmillan Publishers Ltd. (37); copyright 2016].

  • Fig. 3 Representative examples of micro/nanorobot-enabled precision surgery.

    (A) Tetherless thermobiochemically actuated microgrippers capturing live fibroblast cells [adapted with permission from (39)]. (B) Electroforming of implantable tubular magnetic microrobots for wireless eye surgery [adapted with permission from (64)]. (C) Acoustic droplet vaporization and propulsion of perfluorocarbon-loaded microbullets for tissue ablation [adapted with permission from (65)]. (D) Self-propelled nanodriller operating on a single cell [adapted with permission from (67); copyright 2012 American Chemical Society]. (E) Medibots: dual-action biogenic microdaggers for single-cell surgery [adapted with permission from (69)].

  • Fig. 4 Strategies and examples of micro/nanorobots for sensing.

    (A) Functionalization of micro/nanorobot with different bioreceptors toward biosensing of target analytes, including cells, proteins, and nucleic acids. (B) ssDNA-functionalized microrockets for selective hybridization and isolation of nucleic acids [adapted with permission from (75); copyright 2011 American Chemical Society]. (C) Specific intracellular detection of miRNA in intact cancer cells using ultrasound (US)–propelled nanomotors [adapted with permission from (80); copyright 2015 American Chemical Society].

  • Fig. 5 Representative examples of micro/nanorobots for detoxification.

    (A) Transmission electron microscope image of a cell membrane–coated nanosponge used for toxin neutralization [reprinted with permission from Macmillan Publishers Ltd. (81); copyright 2013]. (B) Scheme of the RBC-Mg Janus micromotor moving in biological fluid (left) and their capacity for cleaning of α-toxin [adapted with permission from (82)]. (C) Scanning electron microscope image of a 3D-printed microfish (top) and fluorescence image of the microfish incubated in melittin toxin solution after swimming (bottom) [adapted with permission from (83)].