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Self-propelling magnetic nanorobots capable of intrinsic-navigation in biological fluids with enhanced pharmacokinetics and deeper tissue penetration implicates promising strategy in targeted cancer therapy. Here, multi-component magnetic nanobot designed by chemically conjugating magnetic fe 3 o 4 nanoparticles (NPs), anti-epithelial cell adhesion molecule antibody (anti-EpCAM mAb) to multiwalled carbon nanotubes (CNT) loaded with an anticancer drug, doxorubicin hydrochloride (DOX) is reported. Autonomous propulsion of the nanobots and their external magnetic guidance is enabled by enriching fe 3 o 4 nps with dual catalytic-magnetic functionality. the nanobots propel at high velocities even in complex biological fluids. In addition, the nanobots preferably release DOX in the intracellular lysosomal compartment of human colorectal carcinoma (HCT116) cells by the opening of Fe 3 o 4 np gate. Further, nanobot reduce ex vivo HCT116 tumor spheroids more efficiently than free DOX. The multicomponent nanobot's design represents a more pronounced method in targeting tumors with selfassisted anticancer drug delivery for 'far-reaching' sites in treating cancers. Designing miniaturized and versatile robots in the dimensional-range of a few micrometers or less offer potential for unprecedented biomedical applications, such as refinements in targeted drug delivery platforms 1-7. Miniature robotic systems provide considerable benefits over conventional and micro/nanoparticle-based therapies 8,9. Existing anticancer drug delivery systems demonstrate pharmacokinetic (PK) limitations as they are passive systems driven by the blood fluidics and lack intrinsic navigation for long circulation time, targeting, localized delivery, and tissue penetration 10,11. Furthermore, despite surface functionalization with a specific ligand that allows nanocarriers to increase the active targeting ability; the nanocarriers are unable to guide themselves to a target. Hence, for targeted anticancer delivery of therapeutic payloads to disease sites, drug carriers are desired to possess some distinctive traits, including self-propelling force and velocity, navigational functions, precise cell targeting, drug cargo-towing and finally tissue penetration with the release of drug payload 12-16. Micro/nanomotors with efficient cargo towing and effective penetrating abilities make them excellent delivery vehicles that can meet the necessary features for targeted delivery of therapeutics 6. Chemically propelled micro-/ nanorobots have been widely explored for active drug delivery, and tremendous progresses has been made in the past few years 17. However, designing nanobots for biological functionality is still a challenge as they have some inherent limitations, such as complex preparation technology, difficulty of surface modification, difficulty of motion in biological fluids and depending on the material, poor biocompatibility or biodegradability 6,18,19. Furthermore, none of the reported micro/nanobot system has demonstrated practically useful speed hig...

A rational design of magnetic capturing nanodevices, based on a specific interaction with circulating tumor cells (CTCs), can advance the capturing efficiency and initiate the development of modern smart nanoformulations for rapid isolation and detection of these CTCs from the bloodstream. Therefore, the development and evaluation of magnetic nanogels (MNGs) based on magnetic nanoparticles and linear thermoresponsive polyglycerol for the capturing of CTCs with overexpressed transferrin (Tf(+) ) receptors has been presented in this study. The MNGs are synthesized using a strain-promoted "click" approach which has allowed the in situ surface decoration with Tf-polyethylene glycol (PEG) ligands of three different PEG chain lengths as targeting ligands. An optimal value of around 30% of cells captures is achieved with a linker of eight ethylene glycol units. This study shows the potential of MNGs for the capture of CTCs and the necessity of precise control over the linkage of the targeting moiety to the capturing device.

Nanosized robots with self-propelling and navigating capabilities have become an exciting field of research, attributable to their autonomous motion and specific biomolecular interaction ability for bio-analysis and diagnosis. Here, we report magnesium (Mg)-Fe3O4-based Magneto-Fluorescent Nanorobot (“MFN”) that can self-propel in blood without any other additives and can selectively and rapidly isolate cancer cells. The nanobots viz; Mg-Fe3O4-GSH-G4-Cy5-Tf and Mg-Fe3O4-GSH-G4-Cy5-Ab have been designed and synthesized by simple surface modifications and conjugation chemistry to assemble multiple components viz; (i) EpCAM antibody/transferrin, (ii) cyanine 5 NHS (Cy5) dye, (iii) fourth generation (G4) dendrimers for multiple conjugation and (iv) glutathione (GSH) by chemical conjugation onto one side of Mg nanoparticle. The nanobots propelled efficiently not only in simulated biological media, but also in blood samples. With continuous motion upon exposure to water and the presence of Fe3O4 shell on Mg nanoparticle for magnetic guidance, the nanobot offers major improvements in sensitivity, efficiency and speed by greatly enhancing capture of cancer cells. The nanobots showed excellent cancer cell capture efficiency of almost 100% both in serum and whole blood, especially with MCF7 breast cancer cells.

Here, we report a non-invasive strategy for isolating cancer cells by autonomously propelled carbon nanotube (CNT) microrockets. H2O2-driven oxygen (O2) bubble-propelled microrockets were synthesized using CNT and Fe3O4 nanoparticles in the inner surface and covalently conjugating transferrin on the outer surface. Results show that self-propellant microrockets can specifically capture cancer cells.