Chitosan porous structure-based magnetically actuated microrobot

agnetic Reactivity of Chitosan Porous Microrobots

[0118]In order to examine magnetic reactivity of chitosan porous microrobots, microrobots were placed in a physiological salt solution similar to the inside of the body, followed by physical shaking, and then the magnetic reactivity of the microrobots was investigated using a permanent magnet, and the results are shown in FIGS. 4A and 4B.

[0119]It was verified that the chitosan porous microrobots were concentrated toward the permanent magnet (FIG. 4A). Especially, the chitosan porous microrobots were assembled in several shapes by external magnetic fields (FIG. 4B). That is, the movement of the chitosan porous microrobots according to the direction of a magnetic field was confirmed. This indicates that when chitosan porous microrobots were injected into the body, the movement of the chitosan porous microrobots can be controlled according to the direction of the magnetic field formed outside the body.

ctuation of Chitosan Porous Microrobot

[0120]In order to investigate the actual movement of a chitosan porous microrobot, the microrobot was placed and actuated in a chamber containing a physiological salt solution. The microrobot was moved in a desired direction by controlling magnetic fields of 40 mT and 1.8 T / m generated from an electromagnetically actuated coil device.

[0121]The actuation state of the chitosan porous microrobot delivering cells with stained cytoplasm was checked using a fluorescence microscope (FIG. 5). It was verified that the chitosan porous microrobot could be actuated while containing cells, and especially, the chitosan porous microrobot could be actuated without losing magnetic reactivity thereof even after containing cells. These results indicate that the chitosan porous microrobot containing cells can be manipulatively oriented through a magnetic field, and accurately deliver a therapeutic agent (cells or a drug) to be delivered to a lesion.

n of Viability of Adipose-Derived Stem Cells and Macrophages Contained in Chitosan Porous Microrobot

[0122]The viability of adipose-derived stem cells and macrophages contained in a cell spheroid composed of only stem cells and macrophages, in a chitosan porous structure (CPS), and in a chitosan porous microrobot (CPM) was evaluated.

[0123]In the culture of adipose-derived mesenchymal stem cells and macrophages (Raw 246.7) for cell viability evaluation, fetal bovine serum was added, so that fibronectin contained in the serum was allowed to bind to the surface and the inside of the microrobot well through an integrin receptor (FIG. 6A). The fibronectin bound to the microrobot serves to help a therapeutic agent (cells or a drug) to bind to the surface of the microrobot well.

[0124]After each type of cell spheroids, chitosan porous structures, and chitosan porous microrobots was dispensed into a round-bottom 96-well plate (Corning, USA), adipose-derived stem cells and macrophages cultured by