The Korea Institute of Medical Microrobotics (KIMIRo) announced on Feb. 16 that it has succeeded for the first time in the world in knee cartilage regeneration by means of a stem cell held by a microrobot. Details of the research were published in the Science Robotics journal on Jan. 22 after verification based on cell and animal experiments.
The institute produced the robot with a diameter of 350 micrometers by attaching magnetic particles with a diameter of 1.5 micrometers to the surface of a porous and biodegradable microstructure. The porous structure of the robot is capable of holding a large number of stem cells and facilitating nutrient supply. The biodegradable structure is gradually decomposed in the human body.
The magnetic microparticles on the surface are magnetic nanoparticles authorized by the U.S. FDA. The biodegradable polymer-based particles react to an external magnetic field to precisely transfer the robot to a damaged cartilage and stably fix it to the affected area.
The robot holds a human fat-derived stem cell. The stem cell precisely transferred and transplanted to the damaged cartilage undergoes cellular differentiation into cartilage cells and the effect of regeneration can be maximized.
These days, degenerative arthritis and the necessity of total knee replacement are being dealt with by means of autologous cell transplantation or injection into patients’ knee cartilages. These methods, however, have their own limitations in that the injected cells are incapable of moving on their own. As such, the effects of the existing cell injection techniques are limited in that a lot of cells are necessary and knee incision-based invasive surgeries are required.
The institute has worked on a stem cell navigator to overcome such limitations. The navigator is characterized by being capable of carrying an animal bone marrow-derived adult stem cell.