Magnetically actuated microrobots as a platform for stem cell transplantation

Abstract

Magnetic microrobots were developed for three-dimensional culture and the precise delivery of stem cells in vitro, ex vivo, and in vivo. Hippocampal neural stem cells attached to the microrobots proliferated and differentiated into astrocytes, oligodendrocytes, and neurons. Moreover, microrobots were used to transport colorectal carcinoma cancer cells to tumor microtissue in a body-on-a-chip, which comprised an in vitro liver-tumor microorgan network. The microrobots were also controlled in a mouse brain slice and rat brain blood vessel. Last, microrobots carrying mesenchymal stem cells derived from human nose were manipulated inside the intraperitoneal cavity of a nude mouse. The results indicate the potential of microrobots for the culture and delivery of stem cells.

Magnetically Actuated SiCN‐Based Ceramic Microrobot for Guided Cell Delivery

“…The magnetic microrobots have magnetic nanoparticles (MNPs) attached to a carrier that is typically made of polymers . Several limitations, however, have been pointed out in previous studies.…”

“…The fabricated microrobot was actuated in deionized (DI) water using an external magnetic field generated by an electromagnetic coil system ( Figure a). In our previous studies, we have demonstrated that in the fluidic environment of low Reynolds number, the propulsion efficiency of microrobot is better when it takes a rolling motion than when it does a pulling motion 5a. For this reason, a rotating magnetic field was applied to the microrobot.…”

“…At each H , v L initially increased as ω increased, but decreased rapidly after ω reached a certain value, which is referred to as step‐out frequency ω OUT . This frequency is related to H , the magnetization of the microrobot, drag force, and friction 2a,4d,5d. ω OUT increased as H was increased.…”

Magnetic Actuation Systems for Miniature Robots: A Review

“…Because of their small scale, these robots can access complex and narrow regions of the human body in a minimally invasive manner, for example, in the gastrointestinal (GI) tract, vasculature, brain, and eye . Moreover, they have the potential to perform various tasks, such as targeted delivery, precise surgery, and medical examination . In addition, microsized robots have prospects for in vitro applications, such as cell manipulation and tissue engineering, because of their capability to manipulate down to subcellular entities with high precision and repeatability …”

Magnetically Powered Biodegradable Microswimmers

“…Untethered mobile microrobots have demonstrated great potential in numerous microscale biomedical applications, such as minimally invasive therapy, drug and cell delivery, microsurgery, and in vivo sensing [1][2][3][4][5][6][7][8][9]. According to Purcell's scallop theorem [10], in fluid environments with low Reynolds number (Re), viscous forces dominate compared to inertial forces.…”