17th September 2013

Microrobots for cell and drug delivery in the human body

A team of researchers at the Chinese University of Hong Kong (CUHK) has developed a novel type of magnetic "micro-robot" capable of transporting cells and delivering drugs to specific locations inside the body. This new technology has the potential to revolutionise minimally invasive medical treatment such as targeted therapy and tissue regeneration.

The development of microrobots requires interdisciplinary knowledge including mechatronics, materials science, biology, computing and automation. These tiny devices have the potential to work in very small and confined spaces and thus have broad applications in many fields, but particularly in minimally invasive medical treatment.

Prof. Zhang Li, from CUHK's Department of Mechanical and Automation Engineering, collaborated with Daegu Gyeongbuk Institute of Science and Technology (DGIST) in Korea, and ETH Zurich. Together, they innovated a new microrobot capable of transporting the appropriate amount of cells and therapeutic drugs to specific areas of the body. The team used laser lithography to construct porous 3D scaffolds which were coated with a thin layer of magnetic material (nickel) and biocompatible material (titanium). This allowed remote manipulation of the devices using external magnetic fields to guide them, while causing no harm to living cells.

Prof. Zhang commented: "Our microrobots have enormous potential in on-demand, minimally invasive medical treatments. They allow accurate cell and drug delivery and reduce risk of complications arising from more invasive treatment methods. The low-strength magnetic fields are biologically harmless to living cells and tissues, and are therefore safe to use in the human body. This innovation is a great leap forward in the development of wirelessly-controlled medical microrobots."

One lab test involved cultivating human kidney cells in the microbot model, which grew and interacted with the model, Zhang said. This confirmed that the model could interoperate with the kidney cells, he said, adding that tests were currently conducted on rabbits and mice. This technology could lead to targeted treatment of various diseases such as cancer, cerebral infarction and retinal degeneration.

Professor Zhang is now leading the CUHK research team to improve the performance, intelligence and design of these micro-devices by paying close attention to their locomotion and dynamic properties in fluid. At present, they are just over 100 micrometres (µm) in length. However, as technology improves, they will become even smaller and more sophisticated. Experts believe that nano-scale robots may be possible by 2025 – able to repair individual cells and even work directly inside them. Further into the future, these machines could become a permanent part of our physiology.

The research results of this latest study will be featured as the cover story in a forthcoming issue of Advanced Materials.

Comments »