According to a study published in the latest issue of the journal Nature · communication, the team of the Brain Science Research Institute of the Korean Academy of science and Technology (Kist) has successfully developed an artificial cell membrane that can remain stable on silicon substrate for more than 50 days. This is a new achievement in the field of artificial cells simulating thin film structure. Tunable and controllable 3D cell shapes can be manufactured on silicon substrates on demand.
In nature, cell membrane has unique functions, which can protect the interior from the influence of the external environment, and communicate with the outside world by sensing external chemical or physical stimuli, just like the most accurate biosensor in life. On the one hand, the cell membrane contains a hydrophilic part that is well miscible with water, on the other hand, it contains a hydrophobic part that is not well miscible with water. It turns on and off ion channels like a faucet and converts physical and chemical stimuli into electrical signals, which are then transmitted to cells.
In addition to creating an artificial cell membrane lasting for 5 days in 2018, in 2019, Kist team also demonstrated how to transfer positive ions into the structure with artificial cell membrane. The surface of the artificial cell membrane is attached with proteins, which confirmed the application potential of its biosensor.
However, for the life science research of artificial cell membrane and the actual commercialization of biosensor, it needs at least one month of durability. In order to extend the stability limit of artificial cell membrane, Kist research team focused on a material called block copolymer (BCP).
The research team developed a technology to regularly arrange tens of thousands of holes with a diameter of 8 microns on the silicon substrate, insert a specific amount of BCP solution into each hole through surface treatment, and then dry it. By applying an electric field between the upper plate electrode and the lower silicon substrate of the microfluidic channel, a soap bubble, slender oval or thin tube BCP double-layer structure can be tunably created. This process led the team to discover the possibility of maintaining the structure according to the solution concentration and the applied electric field frequency, and also proposed a method to freely control the size and shape of artificial cell membrane.
By filling the outside of the three-dimensional double-layer BCP structure with porous hydrogels with elastic and resilient properties similar to human substances, the team finally created an artificial cell membrane that can remain stable for more than 50 days.
The researchers said that although the global research on artificial cell membrane has been focused on placing two-dimensional planar structure on silicon substrate, the team has successfully extended the stability period of artificial cell membrane by more than ten times. Following the development of the first 3D artificial cell membrane structure manufacturing technology, this research provides a way for the large-area array manufacturing of artificial cell membrane. It is expected to further develop into a platform technology for biological function research to determine the function of ultra sensitive biosensors similar to cell function, drug screening of new drug development and neurotransmitters and hormones in the brain.