In nature, the cell membrane has a unique function of shielding the interior from the external environment and communicating with the exterior by sensing external chemical or physical stimuli as the most accurate biosensor for life. The cell membrane, which contains a hydrophilic, well-water-miscible part on one side and a hydrophobic, poorly-water-miscible part on the other, opens and closes the ion channels like a water tap and converts a stimulus physico-chemical into an electrical signal which is then transmitted to the cells. Active research around the world on biosensors capable of mimicking the excellent sensing of the cell membrane has been suggested. However, until recently, the limited ability of an artificial cell membrane structure to only last a maximum of 5 days has been a hindrance.
The Korea Institute of Science and Technology (KIST, President Seok-Jin Yoon) announced that the research team led by Dr. Tae Song Kim from the Brain Science Institute has succeeded in developing an artificial cell membrane that can be kept stable for more than 50 days. on a silicon substrate. This is the longest time reported in the field. In addition to creating a five-day-long artificial cell membrane in 2018, in 2019 Dr. Kim’s team demonstrated the transfer of a positive ion inside a structure with a cell membrane. artificial with a protein attached to the surface, confirming its application potential as a biosensor.
However, durability of at least one month is essential for life science research using artificial cell membranes and the practical commercialization of biosensors. To extend the 5-day limit of stability of an artificial cell membrane, the KIST research team focused on a material called block copolymer (BCP). A BCP is a macromolecule composed of two or more blocks, which can be repeatedly aligned as a long row of blocks of antagonistic properties that mimic the hydrophilic and hydrophobic nature of the human cell membrane.
Dr. Kim’s research team has developed a technology that regularly arranges tens of thousands of holes with a diameter of 8 μm (micrometer) on a silicon substrate and inserts a specific amount of BCP solution into each hole by processing surface, and dries it. Next, a soap bubble-shaped, elongated-oval-shaped, or thin-tube-shaped BCP double-layer structure is tunably created by applying an electric field between the upper plate electrode of the microfluidic channel and the lower silicon substrate. . This process led to the discovery of the possibility of maintaining a structure with a specific shape depending on the concentration of the solution and the applied electric field and frequency. This suggests a way to freely control the size and shape of artificial cell membranes, from a sphere, like a soap bubble, to a cylinder, like a tube.
The KIST research team finally created an artificial cell membrane that can be kept stable for more than 50 days by filling the exterior of a three-dimensional, double-layered BCP structure with a porous hydrogel that exhibits excellent water-resistance characteristics. elasticity and resilience similar to that of a human being. bodily matter. In addition, an artificial organ structure was produced by reproducing an epithelial cell in the small intestine, which consists of thousands of tubular structures (cilia) using a BCP double-layer structure, proving its potential for use as a material for artificial organs by binding with β-galactosidase.
While worldwide research on artificial cell membranes has focused on building a two-dimensional planar structure on a silicon substrate, the team succeeded in extending the stability period of an artificial cell membrane by more of ten times following the development of the first tri-dimensional artificial cell membrane structure manufacturing technology. The research, which paved the way for the fabrication of large arrays of artificial cell membranes, is set to further develop into a platform technology for biological functionality research that identifies the roles of ultra-sensitive biosensors resembling cellular functions. , drug screening for the development of new drugs. , and neurotransmitters and hormones in the brain.”
Dr. Tae Song Kim from KIST
Kang, DH., et al. (2022) Tunable and scalable fabrication of a 3D polymorphic artificial cell membrane network based on block copolymers. Nature Communication. doi.org/10.1038/s41467-022-28960-y.
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