Diode of fibroblasts and cardiomyocytes

Scientists have made a "living diode" from a heart muscle

Sofia Dolotovskaya, N+1

American scientists have constructed a "living diode" consisting of two types of cells: excitable cardiomyocytes (heart muscle cells) and non-excitable fibroblasts (connective tissue cells). Such diodes, which conduct an electrical signal in only one direction, can be used to monitor the operation of biosensors, create "organs-on-a-chip" and treat muscle disorders. Article by Can et al. Muscle-Cell-Based “Living Diodes” is published in the journal Advanced Biosystems.

"Live diode": on the left – muscle cells, on the right – fibroblasts
(here and below are pictures from an article in Advanced Biosystems).

A diode is an electronic element that conducts current only in one direction due to low resistance when transmitting current in one direction and high resistance when transmitting current in the other direction. Conductive elements consisting of living cells with such properties can be used in the future, for example, to create biorobots, control the work of biosensors and biocips implanted in tissue, and treat muscle disorders, such as muscle degeneration or cardiac arrhythmia. Also, such diodes can be useful in the development of "organs-on-a–chip" - artificial organs from living cells, which are microcircuits with microfluidic channels lined with living cells.

In the "live diode", the principle of conducting a signal only in one direction is provided by the use of two types of heart tissue cells: cardiomyocytes (muscle cells) and fibroblasts (connective tissue cells). Cardiomyocytes, unlike fibroblasts, are able not only to passively conduct electric current through intercellular contacts, but also to generate excitation (action potential) in response to electrical stimulation (external or coming from neighboring cells). Fibroblasts are not capable of generating excitation and can only passively transmit electric current through intercellular contacts. Due to this, the electrical signal can be initiated by cardiomyocytes and transmitted to both other cardiomyocytes and fibroblasts. Fibroblasts, on the other hand, cannot initiate a signal, but can passively transmit it over a short distance.

Scheme of operation and creation of a "live diode"

Technically, the "living diode" is a rectangle of cells grown by co-cultivation on a substrate of a rubber-like polymer polydimethylsiloxane. To monitor the operation of the diode, a microelectrode panel is also located under the polydimethylsiloxane layer. On one half of the rectangle are cardiomyocytes, and on the other – fibroblasts.

"Live diodes" can be used in the creation of "hybrid" biorobots combining biological and electronic components. Muscle cells are often used as engines for such biorobots. For example, scientists from the University of Illinois at Urbana-Champaign are designing biorobots that move due to the contractions of modified muscle cells that respond to external influences: light or an electromagnetic field. And researchers from Case Western Reserve University have created a biohybrid snail robot, which used the mouth muscles of the California sea snail (Aplysia californica) and 3D-printed polymer components.

Portal "Eternal youth" http://vechnayamolodost.ru  16.02.2017