Most lifelike synthetic eukaryotic cells manufactured yet.
In synthetic biology an artificial cell or minimal cell is an engineered particle which mimics one or many functions of a biological cell. The theory behind these highly desirable synthetic entities is based on the fact that certain functions or structures of biological cells can be replaced or supplemented with a synthetic entity. A living artificial cell has been defined as a completely synthetically made cell which can capture energy, maintain ion gradients, contain macromolecules as well as store information and can mutate, however, such a cell has not yet been technically feasible. Now, a study from researchers at the University of California, San Diego has got the closest to developing an actual functioning synthetic eukaryotic cell. The team state that their synthetic cell can send protein signals to their neighbours, triggering communal behavior, and the artificial nuclei talks to the rest of the cell, releasing RNA which sparks the synthesis of proteins, even responding to signals from other cell mimics.
Previous studies show that researchers have already manufactured synthetic cells which can communicate with each other by exchanging relatively small molecules such as sugars and hydrogen peroxide. However, many of the molecular signals in the human body, include hormones and cytokines that fire up the immune cells, which are proteins that are typically much larger. The current study manufactures artificial cells which have a coat of plastic, a nucleus-like compartment containing DNA which lacks a membrane like a real cell’s nucleus, and whose main ingredients are minerals found in clay, and can synthesize large proteins.
The current study utilises a silicon chip with microscopic fluid-filled channels to extrude tiny droplets which contain raw materials such as DNA, minerals from clay, and individual acrylate molecules. Ultraviolet light and chemical treatment spurs a porous membrane to form around each droplet, with the minerals and DNA inside the droplet condensing into a gel with the texture of a soft contact lens, creating a synthetic nucleus. The lab equipped the nuclei of the some of the cell mimics with DNA which encodes green fluorescent protein (GFP), and added a sticky stretch of DNA that captures GFP molecules to the other artificial cells.
Results show that by adding a mixture of enzymes and other necessities for protein synthesis, such as ribosomes, to the fluid surrounding the cells, they were switched on. Data findings show that this molecular machinery crossed the porous membrane, read the genetic information in the nucleus, and sparked synthesis of GFP. The group state that their imitation cells also exhibited quorum sensing, which came to light when they tested solutions containing different densities of cell mimics, all of which released the activator of GFP synthesis and could make GFP as well when triggered. They go on to add that if a solution contained only a few of the synthetic cells, almost none turned green, and after they reached a threshold density nearly all of them lit up.
The team surmise they have manufactured near perfect artificial cells which can communicate with nearby counterparts and stimulate them to produce proteins. For the future, the researchers state that they hope to equip these or other synthetic cells with the ability to grow and divide, and ensure that they are compatible with their natural counterparts.