Beauty designs "living materials" with biological and non biological components

Biomembrane, shell, bone tissue and other natural biological systems can form a multi-functional, multi-scale aggregation of biological and non biological components according to environmental signals For example, bone is a matrix composed of minerals, living cells and other substances On March 23, the journal Nature materials introduced the latest achievements of MIT engineers Inspired by these natural materials, they synthesized active biomaterials containing biological and non biological components The living cells can react to the environment and produce complex biomolecules The non biological materials can conduct electricity or light By programming cells, researchers "trick" bacterial cells into producing biofilms that can be combined with gold nanoparticles and quantum dots, according to the physicist's organization network The bacteria used in the experiment are Escherichia coli This kind of bacteria can produce biofilm, which contains a kind of starch protein called "spiral fiber", which helps E Each starch fiber is a protein chain composed of the same subunit CSGA, which can be added with peptides (protein fragments), which can capture non biological materials, such as gold nanoparticles The researchers use induced gene circuit and cell communication circuit to enable bacteria to produce different types of spiral fibers under specific conditions, control the properties of biomembrane, and create gold nanowires, conducting biomembrane, quantum dot biomembrane, microcrystals with quantum mechanical properties, etc They first let bacterial cells lose the ability to produce CSGA naturally, and then replaced it with a kind of transgenic line that can only produce CSGA under specific conditions, such as under the condition of AHL molecules, so that the production of spiral fibers can be controlled by regulating the number of AHL in the cell environment Then, they changed E.coli cells so that when they had an ATC molecule, they could produce CSGA with peptides that make histidine These two kinds of transgenic cells can grow in a population, and the composition of biofilm can be controlled by changing the number of AHL and ATC When the two molecules exist at the same time, the biomembrane contains two components: the CGA chain with and without histidine If gold nanoparticles are added, the addition of histidine can "catch" them, forming a line of gold nanowires and conductive networks To add quantum dots to the spirals, the researchers change the cells so that they can produce spirals with spytags attached to them, and by coating the dots with a layer of spycatcher (spytag chaperone), they combine These cells can also grow with bacteria that produce histidine fibers, so that the material can contain both quantum dots and gold nanoparticles The researchers point out that at present this "living material" is just a simple demonstration They are widely used in the future energy fields, such as batteries and solar cells They can also coat the biofilm with enzymes, catalyze the decomposition of cellulose, and transform agricultural wastes into biofuels Other potential applications include diagnostic and therapeutic equipment, tissue engineering scaffolds, etc Growing out of cells, it's like a creature and a machine, which reminds us of transformers Human beings used to rely on the fiber of plants and animals for survival, which is the welfare given by the creator But under the modification of scientists, the bacteria actually secreted the circuit board, which is naturally unimaginable "Bioprinting" is a more fantastic subject than science fiction If the designer is not a master of nanomaterials and genetic engineering, he can not come up with a suitable plan There is no boundary between disciplines As long as researchers do not set limits for themselves, they can open up a new kingdom on the boundary of seemingly isolated disciplines (reporter Chang Lijun)