Existing in nature ever since mammals first had teeth and bones, and crabs first carried their shells around on their backs, living hybrid materials have a long history on planet Earth. New innovations in science and technology seek to purposefully mix living materials and nonliving materials, and create objects and substances that are both. In a recent study at MIT, scientists found E. coli to be useful in the production of a biofilm circuit board; moreover, hybrid materials will someday help humans in the areas of architecture, health, and electronics.
Hybrid materials can be found in almost every part of nature, ranging from the bones that hold the bodies of countless species of animals together to the shells that defend crabs and other crustaceans. The fusing together of inorganic materials, such as the minerals found in bones, and organic materials, such as the somatic cells that help in the assembly of the bones in the human body at an early age, is a phenomenon of nature that is only now starting to be replicated by scientists. Even though these scientists are doing a great job of making many materials that will benefit humankind, the sophistication of the hybrid materials that are found in nature is something that these scientists have, yet to crack the code to (Sanchez).
The study at the Massachusetts Institute of Technology, which took place around March 23, 2014, sought to combine the qualities of Escherichia Coli cells and nonliving materials. The study was led by Timothy Lu. The paper’s main author is Allen Chen, an MIT-Harvard MD-PhD student. The actual study was published in the March 23rd publication of Nature Materials (Trafton).
Nonliving materials that were used in the study are gold nanoparticles, which have the capacity to combine and form gold nanowires that conduct electricity. Other nonliving materials that were used in the study are quantum dots, which are nanocrystals that have quantum mechanical characteristics (Trafton).
The Escherichia Coli bacteria was used in the MIT study because of its ability to produce a biofilm, which is a mass of closely packed bacterial cells. The E. coli is dependent on having amyloid proteins called “curli fibers” (Trafton), which allow the bacteria to adhere to a surface. Each curli is built up out of CsgA, which is a protein subunit. Peptides alter the CsgA and are also used to capture the nonliving materials that float around in the E. coli environment (Pratt; Trafton).
In the first experiment at MIT, the scientists took away the E. coli cells’ ability to make CsgA and replaced it with a genetic circuit that allowed it to produce CsgA, but only when the signaling molecule N-Acyl homoserine lactone (AHL) was present. This way the production of the curli fiber
was controlled by the scientists. Without AHL in the reach of the cells, the CsgA cannot be produced which means that the curli fibers and ultimately the biofilm cannot be produced. When AHL was placed into the environment...