Materials Manufactured from 3D Printed Synthetic Biology Arrays

Many complex, biologically-derived materials have extremely useful structural properties (think wood or silk) but are not used in traditional applications due to design, production, and manufacturing limitations. Living cells naturally specialize in making complex biomaterials on a micro- to nano- scale. We envision combining this ability with the recently emergent technologies of synthetic biology and additive manufacturing to create a new class of human-workable materials: by creating 3D-printed arrays of living cells that have been bioengineered to secrete different material components, we can ultimately produce is nonliving, structural biomaterials with human-designed shape, structure and composition. Biomaterials are the natural materials produced by and integrated into living systems, as well as artificial materials developed to mimic them. They include simple molecules like sugars, complex polymers like collagen, and organic-inorganic composites ranging from macroscale mixtures like microbial mats to the molecularly bound biominerals of bone and nacre. Natural biomaterials, like wood, have three main limitations: nonreproducible microstructure, resource- (and thus mass-)intensive production and crafting, and lack of functional customization. Synthetic biology is the creation of designed living systems. It typically involves re-ordering and re-linking DNA sequences and inserting the modified sequences into a cell, causing the cell to produce a desired biological substance under controlled conditions. Although it has been used to produce bulk pharmaceuticals and biofuels, its use to enable the production of structured, non-living materials is a new application. 3D printing is a manufacturing process in which successive layers of material are laid down and bound together, allowing small plastic or metal items to be manufactured quickly, with down to microscale precision, on an as-needed basis. Most 3D printers are limited to homogenous materials, making them unsuitable for highly structured biomaterials such as the chitin and calcium carbonate complex of shell; although 3D printers which deposit solutions of living cells have been developed, prior work has focused on getting natural cells to grow, bind, and form self-sustaining tissue. Combining this technology with artificially modified cells for biomaterial production is an unexplored concept in advanced manufacturing. Our proposed technique uses a 3D printer with near single cell resolution to deposit a 3D array of bioengineered cells in the shape of a desired product. The cells are programmed to secrete desired biomaterials or biomaterial components, such as polymers, in regulated amounts and rates. The cell array secretes its materials onto a substrate, which both provides additional material to be integrated (e.g., metal ions) and helps bind the materials together. Afterward, the cells and substrate are washed away, leaving a finished, nonliving product with microscale structure and precision. By overcoming the traditional limitations to the structural use of biomaterials, we can add a whole new class of materials to humanity's traditional palette of metals, plastics and ceramics. More »