Polypeptide Bioinks for the 3D Printing of Functional Microbiomes

3D Printing, also known as additive manufacturing (AM), is an enabling technology for the production of bio-enabled materials based on the combination of synthetic and biological building blocks. For the successful design of functional living materials, an ambitious program of fundamental studies is needed to understand the relationship between the chemical/mechanical properties of the hydrogel matrix and the viability/function of embedded living, cellular materials. To address this opportunity, this project seeks to develop multi-arm block copolypeptides as a novel biocompatible hydrogel platform. By controlling dynamic assembly and the selective introduction of photocrosslinkable groups along the peptide backbone, the fabrication of high-fidelity 3D objects under mild, scalable conditions will be studied. Genetically modified E. coli which express GFP (green fluorescent protein) will serve as an initial biological test vehicle to evaluate the viability and function of bacteria embedded during the 3D printing process with future work examining the general extension to other microbial systems in collaboration with Army researchers. A major advance will come from combining high-throughput strategies and 3D printing to control the mechanical properties and dynamic character of these hydrogel-bacterial composites. The unique ability to then examine these synthetic microbiomes under a variety of experimental conditions (dynamic, mechanical and chemical) allows for accelerated discovery of synergistic microbe interactions, proliferation and colony formation. This will lead to a full understanding of material design with a final goal of creating 3D printed synthetic microbiomes. Additionally, this strategy will permit the cooperative expression of active metabolites within a 3D printed synthetic microbiome to be probed while also studying the fate of embedded populations over time. It is postulated that high-throughput strategies combined with rational molecular design will drive innovation in bio-enabled materials and highlight the remarkable potential of these 3D printed hydrogel-microbiome systems.