Additive Manufacturing of Engineered Living Materials with Bio-Augmented Mechanical Properties and Resistance to Degradation

Engineered living materials (ELMs) combine living cells with polymeric matrices to yield unique materials with programmable functions. While the cellular platform and the polymer network determine the material properties and applications, there are still gaps in the ability to seamlessly integrate the biotic (cellular) and abiotic (polymer) components into singular materials, then assemble them into devices and machines. Herein, the additive-manufacturing of ELMs wherein bioproduction of metabolites from the encapsulated cells enhanced the properties of the surrounding matrix is demonstrated. First, aqueous resins are developed comprising bovine serum albumin (BSA) and poly(ethylene glycol diacrylate) (PEGDA) with engineered microbes for vat photopolymerization to create objects with a wide array of 3D form factors. The BSA-PEGDA matrix afforded hydrogels that are mechanically stiff and tough for use in load-bearing applications. Second, the continuous in situ production of l-DOPA, naringenin, and betaxanthins from the engineered cells encapsulated within the BSA-PEGDA matrix is demonstrated. These microbial metabolites bioaugmented the properties of the BSA-PEGDA matrix by enhancing the stiffness (l-DOPA) or resistance to enzymatic degradation (betaxanthin). Finally, the assembly of the 3D printed ELM components into mechanically functional bolts and gears to showcase the potential to create functional ELMs for synthetic living machines is demonstrated.