3D Bioprinting of Food Grade Hydrogel Infused with Living Mycelium in Non-sterile Conditions.

Nicholas Lin, Christopher Moraes, Alireza Taghizadehmakoei, Lorena Polovina, Isobel McLean, Juan C Santana-Martínez, Chloe Naese, Steven James Hallam, Joseph Dahmen

Journal: ACS applied bio materials 2024;7(5):2982-2992

PMID: 38587496

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Abstract

Mycelium is the root-like network of fungi. Mycelium biocomposites prepared by template replication (molding) can function as environmentally friendly alternatives to conventional polystyrene foams, which are energy- and carbon-intensive to manufacture. Recently, several studies have shown that 3D bioprinting technologies can be used to produce high value functional mycelium products with intricate geometries that are otherwise difficult or impossible to achieve via template replication. A diverse range of nutrients, thickeners, and gelling agents can be combined to produce hydrogels suitable for 3D bioprinting. 3D bioprinting with hydrogel formulations infused with living fungi produces engineered living materials that continue to grow after bioprinting is complete. However, a hydrogel formulation optimized for intricate 3D bioprinting of mycelium, which is among the strains most commonly used in mycelium biocomposite fabrication, has yet to be described. Here, we design and evaluate a versatile hydrogel formulation consisting of malt extract (nutrient), carboxymethylcellulose and cornstarch (thickeners), and agar (gelling agent), all of which are easily sourced food grade reagents. We also outline a reproducible workflow to infuse this hydrogel with liquid culture for 3D bioprinting of intricate structures comprised of living mycelium and characterize the changes in height and mass as well as hardness of the prints during mycelium growth. Finally, we demonstrate that the workflow does not require a sterile bioprinting environment to achieve successful prints and that the same mycelium-infused hydrogel can be supplemented with additives such as sawdust to produce mycelium biocomposite objects. These findings demonstrate that 3D bioprinting using mycelium-based feedstocks could be a promising biofabrication technique to produce engineered living materials for applications such as mushroom cultivation, food preparation, or construction of the built environment.

Address: School of Architecture and Landscape Architecture, University of British Columbia, 6333 Memorial Road, Vancouver, British Columbia V6T 1Z2, Canada.; Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.; Department of Chemical Engineering, McGill University, 3610 University Street, Montréal, Québec H3A 0C5, Canada.; School of Architecture and Landscape Architecture, University of British Columbia, 6333 Memorial Road, Vancouver, British Columbia V6T 1Z2, Canada.; Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.; School of Architecture and Landscape Architecture, University of British Columbia, 6333 Memorial Road, Vancouver, British Columbia V6T 1Z2, Canada.; Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.; Department of Chemical Engineering, McGill University, 3610 University Street, Montréal, Québec H3A 0C5, Canada.; Department of Biomedical Engineering, McGill University, 3775 University Street, Montréal, Québec H3A 2B4, Canada.; Rosalind and Morris Goodman Cancer Research Center, McGill University, 1160 Pine Avenue West, Montréal, Québec H3A 1A3, Canada.; Division of Experimental Medicine, McGill University, 1001 Décarie Boulevard, Montréal, Québec H4A 3J1, Canada.; Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.; Graduate Program in Bioinformatics, University of British Columbia, 570 West seventh Avenue, Vancouver, British Columbia V6T 1Z4, Canada.; Genome Science and Technology Program, University of British Columbia, 2329 West Mall, Vancouver, British Columbia V6T 1Z4, Canada.; Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.; ECOSCOPE Training Program, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.

DOI: 10.1021/acsabm.4c00048

MeSH Terms: Pleurotus, Hydrogels, Mycelium, Bioprinting, Printing, Three-Dimensional, Biocompatible Materials, Materials Testing, Particle Size