3D bioprinting of mineralizing cyanobacteria as novel approach for the fabrication of living building materials

Abstract

Living building materials (LBM) are gaining interest in the field of sustainable alternative construction materials to reduce the significant impact of the construction industry on global CO2 emissions. This study investigated the process of three-dimensional bioprinting to create LBM incorporating the cyanobacterium Synechococcus sp. strain PCC 7002, which is capable of producing calcium carbonate (CaCO3) as a biocement. Rheology and printability of biomaterial inks based on alginate-methylcellulose hydrogels containing up to 50 wt% sea sand were examined. PCC 7002 was incorporated into the bioinks and cell viability and growth was characterized by fluorescence microscopy and chlorophyll extraction after the printing process. Biomineralization was induced in liquid culture and in the bioprinted LBM and observed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and through mechanical characterization. Cell viability in the bioprinted scaffolds was confirmed over 14 days of cultivation, demonstrating that the cells were able to withstand shear stress and pressure during the extrusion process and remain viable in the immobilized state. CaCO3 mineralization of PCC 7002 was observed in both liquid culture and bioprinted LBM. In comparison to cell-free scaffolds, LBM containing live cyanobacteria had a higher compressive strength. Therefore, bioprinted LBM containing photosynthetically active, mineralizing microorganisms could be proved to be beneficial for designing environmentally friendly construction materials.

Mycelium as a scaffold for biomineralized engineered living materials

“…In cement and concrete, microbial viability is limited to few days, at best, in most instances 1, 5 . Our results also improve on most reports from hydrogel-sand systems, where microbial viability can be limited to 1-2 weeks unless special storage conditions or anti-desiccants are provided 4, 13, 14, 16, 47–51, 60 . This improved viability enables the possibility of self-healing or environmental responsiveness for longer than has been possible for investigations of ELMs for building material applications to date.…”

“…Fungal mycelium could also be utilized to biomineralize the ELM. Previously, biomineralized ELMs have been stiffened by bacterial biomineralization 5, 8, 11, 12, 14, 16, 36–38 . The most common metabolism employed in these types of materials is urea hydrolysis, facilitated by the production of the urease enzyme by bacterial species such as Sporosarcina pasteurii 11, 15, 39 .…”

Biomimetic Approach for Enhanced Mechanical Properties and Stability of Self-Mineralized Calcium Phosphate Dibasic–Sodium Alginate–Gelatine Hydrogel as Bone Replacement and Structural Building Material

“…Lacroix, J.; etc., 2013 [81] also proposed the use of bioactive glasses as green and safe in situ scaffolds for bone tissue engineering. One study [82] proposed self-healing sustainable hydrogels for guided bone regeneration (GBR), and a few other pieces of literature proposed the use of self-mineralized materials as building material in architecture applications either from existing cementous mineralized materials based on the CO 2 to calcium carbonate reactions [83,84] or by inducing mineralization through a bioactive agent as bacteria or fungi [4,85]. However, the current study goes beyond the literature by not only proposing a sustainable composed hydrogel for self-mineralized material but also by providing sustainable minimized materials and processes in preparing this self-mineralized material.…”

3D bioprinting of microorganisms: principles and applications

“…Novel applications of biomolecule production from cell cultures also reach fields such as the construction industry. Reinhardt et al [ 124 ] utilized cyanobacterium Synechococcus sp. for its capacity of producing calcium carbonate (CaCO 3 ) biomolecules, combined with construction materials like cement.…”

“…This effect increased with higher sand concentrations. Additionally, alternative support materials to sea sand could be used to further improve the environmental sustainability of the ink, but further research is needed to optimize the bioprinting process and to prevent cell outgrowth [ 124 ].…”