Producing programmable living materials with synthetic biology and 3D printing

A new study uses 3D printing and genetically modified plant cells to produce complex, self-repairing materials that could revolutionize biofabrication and construction.

While mainly bacterial and fungal-based cells have been used so far for engineered living materials (ELMs), Ziyi Yu, Zhengao Di and their team are focusing on the unique properties of plant cells. The researchers mixed tobacco plant cells with gelatin and hydrogel microparticles containing Agrobacterium tumefaciens, a bacterium commonly used to transfer DNA into plant genomes. This bio-ink was then 3D printed into shapes such as lattices, snowflakes, leaves and spirals.

After printing, the researchers cured the hydrogel with blue light to solidify the structures. Within 48 hours, the bacteria transferred DNA to the growing tobacco cells, which were then treated with antibiotics to kill the bacteria. In the following weeks, the plant cells produced proteins according to the transferred DNA, including green fluorescent proteins and betalains, plant pigments that are valued as natural dyes and dietary supplements.

By printing a leaf-shaped EPLM with two different bio-inks – one for red pigments along the veins and one for yellow pigments in the rest of the leaf – the researchers demonstrated how their technique can produce complex, spatially controlled and multifunctional structures. Such EPLMs combine the characteristics of living organisms with the stability and durability of non-living substances and could be used, for example, in the production of plant metabolites or pharmaceutical proteins as well as in sustainable construction.

The development of Engineered Plant Living Materials (EPLMs) through 3D printing technologies marks a significant advance in materials science. These materials offer the potential to revolutionize industrial manufacturing processes while increasing sustainability. The research work was supported by several Chinese science funds.