3D-printed living material marries biology and engineering

These "engineered living materials" have been sculpted into various forms through the embedding of genetically modified plant cells within a three-dimensional structure. Researchers detailed in ACS Central Science how they utilised 3D printing technology to infuse a bioink with plant cells, leading to the creation of programmable materials, which may one day be applied in biomanufacturing and sustainable construction.

The primary focus has been on using bacterial and fungal cells; however, the distinctive properties of plant cells have recently garnered significant interest for their potential in engineered plant living materials (EPLMs). Existing plant cell-based materials have exhibited relatively basic structures and functionalities.

Ziyi Yu, Zhengao Di, and their team aimed to expand this by crafting complex-shaped EPLMs that incorporate genetically engineered plant cells capable of customizable behaviours and functions. They combined tobacco plant cells with gelatine and hydrogel microparticles containing Agrobacterium tumefaciens—a bacterium used for DNA transfer in plants—to form this bioink.

This innovative bioink was then 3D printed into various shapes like grids, snowflakes, leaves, and spirals on a flat plate or within a gel-filled container. Subsequently, the printed materials were solidified using blue light.

Over the following 48 hours, the incorporated bacteria transferred DNA to the tobacco cells, which were later cleansed with antibiotics to eliminate the bacteria. As the plant cells proliferated within the EPLMs, they started synthesizing proteins as dictated by the newly incorporated DNA sequences.

This groundbreaking study demonstrated the production of green fluorescent proteins and betalains—plant pigments beneficial as natural colourants and dietary supplements. By using dual bioinks, the team successfully printed a leaf-shaped EPLM, which featured red pigment along its veins and yellow throughout its body, showcasing the potential for creating complex, multifunctional structures. Such advancements suggest that these materials could eventually be utilized as cellular factories for producing plant metabolites or pharmaceutical proteins, and perhaps even in eco-friendly building projects.

You can find the original study titled “Advancing Engineered Plant Living Materials through Tobacco BY-2 Cell Growth and Transfection within Tailored Granular Hydrogel Scaffolds,” here.