3D laser printing with bioinks from microalgae

Microalgae such as the diatom Odontella aurita and the green alga Tetraselmis striata are particularly suitable as “biofactories” for obtaining sustainable materials for 3D laser printing due to their high content of fats and photoactive dyes. An international research team led by researchers from Heidelberg University has succeeded for the first time in using the raw materials obtained from microalgae to produce inks for printing complex biocompatible 3D microstructures.

3D laser printing, in particular the two-photon polymerization process, enables the precise production of micro- and nanostructures. In this process, a focused laser beam is directed onto a photoreactive ink, which leads to local solidification of the material. Until now, petrochemical polymers have mainly been used as inks, but these can be harmful to the environment and potentially toxic. This is where the research of the group led by Prof. Dr. Eva Blasco, who conducts research in the field of macromolecular chemistry and 3D nanofabrication at Heidelberg University, comes in.

“Despite their advantages, microalgae have hardly been considered as raw materials for light-based 3D printing,” says the scientist, who conducts research with her group at the interface of macromolecular chemistry, materials science and 3D nanofabrication. “This allows us to avoid the use of potentially toxic additives such as photoinitiators, which are used in conventional inks.”

Microalgae such as the diatom Odontella aurita and the green alga Tetraselmis striata are characterized by their high content of lipids and photoactive dyes, which makes them ideal candidates for sustainable ink systems. These algae grow quickly, bind carbon dioxide and are biocompatible. The research team extracted the triglycerides contained in the algae and modified them chemically to accelerate their curing under the influence of light. The dyes present in the algae acted as natural photoinitiators, triggering the necessary polymerization reaction.

“Our results not only open up new possibilities for more sustainable 3D printing with light, but also for life science applications – from three-dimensional cell cultures to biocompatible implants,” says Prof. Blasco.

The structures printed with these inks showed high precision and complexity, including overhanging elements and cavities. In tests with cell cultures, the microalgae inks demonstrated almost complete biocompatibility, underlining their suitability for medical applications. The research results were carried out as part of the Cluster of Excellence “3D Matter Made to Order” and published in the journal Advanced Materials. These developments could pave the way for more sustainable and environmentally friendly 3D printing processes that also meet high standards of precision and biocompatibility.