A team from the Vienna University of Technology has developed a method to grow biological tissue with laser beams. The Austrian scientists found that using lasers, molecules could be fixed at exactly the right position in a three-dimensional material, allowing for the creation of objects at a micrometer scale. The technology led to the creation of tiny organic “labs on chips” that serve as sensors by reacting with molecules from the environment.
In order to alter the chemical properties of a material with such precision, the team developed a method to attach molecules at exactly the right place. For example, when growing biological tissue, the method could be used (in theory) to position specific chemical signals and tell them where to attach.
The team’s breakthrough has been dubbed 3D-photografting and it’s the result of a collaboration between two teams from the Vienna University of Technology – Professor Jürgen Stampfl’s materials science team and Professor Robert Liska’s research group for macromolecular chemistry. The two teams have previously worked together in developing new kinds of 3D printers, so the science was not unfamiliar to them.
“Putting together a material from tiny building blocks with different chemical properties would be extremely complicated”, said team member Aleksandr Ovsianikov. “That is why we start from a three dimensional scaffold and then attach the desired molecules at exactly the right positions.”
Working with hydrogel, a material made of macromolecules arranged in a loose meshwork, the team introduced specially selected molecules which are then irradiated with a laser beam. At the positions where the focused laser beam is most intense, a photochemically labile bond is broken. That way, highly reactive intermediates are created which attach to the hydrogel very quickly.
“Much like an artist, placing colors at certain points of the canvas, we can place molecules in the hydrogel – but in three dimensions and with high precision”, says Aleksandr Ovsianikov.