A new method, developed at the Vienna University of Technology, uses laser beams to fix molecules at exactly the right position in a three-dimensional material. The technology will have a range of applications from growing biological tissue, to creating microsensors.
Many techniques exist for creating three dimensional objects on a micrometre scale, but until now, there was no way of attaching molecules at exactly the right place.
The new method, dubbed “3D-photographing” was developed in collaboration in Vienna between Professor Jürgen Stampfl’s material science team and Professor Robert Liska’s macromolecular chemistry research group. The researchers were able to tune the chemical properties of a material at micrometre precision using a laser beam. The findings are published in Advanced Functional Materials.
The researchers begin with a hydrogel – a material made of macromolecules, arranged in a loose meshwork. Between the macromolecules, large pores remain which other molecules or even cells are able to migrate through. Specially selected fluorescent molecules are introduced into the meshwork before a laser beam is used to eradicate certain areas. At high beam intensities, a photochemically labile bond is broken, creating highly reactive intermediates which attach locally and rapidly to the hydrogel.
“Much like an artist, placing colours at certain points of the canvas, we can place molecules in the hydrogel – but in three dimensions and with high precision,” said head author, Aleksandr Ovsianikov.
This technology may have applications in artificially growing biological tissue because cells require a scaffold they can attach to, in order to survive. In nature, the extracellular matrix provides this scaffold using specific amino acids sequences to signal the cells where they are supposed to grow. In order to grow large tissues with specific inner structures (such as capillaries), a three dimension technique is necessary.
The method also holds promise for sensor technology, allowing advancements in lab-on-a-chip technology.