Advance in printing human organs using inkjet printers28 October 2013 Scientists at the Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB) in Stuttgart have developed components of human tissue that can be used as inks for inkjet printing of human organs. The transparent liquids consist of components from the natural tissue matrix and living cells. The substance is based on a well known biological material gelatin, which is derived from collagen, the main constituent of native tissue. The researchers have chemically modified the gelling behaviour of the gelatin so that it remains fluid during printing. After irradiating with UV light, the molecules crosslink and cure to form hydrogels. These are polymers containing a huge amount of water (just like native tissue), but which are stable in aqueous environments and when being warmed up to physiological 37°C. The researchers can control the chemical modification of the biological molecules so that the resulting gels have differing strengths and swelling characteristics. The properties of natural tissue can therefore be imitated — from solid cartilage to soft adipose tissue.
In Stuttgart synthetic raw materials are printed as well that can serve as substitutes for the extracellular matrix. For example a system that cures to a hydrogel devoid of by-products, and can be immediately populated with genuine cells. “We are concentrating at the moment on the ‘natural’ variant.
That way we remain very close to the original material. Even if the
potential for synthetic hydrogels is big, we still need to learn a
fair amount about the interactions between the artificial substances
and cells or natural tissue. Our biomolecule-based variants provide
the cells with a natural environment instead, and therefore can
promote the self-organizing behavior of the printed cells to form a
functional tissue model,” explains Dr. Kirsten Borchers in
describing the approach at IGB. “We would like to increase the number of these in cooperation
with industry and other Fraunhofer Institutes in order to
simultaneously print using various inks with different cells and
matrices. This way we can come closer to replicating complex
structures and different types of tissue,” says Borchers. “This step is very important for printing tissue or entire organs in the future. Only once we are successful in producing tissue that can be nourished through a system of blood vessels can printing larger tissue structures become feasible,” said Borchers.
|
|||