Scientists have
developed a silk-based, 3-D printer ink for use in biomedical
implants or tissue
engineering. Credit: American Chemical Society
(September 5, 2015) Advances
in 3-D printing have led to new ways to make bone and some other relatively
simple body parts that can be implanted in patients. But finding an ideal
bio-ink has stalled progress toward printing more complex tissues with
versatile functions — tissues that can be loaded with pharmaceuticals, for
example. Now scientists, reporting in the journal ACS Biomaterials Science
& Engineering, have developed a silk-based ink that could open up new
possibilities toward that goal.
Most inks currently being developed for 3-D printing are
made of thermoplastics, silicones, collagen and gelatin or alginate. But there
are limits to how these inks can be used. For example, the temperatures, pH
changes and crosslinking methods that may be required to toughen some of these
materials can damage cells or other biological components that researchers
would want to add to the inks. Additives, such as cytokines and antibiotics,
are useful for directing stem cell functions and controlling infections,
respectively. To address these bio-ink limitations, David L. Kaplan and
colleagues turned to silk protein and developed a way to avoid these harsh
processing conditions.