Illustration of
laser-based micropatterning of silk hydrogels. The transparent gels enable
the laser's
photons to be absorbed more than 10 times deeper than with other materials,
without damaging
the cells surrounding the "Tufts" pattern. Courtesy: M.B. A
High resolution, scalability for engineering tissue
scaffolds and implants
(September 23, 2015) Tufts
University biomedical engineers are using low-energy, ultrafast laser
technology to make high-resolution, 3-D structures in silk protein hydrogels.
The laser-based micropatterning represents a new approach to customized
engineering of tissue and biomedical implants.
The work is reported in a paper in PNAS Early Edition
published September 15 online before print: "Laser-based three-dimensional
multiscale micropatterning of biocompatible hydrogels for customized tissue
engineering scaffolds."
Artificial tissue growth requires pores, or voids, to bring
oxygen and nutrients to rapidly proliferating cells in the tissue
scaffold. Current patterning techniques
allow for the production of random, micron-scale pores and the creation of
channels that are hundreds of microns in diameter, but there is little in
between.
The Tufts researchers used an ultrafast, femtosecond laser
to generate scalable, high-resolution 3-D voids within silk protein hydrogel, a
soft, transparent biomaterial that supports cell growth and allows cells to
penetrate deep within it. The
researchers were able to create voids at multiple scales as small as 10 microns
and as large at 400 microns over a large volume.
Further, the exceptional clarity of the transparent silk
gels enabled the laser's photons to be absorbed nearly 1 cm below the surface
of the gel – more than 10 times deeper than with other materials, without
damaging adjacent material.