An inkjet device that prints
tiny “bio-ink” patterns has
been used to simultaneously
grow two different tissues
from the stem cells of adult
mice. Surgeons could one day
use the technology to repair
various damaged tissues at
the same time, the researchers
say.
Inkjet technology uses a
fine stream of droplets to
build structures and is employed
across many industries – from
computer chip design to large
scale manufacturing.
It also has biomedical applications:
researchers use it to place
very precise amounts of biological
material, on the microscale.
For example, some groups have
used the technology to print
cells, and “build” organs.
Now, Julie Phillippi at Carnegie
Mellon University in Pennsylvania,
US, and colleagues have demonstrated
a novel bio-ink printer that
directs a population of muscle-derived
stem cells from adult mice
to differentiate into both
muscle and bone tissue. It
is the first such system to
grow multiple tissues from
a single population of adult
stem cells, the researchers
say.
The technique works by firing
various patterns of different
growth factor proteins onto
the stem cells. By tweaking
the spatial patterning of
the doses, using different
print-heads to deliver various
concentrations of the protein
“bio-ink”, the cells can be
directed to differentiate
into different tissue types,
says Phillippi.
Muscle and bone
“Previously researchers have
been limited to directing
stem cells to differentiate
towards multiple lineages
in separate culture vessels,”
says team member Phil Campbell.
“The inkjet printing technology
allows us to precisely engineer
multiple unique microenvironments
by patterning bio-inks that
could promote differentiation
towards multiple lineages
simultaneously.”
The team has already grown
muscle and bone tissue in
the same dish. Their next
step is to investigate “patterns”
for other tissue types that
occur naturally in the body.
The researchers hope that
the system will one day help
treat people with joint problems
due to age or injury, and
those with conditions that
cause tissue damage, such
as muscular dystrophy. And
surgeons could one day use
the technology in complex
operations.
For many injuries, diseases
or genetic problems, often
cartilage, bone, muscle and
fat are all damaged, says
Phillippi. “Why not repair
it all at the same time?”
she says.
The researchers presented
their results at the annual
meeting of the American Society
for Cell Biology.
