Want to 3D print a kidney? Start by thinking small
Computational model aims to accelerate microfluidic bio-printing that
opens up a pathway for 3D printing any kind of organ at any time

Date:
April 13, 2022
Source:
Stevens Institute of Technology
Summary:
Human organ transplants offer a crucial lifeline to people with
serious illnesses, but there are too few organs to go around:
in the U.S. alone, there are more than 112,000 people currently
waiting for transplants. The promise of 3D printing organs is one
possible solution to address this shortage but has been fraught with
complexity and technical barriers, limiting the type of organs that
can be printed. Researchers are now pushing through these barriers
by leveraging a decades-old technique to reproduce any tissue type.



FULL STORY ========================================================================== Human organ transplants offer a crucial lifeline to people with serious illnesses, but there are too few organs to go around: in the U.S. alone,
there are more than 112,000 people currently waiting for transplants. The promise of 3D printing organs is one possible solution to address this
shortage but has been fraught with complexity and technical barriers,
limiting the type of organs that can be printed. Researchers at Stevens Institute of Technology are now pushing through these barriers by
leveraging a decades-old technique to reproduce any tissue type.


==========================================================================
The work, led by Robert Chang, an associate professor in the mechanical engineering department at Stevens' Schaefer School of Engineering &
Science, could open up pathways for 3D printing any kind of organ at
any time, even skin directly on an open wound.

"Creating new organs to order and saving lives without the need for a
human donor will be an immense benefit to healthcare," said Robert Chang,
whose work appears in the April issue of Scientific Reports. "However,
reaching that goal is tricky because printing organs using "bio-inks" -- hydrogels laden with cultured cells -- requires a degree of fine control
over the geometry and size of printed microfiber that current 3D printers simply can't achieve." Chang and his team, including Ahmadreza Zaei,
first author and doctoral candidate in Chang's lab, hope to change that
by fast-tracking a new 3D printing process that uses microfluidics --
the precise manipulation of liquids through tiny channels -- to operate
at a far smaller scale than has been possible. "The recent publication
aims to improve the controllability and predictability over the structure
of the fabricated microtissues and microfibers enabled by microfluidic bioprinting technology," said Zaeri.

Most current 3D bio-printers are extrusion-based, squirting bio-ink out
of a nozzle to create structures about 200 microns -- around a tenth
as wide as a strand of spaghetti. A microfluidics-based printer could
print biological objects measuring on the order of tens of micrometers
on par with the single cellular scale.

"The scale is very important, because it affects the biology of the
organ," said Chang. "We're operating at the scale of human cells, and that
lets us print structures that mimic the biological features we're trying
to replicate." Besides operating on a smaller scale, microfluidics also enables multiple bio- inks, each containing different cells and tissue precursors, to be used interchangeably within a single printed structure,
in much the same way that a conventional printer combines colored inks
into a single vivid image.

That's important because while researchers have already created simple
organs such as bladders by encouraging the tissue to grow on 3D-printed scaffolding, more complex organs such as livers and kidneys require many different cell types to be precisely combined. "Being able to operate
at this scale, while precisely mixing bio-inks, makes it possible for
us to reproduce any tissue type," said Chang.

Scaling down 3D bio-printing requires painstaking research to figure out exactly how different process parameters such as channel structures, flow speed, and fluid dynamics affect the geometries and material properties
of printed biological structures. To streamline that process, Chang's
team created a computational model of a microfluidic printing head,
enabling them to tweak settings and forecast outcomes without the need
for laborious real-world experimentation.

"Our computational model advances a formulaic extraction that can be
used to predict the various geometrical parameters of the fabricated
structures extruded from the microfluidic channels," said Zaeri.

The team's computational models accurately predicted the results of
real-world microfluidic experiments, and Chang is using his model to
guide experiments on the ways that biological structures with varies
geometries can be printed. The results of this research work can be used
in the printing of combined multiple cell-types bio-ink that can replicate
the tissue with gradients geometrical and compositional properties found
at the intersection of bone and muscle.

Chang is also exploring using microfluidic-enabled 3D printing for the
in-situ creation of skin and other tissues, enabling patients to have replacement tissues printed directly into a wound. "This technology
is still so new that we don't know precisely what it will enable," he
said. "But we know it will open the door to creating new structures and important new types of biology."

========================================================================== Story Source: Materials provided by Stevens_Institute_of_Technology. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Ahmadreza Zaeri, Ralf Zgeib, Kai Cao, Fucheng Zhang, Robert
C. Chang.

Numerical analysis on the effects of microfluidic-based bioprinting
parameters on the microfiber geometrical outcomes. Scientific
Reports, 2022; 12 (1) DOI: 10.1038/s41598-022-07392-0 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/04/220413151120.htm

--- up 6 weeks, 2 days, 10 hours, 51 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)