(AGENPARL) – mar 30 maggio 2023 Source: Tokyo Institute of Technology
For immediate release: May 30, 2023
Headline: *Shedding Light on the Complex Flow Dynamics within the Small
Intestine*
(Tokyo, May 30) *A* *novel microfluidic device revealing diverse and
dynamic flows in the small intestine has now been developed by scientists
from Tokyo Tech. Their innovative experimental platform uses microscopic
fluorescent beads as substitutes for gut bacteria in dissected small
intestine sections, allowing one to visualize and quantitatively analyze
the luminal dynamic flow in the tissues deformed by a pneumatic actuator.*
Science is well aware of the important role that gut bacteria and their
interactions with the gastrointestinal tract play in our overall health.
Villi, tiny finger-like structures that line the inside of the small
intestine (SI), are known to interact with the gut bacteria and trigger a
protective immune response. Despite researching into the molecular
mechanisms underlying these interactions, however, not much is known about
the dynamics of liquid flow around the villi.
While computer simulations have aided such observations, the sheer
complexity of the flow within the SI, also called “luminal flow,”
complicates these experiments. Further, the winding structure of the SI
along with an irregular cross section, and intestinal motility, which plays
a role in food transportation, retention, and mixing, makes things more
challenging. Microscopic observation of luminal flow with sufficient
spatiotemporal resolution is one viable alternative. However, the
difficulty in maintaining and controlling motion in dissected SI tissues
hinders systematic assessments of luminal flow mechanisms.
To remedy this situation, a team of scientists from Tokyo Institute of
Technology, led by Associate Professor Tadashi Ishida and doctoral student
Satoru Kuriu, have recently developed an innovative experimental platform
to study the fine details of luminal flow around the villi. In their study,
published in the journal *Lab on a Chip*
<https://doi.org/10.1039/D3LC00172E&gt; on 22 May 2023, the scientists outline
the design and application of a microfluidic system for observing the
movement of microscopic fluorescent beads in a dissected SI section
obtained from an animal model.
One of the key features of the proposed microfluidic device is the use of
an array of air-driven balloon actuators (ABAs) pressed against the wall of
the SI section from the outside. These small pneumatic components, when
strategically inflated and deflated using an external pump, deform the SI
sample in a way that generates dynamic flows around the villi (Figure 1).
Using this pneumatic-driven microfluidic intestinal channel device, the
scientists conducted several experiments and recorded multiple videos of
the movement of fluorescent beads, which served as substitutes of gut
bacteria in the tissue. “Although the microbeads we used differ from real
gut bacteria in terms of shape or the presence of certain proteins, we
believe that they are simple and good substitutes, at least for the
purposes of flow observation,” explains Dr. Ishida. “Our proposed device
can, therefore, be used to directly analyze physical flow within the SI.”
The scientists tracked individual beads, both manually and with the help of
specialized software that enabled them to conduct detailed quantitative
analysis of the velocity and trajectory of the particles (Figure 2).
With this approach, the team was able to identify various types of unique
flow behaviors around the villi and observe the possible underlying
mechanisms that give rise to them. “Our results suggest that the diverse
flows observed in the SI for transportation, retention, and mixture are
generated by its non-uniform shape and dynamic deformation,” highlights Dr.
Ishida. “For future studies, our analytical demonstration could serve as a
cue for investigating the relationships between some unique subsets of
intestinal cells or tight junctions and gut bacteria.”
In summary, the findings of this study can serve to advance the
understanding of the complex hydrodynamics in human digestive tracts. We
hope this development will pave the way for new insights about our
relationship with the ever-important microscopic gut hitchhikers.
*Reference*
Authors:
Satoru Kuriu1,2,*, Naoyuki Yamamoto3, and Tadashi Ishida2,*
Title:
Development of a microfluidic device to observe dynamic flow around the
villi generated by deformation of small intestinal tissue
Journal:
*Lab on a Chip*
DOI:
10.1039/D3LC00172E
<https://pubs.rsc.org/en/content/articlelanding/2023/LC/D3LC00172E&gt;
Affiliations:
1Institute of Industrial Science, The University of Tokyo
2Department of Mechanical Engineering, School of Engineering, Tokyo
Institute of Technology
3Department of Life Science and Technology, School of Life Science and
Technology, Tokyo Institute of Technology
Figure1 is available in the
https://tokyotech.box.com/s/cd4ef63sx7pdyyq2iz7m1tvqwb73wnnu
Figure 1. Design of the proposed microfluidic device for observing dynamic
flows in the intestine.
Caption: By inflating and deflating the ABAs to deform the SI section, one
can simulate the dynamic flows around the villi. At the same time,
fluorescent microbeads can act as effective substitutes for gut bacteria.
Figure 2. is available in the
https://tokyotech.box.com/s/z5b92kt089jfrn9qz68q8swvp4n60yeh
Figure 2. Quantitative analysis of the movement of fluorescent microbeads
observed via the proposed microfluidic device.
Caption: Tracking the movement of individual microbeads allows the
identification of various types of unique flow around the villi.
*About Tokyo Institute of Technology *
Tokyo Tech stands at the forefront of research and higher education as the
leading university for science and technology in Japan. Tokyo Tech
researchers excel in fields ranging from materials science to biology,
computer science, and physics. Founded in 1881, Tokyo Tech hosts over
10,000 undergraduate and graduate students per year, who develop into
scientific leaders and some of the most sought-after engineers in industry.
Embodying the Japanese philosophy of “monotsukuri,” meaning “technical
ingenuity and innovation,” the Tokyo Tech community strives to contribute
to society through high-impact research.
https://www.titech.ac.jp/english/
*Contact*
Emiko Kawaguchi
Public Relations Division
Tokyo Institute of Technology