Octopus-inspired sucker transfers thin, delicate tissue grafts and
biosensors

Date:
October 16, 2020
Source:
University of Illinois at Urbana-Champaign, News Bureau
Summary:
Thin tissue grafts and flexible electronics have a host of
applications for wound healing, regenerative medicine and
biosensing. A new device inspired by an octopus's sucker rapidly
transfers delicate tissue or electronic sheets to the patient,
overcoming a key barrier to clinical application.



FULL STORY ========================================================================== [Octopus arms with | Credit: (c) maskalin / stock.adobe.com] Octopus
arms with suckers closeup (stock image).

Credit: (c) maskalin / stock.adobe.com [Octopus arms with | Credit:
(c) maskalin / stock.adobe.com] Octopus arms with suckers closeup
(stock image).

Credit: (c) maskalin / stock.adobe.com Close Thin tissue grafts and
flexible electronics have a host of applications for wound healing, regenerative medicine and biosensing. A new device inspired by
an octopus's sucker rapidly transfers delicate tissue or electronic
sheets to the patient, overcoming a key barrier to clinical application, according to researchers at the University of Illinois at Urbana-Champaign
and collaborators.


==========================================================================
"For the last few decades, cell or tissue sheets have been increasingly
used to treat injured or diseased tissues. A crucial aspect of tissue transplantation surgery, such as corneal tissue transplantation surgery,
is surgical gripping and safe transplantation of soft tissues. However, handling these living substances remains a grand challenge because they
are fragile and easily crumple when picking them up from the culture
media," said study leader Hyunjoon Kong, a professor of chemical and biomolecular engineering at Illinois.

Kong's group, along with collaborators at Purdue University, the
University of Illinois at Chicago, Chung-Ang University in South Korea,
and the Korea Advanced Institute for Science and Technology, published
their work in the journal Science Advances.

Current methods of transferring the sheets involve growing them on a temperature-sensitive soft polymer that, once transferred, shrinks and
releases the thin film. However, this process takes 30-60 minutes to
transfer a single sheet, requires skilled technicians and runs the risk
of tearing or wrinkling, Kong said.

"During surgery, surgeons must minimize the risk of damage to soft tissues
and transplant quickly, without contamination. Also, transfer of ultrathin materials without wrinkle or damage is another crucial aspect," Kong said.

Seeking a way to quickly pick up and release the thin, delicate sheets
of cells or electronics without damaging them, the researchers turned to
the animal kingdom for inspiration. Seeing the way an octopus or squid
can pick up both wet and dry objects of all shapes with small pressure
changes in their muscle- powered suction cups, rather than a sticky
chemical adhesive, gave the researchers an idea.

They designed a manipulator made of a temperature-responsive layer of
soft hydrogel attached to an electric heater. To pick up a thin sheet,
the researchers gently heat the hydrogel to shrink it, then press it to
the sheet and turn off the heat. The hydrogel expands slightly, creating suction with the soft tissue or flexible electronic film so it can be
lifted and transferred.

Then they gently place the thin film on the target and turn the heater
back on, shrinking the hydrogel and releasing the sheet.

The entire process takes about 10 seconds.

Next, the researchers hope to integrate sensors into the manipulator,
to further take advantage of their soft, bio-inspired design.

"For example, by integrating pressure sensors with the manipulator, it
would be possible to monitor the deformation of target objects during
contact and, in turn, adjust the suction force to a level at which
materials retain their structural integrity and functionality," Kong
said. "By doing so, we can improve the safety and accuracy of handling
these materials. In addition, we aim to examine therapeutic efficacy of
cells and tissues transferred by the soft manipulator." The National
Science Foundation, the National Institutes of Health, the Department of Defense Vision Research Program and the Jump Applied Research in Community Health through Engineering and Simulation endowment supported this work.


========================================================================== Story Source: Materials provided by University_of_Illinois_at_Urbana-Champaign,_News_Bureau.

Original written by Liz Ahlberg Touchstone. Note: Content may be edited
for style and length.


========================================================================== Related Multimedia:
* YouTube_video:_Octopus-inspired_thin_tissue_transfer ========================================================================== Journal Reference:
1. Byoung Soo Kim, Min Ku Kim, Younghak Cho, Eman E. Hamed, Martha U.

Gillette, Hyeongyun Cha, Nenad Miljkovic, Vinay K. Aakalu,
Kai Kang, Kyung-No Son, Kyle M. Schachtschneider, Lawrence
B. Schook, Chenfei Hu, Gabriel Popescu, Yeonsoo Park, William
C. Ballance, Seunggun Yu, Sung Gap Im, Jonghwi Lee, Chi Hwan
Lee, Hyunjoon Kong. Electrothermal soft manipulator enabling
safe transport and handling of thin cell/tissue sheets and
bioelectronic devices. Science Advances, 2020; 6 (42): eabc5630
DOI: 10.1126/sciadv.abc5630 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201016164312.htm

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