Gel that breaks down, puts itself back together could improve delivery
of oral drugs

Date:
July 16, 2020
Source:
Lehigh University
Summary:
An emerging hydrogel material with the capacity to degrade
and spontaneously reform in the gastrointestinal tract could
help researchers develop more effective methods for oral drug
delivery. In research published in Soft Matter, Lehigh University
rheologists mimic pH environment of GI tract to shed light on
pharmaceutical potential of covalent adaptable hydrogels (CAHs).



FULL STORY ==========================================================================
An emerging hydrogel material with the capacity to degrade and
spontaneously reform in the gastrointestinal tract could help researchers develop more effective methods for oral drug delivery.


==========================================================================
"The majority of drugs and nutrients are absorbed into the body in the intestines, but to get there, they have to traverse the stomach -- a very acidic, harsh environment that can interfere with the active molecules in pharmaceuticals," says Kelly Schultz, an associate professor of chemical
and biomolecular engineering in Lehigh University's P.C. Rossin College
of Engineering and Applied Science.

Schultz and fourth-year chemical engineering PhD student Nan Wu are
studying covalent adaptable hydrogels (CAHs), which are being designed to release molecules as they lose polymer in the stomach but then re-gel on
their own, which protects the molecules and allows them to stay active for targeted delivery in the intestines. The team's microrheology research
is featured in an article and inside cover illustration in the current
issue of Soft Matter.

To characterize the material and provide insight into its pharmaceutical potential, Wu has repurposed a microfluidic device originally developed in Schultz's lab for research into fabric and home care products to create a
"GI tract-on-a-chip." The experimental setup allows her to exchange the
fluid environment around the gel to mimic the pH environment of all the
organs in the GI tract, simulating how the material would react over
time if ingested.

Using microrheology, Wu collects microscopy data and measures how
much particles within the gel wiggle, with some experiments taking
hours and others spanning days, depending on the digestive organ she
is replicating. Wu tracks the particles using an algorithm that yields scientifically meaningful information on the properties of the material,
which was originally developed by University of Colorado at Boulder
professor Kristi S. Anseth.

"CAHs exhibit unusual spontaneous re-gelation that is really surprising," Schultz says. "Typically, gels won't degrade and then reform without
any added stimuli as these do. We've demonstrated viability of CAHs as
means of oral drug and nutrient delivery, and now we're starting to work
on molecular release studies and adding in other components to make the experiments more complex." Wu has been investigating these materials over
the course of her entire PhD studies, says Schultz. "She's doing amazing
work and is committed to understanding every aspect of the research."
Schultz's research lab focuses on the characterization of colloidal
and polymeric gel scaffolds and the development of new techniques to characterize these complex systems, which play important roles in fields
such as health care and consumer products.

"What we do in biomaterials is somewhat unique: There's a lot of work
on the cross-linking chemistry and actually developing these materials,
and there's a lot of animal research that implants and tests them,
but there's not that much work in the middle. A great deal of mystery
lies between designing a material and understanding what's going on
when it's working. We're trying to find new ways that we can replicate
what's going on inside of an animal or a person and collect important measurements to connect the dots and inform further studies."

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


========================================================================== Journal Reference:
1. Nan Wu, Kelly M. Schultz. Microrheological characterization
of covalent
adaptable hydrogel degradation in response to temporal pH changes
that mimic the gastrointestinal tract. Soft Matter, 2020; 16 (27):
6253 DOI: 10.1039/D0SM00630K ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/07/200716123006.htm

--- up 1 day, 1 hour, 55 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)