New Hydrogels Hold, Support Stem Cells

In a first for bone tissue repair, researchers at the University of Rochester, New York, have encased regenerative stem cells in a hydrophilic polymer. This prevented the stem cells from leaving a repair site in the body early and speeded up the healing process, according to Vaun Saxena, writing for Fierce Drug Delivery.

Hydrogels are hydrophilic polymer chains that easily absorb water and are being researched by biotechnologists for their potential drug delivery applications because they exhibit properties similar to human tissue.”Our success opens the door for many—and more complicated—types of bone repair, ” assistant professor of biomedical engineering Danielle Benoit, Ph.D. said in the university’s news release. “For example, we should now be able to pinpoint repairs within the periosteum—or outer membrane of bone material, ” he said.

Currently, according to Benoit, stem cells are injected directly into bone tissue without any protective substance to shield them from the body’s immune system, which sees them as foreign agents. By modifying the hydrogels, the researchers successfully controlled the amount of time it took for the polymers to dissolve, allowing for the customization of stem cell behavior based on specific needs and circumstances.

In a related development researchers at Tohoku University in Japan have come up with a stretchable and durable electrode-hydrogel. This hydrogel withstood repeated stretching and sterilization procedures while maintaining electrical conductivity, Asian Scientist magazine reported. The device kept its shape after being repeatedly bent, stretched to twice its length, immersed in water for 6 months and autoclaved for 20 minutes at a time.

In addition to withstanding that abuse, the Tohoku team said that cultures of neural and muscle cells on the hydrogel were able to “adhere, proliferate and differentiate, ” which are key to developing bio-integrated wearable devices featuring integrated electronics.

“Our study paves the way for the development of complex electronically responsive and spatially controlled nerve muscle cell co-cultures, opening a new avenue of ‘intelligent biorobotics’, ” the Tohoku team, led by Matsuhiko Nishizawa, wrote in Advanced Healthcare Materials.