4D bioengineered materials bend, curl like natural fabrics
Newswise – Tissue engineering has long relied on geometrically static scaffolds seeded with cells in the lab to create new tissue and even organs. The scaffold material – usually a biodegradable polymeric structure – is supplied with cells and the cells, if supplied with the right nutrients, then grow into tissue as the underlying scaffold biodegrades. But this model ignores the extraordinarily dynamic morphological processes that underlie natural tissue development.
Now, researchers from University of Illinois at Chicago have developed new 4D hydrogels – 3D materials that have the ability to change shape over time in response to stimuli – that can transform multiple times in a preprogrammed manner or on demand in response to external trigger signals.
In a new advanced science to study, UIC researchers, led by Eben Alsberg, show that these new materials can be used to help develop tissues that look more like their natural counterparts, which are subjected to forces that cause movement as they form.
“Hydrogels can be programmed or induced to undergo multiple controllable shape changes over time. This strategy creates experimental conditions to mimic or partially stimulate the various continuous shape changes that developing or scarring tissue undergo, and it can allow us to study morphogenesis and also help us design tissue architectures that are more like native tissues, ”said Alsberg, Richard and Loan Hill professor of biomedical engineering and corresponding author of the article.
The new material is made up of different hydrogels that swell or shrink at different rates and extents in response to water or the concentration of calcium. By creating intricate layering patterns, researchers can guide the conglomerate material to somehow bend as the layers swell and / or shrink.
“We can change the shape of these materials by adjusting, for example, the amount of calcium present,” said Alsberg, who is also a professor of orthopedics, pharmacology, and mechanical and industrial engineering at UIC.
In their experiments, the researchers succeeded in causing the hydrogel to form into pockets similar in shape to alveoli, the tiny sac-like structures in the lungs where gas exchange takes place.
Not only are Alsberg hydrogels capable of altering their architecture multiple times, but they are also highly cytocompatible, which means that they may have incorporated cells and the cells remain alive, which many existing 4D materials cannot. to do.
“We are really looking forward to pushing the boundaries of what our unique hydrogel systems can do in terms of tissue engineering,” said Aixiang Ding, UIC postdoctoral research associate and co-first author of the article. . Oju Jeon, UIC research professor, is also co-first author.
UIC’s Rui Tang, Yu Bin Lee and Sang Jin Lee are co-authors of the article.
This research was funded by grants from the National Institutes of Health’s National Institute of Arthritis and Musculoskeletal and Skin Diseases (R01AR069564, R01AR066193), the National Institute of Biomedical Imaging and Bioengineering (R01EB023907) and the National Heart, Lung and Blood Institute (T32HL134622 ).