A team of chemists and bioengineers from Rice University and the University of Houston have achieved a major milestone in their work to create a biomaterial that can be used to grow biological tissues outside the human body. The development of a new manufacturing process to create aligned nanofiber hydrogels could offer new possibilities for tissue regeneration after injury and provide a way to test therapeutic drug candidates without the use of animals.
The research team, led by Jeffrey Hartgerink, professor of chemistry and bioengineering, has developed peptide-based hydrogels that mimic the aligned structure of muscle and nerve tissues. Alignment is essential for tissue functionality, but it is a difficult characteristic to reproduce in the laboratory, since it involves aligning individual cells.
For more than ten years, the team has been designing multidomain peptides (MDPs) that self-assemble into nanofibers. They resemble fibrous proteins found naturally in the body, much like a nanoscale spider web.
In their latest study, published online and featured on the cover of the journal ACS Nano, researchers discovered a new method for creating aligned MDP nanofiber “noodles.” By first dissolving the peptides in water and then extruding them into a salty solution, they were able to create aligned peptide nanofibers, like twisted strands of rope smaller than a cell. By increasing the concentration of ions, or salt, in the solution and repeating the process, they achieved even greater alignment of the nanofibers.
“Our findings demonstrate that our method can produce aligned peptide nanofibers that effectively guide cell growth in the desired direction,” explained lead author Adam Farsheed, who recently received his Ph.D. in bioengineering from Rice. “This is a crucial step toward creating functional biological tissues for regenerative medicine applications.”
One of the key findings of the study was an unexpected discovery: when the alignment of the peptide nanofibers was too strong, the cells no longer aligned. Further investigation revealed that the cells needed to be able to “pull” the peptide nanofibers to recognize the alignment. When the nanofibers were too stiff, the cells could not exert this force and failed to organize themselves into the desired configuration.
“This understanding of cell behavior could have broader implications for tissue engineering and biomaterials design,” Hartgerink said. “Understanding how cells interact with these nanoscale materials could lead to more effective strategies for building tissues.”
Other co-authors of the Rice study include Ph.D. from the chemistry department. graduates Tracy Yu and Carson Cole, graduate student Joseph Swain, and undergraduate researcher Adam Thomas. University bioengineering researcher Jonathan Makhoul, graduate student Eric García Huitron, and Professor K. Jane Grande-Allen were also co-authors of the study. The team of researchers at the University of Houston includes Ph.D. student Christian Zevallos-Delgado, research assistant Sajede Saeidifard, research assistant professor Manmohan Singh and engineering professor Kirill Larin.
This work was supported in part by grants from the National Institutes of Health (R01DE021798, R01EY022362, R01HD095520, R01EY030063), the National Science Foundation (2129122), the National Science Foundation Graduate Research Fellowship Program, and the Welch (C-2141). . The content of this press release is the sole responsibility of the authors and does not necessarily represent the official views of the funding organizations.