A new recipe for patterning cells on a surface holds promise for the repair of damaged nerve tissue. Researchers have developed a technique for adhering and aligning cells on a soft and flexible material, known as hydrogel, with the goal of creating a scaffold on which to grow neurons and provide guidance for the cells to extend the long thin projections, or axons, that serve as the transmission lines of the nervous system.
A key challenge was to find ways to make cells stick to hydrogel, a material that consists of a watery synthetic or natural polymer that resembles not-yet-set gelatin. To overcome this challenge, the researchers engineered a method for applying a cell-adhesive layer atop the hydrogel. First the team applies a hydrophobic (water-repelling) solvent that enabled formation of a titanium or zirconium oxide layer at the hydrogel surface. The next step is the self-assembly of a phosphonate monolayer, bound to the titanium or zirconium oxide coating, that is cell-attractive. By initially masking parts of the hydrogel surface, the researchers can create precisely defined sticky regions, enabling cells to be patterned, and to assemble a patterned extracellular matrix in arrangements that are useful to neural repair.
Team members: Craig Arnold, Susan Dod Brown Professor of Mechanical and Aerospace Engineering; Greg Harris, visiting research collaborator; Romain Fardel, professional specialist; Kelly Lim, research specialist; Stephen Bandini, Ph.D. 2015; Joshua Spechler, Ph.D. 2016; Jeffrey Chen, Class of 2017
Collaborators: At the Mayo Clinic: Anthony Windebank, professor of neurology; Nicolas Madigan, assistant professor of neurology; Ahad Siddiqui, research associate
Development status: Patent protection is pending. Princeton is seeking outside interest for the development of this technology.
Funding: National Institutes of Health, National Science Foundation, New Jersey Commission on Spinal Cord Research