A method for making gels and noodle-shaped strings that is compatible with living cells is reported online this week in Nature Materials. The work shows promise for using these systems as cell scaffolds for long-range signal transmission within the body, for example in the heart and spinal cord.

Samuel Stupp and colleagues heat peptide suspensions to form two-dimensional flat sheets that break on cooling to form a liquid crystal. If this liquid crystal is mixed with cells and hand-drawn using a pipette into a salt solution, a noodle-shaped string composed of aligned fibres with encapsulated cells is formed. These types of gel are only accessible through this thermal route and, in comparison with existing methods to make artificially aligned fibres, do not require the use of highly mechanical or electrical processes that could be harmful to living cells.

The team show how a string with encapsulated cardiac muscle cells transmit electrical signals across the entire structure ― an observation that shows the method could be used in the creation of cell scaffolds for long-range signal transmission in many major organs in the body.