Axons—the long, cable‑like projections that relay electrical signals across the nervous system—depend on tightly wrapped layers of myelin to keep those messages fast and reliable. When this insulation is damaged, as in multiple sclerosis (MS) and other neurodegenerative diseases, signal transmission slows and neurons eventually degenerate. Although oligodendrocytes can repair myelin early on in the process, this capacity declines with age and repeated inflammatory attacks, leaving researchers searching for therapies that can restore myelin more effectively. A team at University College London (UCL) has now developed a more physiologically realistic way to study how myelin forms—and how potential drugs might influence that process. Their new hydrogel‑based axon model, described in Nature Methods in a paper titled “Tunable hydrogel‑based micropillar arrays for myelination studies,” recreates both the geometry and softness of real axons. The platform is designed to address a longstanding problem in the field: many drug candidates that appear promising in rigid, plastic‑based lab models ultimately fail in human trials. “To stop MS, we need therapies that repair myelin,” said senior author Emad Moeendarbary, PhD, professor of cell mechanics and mechanobiology at UCL and CEO of BioRecode. “Promising drug candidates in the past have failed when tested in human patients. One factor might be that laboratory models do not replicate the basic physical properties of the human brain.” The UCL team engineered vertical micropillars—each tens of times thinner than a human hair—using a microfabrication process called photolithography that allowed them to precisely tune diameter, spacing, and stiffness. Unlike earlier artificial…