New research shows that labelling of laminin with a nanoparticle probe enables MRI assessment of blood–brain barrier (BBB) changes caused by neuroinflammation. The iron oxide-based nanoparticles were vectorized with peptide-88, which binds laminin specifically under inflammatory conditions. A comparison of MRI images from a mouse model of autoimmune encephalomyelitis (EAE) and control mice showed increased contrast in the EAE mice following injection with the nanoprobe, demonstrating use of the probe to detect increased BBB permeability.