Nanoscale particles made of the biodegradable copolymer poly(lactide-co-glycolide) might one day help treat autoimmune diseases such as multiple sclerosis (MS), according to a report (Nat. Biotechnol., DOI: 10.1038/nbt.2434). MS occurs when the body’s own immune system attacks myelin—a mixture of lipids and proteins that insulate nerve fibers and assist nerve signal transmission. A research team led by Stephen D. Miller and Lonnie D. Shea of Northwestern University has designed and tested injectable 500-nm peptide-coated particles of this material as well as polystyrene. The particles are coated in myelin peptide segments (antigens) that, when presented to immune cells such as T cells, induce tolerance to the nerve material and halt the progression of MS symptoms in mice. By injecting peptide-coated particles into mice seven days before the normal onset of MS symptoms, the researchers completely protected the rodents from disease. Shea says the team plans to also test the technology on other immune disorders such as asthma.