Type 1 diabetes results from a civil war within the body: the immune system, for reasons not well understood, attacks and destroys blood-sugar-regulating beta cells.  Patients must carefully control their own blood sugar with frequent pinpricks and insulin injections.  But what if doctors could simply replace the destroyed cells?  In this image, researchers have placed beta cells (green) inside a ball of alginate, a seaweed-based polymer, and implanted the ball into a model organism.  This alginate capsule could protect beta cells from immune attacks while still allowing them to sense and regulate blood sugar.