The clinical use of silica vesicles has been barred by a tendency for the nanospheres to clump into aggregates in water-based solutions, reports Nanowerk News. A research team led by Ye Liu from the A*STAR Institute of Materials Research and Engineering in Singapore was able to resolve the problem, though, by attaching water-soluble, brush-shaped polymers called polyethylene glycol to the shells of the silica vesicles. Report