Layer-by-layer engineered capsules and their applications

Over the last 15 years, development of the layer-by-layer (LbL) technique for preparing thin films has greatly improved control over the physical and chemical properties of thin films. When applied to colloidal particles, the LbL technology permits the formation of hollow capsules with engineered features, including size, shape, composition and function. In this review, we outline the potential applications of LbL assembled micro- and nanometer-sized capsules. These lie principally in the areas of drug delivery, sensing, catalysis and microreactors. We focus on the potential use of LbL capsules as drug delivery vehicles and, specifically, on methods for encapsulating and releasing molecules from capsules as well as on targeting capsules to cells.