Nonspherical Nanocapsules as Long-Circulating Drug Delivery Systems

Polymeric nanocapsules have been studied as drug delivery carriers for a great variety of drugs for more than 30 years. In particular, nonspherical polymeric nanoparticles with solid cores are highlighted for their capability to influence cellular uptake and circulation time in the bloodstream. However, the promising combination of nonspherical morphology and the existence of an internal cavity to encapsulate a high dose of pharmaceutical actives has not yet been fully achieved. This review systematically addresses the development of nonspherical nanocapsules with a cross-linked shell or self-assembled membrane (polymersomes). Ellipsoidal, tetrahedral, cubic, protrusion-shaped, dumbbell-shaped, and snowman-shaped nanocapsules are discussed. The relationship between the formed morphologies and the use of different templates, monomers, or methods of polymerization are elucidated for future design of more functional shapes.