Book excerpt: The treatment of ocular diseases poses a significant challenge to drug delivery design, due to the eye's complex anatomy, with a semi-permeable blood-ocular barrier and associated immune privilege. To address some of the delivery challenges, polycationic dendrimers are explored as vehicle for the treatment of posterior chamber disease. Dendrimers are a class of polymeric nanoparticles that are highly branched, multivalent and monodisperse, whose three-dimensional globular architecture has given them the nickname of "synthetic proteins". Dendrimers are synthesized by reacting monomers in a step-wise fashion to produce generationally and radially increasing structures, with core, interior and surface chains that are highly customizable. Polyamidoamine (PAMAM) dendrimers, in particular, have been studied for a wide range of biomedical applications. The high drug loading capacity, by physical encapsulation and chemical conjugation with dendrimer surface groups, over a small hydrodynamic range (diameter d"4 nm) enables their usefulness in nanoparticle form and as building blocks for macro-structures. This dissertation explores the utilization of amine-terminated ( -NH2) PAMAM dendrimers as static or dynamic nanoparticle and hydrogel drug and gene carriers. These formulations are evaluated for their enhancement of the delivered therapeutic bioavailability and prolonged activity from extended release platforms to treat head and neck cancers and retinoblastoma