Treating retinopathies - Nanotechnology as a tool in protecting antioxidants agents

The retina possesses the highest oxygen uptake and glucose oxidation relative to any other tissue, which makes it more susceptible to oxidative stress than other organs or structures. Constant light irradiation, atmospheric oxygen, environmental chemicals, and physical abrasion contribute to oxidative stress as the key factor for the ocular degenerative diseases. Oxidative stress is responsible for the increased vascular permeability, disruption of blood-retinal barrier, apoptotic loss of retinal capillary cells, microvascular abnormalities, and retinal neovascularization. Whenever the antioxidant defense systems are depleted or not functional, vision impairment might be observed. For this reason antioxidants are fundamental agents in prophylactic forms of oxidative diseases. However, considering its sensitive structure, nanotechnology becomes a valid alternative in antioxidant protection, stability, bioavailability, and therapeutic efficacy, without collateral damage or side effects. This review casts light on the improved therapeutic use of antioxidants loaded in novel and pharmaceutically acceptable nanocarriers for ocular disease prevention, in particular retinopathies.