Thermo-Responsive Hydrogels for Ocular Drug Delivery.

Hydrogel as an ocular drug delivery platform holds great potential. Hydrogels are three-dimensional, hydrophilic, polymeric networks capable of absorbing large amounts of water or biological fluids. They have the ability to swell in an aqueous solvent system, holding solvents within a cross-linked gel system for potential sustained delivery. Through manipulation of permeation and diffusion characteristics, they can retain hydrophobic and hydrophilic agents, small molecules and macromolecules. In addition, hydrogel can be combined with nano- or microspheres to enhance delivery capacity. The aqueous environment of hydrogels can also protect cells and pharmacological agents. Depending on the specific structure, they can be nondegradable or degradable in their application.