Characterization of stimuli-responsive and cross-linked nanohydrogels for applications in ophthalmiatrics therapy

Despite high drug-loading capacity, the ocular surface retention and corneal permeability of conventional nano eye drops are still unsatisfactory, thereby limiting therapeutic efficacy. Therefore, the objective of this study was to formulate dexamethasone loaded temperature-sensitive, pH-sensitive and ion-sensitive nanogels by incorporating stimuli-responsive elements, in order to enhance the ocular surface retention and corneal permeability of the encapsulated drug. The nanogels showed excellent rheological properties, along with good strength and viscosity under physiological conditions. Both in vitro and in vivo studies showed that the nanogels enhanced the ocular surface retention and corneal permeability of drugs. The temperature-sensitive gel showed the optimum behavior. The stimuli-responsive nanogels are stable delivery systems that can release drugs into the posterior ocular segment in a targeted and sustained manner.