Emerging Trends in Nanomedicine for Improving Ocular Drug Delivery: Light-Responsive Nanoparticles, Mesoporous Silica Nanoparticles, and Contact Lenses

Abstract

Vision is the most dominant of our senses, and it is crucial in every stage of our lives. Ocular diseases, regardless of whether they cause vision impairment or not, lead to personal and financial hardships. The anatomy and physiology of the eye strongly limit the efficacy of current ocular drug delivery strategies. Nanotechnology has been the ground for the development of powerful strategies in several fields, namely in medicine. This review highlights emerging nanotechnology-based solutions for improving ocular drug delivery and thus the bioavailability and efficacy of drugs. We focus our review on ambitious but promising approaches currently emerging to leverage the efficacy of nanoparticle-based systems in ocular therapy: (i) light-responsive nanoparticles, which enable spatiotemporal control of drug release; (ii) mesoporous silica nanoparticles, which offer high surface area-to-volume ratio, simple surface modification, good biocompatibility, and improved bioavailability; and (iii) contact lenses, which serve as a compliant method of nanoparticles use and as drug delivery systems for the treatment of ocular diseases.

Novel Contact Lenses Embedded with Drug-Loaded Zwitterionic Nanogels for Extended Ophthalmic Drug Delivery

“…However, limited drug-loading and burst release are prevalent problems, with complete drug release from the lens within a few hours. Recently, some innovative strategies, such as in situ creation of a vitamin E barrier [ 9 ], molecular imprinting technology [ 10 ], drug-laden nanoparticles, the introduction of ionic or ‘host-guest’ interactions [ 11 ] and the incorporation of drug-loaded polymer films [ 12 ] have been reported to achieve the continuous release of drugs [ 13 , 14 , 15 , 16 , 17 , 18 ]. Although great efforts have been achieved in drug-eluting contact lenses, however, the critical lens properties, such as optical transparency, ion and oxygen permeability, mechanical durability, serialization and storage stability, as well as patient and practitioner acceptance have yet to be addressed [ 19 ].…”

Modification of Silicone Hydrogel Contact Lenses for the Selective Adsorption of Ofloxacin

“…No evident regularity was observed in the adsorption of CHA and MYR because the adsorption of drug molecules is physical without any specific binding. As shown in Figure 9(b), the MIP-MSL and MSL contact lenses exhibited a certain amount of OFL adsorption and reached 2.86 mg/g and 1.44 mg/g, respectively, which could be used for the drug delivery system [39]. Evidently, the adsorption capacity of the MSL contact lenses was significantly lower than that of the MIP-MSL contact lenses.…”

Metallic Engineered Nanomaterials and Ocular Toxicity: A Current Perspective

“…The eyes are particularly vulnerable to metallic ENMs applied in close proximity, such as zinc oxide (ZnO) and titanium dioxide (TiO 2 ) that are commonly incorporated into commercial sunscreens and cosmetics [ 19 , 20 ]. ENMs are also a focus for ocular drug delivery, where nanodrug carriers are used to enhance drug permeability and control drug release within the eye [ 21 , 22 , 23 , 24 , 25 ]. The purpose of this article is to review (1) the characteristics and general toxicity of ENMs, (2) the relevant ocular anatomy pertaining to ENM exposure, and (3) the published literature regarding ocular toxicity.…”