Distribution of polymeric nanoparticles in the eye: implications in ocular disease therapy

Abstract

Advantages of polymeric nanoparticles as drug delivery systems include controlled release, enhanced drug stability and bioavailability, and specific tissue targeting. Nanoparticle properties such as hydrophobicity, size, and charge, mucoadhesion, and surface ligands, as well as administration route and suspension media affect their ability to overcome ocular barriers and distribute in the eye, and must be carefully designed for specific target tissues and ocular diseases. This review seeks to discuss the available literature on the biodistribution of polymeric nanoparticles and discuss the effects of nanoparticle composition and administration method on their ocular penetration, distribution, elimination, toxicity, and efficacy, with potential impact on clinical applications.

Keywords: Drug delivery system; Ocular biodistribution; Ocular drug delivery; Polymeric nanoparticle.

Fig. 1

Anatomy of the eye and administration routes

Fig. 2

Nanoparticle trafficking routes in the eye

Fig. 3

Blood-retinal barrier [65]. Permission to reproduce this figure is granted under the Creative Commons Attribution License. Figure 3 is reprinted from Frontiers in Immunology, Forrester V & Xu H, Good news–bad news: the Yin and Yang of immune privilege in the eye, 2012, under the Creative Commons Attribution License

Fig. 4

a Retinal cross section of mouse eye showing gradients of fluorescence due to movement of nanoparticles, b Outer to inner gradient in fluorescence c Anterior to posterior gradient in fluorescence [26]. Permission to reproduce this figure has been obtained from Elsevier. Figure 4 is reprinted from Nanomedicine: Nanotechnology, Biology, and Medicine, 12/7, Mahaling B & Katti DS, Physicochemical properties of core–shell type nanoparticles govern their spatiotemporal biodistribution in the eye, 2149–60, 2016, with permission from Elsevier