Dendrimers for Ocular Drug Delivery

Abstract

Existing methods of administering ocular drugs are limited in either their safety or efficiency. Nanomedicine therapies have the potential to address this deficiency by creating vehicles that can control drug biodistribution. Dendrimers are synthetic polymeric nanoparticles with a unique highly organized branching structure. In recent years, promising results using dendrimer vehicles to deliver ocular drugs through different routes of administration have been reported. In this review, we briefly summarize these results with emphasis on the dendrimer modifications used to target different ocular structures.

Keywords: dendrimer; nanomedicine; ocular drug delivery.

Figure 1

Dendrimer routes of ocular administration. Dendrimer based vehicles have shown pre-clinical efficacy in delivering ocular drugs through multiple routes of administration. These include 1) topical application, 2) injection into the vitreous humor, and 3) injection into the tissues around the eye. The eye structure was adapted with permission from the copyright holder of this work from https://en.wikipedia.org/wiki/Eye, retrieved March 1, 2017.

Figure 2

Dendrimer synthesis and structure. PAMAM generations 0.0–3.0, with half generations omitted. Particle size grows linearly with each full generation, but molecular weight and the number of surface groups increase exponentially.

Figure 3

Dendrimer gelation strategies. Dendrimers can be modified with diverse array of reactive groups to form hydrogels. Drug release from these materials can be further controlled by dendrimer type and generation, spacer length, and the mechanism of drug loading.