Interface a key theme for future

Fort Lauderdale, FL-One of the key themes for this year's meeting of the Association for Research in Vision and Ophthalmology (ARVO) was nanotechnology and regenerative medicine. The many presentations on new materials, therapeutic delivery systems, and tissue engineering demonstrated the extent to which these two areas interface in ophthalmic science.

Nanotechnology

The precise definition of what is and what is not "nanotechnology" always seems to be something of a moving target. Products from liposomes to carbon dendrimers to gold nanoparticles were all part of mix at this year's ARVO. Engineered biological products, including viral gene transfer and biosensors for monitoring tissue regeneration, also were topics of posters and slide sessions. These are some of the presentations that caught our attention.

In addition to these reports, a number of studies reported development of therapeutic antibody-coated nanostructures as drug-delivery vehicles: Zhang et al. presented a study of microbubble-conjugated bevacizumab (Avastin, Genentech) or ranibizumab (Lucentis, Genentect) for treatment of age-related macular degeneration (AMD) (Zhang L, et al. IOVS. 2011;52:ARVO E-Abstract 447). The bubbles, about 0.8 to 1.2 µm in diameter, are composed of polyglycolic acid and can be loaded with fluorescent dyes to monitor their dwell time following injection. Both antibodies were efficiently coupled to the surface, so they can be used in proof-of-principle studies for this new delivery system.

In a particularly novel presentation, Sun et al. described a system designed for targeted delivery to lacrimal gland acinar cells (LGAC). The group constructed a bifunctional peptide with nanoparticle assembly function on one end and LGAC targeting on the other. The combination specifically assembled in acinar cells, and thus could provide a means for selective delivery of drugs or gene therapies to the lacrimal gland (Sun G, et al. IOVS. 2011;52:ARVO E-Abstract 430).

There were several presentations in which the particles were used to provide either a direct therapeutic effect or were specifically able to augment existing therapy or diagnosis.

A group from the University of Oklahoma had several presentations describing the properties of "nanoceria," a nanoparticle containing cerium oxide (Kiosseva SV, et al. IOVS. 2011;52:ARVO E-Abstract 421; Cai X, et al. IOVS. 2011;52:ARVO E-Abstract 423). Data suggest that these nanoceria can act as efficient free-radical scavengers, and may modify gene expression and promote photoreceptor cell survival.

In another poster, Awdeh and colleagues described study in which a range of gold nanorod concentrations were tested as a contrast agent in optical coherence tomography (OCT), and showed these gold particles enhanced both the resolution and sensitivity of the OCT signal (Awdeh RM, et al. IOVS. 2011;52:ARVO E-Abstract 455).