Peptide-based nanoparticles eyed as drug delivery system for AMD

TREATING age-related macular degeneration (AMD), one of the most prevalent cause of vision loss, often means delivering drugs right to the source, i.e., injecting them into the back of the eye - at present, the only method for delivering these drugs. This procedure may involve many injections and can be very uncomfortable for the patient, but now a consortium of scientists from around Europe think they may have the solution.

 

Professor Neil Cameron and colleagues of the University of Durham have created a system that utilizes peptides that are capable of assembling themselves into nanoparticles. These biodegradable and biocompatible materials can be used as containers for therapeutic molecules, which can then be delivered to the desired area and released in a controlled fashion. 

 

"The particles we use are around 1000 times thinner than a human hair,” explained Professor Cameron. “This means that they are able to pass through the sub-conjuctival and sub-tenon routes into the eye that are less traumatic for the patient.”

 

In Europe, an estimated 6.5 million elderly currently suffer from AMD, which occurs when cells in the highly sensitive area of ​​the retina known as the macula become gradually damaged causing loss of central vision. While Asians have long been considered a low risk group for AMD, data reviews indicated that they may be just as susceptible.

 

Delivering the required drug to the retina via peptide molecules, the University of Durham researchers believe, might be able to provide a less distressing alternative. 

 

One other advantage of this type of drug-delivery system is that release of the drug is controlled. Peptides are commonly found in the body and endogenous enzymes naturally break them down, so when the peptide-based micro- and nanoparticles containing the drugs are inserted into the eye, they biodegrade and release the drug slowly by diffusion. This gives them an advantage over drugs administered straight into the bloodstream, which have a harder time reaching the eye due to the blood-retinal barrier.

 

PANOPTES project

 

In order to put this system into action, Professor Cameron and his colleagues created a consortium of experts including materials scientists and biochemists. The project, named PANOPTES, has focused on creating methodologies for the industrial manufacture of novel peptide-based nanoparticles and nanocapsules for sustained drug delivery to the back of the eye.

 

The project has involved research groups from three European universities and all three groups have had success in producing nanoparticles. "We can make a few different types and sizes of particles," Professor Cameron said. "Some of them have solid cores, whereas others are more like little capsules, and we have successfully loaded each of them with a number of relevant drugs. The materials have been extensively tested in vitro, and we have also carried out some in vivo testing."

 

PANOPTES aim has been to refine at least one drug delivery system and bring it to the point where it is ready for clinical trials and this looks very likely. Exact results can not be disclosed at present due to commercial interests, but Professor Cameron is confident that what they have created can lead to a solution for eradicating the discomfort in drug delivery for sufferers of AMD.