Magnetic cobalt nanoparticles - coming our way soon?

COS 2012, July 4 - Future therapies for retinal disease may include the use of cobalt or magnetite nanoparticles that are directed to target tissue and cells by use of a magnetic targeting system. According to Dr. Sonia Yeung, clinical assistant professor of ophthalmology at the University of British Columbia, nanoparticles are of interest because they can get to places many other therapeutics can't reach. They have low immunogenicity and are biodegradable, clinically safe, easy to produce and easy to scale up at a relatively low cost.

Yeung's talk, based on the paper she contributed to titled Targeted Delivery of Magnetic Cobalt Nanoparticles to the Eye Following Systemic Administration, won the 2011 Royal College Gold Medal Award in Surgery.

"If you understand the chemistry of the nanoparticle, you can control its function and where it goes," she said. Nanoparticles have three parts: a core where therapeutic drugs, gene therapy components or immune-modulating elements can be packaged; a shell consisting of magnetite or cobalt which provides the magnetic properties; and a coating with targeting and/or therapeutic ligands. Nanoparticles can also be tagged with imaging markers for diagnostics and tracking.

Yeung described work done with mice, which were injected with nanoparticles. Various studies were conducted to determine where the nanoparticles went (with and without magnetic targeting), which tissues absorbed them and what their effect on tissue might be. Studies were then done to determine the effectiveness of unidirectional magnetic fields in targeting the nanoparticles to the eye.

Compared with no magnetic field, there was a threefold to ninefold increase in the quantity of nanoparticles delivered to the eyes with the use of a unidirectional magnetic field, demonstrating that it's possible to focus nanoparticles. More research is needed to determine which kinds of therapeutics might work best with this technology, possibly offering an alternative approach to intravitreal injections or other treatments.

"This is just one of the tools that I think is going to be... in the future of molecular medicine with the goals of early disease detection and targeted therapy," Yeung stated.