EPFL professors Jeff Hubbell and Melody Swartz and PhD student Sai Reddy have engineered nanoparticles that completely overcome these limitations. At a mere 25 nanometers, these particles are so tiny that once injected, they flow through the skins extracellular matrix, making a beeline to the lymph nodes. Within minutes, theyve reached a concentration of DCs thousands of times greater than in the skin. The immune response can then be extremely strong and effective.
In addition, the EPFL team has also engineered a special chemical coating for the nanoparticles that mimics the surface chemistry of a bacterial cell wall. The DCs dont recognize this as a specific invader, but do know that its something foreign, and so a low-level, generic immune reaction known as complement is triggered. This results in a particularly potent immune response without the risk of unpleasant or toxic side effects.
People have been exploring nanoparticles for a while, says Hubbell. Our ideas -- to activate complement as a danger signal, and to exploit the slow interstitial flow towards the lymph nodes are completely new. But it meant that our particles had to be much smaller than anything currently being developed. No other labs have managed to engineer so many levels of functionality into nanoparticles that are smaller than biologically occurring particles, he adds. The beauty of it is that once we have developed the recipe, any lab can make them.
Cost and logistics are important factors, especially for use in developing countries. Unlike other nanoparticle vaccine technologies that degrade in water and thus require expensive drying and handling procedures, the EPFL teams nanoparticles wont degrade until they are in the body. They are in liquid form and dont require refrigeration, so preparation and handling costs are redu
|Contact: Mary Parlange|
Ecole Polytechnique Fd rale de Lausanne