Great Expectations for Nanoparticle Vaccines

In contrast, 100-nm nanoparticles were only 10% as efficient. The surface chemistry of the nanoparticles triggered the complement cascade, generating a danger signal and potently activating dendritic cells.

The complement cascade is a complex system of at least 20 proteins in normal blood serum. The binding of one component to an antigen-antibody complex begins a chemical chain reaction important in many immunological processes, including breakdown of foreign and infected cells, ingestion of foreign particles and cell debris, and inflammation of surrounding tissue.

Results published in the September 16, 2007, issue of Nature Biotechnology revealed that nanoparticles conjugated to the model antigen ovalbumin, generated humoral and cellular immunity in mice in a size- and complement-dependent manner.

"People have been exploring nanoparticles for a while,” said senior author Dr. Jeffery Hubbell, professor of bioengineering at the École Polytechnique Fédérale de Lausanne. "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. The beauty of it is that once we have developed the recipe, any lab can make them.”


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École Polytechnique Fédérale de Lausanne