Vaccination with formulated fatty particles called liposomes protects women from AIDS before sex.
In tests led by Daniel Kohane, MD, PhD, director of the Laboratory for Biomaterials and Drug Delivery at Children's Hospital Boston, liposomes inhibited HIV infection in cell culture and appeared safe in female mice when injected intravaginally.
Liposomes are spherical particles with a double outer layer of lipids (fats) and hollow centres. They are relatively easy and cheap to engineer, and thus present a viable option for developing countries.
Liposomes can be filled with drugs or other compounds, but in this case, Kohane and colleagues found, to their surprise, that the liposomes alone were effective in blocking infection.
"We had been planning do much more complex things, like putting ligands on the surface to increase binding to HIV," said Kohane.
"It was a surprise that liposomes alone worked so well. Simplicity is always better - if liposomes work by themselves, we may not need anything else, and it would be cheaper and potentially much safer," he added.
The study was recently published online in the journal Biomaterials.