Old polymer learns new tracts

Saltzman and colleagues present a simple approach using a known polymer, poly(lactic-co-glycolic acid) (PLGA), to form nanoparticles containing densely packed short-interfering RNA (siRNA) for topical delivery to the female reproductive tract. The biocompatibility of PLGA makes it an excellent candidate for safe, non-irritating delivery to the vaginal tract. In addition to selecting an appropriate material, the authors identified two criteria required for successful nanoparticle mediated siRNA delivery, first, that the particles are small enough to penetrate tissue barriers and be taken up by cells, and second, that large, stable quantities of siRNA can be entrapped and released. The authors established that sustained knockdown of gene expression was possible by administering the nanoparticles directly to the female reproductive tract in mice by showing that the expression of green fluorescent protein (GFP) could be suppressed in GFP-transgenic mice.