Potential use of nanoparticles for transcutaneous vaccine delivery: effect of particle size and charge.

The aim of this study was to investigate the effect of size and charge on the permeation of nanoparticles through the skin as the first step in designing a transdermal vaccine delivery system. Fluorescent particles ranging in size and charge were applied to the surface of full thickness pig skin in a diffusion chamber and the receptor fluid was assayed to determine permeation. Fluorescence microscopy was used to visualise the skin after experiments. The results showed that only 50 and 500 nm particles that were negatively charged were able to permeate the skin. This provides evidence of the potential of nanoparticles as delivery vectors for antigens and DNA for the purpose of transdermal vaccination protocols. The results would indicate that negative particles with sufficient charge may be ideal carriers for this purpose.