  Gold nanoparticles have been synthesized inside ethosomes, vesicles composed
of phospholipid, ethanol and water, which could be very efficient not only in
delivery probes to the skin but also as diagnostic and therapeutic multimodal
agents. High efficiency encapsulation of gold nanoparticles is achieved by a
simple strategy: the nanoparticles synthesis occurs simultaneously with the
ethosomes formation, in the absence of any undesirable reducing agents. A
three-dimensional reconstruction of a gold-embedded ethosome generated by
cryoelectron tomography reveals that the gold particle is localized inside the
lipid bilayer, leaving the ethosome surface and core free for further
functionalization. The resulting gold nanoparticles are homogeneous in size and
shape and, depending on synthesis temperature, the size ranges from 10 to 20
nm, as revealed by TEM. The ethosome-nanoparticles hybrids size has been
investigated by means of dynamic light scattering and has been found to vary
with temperature and gold salt concentration from 700 to 400 nm. Gold
nanoparticles encapsulated ethosomes offer a versatile platform for the
enhancement of pharmacological efficacy in transdermal and dermal delivery
systems.
