The in vivo laser scanning microscope Stratum
(Optilas Ltd., Melbourne, Australia) was
utilized to investigate the potential distribution
and penetration of the topically applied
substances. Pre-investigations excluded any autofluorescence
deriving from the untreated skin,
thus ensuring that the detected signals exclusively
originate from the fluorescent marker curcumin.
The laser scanning microscope consists of a
handpiece, accommodating the optical imaging
system. The handpiece is connected by optical
fibres to the base station, which contains the excitation
laser (argon system, 488 nm) and the spectrometer
with the electronic evaluation system.
The laser focus can be manually shifted into various
depths of the human skin. The excitation
radiation of 488 nm penetrates approximately
with a maximum of 150 lm deep into the human
skin, whilst the spot size of the system is
250 9 250 lm.