Improved Skin Permeability after Topical Treatment with Serine Protease: Probing the Penetration of Rapamycin by Scanning Transmission X-ray Microscopy.

ABSTRACT: Drug penetration in human skin ex vivo following a modification of skin barrier permeability is systematically investigated by scanning transmission X-ray microscopy. Element-selective excitation is used in the O 1s regime for probing quantitatively the penetration of topically applied rapamycin in different formulations with a spatial resolution reaching <75 nm. The data were analyzed by a comparison of two methods: (i) two-photon energies employing the Beer-Lambert law and (ii) a singular value decomposition approach making use of the full spectral information in each pixel of the X-ray micrographs. The latter approach yields local drug concentrations more reliably and sensitively probed than the former. The present results from both approaches indicate that rapamycin is not observed wit

SUBMITTER: Germer G 

PROVIDER: S-EPMC8154144 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature