Search

The increase of tissue transparency through sequential optical immersion clearing treatments and treatment reversibility have high interest for clinical applications. To evaluate the clearing reversibility in a broad spectral range and the magnitude of the transparency created by a second treatment, the present study consisted on measuring the spectral collimated transmittance of lung tissues during a sequence of two treatments with electronic cigarette (e-cig) fluid, which was intercalated with an immersion in saline. The saline immersion clearly reverted the clearing effect in the lung tissue in the spectral range between 220 and 1000 nm. By a later application of a second treatment with the e-cig fluid, the magnitude of the optical clearing effect was observed to be about the double as the one observed in the first treatment, showing that the molecules of the optical clearing agent might have converted some bound water into mobile water during the first treatment., The present research work was supported by the Portuguese Science Foundation, grant no. FCT-UIDB/04730/ 2020. The work of Valery V. Tuchin was carried out with the support of a grant under the Decree of the Government of the Russian Federation No. 220 of 09 April 2010 (agreement no. 075-15-2021-615 of 04 June 2021). Valery V. Tuchin and Luís M. Oliveira contributed equally to this work.