Effect of optical clearing agents on the in vivo optical properties of squamous epithelial tissue.
OBJECTIVE
Optical clearing agents (OCAs) have previously been shown to increase depth penetration within turbid tissue ex vivo. This paper quantifies tissue optical properties of the hamster cheek pouch model in order to provide a means to assess the effect of OCAs quantitatively in vivo.


METHODS
Diffuse reflectance spectra were obtained from both cheeks of 12 hamsters before and after immersion in dimethyl sulfoxide (DMSO), glycerol or a phosphate buffer saline (PBS) control for 20 minutes. A Monte Carlo model was then utilized to derive the wavelength dependent reduced scattering and absorption coefficients.


RESULTS
DMSO caused a statistically significant decrease in the absorption and reduced scattering coefficients derived by the model. Glycerol caused a statistically significant increase in the wavelength dependent absorption coefficient, but no statistically significant changes in the reduced scattering coefficient.


CONCLUSIONS
DMSO and glycerol act upon tissues differently as reflected by the tissue optical properties, implying that not all OCAs are equally effective in optically clearing tissues.
Millon
Stacy R
SR
Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin 53706, USA.
Roldan-Perez
Katherine M
KM
Riching
Kristin M
KM
Palmer
Gregory M
GM
Ramanujam
Nirmala
N
D000042:Absorption; D000818:Animals; D002610:Cheek; D006224:Cricetinae; D004121:Dimethyl Sulfoxide / Q000737:chemistry / Q000494:pharmacology*; D004848:Epithelium / Q000737:chemistry / Q000187:drug effects*; D005990:Glycerol / Q000737:chemistry / Q000494:pharmacology*; D008027:Light; D008297:Male; D008647:Mesocricetus; D023421:Models, Animal; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence
D005990:Glycerol; D004121:Dimethyl Sulfoxide