Kinetics of Rat Skin Optical Clearing at Topical Application of 40%Glucose: Ex Vivo and In Vivo Studies

Optical, molecule diffusion, and mechanical properties of skin and blood microcirculation in the underlying tissues at topical application of 40%-glucose solution in rats were investigated. Optical clearing of ex vivo and in vivo skin was measured within the wavelength range of 400-900 nm using standard spectrometer, and blood microcirculation alterations was measured with laser speckle contrast imaging. Increase of skin collimated transmittance, transverse, and along skin shrinkage and weight loss was observed for the first 20-60 min of immersion, for the longer time, tissue swelling was found. The glucose diffusion coefficients in ex vivo and in vivo rat skin were evaluated as (1.11 ± 0.78) × 10
^-6
and (1.54 ± 0.28) × 10
^-6
cm
²
/s, respectively. The decrease of average rate of microcirculation in 2.2 fold was observed. The results received allow one to evaluate glucose impact on skin tissue optical and mechanical properties and blood microcirculation.