Determination of the diffusion coefficient of 40%-glucose in human gum tissue by optical method

The problem of increasing the depth of light penetration in biotissues, which is solved by the use of immersion agents, including hyperosmotic ones, such as glucose, is urgent because of the significant development of optical technologies and methods used for non-invasive diagnostics of biotissues, as well as for clarifying the protocols of photodynamic therapy, photothermal destruction, optical biopsy, tomography, etc. In this case, it is important to determine the quantitative characteristics of the diffusion of immersion agents in biological tissues. In this work, the effective diffusion coefficient of 40% glucose solution in the human gum mucosa tissue has been determined in vitro, which was (4.1$\pm$ 0.8) $\times$ 10$^{-6}$ cm$^2$/s. The method is based on the recording of the kinetics of changes in the diffuse reflectance spectra and the application of a free diffusion model.