Assessment of tissue biochemical and optical scattering changes due to hypothermic organ preservation: a preliminary study in mouse organs

Abstract

Clinical transplantation medicine currently faces a significant shortage of organ donors to supply the need of an increasingly aged population. Despite this, organs are still discarded due to graft stress induced by hypoxia or ischemia prior to procurement. Approaches to minimize donor organ discard include appropriate organ preservation and monitoring of organ function. Predominant organ preservation strategies involve hypothermia between 0 °C and 12 °C. In this study, we investigate the effect of temperature alone on tissue microstructural and biochemical parameters during cold preservation of mouse organs. To the best of our knowledge, this is the first study evaluating this cooling effect on multiple tissue parameters such as blood oxygenation, concentrations of blood, methemoglobin, water, lipid, and bile as well as scattering amplitude, Mie scattering power and fraction of Rayleigh scattering. These parameters were extracted by using diffuse reflectance spectroscopy spectral fitting at an extended wavelength range between 450 and 1590 nm and a Monte Carlo look-up table including a wide range of tissue optical properties compared to previous studies. Our findings can be used to understand biological processes undertaking cooling to propose new strategies involving optimized cold storage times and composition of organ preservation solutions for minimized cellular and tissue damage.