Influence of glycerol on the mechanical reversibility and thermal damage susceptibility of collagenous tissues

Clinical procedures wherein supraphysiologic temperatures must be achieved in deep layers of tissue via light are often compromised by optical scattering and absorption. Optical clearing of tissue superficial to the target improves the efficacy of such procedures. Glycerol is an attractive chemical agent for achieving dramatic reductions in tissue turbidity, but its net effects on healthy tissue are not fully understood. In this paper, we investigate possible alterations of biaxial mechanical properties in a model collagenous tissue, bovine epicardium, induced by glycerol. Furthermore, we examine the effects of glycerol on the biaxial thermomechanical properties of epicardium constrained at near-physioiogic length. It is seen that mechanical changes induced by glycerol are fully reversed upon rehydration in normal saline. Moreover, glycerol protects cleared tissue by increasing its thermal stability and minimizing thermal alterations of mechanical properties.