Thermophysical properties of a monolayer tissue with respect to freeze-drying

Conservation of tissue structures by means of freeze-drying is still limited as the complex mechanisms taking place at molecular/cellular level are not fully understood. The successful application of hydroxyethyl starch (HES) in combination with maltose, sucrose, and trehalose as stabilizers of lipid bilayers/membranes in red blood cells suggests an extended use of this mixture of cryoprotectants. The effectiveness of such cryoprotectant solutions has been linked to changes in the thermophysical properties of cellular structures. This work deals, in a first step, with the thermophysical properties of a model monolayer tissue--onion epidermis--in binary aqueous solutions of dissacharides. First and second order phase transitions, i.e. melting, crystallisation, and glass transition, are characterised by means of Modulated Differential Scanning Calorimetry (MDSC).