Thermal behavior of water in micro-particles based on alginate gel.

Alginate has been established as a very versatile material in the preparation of hydrogel capsules for trapping therapeutic biomolecules and cells. The physico-chemical properties, the mechanism and the processing of gel formation are now well established. In the frame of a project aiming at the exploitation of encapsulation of therapeutic proteins in alginate gel particles, the procedure of preparation, characterization, gel-drying and re-hydrating has been explored for the shelf-life of the encapsulated biomolecules. Here, the results of a calorimetric study on the freezing and dehydration process of alginate micro-capsules is presented. The work aims at the description of water state(s) and its removal under “controlled conditions” in the presence of bioprotectant sugars.