Although it has been shown that frozen storage is feasible for some of the tissue-engineered products such as bone (Kofron et al., 2003), it is more difficult than that for isolated cells and requires special considerations. Water transport processes may cause difficulties for tissue-scale freezing. While cells at the surface layer would respond to freeze-induced osmotic changes much like cells in suspension, interior cells would dehydrate as a response to the increased intracellular tonicity in the dehydrate surface layers. Accordingly, interior cells dehydrate more slowly than surface cells, which may affect their survival (Karlsson and Toner, 1996)
