Figure 10  Schematic presentation of the steps for in situ gelation in macroporous alginate scaffolds. (A) Am alginate solution with cells is applied on top of a dry scaffold containing calcium ions, (B) rehydration of the scaffold by the alginate solution filling its pores and diffusion of calcium ions from the foam lamellas to the absorbed alginate, and (C) formation of a calcium cross-linked alginate hydrogel inside the pores of the foam. From reference [77].