Supramolecular fabrication of complex 3D hollow polymeric hydrogels with shape and function diversity.

Inspired by the highly importance of hollow structures in nature such as blood vessels and bamboos in matter transportation, properties enhancement or even survival of living creatures, the creation of hollow materials remains considerable interest. However, constructing hollow unique living-like soft and wet polymeric hydrogels with desirable structures and functionalities is still a big challenge. Here, we reported a robust and effective strategy to fabricate complex three-dimensional hollow polymeric hydrogel with designed shape and function diversity on the basis of supramolecular interactions. Through placing a Ca2+ included gelatin core into the solution of alginate, hydrogel shell could be formed along the shape of the gelatin core via coordination between alginate chains and Ca2+ diffused from gelatin. Hollow hydrogel could finally be obtained by dissolving the gelatin core. Various complex 3D hollow structures could be achieved by designing/constructing assembled gelatin core as building block wi...