Soft materials found in nature often have complex architectures.An example is the spinal discs that lie between adjcent vertebrae in the spine: these discs have a hard core surrounded by a soft shell.We are interested in creating new hybrid materials based on polymer hydrogels that can mimic such architectures.Towards this end,we have developed a new approach to creating hybrid hydrogels that comprise different gel types juxtaposed in predetermined zones or patterns and with the properties of each gel being retained.The key to our approach is to ensure that the viscosities of the pregel mixtures are high when they are brought into contact and subsequently polymerized; this limits the diffusion at gel/gel interfaces.