The invention provides a multi-polymer hydrogel article having a first
polymeric, water-swellable material and a second polymeric material,
organized such that a first region substantially comprises the first
polymeric, water-swellable material, a second region adjacent the first
region comprises a mixture of the first polymeric, water-swellable
material and the second polymeric material, and a third region adjacent
the second region substantially comprises the second polymeric material.
The article exhibits an increasing concentration gradient of the second
polymeric material moving from the first region, through the second
region, to the third region. The invention also provides methods for
forming a multi-polymer hydrogel article by (a) forming a hydrogel
structure using a first polymeric, water-swellable material, (b) creating
an aerogel structure having a plurality of open pores by dehydrating the
hydrogel structure, (c) contacting the aerogel structure with a second
polymeric material to incorporate the second polymeric material into at
least a portion of the plurality of open pores to form the multi-polymer
hydrogel article, and (d) rehydrating the multi-polymer hydrogel article.