In one aspect, the invention provides methods for forming a photopatterned
hydrogel. In some embodiments, the methods comprise the step of exposing
a solution comprising a monomer, a crosslinking agent, and a
photoinitiator to a pattern of light comprising a first and a second
light intensity for a period of time and under suitable conditions for
the first light intensity to induce essentially complete conversion of
polymerizable groups on the monomer and the crosslinking agent to form a
patterned hydrogel, and for the second light intensity to induce partial
conversion of the polymerizable groups on the monomer and the
crosslinking agent to form partially polymerized polymers that remain
soluble. In some embodiments, the first light intensity is lower than the
second light intensity. In another aspect, the invention provides methods
for forming porous, photopatterned hydrogels.