Hydrogels
have long been studied as cell encapsulants for engineered
tissue, yet diffusive limitations, suboptimal mechanical properties,
and poor cell distribution limit the use of single-phase hydrogels
for complex tissues scaffolds. Here, a composite hydrogel structure
is presented to overcome these limitations. It is shown that oxygen
inhibition during chain-growth photopolymerization of microgel particles
can be used to directly manipulate the interfacial bond strength between
two hydrogel interfaces in the particulate-composite hydrogels. Using
this principle, a cell-laden particulate-composite hydrogel is fabricated
that overcomes the low cell viability of a single-phase hydrogel,
while allowing the stiffness to be arbitrarily tuned