Visualization of the μgel network architecture in fibrin–μgel composite materials during fibrin polymerization. Fibrin–μgel (8 mg/mL and ϕ = 0.11 ULC μgels) composite networks were formed with 1.0 U/mL thrombin and imaged over time. This movie represents a single focal plane within Movie S2. (Scale bar, 20 μm.)