Generation of Scaffold from Microgels and Mechanical Testing:

The microgels were pelleted by centrifuging at 18,000 G and the supernatant was discarded to form a concentrated solution of microgels. 5 U/mL of FXIII and 1 U/mL of Thrombin were combined in the presence of 10mM Ca²⁺ with the pelleted µgels and allowed to incubate at 37 °C for 90 minutes between two glass slides (1mm thickness) surface coated with sigmacote (Sigma-Aldrich). The mechanical testing on the hydrogel scaffolds was done using a 5500 series Instron. After annealing, the scaffolds were allowed to swell in HEPES buffer saline for 4 hours at room temperature. A 2.5N load cell with a 3.12mm tip in diameter was used at a compression strain rate of 1mm/min and the hydrogel scaffold was indented 0.8mm or 80% of its total thickness.