Synergie 100

Compression tests were performed using a MTS Synergie 100 mechanical tester (MTS Systems, Eden Prairie, MN, USA). Control PEG hydrogels containing no microstructural features were prepared by UV polymerization of the PEGDA and Darocur 1173 solution (36.2% v/v) in 2,6-lutidine in the custom-assembled cylindrical glass vessels. Samples of control PEG, bijel-templated PEG, and fibrin-loaded PEG CBiTHs were cut into cylindrical disks (2 mm height, 2 mm diameter) using a razor blade and a biopsy punch. All samples were hydrated in PBS for at least 1 hour before testing (n=3). The cylindrical disks were placed onto the Synergie 100 stage and the compression adapter was lowered to the sample gap height of 2 mm. TestWorks4 (MTS Systems) was used to acquire data during compression to 50% of the sample height. Stress (σ) was plotted versus strain (ε), and the slope of the initial linear region was calculated using linear regression and reported as the sample’s compressive modulus (E). The stress at each sample’s failure point was reported as the compressive strength (σ_u).

Femurs were mechanically tested in three-point bending using an electromechanical materials testing machine (Synergie 100, MTS Systems, Eden Prairie, MN) as described (12 (link)).