2.3. Cell Counting Kit-8 (CCK-8) Assay

iMatrix-411 solution with various concentrations was coated into 96-well plates (Non-PS, 351172, Falcon & TCPS, 353072, Falcon) making the final density: 0.5, 1, 2, 4, 8, and 16 μg/cm². Cells were seeded into those surface-modified or nonmodified wells at the number of 1 × 10³/well. Cell viability was evaluated by addition of CCK-8 (Dojindo, Japan) into each well (10 μL/well) and incubation for 1 h 45 min. Absorbance was read at the wavelength of 450 nm. For cell proliferation test, cells were seeded in the same manner with lower number (0.5 × 10³/well).