The morphology and microstructure of 3D scaffolds were characterized through Quanta Standard Environmental SEM (FEI, United States). Mechanical compression used MTS insight (MTS, MN, USA) machine according to previous reports (X. Liu & Ma, 2009 (link); Xu, Miszuk, Zhao, Sun, & Fong, 2015 (link); Q. Yao et al., 2016 (link)) with some modifications. Briefly, a sample was placed under the loading cell with 60% of weight (up to 1 kN) applied. All samples were circular discs (5mm in diameter and 1.5mm in thickness). The averages and standard deviations were reported.
Fourier-transform infrared spectroscopy (Thermo Scientific, MA, USA) determined the absorption on an infrared spectrum. Confocal microscopy imagining of MC3T3-E1 in both scaffold at a cell density of 75×103 cells per scaffold were performed according to previous reports (Y. Liu et al., 2018 (link)). Cell-seeded scaffold was cultured for five days in growth medium. Cells were fixed and stained with Texas Red-X Phalloidin (Molecular Probes, NY) and DAPI (SouthernBiotech, AL) according to the manufacturer’s manual. Stained cells were observed under confocal microscopy (FV1200, Olympus, Japan).