Figure 1.
Representative SEM images of collagen self-assembly on Mg (left) and AZ31 (right).
The concentration of collagen in each group is shown on the top left corner of each image.
Figure 2.
EDS analysis of collagen fibril and spherical particles on AZ31 and Mg.
The corresponding element is shown on the top left corner. Scale bar is 400 nm. (A) EDS element mapping, (B) High magnification SEM image of nanoparticles attached on collagen fibril, (C) Elemental composition of a nanoparticle (green star in B) by EDS point analysis.
Figure 3.
Representative SEM images of 200 µg/ml collagen self-assembly in DPBS with different pH values (A–B: 7, C–D: 9, E–F: 11) on Mg surface (A, C, E) and AZ31 (B, D, F).
Figure 4.
Representative SEM images of 200 µg/ml collagen self-assembly on Mg (A, C) and AZ31 (B, D) for 4 h (A, B) and 8 h (C, D).
Arrows indicate the large collagen band.
Figure 5.
3-D surface topography of Mg sample polished by different SiC paper (A: 180 grit; B: 800 grit; C: 1200 grit).
The arithmetic average of surface roughness (Ra) and root mean square (Rq) calculated from 4 different samples are shown on the top left corner.
Figure 6.
Representative SEM images of 200 µg/ml collagen self-assembly on Mg (A, C, E) and AZ31 (B, D, F) with different surface roughness (A–B: RS; C–D: SR; E–F: SS). RS: rough surface; SR: semi-rough surface; SS: smooth surface.
Figure 7.
Collagen adsorption quantification.
Standard curve for quantification of collagen by Picro-sirius red stain kit (A). The amount of collagen absorbed on Mg with different surface roughness at 0.5, 1, 2, 4, and 8 h (B). The amount of collagen absorbed on AZ31 with different surface roughness at 0.5, 1, 2, 4, and 8 h (C).
Figure 8.
Representative SEM images of MC 3T3 cell attachment on collagen self-assembled at Mg (A, C, E) and AZ31 (B, D, F) with different surface roughness (A–B: RS; C–D: SR; E–F: SS).
Figure 9.
Representative fluorescent images of MC 3T3 cells growing on collagen self-assembled at AZ31 with different surface roughness for 1, 4 and 7 d. Live cells are in green color and dead cells are in red color.
Figure 10.
Representative fluorescent image of MC 3T3 cells growing on collagen self-assembled at Mg with different surface roughness for 1, 4 and 7 d. Live cells are in green color and dead cells are in red color.
Figure 11.
Mg2+ concentration after the materials (A-AZ31; B-Mg) were incubated with collagen solution for 2 h and cocultured with cells for 1, 4 and 7 days.
Error bars were omitted for clarity purpose.
Table 1.
The pH of the cell culture media after incubated with cells on materials.