Page 43 - Development of Functional Scaffolds for Bone Tissue Engineering Using 3D-Bioprinting of Cells and Biomaterials - Yasaman Zamani
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and 72 h NaOH-treated scaffolds, some collagen was observed on the strands and in the voids between strands, but it was not as abundant as in the RGD-immobilized and 24 h NaOH-treated scaffolds (Fig. 6a). In the cross-sectional view of control PCL, a relatively homogeneous red color indirectly indicating cell distribution was observed in the upper quarter of the scaffold. For 72 h NaOH-treated scaffold, less intense and less homogeneous red color was observed in the upper half of the scaffold. For 24 h NaOH-treated and RGD-immobilized scaffolds, relatively homogeneous cell distribution throughout the scaffold was observed (Fig. 6b). Collagen deposition on 24 h NaOH-treated and RGD-immobilized scaffolds was significantly increased compared to unmodified controls (24 h NaOH-treated scaffolds, 1.6-fold; RGD-immobilized scaffolds, 2.1-fold increase; Fig. 6c). Moreover, collagen deposition on the RGD-immobilized scaffolds was significantly higher compared to 24 h NaOH-treated scaffolds (Fig. 6c).
Figure 6. Collagenous matrix deposition by MC3T3-E1 on control PCL, 24 and 72 h NaOH-treated, and RGD- immobilized scaffolds after 14 days of culture. (a) Collagenous matrix deposition visualized by picrosirius red staining. More collagen (red) was observed on 24 h NaOH-treated and RGD-immobilized compared to 72 h NaOH-treated and control PCL scaffolds. (b) Cross sectional view of scaffolds demonstrating cell distribution. For the control PCL, a relatively homogeneous red color indirectly indicating cell distribution was observed in the upper quarter of the scaffold. For 72 h NaOH-treated scaffold, less intense and less homogeneous red color was observed in the upper half of the scaffold. For 24 h NaOH-treated and RGD-immobilized scaffolds, relatively homogeneous cell distribution throughout the scaffold was observed (c) Quantification of the staining. Collagen deposition was significantly higher on RGD- immobilized scaffold compared to all other groups. Collagen deposition was significantly higher on 24 h NaOH-treated compared to 72 h NaOH-treated and control PCL scaffolds. Scale bar, 500 μm. Values are mean ± SD (n=3). *Significantly different from other groups, p<0.05, #significantly different from 72 h NaOH-treated and control PCL, p<0.05.
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