Page 426 - IJB-9-2

International Journal of Bioprinting Design and 3D printing of TPMS breast scaffolds

without any structural fracture or inclination, overcoming all designed Gyroid scaffolds with channels meets the
the contradiction between the low elastic modulus and the requirements for elastic modulus in the actual use. On
stability of breast scaffolds in the previous study . This is the other hand, it can be seen from the cyclic compression
[32]
consistent with the stress distribution results of the scaffold curve that the rebound performance of the scaffolds after
in the compression simulation. The deformation occurs in compression remains highly consistent. At the beginning
the high stress area, while the high stress areas of Gyroid of every compression, the stress starts to rise when the
are distributed uniformly on the surface inside the scaffold, strain reaches about 20%, meaning that the rebound height
resulting in the uniform deformation of Gyroid scaffold of the scaffold is 80% of the total height of the scaffold. It
during compression process. Interestingly, although there indicates that the scaffold has excellent height retention
are defects described previously in the printed TPMS characteristics, which were rarely reported.
scaffolds, the mechanical properties are roughly coincident
with the results predicted by simulation model, since these 3.4. The fabrication and characterization of TPMS
defects only damaged the mechanical properties of the scaffold loaded with hydrogel
local areas instead of the primary structure of the scaffolds. This study successfully combined the TPMS scaffold
The uniaxial cyclic compression test results (Figure 6C) and PEGDA/GelMA hydrogel to produce a cell-loaded
show that the mechanical properties of the scaffold breast scaffold through hydrogel perfusion. The results
significantly decreased after the first compression, but (Figure 7A) show that the hydrogel can be effectively
the mechanical properties remained stable during the solidified in the TPMS scaffold by the perfusion method,
subsequent multiple compression processes. After several and the hydrogel can be well combined with the TPMS
times of compression, the elastic modulus of scaffolds scaffold. Subsequently, the biocompatibility of the scaffold
(Figure 6B) decreased significantly compared with that was evaluated by live/dead assay, and the growth of hADSCs
of the single compression, and their elastic moduli are in hydrogel only and in the scaffold was compared. The
0.45MPa, 0.35MPa, 0.17MPa, 0.10MPa, 0.066MPa, and fluorescent staining results (Figure 7B) show that hADSCs
0.040MPa, respectively. The elastic moduli of the scaffolds have good biological activity in PEGDA/GelMA hydrogel
in cyclic compression were 14.20%, 18.72%, 9.77%, with a high cell survival rate, and some cells have spread out
12.05%, 20.00%, and 20.00% of the elastic moduli of the and have a long fusiform shape. In the scaffold, hADSCs
single compression. Practically, the breast scaffold will in the hydrogel were uniformly distributed and showed
inevitably be compressed under the external load during high cell activity, indicating the good biocompatibility
breast reconstruction. Therefore, from this perspective, of the TPMS scaffold loaded with hydrogel. To the best

A

B

Figure 7. The fabrication and biocompatibility assessment of triply periodic minimal surface (TPMS) scaffold loaded with hydrogel: (A) TPMS scaffold
incorporated with poly (ethylene glycol) diacrylate/gelatin methacrylate hydrogel; and (B) the live/dead florescent staining of hydrogel loaded with human
adipose-derived stem cells in hydrogel only and in TPMS scaffold loaded with hydrogel.

Volume 9 Issue 2 (2023) 418 https://doi.org/10.18063/ijb.685