PSI - Issue 52

Dita Puspitasari et al. / Procedia Structural Integrity 52 (2024) 410–417 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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This low porosity may be affected by the freeze-drying method (Negut et al. (2010)) as the pressure compresses the scaffold and results in a shrinking size of the pores. However, these porosity results were obtained only from a single 2D image of each sample. Therefore, micro-CT was performed as well to obtain the total porosity of each scaffold. High porosity promotes water and nutrition diffusion but degrades mechanical properties. Even if the scaffold has a constant porosity, a decrease in mean pore size will cause tighter pores which can limit cell migration (Cengiz et al. (2018). The mean size of the opening between two neighboring pores, which aids in the passage of soluble substances, oxygen, nutrients, cell migration, and tissue invasion within the scaffold, can be used to describe the interconnectivity of pores. However, as the number of interconnected pores increased, the modulus elasticity of the scaffold decreased (Somo et al. (2015)).

Table 1. SEM test result

Pore Size (μm)

Interconnected Pore (μm)

Sample

Porosity [%]

Range

Average Range

Average

Cross Section 44.63

54-299 129 28-153 97 51-281 152

12-79

31

10% 50S50P-05

Surface

39.14

-

Cross Section 44.56

13-77

31

10% 75S25P-05

Surface

44.56

22-74

50

-

Fig. 1. Surface and cross section image of SEM test result

3.2.

Micro-CT Reconstruction

Fig. 2. 3D image of a) 10% 50S50P-05 and b) 10% 75S25P-05 hydrogels.

The micro-CT tests resulting 436 slice images. These images were then stacked and reconstructed into a 3D model as shown in Fig. 3 by using Bruker Dataviewer software. The software calculated the total porosity and the interconnected pore of the hydrogel as shown in Table 2. Sample with concentration of 10% 75S25P-05 showed higher interconnected pores than 10% 50S50P-05, with total porosity reached 91.75%. Wherein the ideal porosity of scaffold