Page 267 - IJB-9-3

International Journal of Bioprinting Performance of Bredigite-based bone scaffolds

Figure 2. Bredigite bone tissue-engineered scaffold.

selected for each sample. Open-rod models with different were 1, 2, 4, and 8 days for measuring the pH value of the
porosities and TPMS model supports were subjected to sample degradation solution. Each sample was placed in
pressure experiments using an electronic universal testing 10 mL of the SBF (prepared according to the composition
machine, as shown in Figure 4. As shown in Figure 4a, of human plasma ), and the samples to be tested were
[45]
the bone scaffold sample is placed on the test bench of completely immersed in the SBF. Each sample group was
the electronic universal testing machine, and the loading numbered and placed in a 37.5°C (constant temperature)
speed is set to 1 mm/min. The maximum pressure of water bath after sealing.
the indenter is 2000 N, and a preload of 0.1 N is set for
the pressure experiment until the bone scaffold sample 2.3.2. Weight loss rate and ion release of the scaffold
is destroyed to complete the experiment, as shown in during degradation
Figure 4 (b). The pressure and displacement data during The bracket of Group 1 was washed with ultra-clean water
the entire compression process were recorded to plot the and baked in an oven at 60°C for 24 h. After being dried,
pressure–displacement curve, which was converted into the bracket was removed and weighed (G1). The mass loss
a stress–strain curve by using Equation I to analyze the rate of bredigite bone scaffolds was calculated by using
compressive strength of the bracket. Equation II.
F ∆ L GG−
σ = , ε = (I) Weight loss ratio = 1 ×100% (II)
A L G
Where F is pressure, A is compression area, ΔL is length of Where G is undried weight of the bracket and G is the
strain, and L is original length. dried weight of the bracket. 1

2.3 Degradation performance of bredigite bone The immersion solution was diluted 10 times, and
tissue-engineered scaffolds the concentrations of Ga and Mg ions in the diluted
2+
2+
2.3.1. Experimental protocol for degradation of bone immersion solution were determined by performing
tissue-engineered scaffolds inductively coupled plasma atomic emission spectroscopy
The prepared bone scaffolds were divided into four groups, to study the ion release of different scaffolds during
namely Groups 1, 2, 3, and 4. Each group comprised the degradation process. Ga and Mg standard
2+
2+
18 samples of three different porosities, two different samples were configured at the beginning of the test.
structure types, and three parallel samples. The grouping The standard solution was 1 mg/mL, that is, 1000 mg/L.
and degradation times are presented in Table 3. The The standard sample was diluted 100 times to produce the
degradation times of the groups are 2, 4, 6, and 8 weeks. The standard solution with a concentration of 10 mg/L, that is,
quality, ion release, surface morphology, mineralization, 1 mL SBF was added to a 100-mL volumetric bottle. The
and mechanical properties of the samples after degradation remaining ions were diluted 200 times to 5 mg/L, that is,
were evaluated. The degradation times of the four groups 0.5 mL SBF was added to a 100-mL volumetric flask.

Volume 9 Issue 3 (2023) 259 https://doi.org/10.18063/ijb.708