Page 159 - IJB-9-5

International Journal of Bioprinting Guide about the effects of sterilization on 3D-printed materials for medicine

Figure 2. Prealignment between a MED610 control tensile (gray) and a MED610 tensile that was sterilized with AU134 method (blue).

(2) Transform the point cloud data into the desired
reference frame (e.g., World Coordinate System
[WCS]) by applying a transformation matrix.
(3) Compute the distances between the points along the
x, y, and z axes.
(4) Determine the average distance between the points.
(5) Each point in the cloud had an RGB color value
assigned.

The obtained file in .txt format of each analysis was then
analyzed to obtain the average distance (see Figure S36).

3. Results

3.1. Mechanical testing of the 3D-printed materials Figure 3. PLA sterilization comparison. Data are represented as mean
3.1.1. Polylactic acid values. N = 3 PLA Control/group; N = 3 PLA HPO/group.
Figure 3 shows the mechanics testing performed on
the 3D-printed PLA samples, with the group of samples planning. Table 4 shows different mechanical properties of
sterilized by HPO and the control samples (not sterilized) ABS with different methods.
being compared. Overall, it seems that the HPO
sterilization does not significantly change the behavior of 3.1.3. MED610
the mechanical properties of PLA. Table 3 shows different Figure 5 shows the mechanics of the control samples and
mechanical properties about PLA with different methods. 3D-printed MED610 samples sterilized by HPO, AU121,
Other sterilization methods were not tested with PLA as and AU134. Among the three different sterilization
its Tg is lower (Table 2) than the temperature reached in techniques, autoclave has a bigger influence on the
AU121 and AU134 sterilization methods. mechanical properties in comparison to HPO. A similar
tensile strength was found between control samples and
3.1.2. Acrylonitrile butadiene styrene HPO-sterilized samples (with a difference of 0.64%),
Figure 4 shows the mechanics of the 3D-printed ABS although there was a major difference when compared
samples sterilized by HPO and the control samples. The to both AU121 (17.40%) and AU134 (14.57%), showing
effect of HPO sterilization on the ABS samples was not the AU134 results in higher tensile strength in samples
significantly different when compared to the control compared to the control samples. Table 5 shows different
samples. The results showed differences below 10% in mechanical properties of MED610 with different methods.
elongation at break (8%) and tensile strength (2.4%) It can be noticed that one specimen of AU134 has a
between HPO samples and control samples. This means significant difference with respect to others specimens,
that the use of this method is effective for its use in surgical which can be attributed to a printing defect.

Table 3. Mechanical properties of the 3D-printed PLA
Parameters Mechanical properties
Tensile strength (MPa) Young’s modulus (MPa) Elongation at yield (%) Elongation at break (%)
Control 21.85 ± 0.37 1568 ± 45 0.44 ± 0.74 4.18 ± 1.96
HPO 21.63 ± 1.2204 1408 ± 40 1.37 ± 0.10 4.11 ± 0.58
Data are represented as mean ± SD. N = 3 PLA Control/group; N = 3 PLA HPO/group.

Volume 9 Issue 5 (2023) 151 https://doi.org/10.18063/ijb.756