Page 55 - IJB-9-2

International Journal of Bioprinting Biocompatible materials and Multi Jet Fusion

Figure 7. In vivo study. (a) Appearance of PCL grafts at 9 months and 12 months after implantation (red arrows: crack). (b) Biodegradability. (c) Tensile
strength of PCL grafts before and 12 months after implantation.

fractured samples at 9 months, and this phenomenon was 4. Conclusion
found in one sample at 12 months. In order to investigate the A screw-type 3D bioprinter was developed, and a PCL
strength according to the biodegradation of the sample, the graft with improved uniformity and stability in the body
tensile strength of the 12-month samples were measured. was fabricated using the bioprinter. As a graft with high
As a result, the tensile strength of the PCL grafts fabricated porosity and excellent physical and mechanical properties,
by screw-type bioprinter was 3.07 ± 0.47 MPa, which was it is expected to be widely used in the field of regenerative
about 4.45 times higher than that of the PCL graft prepared medicine, and, specifically, be applied in the skull, orbit,
by the pneumatic pressure-type bioprinter, which was 0.69 and septum. In addition, productivity was improved
± 0.24 MPa. In addition, it was shown to maintain the through an increase in the quality of product. We consider
strength of about 49.63% compared to the sample before that this can be applied to mass production systems and
implantation.
widely used in biomedical industry.
PCL is biodegraded by hydrolysis in the body and
then absorbed by the body . In general, as the molecular Acknowledgments
[1]
weight of polymers decreases, the mechanical strength also None.
decreases . In this study, the tensile strength decreased
[19]
as degradation progressed in both groups. However, Funding
compared to the sample prepared by the pneumatic
pressure-type bioprinter, the PCL graft fabricated by the This work was supported by the Technology Innovation
screw-type bioprinter had a tensile strength value about Program (Project No. 20008686) funded by the Ministry
4.45 times higher despite having a similar molecular of Trade, Industry & Energy (MOTIE, Republic of
weight. When we compared the tensile strength of single Korea) and the Basic Science Research Program (NRF-
fibers printed by the two types of bioprinter, the strength 2018R1D1A1B07040482) through the National Research
of the single layer printed with the screw-type bioprinter Foundation of Korea (NFR), funded by the Ministry of
was about 34.76% higher, and the adhesive force between Education, Science and Technology.
the layers was also about 2.72 times higher. It is considered
that the stability of the final product in the body was higher Conflict of interest
due to this structural stability. The authors declare no conflicts of interest.

Volume 9 Issue 2 (2023) 47 https://doi.org/10.18063/ijb.v9i2.652