Page 125 - IJB-7-1

Custodio, et al.
embedded within the PLA matrix served as nucleation References
sites for the deposition of calcium salts and apatite species
present from the SBF solution. X-ray diffractograms 1. Najmon JC, Raeisi S, Tovar A, 2019, Review of Additive
shown in Figure 9B report of the evolution of peaks after Manufacturing Technologies and Applications in the
the immersion in SBF for 72 h. The characteristic peak Aerospace Industry. Additive Manufacturing for the
at 2θ ~32° confirm the growth of apatite species on the Aerospace Industry. Elsevier Inc., Amsterdam, Netherlands.
3D printed samples during the immersion bioactivity . https://doi.org/10.1016/b978-0-12-814062-8.00002-9
[18]
Other well-defined peaks could be attributed to other salt 2. Wiese M, Thiede S, Herrmann C, 2020, Rapid Manufacturing
species present in the SBF solution being deposited onto
the 3D printed substrates. of Automotive Polymer Series Parts: A Systematic Review
of Processes, Materials and Challenges. Addit Manuf,
4. Conclusion 36:101582.

The HAp used in this study was successfully synthesized https://doi.org/10.1016/j.addma.2020.101582
as confirmed by the FTIR and XRD spectra. Pure PLA 3. Ng WL, Chua CK, Shen YF, 2019, Print Me An Organ! Why
exhibited a broad infrared spectrum indicating the We Are Not There Yet. Prog. Polym. Sci., 97:101145.
amorphous structure of the polymer. The 3D printed https://doi.org/10.1016/j.progpolymsci.2019.101145
PLA/HAp composite samples exhibited XRD diffraction 4. Lee JM, Ng WL, Yeong WY, 2019, Resolution and Shape
peaks characterized by the presence of HAp with the in Bioprinting: Strategizing Towards Complex Tissue and
peak intensity increasing as a function of HAp powder
loading. Moreover, composites’ density decreases as Organ Printing. Appl. Phys. Rev., 6:011307.
the HAp loading was increased. The elastic modulus https://doi.org/10.1063/1.5053909
increased from 2.3 to 3.5 GPa and the tensile strength 5. Lao W, Li M, Wong TN, et al., 2020, Improving Surface
increased from 32.7 to 47.3 MPa with 15% HAp loading. Finish Quality in Extrusion-based 3D Concrete Printing
The preliminary in vitro bioactivity test of the 3D printed Using Machine Learning-based Extrudate Geometry Control.
PLA/HAp composite samples in SBF solutions for 24, 48, Virtual Phys Prototyp, 15:178–93.
and 72 h indicated varying weight gains progressively as
well as the evolution of XRD peaks. These indicate that https://doi.org/10.1080/17452759.2020.1713580
HAp particles embedded within the PLA matrix served 6. Ahmed ZY, Bos FP, van Brunschot MCA, et al., 2020, On-
as nucleation sites for the deposition of calcium salts and demand Additive Manufacturing of Functionally Graded
apatite species present from the SBF solution. Concrete. Virtual Phys Prototyp, 15:194–210.
https://doi.org/10.1080/17452759.2019.1709009
Author contributions 7. Alizadeh-Osgouei M, Li Y, Wen C. 2019, A Comprehensive
B.A.B. led the project and edited the paper. J.R.C., C.L.C., Review of Biodegradable Synthetic Polymer-ceramic
and P.J.M.B. designed the study. P.J.M.B. and S.R.C. Composites and their Manufacture for Biomedical
performed the HAp synthesis and biomineralization, Applications. Bioact Mater, 4:22–36.
respectively. P.J.M.B. and C.L.C. performed the filament
extrusion. C.L.C. performed most experiments, 3D https://doi.org/10.1016/j.bioactmat.2018.11.003
printing, characterizations, data analysis, and wrote the 8. Ng WL, Lee JM, Zhou M, et al., 2020, Vat Polymerization-
paper with help from V.U. L. and J.R.C. based Bioprinting Process, Materials, Applications and
Regulatory Challenges. Biofabrication, 12:022001.
Conflicts of interest https://doi.org/10.1088/1758-5090/ab6034
The authors declare that they have no conflicts of interest. 9. Gayer C, Ritter J, Bullemer M, et al., 2019, Development of
a solvent-free polylactide/calcium carbonate composite for
Acknowledgments
selective laser sintering of bone tissue engineering scaffolds.
We acknowledge the funding of this research project from Mater Sci Eng C, 101:660–73.
the Department of Science and Technology – Grants-In- https://doi.org/10.1016/j.msec.2019.03.101
Aid (Department of Science and Technology [DOST]- 10. Percoco G, Uva AE, Fiorentino M, et al., 2020,
GIA). We are also grateful for the technical support
provided by the Advanced Device and Materials Testing Mechanobiological Approach to Design and Optimize Bone
Laboratory, and the Standards and Testing Division of Tissue Scaffolds 3D Printed with Fused Deposition Modeling:
the Industrial Technology Development Institute of the A Feasibility Study. Materials (Basel), 13: 648.
DOST, Philippines. https://doi.org/10.3390/ma13030648

International Journal of Bioprinting (2021)–Volume 7, Issue 1 121