Mechanical and Biocompatibility Properties of Sintered Titanium Powder for Mimetic 3D-Printed Bone Scaffolds

Sanghyeon Choi; Ji-Woong Kim; Seungtaek Lee; Woo Young Yoon; Yuna Han; Ki-Joo Kim; Jong-Won Rhie; Tae-Suk Suh; Kyung-Don Lee

doi:10.1021/acsomega.1c06974

Mechanical and Biocompatibility Properties of Sintered Titanium Powder for Mimetic 3D-Printed Bone Scaffolds

ACS Omega. 2022 Mar 16;7(12):10340-10346. doi: 10.1021/acsomega.1c06974. eCollection 2022 Mar 29.

Authors

Sanghyeon Choi¹, Ji-Woong Kim¹, Seungtaek Lee¹, Woo Young Yoon¹, Yuna Han^{2

3}, Ki-Joo Kim³, Jong-Won Rhie^{2

3}, Tae-Suk Suh⁴, Kyung-Don Lee⁵

Affiliations

¹ Department of Materials Science and Engineering, Korea University, Seoul 136-701, Republic of Korea.
² Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 03083, Republic of Korea.
³ Department of Plastic and Reconstructive Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea.
⁴ Department of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul 03083, Republic of Korea.
⁵ Institute for Advanced Engineering, Yongin-si 17180, Republic of Korea.

Abstract

A composite comprising Ti and NaCl powders was sintered similar to a three-dimensional (3D)-printed patient-customized artificial bone scaffold. Additionally, a proper microstructure of the mimetic scaffold and the optimum processing parameters for its development were analyzed. The mechanical properties of the metal-based porous-structured framework used as an artificial bone scaffold were an optimum replacement for the human bone. Thus, it was confirmed that patient-customized scaffolds could be manufactured via 3D printing. The 3D-printed mimetic specimens were fabricated by a powder-sintering method using Ti for the metal parts, NaCl as the pore former, and polylactic acid as the biodegradable binder. Scanning electron microscopy (SEM) images showed that pores were formed homogeneously, while X-ray computed tomography confirmed that open pores were generated. The porosity and pore size distribution were measured using a mercury porosimeter, while the flexural strength and flexural elastic modulus were calculated using the three-point bending test. Based on these measurements, a pore-former content of 15 vol % optimized the density and flexural strength to 2.52 g cm^-2 and 283 MPa, respectively, similar to those of the actual iliac bone. According to the 3D-printing production method, a selective laser-sintering process was applied for the fabrication of the mimetic specimen, and it was determined that the microstructure and properties similar to those of previous metal specimens could be achieved in the as-prepared specimen. Additionally, a decellularized extracellular matrix (dECM) was used to coat the surfaces and interiors of the specimens for evaluating their biocompatibilities. SEM image analysis indicated that the adipose-derived stem cells grew evenly inside the pores of the coated specimens, as compared with the bulky Ti specimens without the dECM coating. The doubling time at 65% was measured at 72, 75, and 83 h for specimens with pore-former contents of 5, 10, and 15 vol %, respectively. The doubling time without the pore former was 116 h. As compared with the specimens without the pore former (73 h), 15% of the dECM-coated specimens showed a doubling time of 64%, measured at 47 h.