Mechanical and biological evaluation of lattice structured hydroxyapatite scaffolds produced via stereolithography additive manufacturing

• Published in: Materials & design Vol. 214; p. 110372
• Main Authors: Kang, Jin-Ho, Sakthiabirami, Kumaresan, Jang, Kyoung-Jun, Jang, Jae-Gon, Oh, Gye-Jeong, Park, Chan, Fisher, John G., Park, Sang-Won
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2022; Elsevier
• Subjects: Additive manufacturing; Hydroxyapatite; Octahedral structure; Photopolymerization suspension; Stereolithography apparatus; Hydroxyapatite; Additive manufacturing; Photopolymerization suspension; Octahedral structure; Stereolithography apparatus
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2021.110372

Engineering of HA scaffolds with an octahedral structure with improved mechanical properties as a potential alternative for critical-sized bone defects. [Display omitted] •3D hydroxyapatite scaffold with an octahedral structure was fabricated using stereolithography apparatus.•The constructed samples with HA suspension (35 vol%) exhibits the highest strength and density than other volume fractions.•The octahedral scaffold structure results in improved compressive strength compared to the other basic structures. A photocurable hydroxyapatite (HA) suspensions were prepared and optimized to construct three-dimensional (3D) scaffolds with lattice structures for application in bone tissue engineering. The HA suspensions were categorized into five groups based on the HA contents (designated as HA 30, 32.5, 35, 37.5, and 40 (vol%)). This study demonstrated the applicability of the optimized HA suspension for manufacturing scaffolds using a commercially available stereolithography apparatus (SLA). Disk samples prepared with the HA 35 suspension exhibited the highest bending strength and relative density. Cell attachment experiments revealed that the sintered HA disks did not exhibit cytotoxicity. Furthermore, various types of scaffolds (octahedral, circular, and frame) were designed and constructed using the optimal HA suspension. The designed octahedral scaffold exhibited the highest compressive strength, achieved a break strength improvement of 245% compared with the circular scaffolds, and showed significant differences from the other scaffold types in bone cell proliferation and differentiation experiments. The ceramic suspension formulation proposed herein can be commonly applied for all commercialized 3D SLAs. Furthermore, the use of the octahedral scaffold effectively overcomes the strength issues associated with the ceramic product. This study would aid future research on scaffolds containing various biomaterials and designs prepared using additive manufacturing technology.