UV curing–assisted 3D plotting of core-shelled feedrod for macroporous hydroxyapatite scaffolds comprised of microporous hollow filaments

• Published in: Journal of the European Ceramic Society 2021-10, Vol.41 (13), p.6729-6737
• Main Authors: Jeon, Jong-Won, Maeng, Woo-Youl, Lee, Hyun, Koh, Young-Hag, Kim, Hyoun-Ee
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Microporous filament; Photopolymerization; Pore-forming agent; Porous ceramic
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2021.07.006

•UV curing-assisted 3D plotting was used to produce macro/microporous hollow scaffolds.•A photocurable feedrod comprised of HA shell and CB core was used to produce hollow filaments.•Micropores in HA filaments were created by the removal of camphene-camphor crystals. The present study demonstrates the manufacturing of macroporous hydroxyapatite (HA) scaffolds, comprised of microporous hollow filaments with high shape retention, by UV curing-assisted 3D plotting using a feedrod comprised of a photocurable HA shell and a carbon black (CB) core. Two types of scaffolds with different filament interspaces (0.5 mm and 1 mm) were produced by depositing core-shelled filaments extruded through a 1.07-mm-diameter nozzle with in situ polymerization process. Both scaffolds exhibited that the hollow HA filaments were produced after the removal of CB core by heat-treatment, while micropores in the HA walls were created as the replica of camphene-camphor crystals. Overall porosity and macroporosity obtained using a camphene-camphor content of 60 vol% increased from 74.3 vol% to 79.3 vol% and from 50.7 vol% and 64.6 vol%, respectively, with an increase in filament interspace sizes from 0.5 mm to 1 mm. Both scaffolds exhibited reasonably high compressive strengths (2.36 ― 3.58 MPa) and modulus (68–86 MPa).