IADR Abstract Archives
Human Osteoblasts Are Sensitive to Porosity of High-Resolution, Additively-Manufactured 3D-Constructs
Objectives: The objective of this study was to analyze effects of porosity on proliferation and maturation of normal human osteoblasts (NHOst) using 3D titanium-aluminum-vanadium (Ti6Al4V) constructs fabricated by additive manufacturing based on a high-resolution human trabecular bone CT.
Methods: 2D (15mmx1mm) and 3D (15mmx5mm) Ti6Al4V constructs were manufactured from CT scans of human femoral trabecular bone using laser sintering in low, medium and high porosities (LP/MP/HP). Surfaces were grit-blasted and acid-etched to achieve micro and nanoscale roughness. Porosity, surface chemistry, topography and compressive modulus were characterized on 3D constructs, and wettability was analyzed on 2D surfaces. MG63 osteoblast-like cells and NHOst cells were seeded at 60,000 cells/construct/well and harvested 24h after confluence on TCPS. DNA, alkaline phosphatase specific activity (ALP), osteocalcin (OCN) and bone morphogenetic proteins 2 and 4 (BMP2/BMP4) were analyzed as markers for osteoblast proliferation, differentiation, maturation, or local factor production. Data were analyzed by ANOVA with Bonferroni post-test (n=6/variable).
Results: 3D constructs contained mostly O, C and Ti on their surfaces. 2D contact angle was 62+19o. Surfaces had microscale roughness with homogeneous nanoscale features. Total porosity ranged from 41.0±0.3 to 76.1±0.8%. For MG63 and NHOst cells, DNA decreased on 2D surfaces compared to TCPS, and decreased on LP and MP constructs compared to 2D. MG63 ALP increased on 2D surfaces compared to TCPS, but decreased on 3D constructs. NHOst cell ALP decreased on all surfaces compared to TCPS. For both MG63 and NHOst cells, OCN was increased on 3D constructs compared to TCPS and 2D; BMP2 and BMP4 increased on LP and MP constructs compared to TCPS, 2D and HP.
Conclusions: Osteoblasts exhibited greater differentiation, maturation and local factor production in a human trabecular bone-like 3D environment compared to 2D, and this depended on porosity.
Methods: 2D (15mmx1mm) and 3D (15mmx5mm) Ti6Al4V constructs were manufactured from CT scans of human femoral trabecular bone using laser sintering in low, medium and high porosities (LP/MP/HP). Surfaces were grit-blasted and acid-etched to achieve micro and nanoscale roughness. Porosity, surface chemistry, topography and compressive modulus were characterized on 3D constructs, and wettability was analyzed on 2D surfaces. MG63 osteoblast-like cells and NHOst cells were seeded at 60,000 cells/construct/well and harvested 24h after confluence on TCPS. DNA, alkaline phosphatase specific activity (ALP), osteocalcin (OCN) and bone morphogenetic proteins 2 and 4 (BMP2/BMP4) were analyzed as markers for osteoblast proliferation, differentiation, maturation, or local factor production. Data were analyzed by ANOVA with Bonferroni post-test (n=6/variable).
Results: 3D constructs contained mostly O, C and Ti on their surfaces. 2D contact angle was 62+19o. Surfaces had microscale roughness with homogeneous nanoscale features. Total porosity ranged from 41.0±0.3 to 76.1±0.8%. For MG63 and NHOst cells, DNA decreased on 2D surfaces compared to TCPS, and decreased on LP and MP constructs compared to 2D. MG63 ALP increased on 2D surfaces compared to TCPS, but decreased on 3D constructs. NHOst cell ALP decreased on all surfaces compared to TCPS. For both MG63 and NHOst cells, OCN was increased on 3D constructs compared to TCPS and 2D; BMP2 and BMP4 increased on LP and MP constructs compared to TCPS, 2D and HP.
Conclusions: Osteoblasts exhibited greater differentiation, maturation and local factor production in a human trabecular bone-like 3D environment compared to 2D, and this depended on porosity.