Three-Dimensionally Printed Polycaprolactone and β-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering: An In Vitro Study

PurposeThe purpose of this study was to evaluate porcine bone marrow–derived progenitor cell (pBMPC) proliferation and penetration into a novel 3-dimensionally printed scaffold.Materials and MethodsFour different tissue engineering scaffolds to evaluate pBMPC proliferation and penetration were examined. Scaffolds were fabricated from polycaprolactone (PCL) or the combination of β-tricalcium phosphate (β-TCP) and PCL (50:50), with 2 separate channel sizes (1 mm [small (S)] vs 2 mm [large (L)]). Scaffolds were fabricated into 20 × 20 × 7–mm blocks by use of a TheriForm machine (Integra Life Sciences, Akron, OH). Four groups of scaffolds were examined for pBMPC proliferation and penetration: group 1, β-TCP/PCL S; group 2, β-TCP/PCL L; group 3, PCL S; and group 4, PCL L. Nonparametric mean (Kruskal-Wallis) and multiple comparisons tests were used to compare the 4 groups.ResultsNo shrinkage or deformation was noted in any of the scaffold groups after 2 weeks of culture. Mean surface cell counts ranged from 13.4 to 87.8 cells/0.57 mm2, with group 1 (β-TCP/PCL S) having statistically significantly higher counts than the other groups (P < .001). Mean interior cell counts ranged from 10.9 to 75.6 cells/0.57 mm2, with group 1 having the greatest interior cell count (P < .001). Total collagen formation ranged from 0.2% to 86%, with group 1 having the highest collagen formation (P < .001).ConclusionsThe 3-dimensionally printed scaffold (β-TCP/PCL) with 1-mm channels showed greater cellular proliferation, penetration, and collagen formation after a 2-week in vitro culture than the other scaffolds evaluated. β-TCP/PCL S scaffolds warrant further evaluation for bone tissue engineering in vivo.