Objective: To explore the relationship between bore diameter of porous hydroxyapatite (HA) scaffolds and the adhesion, proliferation and metabolism of osteoblasts by 3D cultivation.
Methods: MC3T3-E1 cell suspension was separately dropped axially through different bore diameter scaffolds (Group A:150 µm, Group B:300 µm) to confirm initial seeding. Then scaffolds were transferred into a perfusion bioreactor of 5% CO2 at 37°C for 5 days with an average flow of 3.4 ml/min. After perfusion cultivation, cell proliferation between different groups of scaffolds was determined by methyl thiazolyl tetrazolium (MTT) assay and cell metabolic activities were determined by glucose consumption. Lastly cell adhesion and proliferation were observed directly by scanning electronic microscope (SEM).
Results: The results of MTT assay showed that the optical density/mass ratios were 1.31 ± 0.26 in group A and 1.51 ± 0.43 in group B. There was no significant difference (t test, P = 0.36). Glucose consumption in group A was significantly lower than that in group B [(162.38 ± 33.09) vs (217.97 ± 27.91) µmol/L, P = 0.01]. The adhesion, proliferation, pseudopodia and extracellular matrix of osteoblasts in internal part of scaffolds after perfusion cultivation were observed by SEM.
Conclusion: With excellent biocompatibility, porous HA scaffolds are available for fabricating tissue engineering bones. There is no effect of bore diameter on the proliferation of osteoblasts. But it affects the metabolic activity of osteoblasts. So bore diameter may be increased within a feasible range on the premise of mechanical properties.