Effect of electrical stimulation and scaffold architecture on osteogenesis of osteogenic cells

Abstract

Bone tissue engineering has been a growing area of research due to an increase in bone diseases and fractures. Bone piezoelectricity, discovered by Fukuda and Yasuda, has led to the increasing interest in electrical stimulation for bone regeneration. Pulsed electromagnetic fields (PEMF) and piezoelectric material PVDF, were reported to positively impact on various stages of osteogenesis. Our previous study has shown the enhancement for bone regeneration using these two stimulations synergistically on 2 dimensional polycaprolactone-tricalciumphosphate (PCL-TCP) films. In this paper, the effects of PVDF coating under PEMF treatment of 0.6 mT, at 50 Hz frequency in 3D-printed PCL-TCP scaffolds, on the proliferation and mineralization of osteoblast precursor cells MC3T3-E1 were investiaged. Cell metabolic activity was assessed by alamarBlue time-course measurements and results indicated an increased in metabolic activity with electroactive material under PEMF exposure. Cell mineralization assessed by calcium deposition analysis at day 28, showed an increased in calcium with electroactive material with PEMF exposure. Alizarin Red staining was used to visualize the calcium deposition in the different groups and showed the highest calcium density for those groups with electroactive material. Quantitative polymerase chain reaction (qPCR) was done to monitor upregulation of genes corelated with osteoblastic differentiation and maturation. In summary, the results suggested that PEMF stimulation with electroactive material in 3D architecture could improve osteogenesis in vitro. Thus, this paper highlights the importance of selecting an electroactive scaffold material that would enhance the effect of PEMF on osteoblastic cells in a 3D environment.