Sequential application of mineralized electroconductive scaffold and electrical stimulation for efficient osteogenesis.

Osteogenic differentiation is enhanced by many inductive factors including biochemical agents, biomechanical stresses, and electrical stimulation. Regularly studies have focused on one factor at a time, while synergies can promote more effective and functional osteogenesis. Herein, for the first time, functional synergism between application of electrical stimulation and HA nanoparticles was evaluated in osteogenic differentiation. Prepared electrospun biocompatible conductive scaffold by amalgamating chitosan, aniline-pentamer, and hydroxyapatite incorporation was seeded by human bone-marrow-derived mesenchymal stem cells. The cells seeded on the scaffolds with and without hydroxyapatite were exposed to electrical stimulation and subsequently, osteogenic molecular markers and related signaling pathways were investigated. In general, all investigated osteogenic markers (osteocalcin, alkaline phosphatase, osteonectin, and Runx2) were upregulated transcriptionally in the cells seeded on the chitosan-embedded scaffolds. Separate utilization of electrical stimulation or hydroxyapatite-enhanced osteogenesis, while the cells exposed to both stimulators simultaneously, expressed higher levels of some of osteogenic genes significantly. Considering the functions and the positions of the markers in osteogenic signaling pathways, it can be concluded that HA might cooperate in the allocation of stem cells to osteoprogenitors in the early phase of osteogenesis while electrical stimulation helps committed cells with maturation and acquiring functional phenotypes. Altogether investigation of the synergism between different stimulators and exploiting the interactions in an optimized manner could lead to more efficient osteogenesis protocol for effective bone regeneration and tissue engineering.