Functional synergism of electrical stimulation and electroactive biopolymer for bone tissue engineering

Introduction Current tissue regenerative strategies rely mainly on tissue repair by transplantation of the synthetic/natural implants. However, limitations of the existing strategies have increased the demand for tissue engineering approaches. Appropriate cell source, effective cell modification, and proper supportive matrices are three bases of tissue engineering. Selection of appropriate methods for cell stimulation, scaffold synthesis, and tissue transplantation play a definitive role in tissue engineering. Although the variety of the players are available, but proper combination and functional synergism determine the practical efficacy. Osteogenic differentiation is enhanced by many inductive factors including biochemical agents, biomechanical stresses and electrical stimulation. Methods Regularly studies have focused on one factor at a time, while synergies can promote more effective and functional osteogenesis. Herein, functional synergism between application of electrical stimulation and chitosan/aniline-pentamer/hydroxyapatite was evaluated in effective osteogenesis of 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. Results and ConclusionSeparate 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

Keywords:

Stiulation , Biopolymer , Controlled system , Bone tissue