Enhanced Osteogenic and Neurogenic Differentiation of Dental Pulp Stem Cells by Micro-Current Stimulation and Chitosan-Poly(Ethylene Glycol) Blended Calcium Phosphate Cement

Abstract

Bioelectricity plays multiple roles in the human body, including cellular signaling and molecular-level expression. It can be hypothesized that applying microcurrent to the human body can induce physiological change, optimally producing desired therapeutic effects. In this research, we developed an indium tin oxide (ITO) conductive glass-based microcurrent stimulation (MCS) device incorporating chitosan-poly(ethylene glycol) blended calcium phosphate cement (CS/PEG-CPC) to ultimately regenerate dental pulp by simultaneously differentiating dental pulp stem cells (DPSCs) into osteogenic and neurogenic tissues. To optimize accurate MCS parameter for desired DPSC differentiation, various parameters including pulse type, treatment duration, frequency, intensity, pulse duration were determined through comprehensive studies. The results showed that biphasic pulse stimulation with a current of 100 mu A, electric charge of 100 mC, and pulse duration of 200 mu s significantly enhanced cell viability. Osteogenic differentiation, including calcium deposition and marker expression (TGF-beta 1, calmodulin, Runx2, OPN, DSPP), was enhanced at 100 mu A, 180mC, and pulse duration of 800 mu s. While neurogenic differentiation, including neurite elongation and marker expression (Tuj1, MAP2, NeuN, GFAP), was enhanced at a pulse duration of 100 mu s, there was no significant difference with 800 mu s. Furthermore, pulse duration of 800 mu s induced higher ATP concentration in neurogenic differentiation, suggesting enhanced cellular activities including differentiation. Therefore, a pulse duration of 800 mu s was considered a suitable parameter for simultaneous regeneration promoting both osteogenic and neurogenic differentiation. Therefore, MCS with CS/PEG shows promise for inducing dental pulp regeneration, potentially leading to complete tooth regeneration and future clinical applications.