Electrical Stimulation through Conductive Substrate to Enhance Osteo-Differentiation of Human Dental Pulp-Derived Stem Cells

Abstract

Human dental pulp-derived stem cells (hDPSCs) are promising cellular sources for bone healing. The acceleration of their differentiation should be beneficial to their clinical application. Therefore, a conductive polypyrrole (PPy)-made electrical stimulation (ES) device was fabricated to provide direct-current electric field (DCEF) treatment, and its effect on osteo-differentiation of hDPSCs was investigated in this study. To determine the optimal treating time, electrical field of 0.33 V/cm was applied to hDPSCs once for 4 h on different days after the osteo-induction. The alizarin red S staining results suggested that ES accelerated the mineralization rates of hDPSCs. The quantification analysis results revealed a nearly threefold enhancement in calcium deposition by ES at day 0, 2, and 4, whereas the promotion effect in later stages was in vain. To determine the ES-mediated signaling pathway, the expression of genes in the bone morphogenetic protein (BMP) family and related receptors were quantified using qPCR. In the early stages of osteo-differentiation, the mRNA levels of BMP2, BMP3, BMP4, and BMP5 were increased significantly in the ES groups, indicating that these genes were involved in the specific signaling routes induced by ES. We are the first using DCEF to improve the osteo-differentiation of hDPSCs, and our results promise the therapeutic applications of hDPSCs on cell-based bone tissue engineering.

Electrical Stimulation Decreases Dental Pulp Stem Cell Osteo-/Odontogenic Differentiation

“…19,21,22 Recently, Cheng et al demonstrated that electrically conductive films increased osteogenic differentiation of human DPSCs. 23 Despite these recent findings, exactly how EStim influences dental tissuederived stem cells is poorly understood. In this study, we investigated the effects EStim has on osteo-/ odontogenic potential of DPSCs, with an eye toward its potential use in combination with TE approaches for improving outcomes in dental treatments.…”

“…32 Lower electrical resistance on polypyrrole (PPy) films was found to correlate with higher levels of mineralization in DPSCs. 23 Oliveira, et al; BioResearch Open Access 2020, 9.1 http://online.liebertpub.com/doi/10.1089/biores.2020.0002…”

“…21,22 Few studies exist that test the effect of EStim on DPSCs or the concept of combining DPSCs and EStim for TE applications. 23 Combined with TE approaches for alveolar bone regeneration, EStim could potentially shorten waiting periods in guided bone regeneration treatments, implant surgery, and initiation of prosthetic procedures. In this study, we isolated and characterized rat DPSCs and analyzed the influence EStim has on their osteo-/odontogenic differentiation, with an eye toward using EStim to optimize DPSC-based TE dental treatments.…”

Electrical stimulation in bone tissue engineering treatments

“…Previous in vitro experiments that exposed cells and/or scaffolds to EStim, demonstrated its ability to influence cell functions associated with enhanced bone healing [7][8][9][10][11][12][13][14]. These experiments were conducted on a variety of different cell types; bone marrow-derived mesenchymal stem cells (BM-MSC), from human and animal origin [10,11,[15][16][17][18][19][20][21][22][23][24][25]; adipose-derived mesenchymal stem cells (AT-MSC) [11,20,[26][27][28][29][30], mouse osteoblast-like cells [31][32][33] and more recently, human dental pulp stem cells (DPSC) [34]. The above cell types are commonly studied for use in BTE applications.…”

Special Issue on “Biomaterials for Bone Tissue Engineering”

“…Several works have been published in this Special Issue regarding the experimentation of the different techniques in BTE to enhance bone growth and regeneration processes. Cheng et al [6] applied an electrical stimulation on human dental pulp-derived stem cells to promote bone healing. The results presented in this work are promising, and reveal an enhancement in calcium deposition at different days of the tests.…”