Comprehensive Evaluation of Surface Potential Characteristics on Mesenchymal Stem Cells’ Osteogenic Differentiation

Abstract

The surface electric potential of biomaterials has been extensively proven to play a critical role in stem cells’ fate. However, there are ambiguous reports on the relation of stem cells’ osteogenic capacity to surface potential characteristics (potential polarity and intensity). To address this, we adopted a surface with a wide potential range and both positive/negative polarity in a comprehensive view to get insight into surface potential-regulating cellular osteogenic differentiation. Tb x Dy1–x Fe2 alloy/poly­(vinylidene fluoride-trifluoroethylene) magnetoelectric films were prepared, and the film could provide controllable surface potential characteristics with positive or negative polarity and potential (ϕME) intensity variation from 0 to ±120 mV as well as keep the surface chemical composition and microstructure unchanged. Cell culture results showed that osteogenic differentiation of mesenchymal stem cells on both positive and negative potential films was obviously upregulated when the /ϕME/ intensities were set from 0–55 mV. Differently, the highest upregulated osteogenic differentiation on the positive potential films corresponded to the /ϕME/ intensity from 35–55 mV and was better than that on the negative potential films whereas the highest on the negative potential films corresponded to the /ϕME/ intensity from 0–35 mV and was better than that on the positive potential films. This fact could illustrate why previous reports appeared ambiguously; i.e., the comparative result in osteogenic differentiation between the positive and negative potential films strongly depends on the selection of surface potential intensity. On the basis of assaying of the exposed functional sites (RGD and PHSRN) of the adsorbed fibronectin (FN) and the expression of cellular integrin α5 and β1 subunits, the difference in the behavior between the positive and negative potential films was attributed to the distinct conformation of adsorbed fibronectin (FN) and the opposite changing trend with /ϕME/ for the two films, which triggers the osteogenesis-related FAK/ERK signaling pathway to a different extent. This study could provide new cognition for the in-depth understanding of the regulation mechanism underlying surface potential characteristics in cell behaviors.

Accelerated Osteogenesis of Heterogeneous Electric Potential Gradient on CFO/P(VDF‐TrFE) Membranes

“…At the same time, considering the effect of surface potential on the cell microenvironment, a moderate surface potential intensity can establish the optimal integrin-binding state to produce the strongest osteogenic differentiation behavior. [15] Therefore, we speculated that the membranes with 200 µm positive and negative response repeat length might receive the optimal electrical activity. The piezoelectric coefficients of the membrane change in a chordal function along the repeating direction (Figure 1I), which was consistent with the PFM response.…”

“…differentiation ability of cells, studies have shown that the positive and negative changes of the surface potential can also improve the osteogenic differentiation ability of cells by regulating the conformation of adsorbed proteins, intracellular and extracellular ions and the activation state of integrins. [15,16] In other words, the surface electrical properties of the material would regulate the integrin state of the cell-material interface and cell ion channels, thereby inducing the rearrangement of the cytoskeleton and mediating the osteogenesis-related signal cascade, eventually enhancing bone tissue regeneration. [17] Although P(VDF-TrFE) can indeed promote rapid bone formation in situ, it still needs to be reasonably designed to maximize its electrical activity for future clinical applications.…”

Thermosensitive Polysaccharide Hydrogel As a Versatile Platform for Prolonged Salmon Calcitonin Release and Calcium Regulation

“…Meanwhile, OCA tightly integrates with cells and peptide via Schiff’s base reaction can also enhance osteo-inductive effect of sCT. Another important factor on osteogenic differentiation is the negative charge, rooting in carboxyl groups on the backbone of alginate, which can induce intracellular calcium ions to deposit in the extracellular matrix . These results reveal that sCT-OCA-HPCH, with optimal osteogenic induction, can enhance ALP activity, promote osteoblasts to absorb calcium from surrounding microenvironment, and assist calcium deposition outside of the osteoblasts.…”

Enhanced osteogenic differentiation of mesenchymal stem cells on P(VDF‐TrFE) layer coated microelectrodes

“…The role of electrical stimulation on cellular growth behavior could be attributed to the change of intracellular Ca 2+ concentration upon the applied surface electric field to activate calcium‐mediated PKC upstream signaling pathway, finally regulate the osteogenic differentiation 23,27‐29 . And the regulating mechanism on polarized P(VDF‐TrFE) is illustrated as: the surface charges modulates the adsorption conformation of fibronectin, changes the binding of integrin receptors, affects both of the formation of focal adhesion complexes and the activation of the FAK/ERK upstream signaling pathway 22,30,31 …”