Fig. 5.

Piezoelectric stimulation influences p-MLC expression and intercellular Ca²⁺ level in L-PDLSCs. (A) TEM images for intracellular localization of NPs. CP: Cytoplasm, Red arrow indicated NPs. (B, C) Representative p-MLC fluorescence image of L-PDLSCs exposed to the different groups at 3 days. (D) Intracellular Ca²⁺ level of L-PDLSCs after various treatments. (E) Mechanism schematic for the piezoelectric stimulation-mediated osteogenic differentiation of L-PDLSCs: i) piezoelectricity boosts Δψ_m, ii) promotes intracellular ATP synthesis; iii) piezoelectricity and elevated ATP cause a rise in [Ca²⁺]_i; iv) ATP hydrolysis and Ca²⁺ drive MLC phosphorylation mediating cell contraction and reorganization, and v) further osteogenic differentiation.