Non-destructive evaluation of dental stem cell proliferation in 3D hydrogel cultures via electrochemical impedance

Three-dimensional (3D) culture systems are becoming common in tissue regeneration research, for better mimic in vivo conditions. However, non-destructive evaluation of 3D cultures remains challenging. Electrochemical impedance spectroscopy (EIS) could represent an alternative and automated testing for in vitro research. In this study, hydrogels consisting of 1%alginate/2%agarose were combined with gingival (GT-MSCs) and dental pulp (DP-MSCs) stem cells. Cells were cultured in hydrogels, assessed via microscopy, resazurin assay, and Calcein-AM staining, and compared to EIS measurements. EIS was measured (10 6 –10 −2 Hz) to optimize viability sensing. Hydrogels supported viability, with EIS revealing distinct dielectric behaviors: DP-MSCs showed slow impedance rise during the whole testing (1.4 × 10 5 Ω·cm 2 at 10 –2 Hz at 168 h), indicating low cell growth, while GT-MSCs exhibited higher impedance (1.6 × 10 4 Ω·cm 2 at 120 h), reflecting higher viability. EIS proved to be a valuable for culture monitoring, distinguishing cell-type-specific responses and validating hydrogel efficacy in supporting cell growth.