Capacitive Coupling Electrical Stimulation Of The Proliferation Of Human Dental Pulp Cells

Objective: Isolate and cultivate human pulp cells to study their biological Characterization. This study assess Capacitively coupled electric fields as a new type of electrical stimulation to induce the proliferation of the human dental pulp cell. In addition,The study is to explore the application of the capacitively coupled electric fields in dental tissue engineering.Methods: Isolate, cultivate and induce human pulp cells to differentiate mineralized tissue under the conditions of inducement.Study cell surface molecule express by flow cytometry. Study the protein and gene expression through immunohistochemical staining and RT-PCR (Reverse transcription-polymerase chain reaction), detect the ability of differentiate through alkaline phosphatase (ALP), alizarin bordeaux and dentin sialoprotein (DSP) staining. Apply serial sub-cultivation to confirm that human pulp cells have the property of self-renewal and high reproductive activity. In the base of study their biological Characterization, The fourth generation human dental pulp cell were induced by different frequency Capacitively coupled electric fields of 5,25,50,75,100KHz, 30V/cm, 30min/d, continue 4 days. The control group cultured with same environment but without Capacitively coupled electric fields. 1. Morphological changes of the human dental pulp cell were observed under phase contrast microscope. 2. The method of MTT was employed to evaluate the level of proliferation. and drawed the growth curves of the cells. 3. The parameter regarding the variation of the cell cycle were detected with the flow cytometry(FCM).Result: Human pulp cells can keep vigorous activity after highly serial sub-cultivation. Immunohistochemical staining and RT-PCR showed that, DSPP and ALP were undetectable in the cells. After cultivated under mineralized inducement condition, ALP, alizarin bordeaux and DSP staining can be detected. Resust of capacitively coupled electric fields show: 1,Cell morphology induced by different frequency Capacitively coupled electric fields had not significant changed. 2,The growth curves of human dental pulp cell induced by Capacitively coupled electric fields displaced compared with the controlled group.The 50 KHz group was the most significant. 3,The human dental pulp cell cycle were changed induced by Capacitively coupled electric fields , percentage of cells at the S phase had concerned with frequency. Conclusion: The human pulp cells aquired in our experiment are easily isolated and cultivated. They are undifferentiated and have some potential properties of stem cells: high reproductive activity and the trend of osteogenesis as well. Taken together, these results indicate that the human pulp cells can act as seed cells for dental tissue engineering. Frequency was one of the most inportant factors on accelerating human dental pulp cell proliferation in vitro. Differnet frequency of Capacitively coupled electric fields could cause the different effets. 50KHz maybe the suitable frequency.