Optimization of electrical stimulation parameters for MG-63 cell proliferation on chitosan/functionalized multiwalled carbon nanotube films

Over the past decade, electrical stimulation and conductive materials have been investigated for their effects on cell behaviors. Although numerous studies have been conducted in these fields, fewer studies have been dedicated to the combination of electrical stimulation and conductive materials. Additionally, precise and optimal protocols for electrical stimulation are yet to be determined. In the current study, the in vitro effects of electrical stimulation on MG-63 cell lines have been studied. The cells were cultured on pseudo conductive chitosan/functionalized multiwalled carbon nanotubes films for better guidance of electrical current to the cells. These composite films with different contents of f-MWCNT (0.0%, 0.05%, 0.1%, 0.2%, and 0.4% w/v) were fabricated and characterized. The stimulations were conducted by means of an electrical stimulation device which was designed and fabricated for the purpose of this investigation. Different electrical signaling regimes which were designed by MiniTab software were then applied to the cells in order to find the optimum regime for augmenting cell proliferation. The results of MTT assays after 3, 7 and 10 days of electrical stimulation were used to determine the optimum regime for cell proliferation. Additionally, alkaline phosphatase assay, alizarin red staining and scanning electron microscopy were conducted and the results were analyzed. Finally, 1 volt, 0.4% f-MWCNT content, 50 Hz frequency and 5% duty cycle were determined as optimum electrical stimulation parameters for MG-63 cell proliferation long term.