title: Electrical stimulation to promote osteogenesis using conductive polypyrrole films.
abstract: In this study, we developed an electrical cell culture and monitoring device. Polypyrrole (PPy) films with different resistances were fabricated as conductive surfaces to investigate the effect of substrate-mediated electrical stimulation. The physical and chemical properties of the devices, as well as their biocompatibilities, were thoroughly evaluated. These PPy films had a dark but transparent appearance, on which the surface cells could be easily observed. After treating with the osteogenic medium, rat bone marrow stromal cells cultured on the PPy films differentiated into osteoblasts. The cells grown on the PPy films had up-regulated osteogenic markers, and an alkaline phosphatase activity assay showed that the PPy films accelerated cell differentiation. Alizarin red staining and calcium analysis suggested that the PPy films promoted osteogenesis. Finally, PPy films were subjected to a constant electric field to elucidate the effect of electrical stimulation on osteogenesis. Compared with the untreated group, electrical stimulation improved calcium deposition in the extracellular matrix. Furthermore, PPy films with lower resistances allowed larger currents to stimulate the surface cells, which resulted in higher levels of mineralization. Overall, these results indicated that this system exhibited superior electroactivity with controllable electrical resistance and that it can be coated directly to produce medical devices with a transparent appearance, which should be beneficial for research on electrical stimulation for tissue regeneration.
authors.affiliation: Department of Chemical and Materials Engineering, National Central University, Jhongli City, Taiwan. Electronic address: huweiwen@cc.ncu.edu.tw.
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Hu
authors.affiliation: Department of Chemical and Materials Engineering, National Central University, Jhongli City, Taiwan.
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Hsu
authors.affiliation: Institute of Biomedical Engineering, National Central University, Jhongli, Taiwan; Department of Medical Research, Cathay General Hospital, Taipei, Taiwan.
authors.forename: Yu-Che
authors.initials: YC
authors.lastname: Cheng
authors.affiliation: Department of Mechanical Engineering, National Central University, Jhongli, Taiwan.
authors.forename: Chuan
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Chemical and Materials Engineering, National Central University, Jhongli City, Taiwan; Institute of Biomedical Engineering, National Central University, Jhongli, Taiwan.
authors.forename: Ruoh-Chyu
authors.initials: RC
authors.lastname: Ruaan
authors.affiliation: Department of Medical Research, Cathay General Hospital, Taipei, Taiwan; School of Medicine, Fu Jen Catholic University, Taipei, Taiwan; Department of Anesthesiology, Sijhih Cathay General Hospital, Sijhih City, Taipei, Taiwan.
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Chien
authors.affiliation: Department of Mechanical Engineering, National Central University, Jhongli, Taiwan.
authors.forename: Chih-Ang
authors.initials: CA
authors.lastname: Chung
authors.affiliation: Department of Mechanical Engineering, National Central University, Jhongli, Taiwan.
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Tsao
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001854:Bone Marrow Cells / Q000166:cytology; D002454:Cell Differentiation; D002478:Cells, Cultured; D004558:Electric Stimulation; D059630:Mesenchymal Stem Cells / Q000166:cytology; D010012:Osteogenesis / Q000502:physiology*; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D051381:Rats
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole
keywords: Bone marrow stromal cells; Direct current field; Electrical stimulation; Mineralization; Osteogenesis; Polypyrrole