title: Novel current-conducting composite substrates for exposing osteoblasts to alternating current stimulation.
abstract: The present study demonstrates that novel nanocomposites consisting of blends of polylactic acid and carbon nanotubes effectively can be used to expose cells to electrical stimulation. When osteoblasts cultured on the surfaces of these nanocomposites were exposed to electric stimulation (10 microA at 10 Hz) for 6 h/day for various periods of time, there was a 46% increase in cell proliferation after 2 days, a 307% increase in the concentration of extracellular calcium after 21 consecutive days, and upregulation of mRNA expression for collagen type-I after both 1 and 21 consecutive days. These results provide evidence that electrical stimulation delivered through novel, current-conducting polymer/nanophase composites promotes osteoblast functions that are responsible for the chemical composition of the organic and inorganic phases of bone. Furthermore, this evidence elucidates aspects of the cellular/molecular-level mechanisms involved in new bone formation under electrical stimulation.
authors.affiliation: Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8(th) Street, Troy, New York 12180-3590, USA.
authors.forename: P R
authors.initials: PR
authors.lastname: Supronowicz
authors.forename: P M
authors.initials: PM
authors.lastname: Ajayan
authors.forename: K R
authors.initials: KR
authors.lastname: Ullmann
authors.forename: B P
authors.initials: BP
authors.lastname: Arulanandam
authors.forename: D W
authors.initials: DW
authors.lastname: Metzger
authors.forename: R
authors.initials: R
authors.lastname: Bizios
mesh_terms: D000818:Animals; D001857:Bone Matrix / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D017554:Carbon Compounds, Inorganic; D002455:Cell Division / Q000187:drug effects; D003188:Composite Resins / Q000737:chemistry* / Q000494:pharmacology; D004553:Electric Conductivity / Q000627:therapeutic use*; D004558:Electric Stimulation / Q000379:methods*; D005109:Extracellular Matrix / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D019344:Lactic Acid; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D010012:Osteogenesis / Q000187:drug effects; D011108:Polymers; D019736:Prostheses and Implants; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D017554:Carbon Compounds, Inorganic; D003188:Composite Resins; D011108:Polymers; C031979:carbon-polylactic acid polymer; D019344:Lactic Acid; D002118:Calcium