title: Toxicity induced enhanced extracellular matrix production in osteoblastic cells cultured on single-walled carbon nanotube networks.
abstract: A central effort in biomedical research concerns the development of materials for sustaining and controlling cell growth. Carbon nanotube based substrates have been shown to support the growth of different kinds of cells (Hu et al 2004 Nano Lett. 4 507-11; Kalbacova et al 2006 Phys. Status Solidi b 13 243; Zanello et al 2006 Nano Lett. 6 562-7); however the underlying molecular mechanisms remain poorly defined. To address the fundamental question of mechanisms by which nanotubes promote bone mitosis and histogenesis, primary calvariae osteoblastic cells were grown on single-walled carbon nanotube thin film (SWNT) substrates. Using a combination of biochemical and optical techniques we demonstrate here that SWNT networks promote cell development through two distinct steps. Initially, SWNTs are absorbed in a process that resembles endocytosis, inducing acute toxicity. Nanotube-mediated cell destruction, however, induces a release of endogenous factors that act to boost the activity of the surviving cells by stimulating the synthesis of extracellular matrix.
authors.affiliation: Materials Science and Engineering, School of Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
authors.forename: Wojtek
authors.initials: W
authors.lastname: Tutak
authors.forename: Ki Ho
authors.initials: KH
authors.lastname: Park
authors.forename: Anatoly
authors.initials: A
authors.lastname: Vasilov
authors.forename: Valentin
authors.initials: V
authors.lastname: Starovoytov
authors.forename: Giovanni
authors.initials: G
authors.lastname: Fanchini
authors.forename: Shi-Qing
authors.initials: SQ
authors.lastname: Cai
authors.forename: Nicola C
authors.initials: NC
authors.lastname: Partridge
authors.forename: Federico
authors.initials: F
authors.lastname: Sesti
authors.forename: Manish
authors.initials: M
authors.lastname: Chhowalla
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D018929:Cell Culture Techniques; D016923:Cell Death; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D002479:Inclusion Bodies / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D008855:Microscopy, Electron, Scanning; D037742:Nanotubes, Carbon / Q000633:toxicity / Q000648:ultrastructure; D010006:Osteoblasts / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats
chemical_list: D016326:Extracellular Matrix Proteins; D037742:Nanotubes, Carbon; D000469:Alkaline Phosphatase