title: Growth and follow-up of primary cortical neuron cells on nonfunctionalized graphene nanosheet film.
abstract: BACKGROUND
  Conductive biomaterials are an ideal biosubstrate for modifying cellular behaviors by conducting either internal or external electrical signals. In this study, based on a simple-preparation graphite exfoliation method in organic reagent, a nonfunctionalized graphene nanosheet film (NGNF) with high conductivity and large size was simply fabricated through spraying coating. The biocompatibility of the NGNF was carefully tested with primary cortical neuron cells, and its biocompatibility properties were compared with a chemical vapor deposition (CVD) graphene film.
  
  
  METHODS
  Nonfunctionalized graphene nanosheet (NGN) was first exfoliated from graphite with a flat-tip ultrasonicator probe, and then spray-coated onto glass slide substrate to form the film. The morphology of NGNF was observed with light microscopy and SEM. The morphology and neuronal network formation of primary cortical neuron cells onto NGNF, as shown by DAPI and Alexa Fluor® 488 staining, were observed with fluorescent microscopy. Cell viability and proliferation were measured with MTT.
  
  
  RESULTS
  NGNF had better cell biocompatibility than CVD graphene film. MTT test showed that NGNF exhibited no cytotoxicity. According to neuronal network formation at 7 days of cell culture, primary neuron cells aggregated into 50-μm "nuclei"; the average neurite number and length were 3 and 100 μm, respectively. However, these values were almost doubled after 14 days of cell culture.
  
  
  CONCLUSIONS
  These results may improve the use of NGNF as a conductive scaffold for nerve regeneration.
authors.affiliation: Chongqing Key Lab of Catalysis and Functional Organic Molecules, College of Environment and Resources, Chongqing Technology and Business University, Chongqing - PR China.
authors.forename: Shiyun
authors.initials: S
authors.lastname: Meng
authors.affiliation: Key Lab of Catalysis Science and Technology of Chongqing Education Commission, College of Environment and Resources, Chongqing Technology and Business University, Chongqing - PR China.
authors.forename: Rong
authors.initials: R
authors.lastname: Peng
mesh_terms: D000818:Animals; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D008567:Membranes, Artificial; D016501:Neurites / Q000378:metabolism*; D061251:Primary Cell Culture / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D006108:Graphite