title: Fibronectin-tethered graphene oxide as an artificial matrix for osteogenesis.
abstract: An artificial matrix (Fn-Tigra), consisting of graphene oxide (GO) and fibronectin (Fn), is developed on pure titanium (Ti) substrates via an electrodropping technique assisted with a custom-made coaxial needle. The morphology and topography of the resulting artificial matrix is orderly aligned and composed of porous microcavities. In addition, Fn is homogenously distributed and firmly bound onto GO as determined via immunofluorescence and elemental mapping, respectively. The artificial matrix is moderately hydrophobic (63.7°), and exhibits an average roughness of 546 nm and a Young's modulus (E) of approximately 4.8 GPa. The biocompatibility, cellular behavior, and osteogenic potential of preosteoblasts on Fn-Tigra are compared to those of cells cultured on Ti and Ti-GO (Tigra). Cell proliferation and viability are significantly higher on Fn-Tigra and Tigra than that of cells grown on Ti. Focal adhesion molecule (vinculin) expression is highly activated at the central and peripheral area of preosteoblasts when cultured on Fn-Tigra. Furthermore, we demonstrate enhanced in vitro osteogenic differentiation of preosteoblasts cultured on Fn-Tigra over those cultured on bare Ti, as determined via Alizarin red and von Kossa staining, and the analysis of osteocalcin, type I collagen, alkaline phosphatase activity, and calcium contents. Finally, we investigate the biophysical and biomechanical properties of the cells using AFM. While the height and roughness of preosteoblasts increased with time, cell surface area decreased during in vitro osteogenesis over 2 weeks. In addition, the E of cells cultured on Tigra and Fn-Tigra increase in a statistically significant and time-dependent manner by 30%, while those cultured on bare Ti retain a relatively consistent E. In summary, we engineer a biocompatible artificial matrix (Fn-Tigra) capable of osteogenic induction and consequently demonstrate its potential in bone tissue engineering applications.
authors.affiliation: Department of Biomedical Engineering, Korea University of Science and Technology (KUST), Daejon, 305-333, Korea. Center for Biomaterials, Korea Institute of Science and Technology (KIST), Seoul, 136-791, Korea.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Subbiah
authors.forename: Ping
authors.initials: P
authors.lastname: Du
authors.forename: Se Young
authors.initials: SY
authors.lastname: Van
authors.forename: Muhammad
authors.initials: M
authors.lastname: Suhaeri
authors.forename: Mintai P
authors.initials: MP
authors.lastname: Hwang
authors.forename: Kangwon
authors.initials: K
authors.lastname: Lee
authors.forename: Kwideok
authors.initials: K
authors.lastname: Park
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D055119:Elastic Modulus; D004563:Electrochemistry / Q000379:methods; D005353:Fibronectins / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D010087:Oxides / Q000737:chemistry*; D016062:Porosity; D011312:Pressure; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*; D014025:Titanium / Q000737:chemistry*; D016596:Vinculin / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D024042:Collagen Type I; D005353:Fibronectins; D010087:Oxides; D015675:Osteocalcin; D016596:Vinculin; D006108:Graphite; D014025:Titanium; D000469:Alkaline Phosphatase; D002118:Calcium