title: Titania-hydroxyapatite nanocomposite coatings support human mesenchymal stem cells osteogenic differentiation.
abstract: In addition to mechanical and chemical stability, the third design goal of the ideal bone-implant coating is the ability to support osteogenic differentiation of mesenchymal stem cells (MSCs). Plasma-sprayed TiO(2)-based bone-implant coatings exhibit excellent long-term mechanical properties, but their applications in bone implants are limited by their bioinertness. We have successfully produced a TiO(2) nanostructured (grain size <50 nm) based coating charged with 10% wt hydroxyapatite (TiO(2)-HA) sprayed by high-velocity oxy-fuel. On Ti64 substrates, the novel TiO(2)-HA coating bond 153× stronger and has a cohesive strength 4× higher than HA coatings. The HA micro- and nano-sized particles covering the TiO(2)-HA coating surface are chemically bound to the TiO(2) coating matrix, producing chemically stable coatings under high mechanical solicitations. In this study, we elucidated the TiO(2)-HA nanocomposite coating surface chemistry, and in vitro osteoinductive potential by culturing human MSCs (hMSCs) in basal and in osteogenic medium (hMSC-ob). We assessed the following hMSCs and hMSC-ob parameters over a 3-week period: (i) proliferation; (ii) cytoskeleton organization and cell-substrate adhesion; (iii) coating-cellular interaction morphology and growth; and (iv) cellular mineralization. The TiO(2) -HA nanocomposite coatings demonstrated 3× higher hydrophilicity than HA coatings, a TiO(2)-nanostructured surface in addition to the chemically bound HA micron- and nano-sized rod to the surface. hMSCs and hMSC-ob demonstrated increased proliferation and osteoblastic differentiation on the nanostructured TiO(2)-HA coatings, suggesting the TiO(2)-HA coatings nanostructure surface properties induce osteogenic differentiation of hMSC and support hMSC-ob osteogenic potential better than our current golden standard HA coating.
authors.affiliation: National Research Council Canada - Industrial Materials Institute, 75 boul de Mortagne, Boucherville, QC J4B 6Y4, Canada. sashka.dimitrievska@yale.edu
authors.forename: Sashka
authors.initials: S
authors.lastname: Dimitrievska
authors.forename: Martin N
authors.initials: MN
authors.lastname: Bureau
authors.forename: John
authors.initials: J
authors.lastname: Antoniou
authors.forename: Fackson
authors.initials: F
authors.lastname: Mwale
authors.forename: Alain
authors.initials: A
authors.lastname: Petit
authors.forename: Rogerio S
authors.initials: RS
authors.lastname: Lima
authors.forename: Basil R
authors.initials: BR
authors.lastname: Marple
mesh_terms: D000368:Aged; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002448:Cell Adhesion; D049109:Cell Proliferation; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D017886:Durapatite / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D008875:Middle Aged; D053761:Nanocomposites / Q000737:chemistry*; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D020099:Coated Materials, Biocompatible; C009495:titanium dioxide; D017886:Durapatite; D014025:Titanium