TY - JOUR
T1 - Superposition of nanostructures on microrough titanium-aluminum-vanadium alloy surfaces results in an altered integrin expression profile in osteoblasts
AU - Gittens, Rolando A.
AU - Olivares-Navarrete, Rene
AU - Hyzy, Sharon L.
AU - Sandhage, Kenneth H.
AU - Schwartz, Zvi
AU - Boyan, Barbara D.
N1 - Funding Information:
This research was supported by USPHS AR052102 and the ITI Foundation. RAG was partially supported by a fellowship from the Government of Panama (IFARHU-SENACYT). Support for the work of KHS was provided by the U.S. Department of Energy, Office of Basic Energy Sciences (Award No. DE-SC0002245). The Smooth and Rough specimens were provided by Titan Spine LLC. RAG attendance at the 11th ICCBMT Conference 2013 to present these results was covered by Titan Spine LLC. BDB is a consultant for Titan Spine LLC.
PY - 2014
Y1 - 2014
N2 - Recent studies of new surface modifications that superimpose well-defined nanostructures on microrough implants, thereby mimicking the hierarchical complexity of native bone, report synergistically enhanced osteoblast maturation and local factor production at the protein level compared to growth on surfaces that are smooth, nanorough, or microrough. Whether the complex micro/nanorough surfaces enhance the osteogenic response by triggering similar patterns of integrin receptors and their associated signaling pathways as with well-established microrough surfaces, is not well understood. Human osteoblasts (hOBs) were cultured until confluent for gene expression studies on tissue culture polystyrene (TCPS) or on titanium alloy (Ti6Al4V) disks with different surface topographies: smooth, nanorough, microrough, and micro/nanorough surfaces. mRNA expression of osteogenesis-related markers such as osteocalcin (BGLAP) and bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2), BMP4, noggin (NOG) and gremlin 1 (GREM1) were all higher on microrough and micro/nanorough surfaces, with few differences between them, compared to smooth and nanorough groups. Interestingly, expression of integrins α1 and α2, which interact primarily with collagens and laminin and have been commonly associated with osteoblast differentiation on microrough Ti and Ti6Al4V, were expressed at lower levels on micro/nanorough surfaces compared to microrough ones. Conversely, the αv subunit, which binds ligands such as vitronectin, osteopontin, and bone sialoprotein among others, had higher expression on micro/nanorough surfaces concomitantly with regulation of the β3 mRNA levels on nanomodified surfaces. These results suggest that the maturation of osteoblasts on micro/nanorough surfaces may be occurring through different integrin engagement than those established for microrough-only surfaces.
AB - Recent studies of new surface modifications that superimpose well-defined nanostructures on microrough implants, thereby mimicking the hierarchical complexity of native bone, report synergistically enhanced osteoblast maturation and local factor production at the protein level compared to growth on surfaces that are smooth, nanorough, or microrough. Whether the complex micro/nanorough surfaces enhance the osteogenic response by triggering similar patterns of integrin receptors and their associated signaling pathways as with well-established microrough surfaces, is not well understood. Human osteoblasts (hOBs) were cultured until confluent for gene expression studies on tissue culture polystyrene (TCPS) or on titanium alloy (Ti6Al4V) disks with different surface topographies: smooth, nanorough, microrough, and micro/nanorough surfaces. mRNA expression of osteogenesis-related markers such as osteocalcin (BGLAP) and bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2), BMP4, noggin (NOG) and gremlin 1 (GREM1) were all higher on microrough and micro/nanorough surfaces, with few differences between them, compared to smooth and nanorough groups. Interestingly, expression of integrins α1 and α2, which interact primarily with collagens and laminin and have been commonly associated with osteoblast differentiation on microrough Ti and Ti6Al4V, were expressed at lower levels on micro/nanorough surfaces compared to microrough ones. Conversely, the αv subunit, which binds ligands such as vitronectin, osteopontin, and bone sialoprotein among others, had higher expression on micro/nanorough surfaces concomitantly with regulation of the β3 mRNA levels on nanomodified surfaces. These results suggest that the maturation of osteoblasts on micro/nanorough surfaces may be occurring through different integrin engagement than those established for microrough-only surfaces.
KW - Bone
KW - Integrin gene expression
KW - Metallic implants
KW - Nanostructures
KW - Osseointegration
KW - Surface properties
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U2 - 10.3109/03008207.2014.923881
DO - 10.3109/03008207.2014.923881
M3 - Article
C2 - 25158204
AN - SCOPUS:84906672161
VL - 55
SP - 164
EP - 168
JO - Connective Tissue Research
JF - Connective Tissue Research
SN - 0300-8207
IS - SUPPL. 1
ER -