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Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein

Orthopedic implant failure due to aseptic loosening and mechanical instability remains a major problem in total joint replacement. Improving osseointegration at the bone-implant interface may reduce micromotion and loosening. Bone sialoprotein (BSP) has been shown to enhance bone formation when coat...

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Autores principales: Baranowski, Andreas, Klein, Anja, Ritz, Ulrike, Ackermann, Angelika, Anthonissen, Joris, Kaufmann, Kerstin B., Brendel, Christian, Götz, Hermann, Rommens, Pol M., Hofmann, Alexander
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4844107/
https://www.ncbi.nlm.nih.gov/pubmed/27111551
http://dx.doi.org/10.1371/journal.pone.0153978
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author Baranowski, Andreas
Klein, Anja
Ritz, Ulrike
Ackermann, Angelika
Anthonissen, Joris
Kaufmann, Kerstin B.
Brendel, Christian
Götz, Hermann
Rommens, Pol M.
Hofmann, Alexander
author_facet Baranowski, Andreas
Klein, Anja
Ritz, Ulrike
Ackermann, Angelika
Anthonissen, Joris
Kaufmann, Kerstin B.
Brendel, Christian
Götz, Hermann
Rommens, Pol M.
Hofmann, Alexander
author_sort Baranowski, Andreas
collection PubMed
description Orthopedic implant failure due to aseptic loosening and mechanical instability remains a major problem in total joint replacement. Improving osseointegration at the bone-implant interface may reduce micromotion and loosening. Bone sialoprotein (BSP) has been shown to enhance bone formation when coated onto titanium femoral implants and in rat calvarial defect models. However, the most appropriate method of BSP coating, the necessary level of BSP coating, and the effect of BSP coating on cell behavior remain largely unknown. In this study, BSP was covalently coupled to titanium surfaces via an aminosilane linker (APTES), and its properties were compared to BSP applied to titanium via physisorption and untreated titanium. Cell functions were examined using primary human osteoblasts (hOBs) and L929 mouse fibroblasts. Gene expression of specific bone turnover markers at the RNA level was detected at different intervals. Cell adhesion to titanium surfaces treated with BSP via physisorption was not significantly different from that of untreated titanium at any time point, whereas BSP application via covalent coupling caused reduced cell adhesion during the first few hours in culture. Cell migration was increased on titanium disks that were treated with higher concentrations of BSP solution, independent of the coating method. During the early phases of hOB proliferation, a suppressive effect of BSP was observed independent of its concentration, particularly when BSP was applied to the titanium surface via physisorption. Although alkaline phosphatase activity was reduced in the BSP-coated titanium groups after 4 days in culture, increased calcium deposition was observed after 21 days. In particular, the gene expression level of RUNX2 was upregulated by BSP. The increase in calcium deposition and the stimulation of cell differentiation induced by BSP highlight its potential as a surface modifier that could enhance the osseointegration of orthopedic implants. Both physisorption and covalent coupling of BSP are similarly effective, feasible methods, although a higher BSP concentration is recommended.
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spelling pubmed-48441072016-05-05 Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein Baranowski, Andreas Klein, Anja Ritz, Ulrike Ackermann, Angelika Anthonissen, Joris Kaufmann, Kerstin B. Brendel, Christian Götz, Hermann Rommens, Pol M. Hofmann, Alexander PLoS One Research Article Orthopedic implant failure due to aseptic loosening and mechanical instability remains a major problem in total joint replacement. Improving osseointegration at the bone-implant interface may reduce micromotion and loosening. Bone sialoprotein (BSP) has been shown to enhance bone formation when coated onto titanium femoral implants and in rat calvarial defect models. However, the most appropriate method of BSP coating, the necessary level of BSP coating, and the effect of BSP coating on cell behavior remain largely unknown. In this study, BSP was covalently coupled to titanium surfaces via an aminosilane linker (APTES), and its properties were compared to BSP applied to titanium via physisorption and untreated titanium. Cell functions were examined using primary human osteoblasts (hOBs) and L929 mouse fibroblasts. Gene expression of specific bone turnover markers at the RNA level was detected at different intervals. Cell adhesion to titanium surfaces treated with BSP via physisorption was not significantly different from that of untreated titanium at any time point, whereas BSP application via covalent coupling caused reduced cell adhesion during the first few hours in culture. Cell migration was increased on titanium disks that were treated with higher concentrations of BSP solution, independent of the coating method. During the early phases of hOB proliferation, a suppressive effect of BSP was observed independent of its concentration, particularly when BSP was applied to the titanium surface via physisorption. Although alkaline phosphatase activity was reduced in the BSP-coated titanium groups after 4 days in culture, increased calcium deposition was observed after 21 days. In particular, the gene expression level of RUNX2 was upregulated by BSP. The increase in calcium deposition and the stimulation of cell differentiation induced by BSP highlight its potential as a surface modifier that could enhance the osseointegration of orthopedic implants. Both physisorption and covalent coupling of BSP are similarly effective, feasible methods, although a higher BSP concentration is recommended. Public Library of Science 2016-04-25 /pmc/articles/PMC4844107/ /pubmed/27111551 http://dx.doi.org/10.1371/journal.pone.0153978 Text en © 2016 Baranowski et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Baranowski, Andreas
Klein, Anja
Ritz, Ulrike
Ackermann, Angelika
Anthonissen, Joris
Kaufmann, Kerstin B.
Brendel, Christian
Götz, Hermann
Rommens, Pol M.
Hofmann, Alexander
Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein
title Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein
title_full Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein
title_fullStr Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein
title_full_unstemmed Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein
title_short Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein
title_sort surface functionalization of orthopedic titanium implants with bone sialoprotein
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4844107/
https://www.ncbi.nlm.nih.gov/pubmed/27111551
http://dx.doi.org/10.1371/journal.pone.0153978
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