title: Increased bone remodelling around titanium implants coated with chondroitin sulfate in ovariectomized rats.
abstract: Coating titanium implants with artificial extracellular matrices based on collagen and chondroitin sulfate (CS) has been shown to enhance bone remodelling and de novo bone formation in vivo. The aim of this study was to evaluate the effect of estrogen deficiency and hormone replacement therapy (HRT) on the osseointegration of CS-modified Ti implants. 30 adult female, ovariectomized Wistar rats were fed either with an ethinyl-estradiol-rich diet (E) to simulate a clinical relevant HRT or with a genistein-rich diet (G) to test an alternative therapy based on nutritionally relevant phytoestrogens. Controls (C) received an estrogen-free diet. Uncoated titanium pins (Ti) or pins coated with type-I collagen and CS (Ti/CS) were inserted 8weeks after ovarectomy into the tibia. Specimens were retrieved 28days after implantation. Both the amount of newly formed bone and the affinity index (P<0.05) were moderately higher around Ti/CS implants as compared to uncoated Ti. The highest values were measured in the G-Ti/CS and E-Ti/CS groups, the lowest values for the E-Ti and G-Ti controls. Quantitative synchrotron radiation micro-computed tomography (SRμCT) revealed the highest increase in total bone formation around G-Ti/CS as compared to C-Ti (P<0.01). The effects with respect to direct bone apposition were less pronounced with SRμCT. Using scanning nanoindentation, both the indentation modulus and the hardness of the newly formed bone were highest in the E-Ti/CS, G-Ti/CS and G-Ti groups as compared to C-Ti (P<0.05). Coatings with collagen and CS appear to improve both the quantity and quality of bone formed around Ti implants in ovarectomized rats. A simultaneous ethinyl estradiol- and genistein-rich diet seems to enhance these effects.
authors.affiliation: Department of Trauma and Reconstructive Surgery, University Hospital "Carl Gustav Carus", Technische Universität Dresden, Fetscherstrasse 74, Dresden 01307, Germany; Institute of Immunology, Medical Faculty "Carl Gustav Carus", Technische Universität Dresden, Fetscherstrasse 74, Dresden 01307, Germany. Electronic address: Jan.Dudeck@tu-dresden.de.
authors.forename: Jan
authors.initials: J
authors.lastname: Dudeck
authors.affiliation: Department of Trauma and Reconstructive Surgery, University Hospital "Carl Gustav Carus", Technische Universität Dresden, Fetscherstrasse 74, Dresden 01307, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Rehberg
authors.affiliation: Max Bergmann Center of Biomaterials, Technische Universität Dresden, Budapester Str. 27, Dresden 01069, Germany.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Bernhardt
authors.affiliation: Department of Trauma and Reconstructive Surgery, University Hospital "Carl Gustav Carus", Technische Universität Dresden, Fetscherstrasse 74, Dresden 01307, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schneiders
authors.affiliation: Institute for Zoology, Chair for Molecular Cell Physiology and Endocrinology, Technische Universität Dresden, Zellescher Weg 2b, Dresden 01062, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Zierau
authors.affiliation: Biomedical Engineering Division, School of Bio-Sciences and Technology, VIT University, Vellore, Tamilnadu 623014, India; Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Potsdam-Golm Science Park, Am Mühlenberg 1, Potsdam 14476, Germany.
authors.forename: Manjubala
authors.initials: M
authors.lastname: Inderchand
authors.affiliation: BAM Federal Institute for Materials Research and Testing, Unter den Eichen 87, Berlin 12205, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Goebbels
authors.affiliation: Institute for Zoology, Chair for Molecular Cell Physiology and Endocrinology, Technische Universität Dresden, Zellescher Weg 2b, Dresden 01062, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Vollmer
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Potsdam-Golm Science Park, Am Mühlenberg 1, Potsdam 14476, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Fratzl
authors.affiliation: Max Bergmann Center of Biomaterials, Technische Universität Dresden, Budapester Str. 27, Dresden 01069, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Scharnweber
authors.affiliation: Department of Trauma and Reconstructive Surgery, University Hospital "Carl Gustav Carus", Technische Universität Dresden, Fetscherstrasse 74, Dresden 01307, Germany; Center for Regenerative Therapies Dresden (CRTD), Tatzberg 47, Dresden 01307, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Rammelt
mesh_terms: D000818:Animals; D016723:Bone Remodeling; D002809:Chondroitin Sulfates; D020099:Coated Materials, Biocompatible; D005260:Female; D010052:Ovariectomy; D019736:Prostheses and Implants; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D002809:Chondroitin Sulfates; D014025:Titanium
keywords: Chondroitin sulfate; Estrogen replacement therapy; Osseointegration; Osteoporosis; Scanning nanoindentation