title: Hydroxyapatite coating of cellulose sponge does not improve its osteogenic potency in rat bone.
abstract: Regenerated cellulose sponges were coated biomimetically with hydroxyapatite to increase their osteogenic properties. Induction of apatite precipitation was carried out with bioactive glass in simulated body fluid (SBF) for 24 h and the final coating was carried out in 1.5 x concentrated SBF for 14 days. Biomimetically mineralized and non-mineralized sponges were then implanted into standard size femoral cortical defects of rats, and the invasion of bone into the implant was followed up to one year. The apatite coating did not improve the osteoconductive property of cellulose in this rat cortical defect model. In fact, it generated a strong and highly cellular inflammatory reaction and less osteoid tissue. The biomimetic implants contained more immunodetectable TGFbeta1 (a strong stimulator of fibroblast activity) than untreated implants, and also bound more TGFbeta1 in vitro, which could, at least in part, explain the fibrotic invasion of biomimetically mineralized sponges.
authors.affiliation: Department of Medical Biochemistry and Molecular Biology, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland.
authors.forename: Erika
authors.initials: E
authors.lastname: Ekholm
authors.forename: Miretta
authors.initials: M
authors.lastname: Tommila
authors.forename: Ari-Pekka
authors.initials: AP
authors.lastname: Forsback
authors.forename: Matis
authors.initials: M
authors.lastname: Märtson
authors.forename: Johanna
authors.initials: J
authors.lastname: Holmbom
authors.forename: Virpi
authors.initials: V
authors.lastname: Aäritalo
authors.forename: Christa
authors.initials: C
authors.lastname: Finnberg
authors.forename: Asko
authors.initials: A
authors.lastname: Kuusilehto
authors.forename: Jukka
authors.initials: J
authors.lastname: Salonen
authors.forename: Antti
authors.initials: A
authors.lastname: Yli-Urpo
authors.forename: Risto
authors.initials: R
authors.lastname: Penttinen
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000008:administration & dosage* / Q000737:chemistry*; D002482:Cellulose / Q000008:administration & dosage / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000008:administration & dosage / Q000737:chemistry; D017886:Durapatite / Q000008:administration & dosage / Q000737:chemistry*; D005264:Femoral Fractures / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008422:Materials Testing; D010012:Osteogenesis / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016212:Transforming Growth Factor beta / Q000378:metabolism; D053773:Transforming Growth Factor beta1; D016896:Treatment Outcome
chemical_list: D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D002482:Cellulose; D017886:Durapatite