title: Ectopic bone formation associated with mesenchymal stem cells in a resorbable calcium deficient hydroxyapatite carrier.
abstract: Bone substitute materials can induce bone formation in combination with mesenchymal stem cells (MSC). The aim of the current study was to examine ectopic in vivo bone formation with and without MSC on a new resorbable ceramic, called calcium deficient hydroxyapatite (CDHA). Ceramic blocks characterized by a large surface (48 m2/g) were compared with beta-tricalcium phosphate (beta-TCP), hydroxyapatite (HA) ceramics (both ca. 0.5 m2/g surface) and demineralized bone matrix (DBM). Before implantation in the back of SCID mice carriers were freshly loaded with 2x10(5) expanded human MSC or loaded with cells and kept under osteogenic conditions for two weeks in vitro. Culture conditions were kept free of xenogenic supplements. Deposits of osteoid at the margins of ceramic pores occurred independent of osteogenic pre-induction, contained human cells, and appeared in 416 MSC/CDHA composites compared to 216 MSC/beta-TCP composites. ALP activity was significantly higher in samples with MSC versus empty controls (p<0.001). Furthermore, ALP was significantly (p<0.05) higher for all ceramics when compared to the DBM matrix. Compared to previous studies, overall bone formation appeared to be reduced possibly due to the strict human protocol. Ectopic bone formation in the novel biomaterial CDHA varied considerably with the cell pool and was at least equal to beta-TCP blocks.
authors.affiliation: Department of Orthopaedic Surgery, University of Heidelberg, Schlierbacher Landstr. 200a, 69118 Heidelberg, Germany. Philip.Kasten@gmx.de
authors.forename: Philip
authors.initials: P
authors.lastname: Kasten
authors.forename: Julia
authors.initials: J
authors.lastname: Vogel
authors.forename: Reto
authors.initials: R
authors.lastname: Luginbühl
authors.forename: Philip
authors.initials: P
authors.lastname: Niemeyer
authors.forename: Marcus
authors.initials: M
authors.lastname: Tonak
authors.forename: Helga
authors.initials: H
authors.lastname: Lorenz
authors.forename: Lars
authors.initials: L
authors.lastname: Helbig
authors.forename: Stefan
authors.initials: S
authors.lastname: Weiss
authors.forename: Jörg
authors.initials: J
authors.lastname: Fellenberg
authors.forename: Albrecht
authors.initials: A
authors.lastname: Leo
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Simank
authors.forename: Wiltrud
authors.initials: W
authors.lastname: Richter
mesh_terms: D000368:Aged; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001673:Biodegradation, Environmental; D001792:Blood Platelets / Q000378:metabolism; D001861:Bone Regeneration; D018786:Bone Substitutes; D001842:Bone and Bones / Q000378:metabolism*; D002118:Calcium / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry; D002478:Cells, Cultured; D002516:Ceramics; D017886:Durapatite / Q000737:chemistry; D005260:Female; D006801:Humans; D006882:Hydroxyapatites / Q000737:chemistry*; D017403:In Situ Hybridization; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D051379:Mice; D016513:Mice, SCID; D008875:Middle Aged; D010006:Osteoblasts / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D013499:Surface Properties; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D006882:Hydroxyapatites; C485817:beta-tricalcium phosphate; D015675:Osteocalcin; D017886:Durapatite; D000469:Alkaline Phosphatase; C018392:tricalcium phosphate; D002118:Calcium