title: Ectopic bone formation in nude rats using human osteoblasts seeded poly(3)hydroxybutyrate embroidery and hydroxyapatite-collagen tapes constructs.
abstract: OBJECTIVE
  The aim of this study was to evaluate the ectopic bone formation using tissue engineered cell-seeded constructs with two different scaffolds and primary human maxillary osteoblasts in nude rats over an implantation period of up to 96 days.
  
  
  METHODS
  Collagen I-coated Poly(3)hydroxybutyrate (PHB) embroidery and hydroxyapatite (HAP) collagen tapes were seeded with primary human maxillary osteoblasts (hOB) and implanted into athymic rnu/run rats. A total of 72 implants were placed into the back muscles of 18 rats. 24, 48 and 96 days after implantation, histological and histomorphometric analyses were made. The osteoblastic character of the cells was confirmed by immunocytochemistry and RT-PCR for osteocalcin.
  
  
  RESULTS
  Histological analysis demonstrated that all cell-seeded constructs induced ectopic bone formation after 24, 48 and 96 days of implantation. There was more mineralized tissue in PHB constructs than in HAP-collagen tapes (at day 24; p < 0.05). Bone formation decreased with the increasing length of the implantation period. Osteocalcin expression verified the osteoblastic character of the cell-seeded constructs after implantation time. No bone formation and no osteocalcin expression were found in the control groups.
  
  
  CONCLUSIONS
  Cell-seeded constructs either with PHB embroidery or HAP-collagen tapes can induce ectopic bone formation. However, the amount of bone formed decreased with increasing length of implantation.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus, Dresden.
authors.forename: Ronald
authors.initials: R
authors.lastname: Mai
authors.forename: Manolo Gunnar
authors.initials: MG
authors.lastname: Hagedorn
authors.forename: Michael
authors.initials: M
authors.lastname: Gelinsky
authors.forename: Carsten
authors.initials: C
authors.lastname: Werner
authors.forename: Dritan
authors.initials: D
authors.lastname: Turhani
authors.forename: Heike
authors.initials: H
authors.lastname: Späth
authors.forename: Tomas
authors.initials: T
authors.lastname: Gedrange
authors.forename: Günter
authors.initials: G
authors.lastname: Lauer
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use; D003094:Collagen / Q000627:therapeutic use; D017886:Durapatite / Q000627:therapeutic use; D006801:Humans; D006885:Hydroxybutyrates / Q000627:therapeutic use; D008297:Male; D008437:Maxilla / Q000166:cytology; D009999:Ossification, Heterotopic; D010006:Osteoblasts / Q000637:transplantation*; D015675:Osteocalcin / Q000032:analysis*; D011091:Polyesters / Q000627:therapeutic use; D000091402:Prohibitins; D051381:Rats; D011923:Rats, Nude; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D000094122:Polyhydroxybutyrates
chemical_list: D001672:Biocompatible Materials; D003094:Collagen; D017886:Durapatite; D006885:Hydroxybutyrates; D015675:Osteocalcin; D011091:Polyesters; D000091402:Prohibitins; C000717328:PHB protein, human; C000717332:Phb protein, rat; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates