Ectopic bone formation in nude rats using human osteoblasts seeded poly(3)hydroxybutyrate embroidery and hydroxyapatite-collagen tapes constructs.
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.
Mai
Ronald
R
Department of Oral and Maxillofacial Surgery, University Hospital Carl Gustav Carus, Dresden.
Hagedorn
Manolo Gunnar
MG
Gelinsky
Michael
M
Werner
Carsten
C
Turhani
Dritan
D
Späth
Heike
H
Gedrange
Tomas
T
Lauer
Günter
G
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
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