Directly auto-transplanted mesenchymal stem cells induce bone formation in a ceramic bone substitute in an ectopic sheep model.
Bottom Line: Bone matrix proteins were up-regulated in constructs following direct auto-transplantation and in expanded MSC as well as in BMP-2 constructs.Up-regulation was detected using immunohistology methods and RT-PCR.Dense vascularization was demonstrated by CD31 immunohistology staining in all three groups.
Affiliation: Department of Plastic and Hand Surgery, University Hospital of Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany.Show MeSH
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Mentions: A TUNEL assay was performed to analyse apoptosis. In the first and second week a higher apoptosis could be detected compared to later explantation time-points (Fig. 3A–D, A/B 2 weeks, C/D 4 weeks, A/C expanded MSC, B/D directly auto-transplanted MSC), while the apoptosis decreased from week 1 to week 2. At later time-points only single apoptotic cells were visible. Proliferation was assessed by Ki67 staining. A constant proliferation could be detected over all explantation time-points (Fig. 4A–D, A/B 2 weeks, C/D 4 weeks, A/C expanded MSC, B/D directly auto-transplanted MSC). Despite different marker expression profiles, both cell isolation protocols, directly auto-transplanted or expanded MSC, displayed a constant proliferation and low apoptosis. Therefore, both populations were regarded as suitable for the following implantation studies comparing directly auto-transplanted versus expanded MSC aiming at bone tissue engineering.
Affiliation: Department of Plastic and Hand Surgery, University Hospital of Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany.