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Influence of osteogenic stimulation and VEGF treatment on in vivo bone formation in hMSC-seeded cancellous bone scaffolds.

Lenze U, Pohlig F, Seitz S, Ern C, Milz S, Docheva D, Schieker M - BMC Musculoskelet Disord (2014)

Bottom Line: One osteogenically stimulated group was additionally treated with 0.8 μg VEGF prior to subcutaneous implantation in athymic mice.After 2 and 12 weeks in vivo, constructs and selected organs were harvested for histological and molecular analysis.Human DNA was detected in all inoculated scaffolds, but a significant decrease in cells was observed after 2 weeks with no further decrease after 12 weeks in vivo.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Experimental Surgery and Regenerative Medicine, Department of Surgery, University of Munich (LMU), Munich, Germany. denitsa.docheva@med.uni-muenchen.de.

ABSTRACT

Background: Tissue engineering approaches for reconstruction of large bone defects are still technically immature, especially in regard to sufficient blood supply. Therefore, the aim of the present study was to investigate the influence of osteogenic stimulation and treatment with VEGF on new bone formation and neovascularization in hMSC-loaded cancellous bone scaffolds in vivo.

Methods: Cubic scaffolds were seeded with hMSC and either cultured in stem cell medium or osteogenic stimulation medium. One osteogenically stimulated group was additionally treated with 0.8 μg VEGF prior to subcutaneous implantation in athymic mice. After 2 and 12 weeks in vivo, constructs and selected organs were harvested for histological and molecular analysis.

Results: Histological analysis revealed similar vascularization of the constructs with and without VEGF treatment and absence of new bone formation in any group. Human DNA was detected in all inoculated scaffolds, but a significant decrease in cells was observed after 2 weeks with no further decrease after 12 weeks in vivo.

Conclusion: Under the chosen conditions, osteogenic stimulation and treatment with VEGF does not have any influence on the new bone formation and neovascularization in hMSC-seeded cancellous bone scaffolds.

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Related in: MedlinePlus

Tissue after 2 weeks. Granulation tissue (*) was observed in all groups after 2 weeks in vivo. [Gp = Group, os-hMSCs = osteogenically stimulated hMSCs] Hematoxylin-Eosin: scale bars: 200 μms.
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Fig4: Tissue after 2 weeks. Granulation tissue (*) was observed in all groups after 2 weeks in vivo. [Gp = Group, os-hMSCs = osteogenically stimulated hMSCs] Hematoxylin-Eosin: scale bars: 200 μms.

Mentions: After an implantation period of 2 weeks, an incipient ingrowth of fibrous- and granulation tissue as well as small vessels was observed in each scaffold. In all groups (1. unstimulated empty scaffolds, 2. inoculated with hMSCs, 3. inoculated with osteogenic stimulated hMSCs, 4. inoculated with osteogenically stimulated hMSCs and treated with VEGF), newly formed capillaries and small vessels were detected, lying evenly distributed mainly in the outer regions of the scaffold (Figure 3). Granulation tissue was also observed in all groups (Figure 4). Inner parts of the constructs contained scattered fat cells, inflammatory cells, and sometimes necrotic areas. Multinucleated giant cells were found in scaffolds from all groups. These cells were mostly aligned in groups of 2–4 along the edge of the scaffolds. Fat cells were observed within loose fibrous tissue, especially in outlying areas covering more than 20% of the scaffold surface. No apparent differences in the occurrence and distribution of necrotic areas were detected. Newly formed osteoid, bone- or cartilage tissue was not apparent after an implantation period of 2 weeks.


Influence of osteogenic stimulation and VEGF treatment on in vivo bone formation in hMSC-seeded cancellous bone scaffolds.

Lenze U, Pohlig F, Seitz S, Ern C, Milz S, Docheva D, Schieker M - BMC Musculoskelet Disord (2014)

Tissue after 2 weeks. Granulation tissue (*) was observed in all groups after 2 weeks in vivo. [Gp = Group, os-hMSCs = osteogenically stimulated hMSCs] Hematoxylin-Eosin: scale bars: 200 μms.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4216837&req=5

Fig4: Tissue after 2 weeks. Granulation tissue (*) was observed in all groups after 2 weeks in vivo. [Gp = Group, os-hMSCs = osteogenically stimulated hMSCs] Hematoxylin-Eosin: scale bars: 200 μms.
Mentions: After an implantation period of 2 weeks, an incipient ingrowth of fibrous- and granulation tissue as well as small vessels was observed in each scaffold. In all groups (1. unstimulated empty scaffolds, 2. inoculated with hMSCs, 3. inoculated with osteogenic stimulated hMSCs, 4. inoculated with osteogenically stimulated hMSCs and treated with VEGF), newly formed capillaries and small vessels were detected, lying evenly distributed mainly in the outer regions of the scaffold (Figure 3). Granulation tissue was also observed in all groups (Figure 4). Inner parts of the constructs contained scattered fat cells, inflammatory cells, and sometimes necrotic areas. Multinucleated giant cells were found in scaffolds from all groups. These cells were mostly aligned in groups of 2–4 along the edge of the scaffolds. Fat cells were observed within loose fibrous tissue, especially in outlying areas covering more than 20% of the scaffold surface. No apparent differences in the occurrence and distribution of necrotic areas were detected. Newly formed osteoid, bone- or cartilage tissue was not apparent after an implantation period of 2 weeks.

Bottom Line: One osteogenically stimulated group was additionally treated with 0.8 μg VEGF prior to subcutaneous implantation in athymic mice.After 2 and 12 weeks in vivo, constructs and selected organs were harvested for histological and molecular analysis.Human DNA was detected in all inoculated scaffolds, but a significant decrease in cells was observed after 2 weeks with no further decrease after 12 weeks in vivo.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Experimental Surgery and Regenerative Medicine, Department of Surgery, University of Munich (LMU), Munich, Germany. denitsa.docheva@med.uni-muenchen.de.

ABSTRACT

Background: Tissue engineering approaches for reconstruction of large bone defects are still technically immature, especially in regard to sufficient blood supply. Therefore, the aim of the present study was to investigate the influence of osteogenic stimulation and treatment with VEGF on new bone formation and neovascularization in hMSC-loaded cancellous bone scaffolds in vivo.

Methods: Cubic scaffolds were seeded with hMSC and either cultured in stem cell medium or osteogenic stimulation medium. One osteogenically stimulated group was additionally treated with 0.8 μg VEGF prior to subcutaneous implantation in athymic mice. After 2 and 12 weeks in vivo, constructs and selected organs were harvested for histological and molecular analysis.

Results: Histological analysis revealed similar vascularization of the constructs with and without VEGF treatment and absence of new bone formation in any group. Human DNA was detected in all inoculated scaffolds, but a significant decrease in cells was observed after 2 weeks with no further decrease after 12 weeks in vivo.

Conclusion: Under the chosen conditions, osteogenic stimulation and treatment with VEGF does not have any influence on the new bone formation and neovascularization in hMSC-seeded cancellous bone scaffolds.

Show MeSH
Related in: MedlinePlus