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Engraftment of Prevascularized, Tissue Engineered Constructs in a Novel Rabbit Segmental Bone Defect Model.

Kaempfen A, Todorov A, Güven S, Largo RD, Jaquiéry C, Scherberich A, Martin I, Schaefer DJ - Int J Mol Sci (2015)

Bottom Line: Instead, a variable amount of necrotic tissue formed.Although necrotic area correlated significantly with amount of vessels and the 2-step strategy had significantly more vessels than the 1-step strategy, no significant reduction of necrotic area was found.In conclusion, the animal model developed here represents a highly challenging situation, for which a suitable engineered bone graft with better prevascularization, better resorbability and higher osteogenicity has yet to be developed.

View Article: PubMed Central - PubMed

Affiliation: Clinic for Plastic, Reconstructive, Aesthetic and Hand Surgery, University Hospital Basel, 4031 Basel, Switzerland. alexander.kaempfen@usb.ch.

ABSTRACT
The gold standard treatment of large segmental bone defects is autologous bone transfer, which suffers from low availability and additional morbidity. Tissue engineered bone able to engraft orthotopically and a suitable animal model for pre-clinical testing are direly needed. This study aimed to evaluate engraftment of tissue-engineered bone with different prevascularization strategies in a novel segmental defect model in the rabbit humerus. Decellularized bone matrix (Tutobone) seeded with bone marrow mesenchymal stromal cells was used directly orthotopically or combined with a vessel and inserted immediately (1-step) or only after six weeks of subcutaneous "incubation" (2-step). After 12 weeks, histological and radiological assessment was performed. Variable callus formation was observed. No bone formation or remodeling of the graft through TRAP positive osteoclasts could be detected. Instead, a variable amount of necrotic tissue formed. Although necrotic area correlated significantly with amount of vessels and the 2-step strategy had significantly more vessels than the 1-step strategy, no significant reduction of necrotic area was found. In conclusion, the animal model developed here represents a highly challenging situation, for which a suitable engineered bone graft with better prevascularization, better resorbability and higher osteogenicity has yet to be developed.

No MeSH data available.


Related in: MedlinePlus

Representative tartrate resistant acid phosphatase (TRAP) stainings. Black bar represents 50 mm in each image. (A) Schematical display of TRAP staining location; (B) Normal bone has closely associated TRAP positive osteoclasts; (C) Periost around fracture displays increased presence of TRAP positive cells; (D) Tutobone scaffold with invading granulation tissue, however no closely associated TRAP positive cells.
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ijms-16-12616-f005: Representative tartrate resistant acid phosphatase (TRAP) stainings. Black bar represents 50 mm in each image. (A) Schematical display of TRAP staining location; (B) Normal bone has closely associated TRAP positive osteoclasts; (C) Periost around fracture displays increased presence of TRAP positive cells; (D) Tutobone scaffold with invading granulation tissue, however no closely associated TRAP positive cells.

Mentions: A TRAP staining was performed to investigate the remodeling of the scaffold by osteoclasts. TRAP positive osteoclasts were found in normal trabecular bone adjacent to the defect site as well as in parts of the calcified callus (Figure 5B). TRAP positive cells were also observed inside the periost in the vicinity of the defect site (Figure 5C). However, no TRAP positive cells were observed in contact with the scaffold material in any of the samples, even though there was a clear presence of granulation tissue (Figure 5D).


Engraftment of Prevascularized, Tissue Engineered Constructs in a Novel Rabbit Segmental Bone Defect Model.

Kaempfen A, Todorov A, Güven S, Largo RD, Jaquiéry C, Scherberich A, Martin I, Schaefer DJ - Int J Mol Sci (2015)

Representative tartrate resistant acid phosphatase (TRAP) stainings. Black bar represents 50 mm in each image. (A) Schematical display of TRAP staining location; (B) Normal bone has closely associated TRAP positive osteoclasts; (C) Periost around fracture displays increased presence of TRAP positive cells; (D) Tutobone scaffold with invading granulation tissue, however no closely associated TRAP positive cells.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490464&req=5

ijms-16-12616-f005: Representative tartrate resistant acid phosphatase (TRAP) stainings. Black bar represents 50 mm in each image. (A) Schematical display of TRAP staining location; (B) Normal bone has closely associated TRAP positive osteoclasts; (C) Periost around fracture displays increased presence of TRAP positive cells; (D) Tutobone scaffold with invading granulation tissue, however no closely associated TRAP positive cells.
Mentions: A TRAP staining was performed to investigate the remodeling of the scaffold by osteoclasts. TRAP positive osteoclasts were found in normal trabecular bone adjacent to the defect site as well as in parts of the calcified callus (Figure 5B). TRAP positive cells were also observed inside the periost in the vicinity of the defect site (Figure 5C). However, no TRAP positive cells were observed in contact with the scaffold material in any of the samples, even though there was a clear presence of granulation tissue (Figure 5D).

Bottom Line: Instead, a variable amount of necrotic tissue formed.Although necrotic area correlated significantly with amount of vessels and the 2-step strategy had significantly more vessels than the 1-step strategy, no significant reduction of necrotic area was found.In conclusion, the animal model developed here represents a highly challenging situation, for which a suitable engineered bone graft with better prevascularization, better resorbability and higher osteogenicity has yet to be developed.

View Article: PubMed Central - PubMed

Affiliation: Clinic for Plastic, Reconstructive, Aesthetic and Hand Surgery, University Hospital Basel, 4031 Basel, Switzerland. alexander.kaempfen@usb.ch.

ABSTRACT
The gold standard treatment of large segmental bone defects is autologous bone transfer, which suffers from low availability and additional morbidity. Tissue engineered bone able to engraft orthotopically and a suitable animal model for pre-clinical testing are direly needed. This study aimed to evaluate engraftment of tissue-engineered bone with different prevascularization strategies in a novel segmental defect model in the rabbit humerus. Decellularized bone matrix (Tutobone) seeded with bone marrow mesenchymal stromal cells was used directly orthotopically or combined with a vessel and inserted immediately (1-step) or only after six weeks of subcutaneous "incubation" (2-step). After 12 weeks, histological and radiological assessment was performed. Variable callus formation was observed. No bone formation or remodeling of the graft through TRAP positive osteoclasts could be detected. Instead, a variable amount of necrotic tissue formed. Although necrotic area correlated significantly with amount of vessels and the 2-step strategy had significantly more vessels than the 1-step strategy, no significant reduction of necrotic area was found. In conclusion, the animal model developed here represents a highly challenging situation, for which a suitable engineered bone graft with better prevascularization, better resorbability and higher osteogenicity has yet to be developed.

No MeSH data available.


Related in: MedlinePlus