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Hypoxia impedes vasculogenesis of in vitro engineered bone.

ABSTRACT: To ensure the survival of engineered bone after implantation, we combined human endothelial colony forming cells (ECFCs) and multipotent stromal cells (MSCs) as a proof of concept in a co-culture model to create in vitro prevascularized bone constructs. We hypothesized that a hypoxic stimulus will contribute to prevascularization of engineered bone. Bone marrow-derived MSCs and ECFCs from human adult peripheral blood were allowed to form co-culture pellets containing ECFCs and MSCs (1:4) or MSCs only in controls. After culture under normoxia or hypoxia (5%), pellets were harvested and processed for immunohistochemistry of CD31, ?-smooth muscle actin, and osteocalcin. Expression of vascular endothelial growth factor and SDF-1? was analyzed by PCR to elucidate their involvement in hypoxic stimulation of prevascularization. The normoxic condition in co-cultures of MSCs and ECFCs supported the formation and maintenance of prevascular structures, including organized CD31-positive cells embraced by differentiated mural cells. These structures failed to form in hypoxic conditions, thereby rejecting the hypothesis that hypoxia stimulates prevasculogenesis in three-dimensional engineered bone constructs. Further, the formation of prevascular structures was paralleled by increased SDF-1? expression. It is suggested that actual oxygen levels were below 5% in the hypoxic co-cultures, which prevented prevascular structure formation. In conclusion, our normoxic co-culture model containing cells from clinically relevant sources sustained simultaneous endothelial, smooth muscle, and osteogenic differentiation.

SUBMITTER: Gawlitta D

PROVIDER: S-EPMC3246420 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature

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Hypoxia impedes vasculogenesis of in vitro engineered bone.

Gawlitta Debby D Fledderus Joost O JO van Rijen Mattie H P MH Dokter Inge I Alblas Jacqueline J Verhaar Marianne C MC Dhert Wouter J A WJ

Tissue engineering. Part A 20111004 1-2

To ensure the survival of engineered bone after implantation, we combined human endothelial colony forming cells (ECFCs) and multipotent stromal cells (MSCs) as a proof of concept in a co-culture model to create in vitro prevascularized bone constructs. We hypothesized that a hypoxic stimulus will contribute to prevascularization of engineered bone. Bone marrow-derived MSCs and ECFCs from human adult peripheral blood were allowed to form co-culture pellets containing ECFCs and MSCs (1:4) or MSCs ...[more]

PMID: 21859278

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Hypoxia impedes vasculogenesis of in vitro engineered bone.

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Hypoxia impedes vasculogenesis of in vitro engineered bone.

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