Tissue-Engineered Fabrication of an Osteochondral Composite Graft Using Rat Bone Marrow-Derived Mesenchymal Stem Cells

Abstract

This study tested the tissue engineering hypothesis that construction of an osteochondral composite graft could be accomplished using multipotent progenitor cells and phenotype-specific biomaterials. Rat bone marrow-derived mesenchymal stem cells (MSCs) were culture-expanded and separately stimulated with transforming growth factor-beta1 (TGF-beta1) for chondrogenic differentiation or with an osteogenic supplement (OS). MSCs exposed to TGF-beta1 were loaded into a sponge composed of a hyaluronan derivative (HYAF-11) for the construction of the cartilage component of the composite graft, and MSCs exposed to OS were loaded into a porous calcium phosphate ceramic component for bone formation. Cell-loaded HYAFF-11 sponge and ceramic were joined together with fibrin sealant, Tisseel, to form a composite osteochondral graft, which was then implanted into a subcutaneous pocket in syngeneic rats. Specimens were harvested at 3 and 6 weeks after implantation, examined with histology for morphologic features, and stained immunohistochemically for type I, II, and X collagen. The two-component composite graft remained as an integrated unit after in vivo implantation and histologic processing. Fibrocartilage was observed in the sponge, and bone was detected in the ceramic component. Observations with polarized light indicated continuity of collagen fibers between the ceramic and HYAFF-11 components in the 6-week specimens. Type I collagen was identified in the neo-tissue in both sponge and ceramic, and type II collagen in the fibrocartilage, especially the pericellular matrix of cells in the sponge. These data suggest that the construction of a tissue-engineered composite osteochondral graft is possible with MSCs and different biomaterials and bioactive factors that support either chondrogenic or osteogenic differentiation.

Calcite Biohybrids as Microenvironment for Stem Cells

“…Mixtures of HA with hydroxyapatite and calcium phosphate ceramics for developing composite biomaterials [57][58][59][60][61] resulted in prolonged scaffold stability and reduced degradation rates, but the composite exhibited impaired biological activity. Described here is a novel combination of non-modified HA with natural calcite that produces a biohybrid with unique biological activities.…”

2010 Nicolas Andry Award: Multipotent Adult Stem Cells from Adipose Tissue for Musculoskeletal Tissue Engineering

“…To promote cartilage repair, several surgical techniques have been developed to induce bleeding and clot formation, including drilling or microfracture of the subchondral bone [1,8,29,31,43]. Numerous tissue engineering approaches have been proposed for enhancing cartilage regeneration in vitro or in vivo [2,12,14,30,34,41,55,56,70,77,79,81].…”

Engineering osteochondral constructs through spatial regulation of endochondral ossification

“…Tissue engineering applications aim to replace or regenerate damaged tissues through the combinations of cells, three-dimensional scaffolds and signalling molecules [4][5]. A number of strategies have been implemented to engineer osteochondral constructs including bi-phasic scaffolding [6][7][8][9][10][11][12], bioreactor technologies [13][14][15][16], and growth factor/gene delivery [17][18][19][20]. Engineered anatomically accurate osteochondral grafts have also been suggested as a potential approach to joint condyle repair [21][22].…”