In vitro generation of an osteochondral construct using injectable hydrogel composites encapsulating rabbit marrow mesenchymal stem cells

Abstract

Injectable, biodegradable hydrogel composites of crosslinked oligo(poly(ethylene glycol) fumarate) (OPF) and gelatin microparticles (MPs) were utilized to fabricate a bilayered osteochondral construct consisting of a chondrogenic layer and an osteogenic layer, and to investigate the differentiation of rabbit marrow mesenchymal stem cells (MSCs) encapsulated in both layers in vitro. The results showed that MSCs in the chondrogenic layer were able to undergo chondrogenic differentiation, especially in the presence of TGF-β1-loaded MPs. In the osteogenic layer, cells maintained their osteoblastic phenotype. Although calcium deposition in the osteogenic layer was limited, cells in the osteogenic layer significantly enhanced chondrogenic differentiation of MSCs in the chondrogenic layer. The greatest effect was observed when MSCs were encapsulated with TGF-β1-loaded MPs and cultured with osteogenic cells in the bilayered constructs. Overall, this study demonstrates the fabrication of bilayered hydrogel composites that mimic the structure and function of osteochondral tissue, along with the application of these composites as cell and growth factor carriers.

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].…”

Hydrogels for the Repair of Articular Cartilage Defects

“…139 The release of TGFb1 or TGFb3 from OPF hydrogels was also used to stimulate chondrogenic differentiation of MSCs in vitro, which was enhanced by co-culture with osteogenic cells in a subchondral layer of the hydrogel. 154,235 The rate of release of dexamethasone was controlled from hydrogels composed of Pluronic and hyaluronic acid through the use of porous and nonporous microparticles of poly(lactic-co-glycolic acid). 236 The faster release profile, which was 100% release in 4 weeks, resulted in greater chondrogenesis by encapsulated MSCs after 4 weeks of subcutaneous implantation.…”

“…152 These hydrogels have also been used to evaluate the effects of the controlled release of various growth factors on cartilage formation in vitro and in vivo, and the main results of these studies are described later. 79,151,[153][154][155] Pluronic Ò (BASF, Ludwigshafen, Germany) hydrogels are composed of poloxamers or triblock copolymers of PEG and poly(propylene oxide). Hydrogels prepared from Pluronics [156][157][158][159] For example, these properties of Pluronic F127 hydrogels were improved with the addition of crosslinked hyaluronic acid and evaluated in osteochondral defects in rabbits.…”

Controlled Release Strategies for Bone, Cartilage, and Osteochondral Engineering—Part II: Challenges on the Evolution from Single to Multiple Bioactive Factor Delivery

“…188 Many approaches have been used to fabricate scaffolds for osteochondral application by changing material composition, mechanical properties, and architecture between the chondrogenic and osteogenic layers. [172][173][174][188][189][190][191][192][193] Hierarchical scaffolds loaded with inductive factors disposed in two phases or even in gradients, capable of stimulating each layer toward the maturation of the specific tissue, are being increasingly explored. By using gradients of multiple bioactive factors, multiple tissue regeneration can be addressed via a single-cell source; that is, stem cells can differentiate along different lineages within the same constructs.…”