Hydrogel to guide chondrogenesis versus osteogenesis of mesenchymal stem cells for fabrication of cartilaginous tissues

Abstract

The ideal combination of hydrogel components for regeneration of cartilage and cartilaginous interfaces is a significant challenge because control over differentiation into multiple lineages is necessary. Stabilization of the phenotype of stem cell derived chondrocytes is needed to avoid undesired progression to terminal hypertrophy and tissue mineralization. A novel ternary blend hydrogel composed of methacrylated poly(ethylene glycol) (PEG), gelatin, and heparin (PGH) was designed to guide chondrogenesis by bone marrow derived mesenchymal stem cells (BMSCs) and maintenance of their cartilaginous phenotype. The hydrogel material effects on chondrogenic and osteogenic differentiation by BMSCs were evaluated in comparison to methacrylated gelatin hydrogel (GEL), a conventional bioink used for both chondrogenic and osteogenic applications. PGH and GEL hydrogels were loaded with goat BMSCs and cultured in chondrogenic and osteogenic mediums in vitro over six weeks. The PGH showed no sign of mineral deposition in an osteogenic environment in vitro. To further evaluate material effects, the hydrogels were loaded with adult human BMSCs (hBMSCs) and transforming growth factor β-3 and grown in subcutaneous pockets in mice over eight weeks. Consistent with the in vitro results, the PGH had greater potential to induce chondrogenesis by BMSCs in vivo compared to the GEL as evidenced by elevated gene expression of chondrogenic markers, supporting its potential for stable cartilage engineering. The PGH also showed a greater percentage of GAG positive cells compared to the GEL. Unlike the GEL, the PGH hydrogel exhibited anti-osteogenic effects in vivo as evidenced by negative Von Kossa staining and suppressed gene expression of hypertrophic and osteogenic markers. By nature of their polymer composition alone, the PGH and GEL regulated BMSC differentiation down different osteochondral lineages. Thus, the PGH and GEL are promising hydrogels to regenerate stratified cartilaginous interfacial tissues in situ, such as the mandibular condyle surface, using undifferentiated BMSCs and a stratified scaffold design.

Synthesis of an injectable heparin conjugated poloxamer hydrogel with high elastic recoverability for temporomandibular joint disorders

“…43 However, limited studies have been reported on the use of heparin-containing hydrogels for chondrogenesis in cartilage tissue engineering. 44 In one of them, it has been shown that the presence of heparin in hydrogels promotes chondrocyte proliferation and differentiation for cartilage regeneration, 45 while another has been reported the appropriate environment for cartilage tissue formation from chondrocytes could be provided by heparin based hydrogel. 46 The Live&Dead analysis results were consistent with MTT results (Figure 5c-f and Figure S2).…”

Current researches on design and manufacture of biopolymer-based osteochondral biomimetic scaffolds

“…In 3D culture, the hydrogel creep promotes the spreading and osteogenic differentiation of MSCs, and the substrate stress relaxation alters cell morphology in addition to the enhanced cell spreading and proliferation [28]. In view of the intricate interactions between cells and hydrogels, it is challenging to tailor the differentiation of OC scaffolds into multiple lineages by the desirable combination of hydrogels [29]. In addition, it is another major challenge presented by clinical application of load-bearing OC scaffolds to overcome the low fracture energies/low elastic modulus of hydrogel substitutes [30]; encouragingly, the current strategies including structure-inserted hydrogels [31], high-strength hydrogels [32] and particle-enhanced hydrogels [33,34] are potential to solve this issue.…”

ChondroGELesis: Hydrogels to harness the chondrogenic potential of stem cells

“…In cartilage tissue engineering, other more specialised cell types, such as human articular chondrocytes (ACs) and chondroprogenitor cells, have also been utilised. However, cell sourcing and issues with cell expansion limit their regenerative capacity (5).…”