A comparison of different bioinks for 3D bioprinting of fibrocartilage and hyaline cartilage

Abstract

Cartilage is a dense connective tissue with limited self-repair capabilities. Mesenchymal stem cell (MSC) laden hydrogels are commonly used for fibrocartilage and articular cartilage tissue engineering, however they typically lack the mechanical integrity for implantation into high load bearing environments. This has led to increased interested in 3D bioprinting of cell laden hydrogel bioinks reinforced with stiffer polymer fibres. The objective of this study was to compare a range of commonly used hydrogel bioinks (agarose, alginate, GelMA and BioINK™) for their printing properties and capacity to support the development of either hyaline cartilage or fibrocartilage in vitro. Each hydrogel was seeded with MSCs, cultured for 28 days in the presence of TGF-β3 and then analysed for markers indicative of differentiation towards either a fibrocartilaginous or hyaline cartilage-like phenotype. Alginate and agarose hydrogels best supported the development of hyaline-like cartilage, as evident by the development of a tissue staining predominantly for type II collagen. In contrast, GelMA and BioINK (a PEGMA based hydrogel) supported the development of a more fibrocartilage-like tissue, as evident by the development of a tissue containing both type I and type II collagen. GelMA demonstrated superior printability, generating structures with greater fidelity, followed by the alginate and agarose bioinks. High levels of MSC viability were observed in all bioinks post-printing (∼80%). Finally we demonstrate that it is possible to engineer mechanically reinforced hydrogels with high cell viability by co-depositing a hydrogel bioink with polycaprolactone filaments, generating composites with bulk compressive moduli comparable to articular cartilage. This study demonstrates the importance of the choice of bioink when bioprinting different cartilaginous tissues for musculoskeletal applications.

Meniscus ECM‐functionalised hydrogels containing infrapatellar fat pad‐derived stem cells for bioprinting of regionally defined meniscal tissue

“…The 3D bioplotter from RegenHU (3D Discovery, Switzerland) was used for printing of alginate-ECM bioinks using previously established settings (Daly, Critchley, Rencsok, & Kelly, 2016). PCL with a molecular weight of 45.000 (Sigma-Aldrich, Ireland) was first melted at 70°C in the printing chamber.…”

3D bioprinting for cell culture and tissue fabrication

“…It was found that alginate and agarose were suitable for hyaline-like cartilage fabrication, while GelMA and BioINK TM for the formation of fibrocartilage-like tissue. Moreover, MSCs encapsulated in all the constructs showed the viability of above 80% [61]. As shown in Fig.…”

“…It was demonstrated that the hydrogels could direct cell migration, chondrocytes moving to hyaluronic acid, while osteoblasts migrating to type I collagen [60]. Daly et al [61] aimed to screen out proper hydrogels to induce bone marrow stem cells (BMSCs) to differentiate toward cartilage. The commonly used hydrogels including agarose, alginate, GelMA and BioINK TM were employed to construct cartilage structures.…”

Tailoring Bioengineered Scaffolds for Regenerative Medicine

“…Cell viability during 3D bioprinting is dependent on the shear stress experienced during extrusion, which in turn is dependent on the viscosity of the solution, the applied pressure, and the needle diameter. In addition, any post-printing bioink cross-linking may also impact on cell viability [62]. Cell viability can be measured with Live/Dead Viability/ Cytotoxicity assay after printing [63] and could vary with dispensing pressure and nozzle diameter.…”