title: 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.
authors.affiliation: Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland. Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin, Dublin, Ireland. Advanced Materials and Bioengineering Research Centre (AMBER), Royal College of Surgeons in Ireland andTrinity College Dublin, Dublin, Ireland.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Daly
authors.forename: Susan E
authors.initials: SE
authors.lastname: Critchley
authors.forename: Emily M
authors.initials: EM
authors.lastname: Rencsok
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kelly
mesh_terms: D000464:Alginates / Q000737:chemistry; D000818:Animals; D062028:Bioprinting / Q000379:methods*; D001854:Bone Marrow Cells / Q000166:cytology; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000187:drug effects; D019245:Compressive Strength; D051445:Fibrocartilage / Q000502:physiology*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D051457:Hyaline Cartilage / Q000502:physiology*; D020100:Hydrogels / Q000737:chemistry; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism; D066330:Printing, Three-Dimensional; D012685:Sepharose / Q000737:chemistry; D013552:Swine; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*; D016212:Transforming Growth Factor beta / Q000494:pharmacology
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D020100:Hydrogels; D016212:Transforming Growth Factor beta; D020723:Glucuronic Acid; D012685:Sepharose