3D bioprinting of human adipose-derived stem cells and their tenogenic differentiation in clinical grade medium

Defining the best combination of cells and biomaterials is a key challenge for the development of tendon tissue engineering (TE) strategies. Adipose-derived stem cells (ASCs) are ideal candidate for this purpose. In addition, controlled cell-based products adherent to Good Manufacturing Practice (GMP) are required for their clinical scale-up. With this aim, in this study, ASC 3D bioprinting and GMP compliant tenogenic differentiation were investigated. In detail, primary human ASCs were embedded within a nanofibrillar-cellulose/alginate bioink and 3D bioprinted into multi-layered square-grid matrices. Bioink viscoelastic properties and scaffold ultrastructure morphology were analyzed by rheology and scanning electron microscopy (SEM). The optimal cell concentration for printing among 3, 6, 9.0x106 ASC/ml was evaluated in terms of cell viability. ASC morphology was characterized by SEM and F-actin immunostaining. Tenogenic differentiation ability was evaluated after induction by BMP-12, TGF-β3, CTGF and ascorbic acid supplementation (TENO) in terms of cell viability, morphology and expression of scleraxis and collagen-type III. Pro-inflammatory cytokine release was also assessed. Bioprinted ASCs showed high viability and survival and exhibited a tenocyte-like phenotype after biochemical induction, with no inflammatory response to the bioink.In conclusion, we reported a first proof-of-concept for the clinical scale-up of ASC 3D bioprinting for tendon TE. ; JRC.F.2 - Consumer Products Safety