Microwell-mediated micro cartilage-like tissue formation of adipose-derived stem cell

Abstract

In cartilage tissue engineering, various technical approaches using postnatal stem cells, three-dimensional (3D) scaffolds composed of synthetic or natural polymers, and culture systems have been applied to develop 3D cartilage-like tissue. In this study, scaffold-free 3D micro-cartilage-like tissue was developed via microwell-mediated cell spheroid formation and 3D dynamic chondrogenic culture in a bioreactor. First, homogenous micro-cell spheroids were generated by the self-condensation of adipose tissue-derived stem cells (ADSCs) in microfabricated poly(ethylene glycol) (PEG) hydrogel microwells. Next, chondrogenic differentiation of the micro-ADSC spheroids was induced in the presence of transforming growth factor-beta 3 under dynamic 3D culture conditions using a high aspect ratio vessel bioreactor. Several hundred viable ADSC spheroids could be generated at a time from ADSC culture in PEG microwells. The 3D dynamic chondrogenic culture of ADSCs in the bioreactor facilitated the chondrogenic mRNA expression of proteins such as sox-9, runx2, osterix, type II collagen, and aggrecan, and the well deposition of glycosaminoglycan and type II collagen, which finally generated micro-cartilage-like tissue. Therefore, the hydrogel microwell arrays could be useful for efficiently deriving initial cell condensation-mediated chondrogenic differentiation, and for developing 3D cell-based micro-cartilage-like tissue with stem cells in a controlled manner.