Effects of scaffold geometry on chondrogenic differentiation of adipose-derived stem cells.

Scaffold geometry is known a biophysical spatial cue to modulate stem cell fate. However, the effect of regulating topography on the chondrogenic differentiation of adipose-derived stem cells (ADSCs) is not fully understood. In this study, a spatial-controlled scaffold was prepared using a microfluidic device with a reference freeze-dried prepared random porous scaffold. Rabbit ADSCs were seeded into the organized or random scaffolds to evaluate the regulation of spatial cue to chondrogenesis. In addition to viability, the ADSC-derived chondrocytes had relatively higher glycosaminoglycan productions in the organized scaffolds than in the random scaffolds. Cells spontaneously aggregated as spheroids within the microbubble of the organized scaffolds, while non-uniform distribution of cells was noticed in the random ones. In addition, the differentiated chondrocytes in organized scaffolds displayed a higher level of COL2A1 and SOX-9 but lower COL10 mRNA expression relative to those in random scaffolds, suggesting that scaffold geometry influenced chondrogenic differentiation to ADSCs. Otherwise, the scaffold geometry also regulated the orientation of cytoskeletons. The signal intensity of ADSCs/organized scaffolds in MRI was similar with the native cartilage of stifle joint. Moreover, histological examinations showed that the ADSCs/organized scaffold samples retrieved from SCID mice had a functional phenotype as hyaline cartilage. In conclusion, the cues from spatial structure affect the chondrogenic differentiation to ADSCs which suggesting that organized scaffold shall benefit cartilage regeneration.