Artificial decellularized extracellular matrix improves the regenerative capacity of adipose tissue derived stem cells on 3D printed polycaprolactone scaffolds

Ideal tissue engineering frameworks should be both an optimal biological microenvironment and a shape and stability providing framework. In this study we tried to combine the advantages of cell-derived artificial extracellular matrix (ECM) with those of 3D printed polycaprolactone (PCL) scaffolds. In Part A, both chondrogenic and osteogenic ECMs were produced by human adipose derived stem cells (hASCs) on 3D-printed PCL scaffolds and then decellularized to create cell free functionalized PCL scaffolds, named acPCL and aoPCL respectively. The decellularization resulted in a significant reduction of the DNA content as well as the removal of nuclei while the ECM was largely preserved. In Part B the bioactivation and the effect of the ac/aoPCL scaffolds on the proliferation, differentiation, and gene expression of hASCs was investigated. The ac/aoPCL scaffolds were found to be non-toxic and allow good adhesion, but do not affect proliferation. In the in vitro investigation of cartilage regeneration, biochemical analysis showed that acPCL scaffolds have an additional effect on chondrogenic differentiation as gene expression analysis showed markers of cartilage hypertrophy. The aoPCL showed a large influence on the differentiation of hASCs. In control medium they were able to stimulate hASCs to produce calcium alone and all genes relevant investigated for osteogenesis were significantly higher expressed on aoPCL than on unmodified PCL. Therefore, we believe that ac/aoPCL scaffolds have a high potential to improve regenerative capacity of unmodified PCL scaffolds and should be further investigated.