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[In vitro cartilage tissue engineering with cartilage extracellular matrix-derived porous scaffolds and bone marrow mesenchymal stem cells].

OBJECTIVE
To develop a novel cartilage ECM-derived porous scaffold (CEDPS) and investigate the attachment, proliferation and distribution of bone marrow mesenchymal stem cells (BMSCs) cultured in vitro within the scaffolds.


METHODS
Cartilage microfilaments were prepared after pulverization and gradient centrifugation and prepared into suspension after acellularization treatment. The scaffolds were examined by histological staining, scanning electron microscope (SEM), biochemical and biomechanical analysis. After labeling with PKH26, the canine BMSCs were seeded onto the scaffolds. The attachment, proliferation and differentiation of cells were observed by inverted fluorescent microscope and SEM.


RESULTS
On histology, most extracellular matrices were retained in the scaffold after the removal of cell fragments. Safranin O staining and immunofluorescence examination with collagen II antibodies provided positive results. Biochemical analysis showed that the collagen content was (708.2 ± 44.7) µg/mg, glycosaminoglycan (254.7 ± 25.9) µg/mg and DNA (0.021 ± 0.007) µg/mg. Mechanical testing showed the compression moduli (E) were (1.226 ± 0.288) and (0.052 ± 0.007) MPa under dry and wet conditions respectively. Inverted fluorescent microscope and SEM showed moderate cell adhesion, chondrocyte-like morphology and matrix synthesis around cells.


CONCLUSION
The CEDPS retains most extracellular matrices after a thorough decellularization so as to possess an excellent microstructure with ideal biomechanical characteristics and a good biocompatibility. Thus it is a suitable candidate as an alternative cell-carrier for cartilage tissue engineering. Chondrogenic BMSCs and CEDPS may be used to construct cartilage-like tissue in vitro.