A novel bilayered scaffold constructed with cartilage extracellular matrix/acellular bone matrix for osteochondral tissue engineering

Abstract

Objective To fabricate a novel bilayered scaffold constructed with cartilage extracellular matrix (CECM) and acellular bone matrix (ACBM) for osteochondral tissue engineering.Methods The bone layer of the osteochondral scaffold was prepared using canine bone cancellous bone columns, and the cartilage layer was fabricated using CECM.After CECM microfilaments were decellularized, the biphasic scaffolds were fabricated by soaking the ACBM columns into cylindrical silicon moulds with a 30 g/L CECM suspension using simple freeze-drying method.After the scaffolds were cross-linked, the porosity was measureed.MTT test was also done to assess cytotoxicity of the scaffolds.Canine bone marrow-derived mesenchymal stem cells (BMSCs) were induced by chondrogenic medium and seeded into novel scaffold.Cell proliferation and differentiation were analyzed using inverted microscopy, scanning electron microscopy (SEM)and Dead/Live staining method.Results SEM and Micro-CT revealed a 3-D interconnected porous structure, with the CECM pore diameter of 155 ± 34 μm and the porosity of 91.3% ± 2.0%.Cytotoxicity testing with MTT revealed no significant difference in absorbance among different extracts, showing no cytotoxic effect of the scaffold on BMSCs.Inverted microscopy and SEM showed that the novel scaffold could provide a suitable 3-D environment to support the adhesion, proliferation and differentiation of BMSCs to chondroeytes in culture with chondrogenic medium.Confocal microscopy of cell-scaffold constructs revealed cells with green fluorescence.Conclusion Since the novel CECM/ACBM bilayered integrated osteochondral scaffold has good mircostructure, non-toxicity and good biocompatibility, it may be a suitable candidate as an alternative cell-carrier for osteochondral tissue engineering. Key words: Tissue engineering; Extracellular matrix; Bone marrow cells; Scaffold