Research on a novel bilayered scaffold being used in tissue engineering (TE) of osteochondral repair

[Objective]To explore the potential of a novel collagen I /chitosan /Nanoβ-tricalcium phosphate(β-TCP)bilayered scaffold for being used in tissue engineering(TE)of osteochondral repair.[Method]Bilayered scaffolds were produced with collagen Ⅰ,chitosan andβ-TCP,using a special cross-linking and freeze drying method.The pore size,porosity and interpores of the scaffold were observed by scanning electron microscopy(SEM).Rabbit bone mesenchymal stem cells(BMSC)were isolated and amplified,then inoculated onto the scaffold.By SEM scanning,the condition of the cells adhering onto the scaffold was observed.The proliferation of the cells on the scaffolds was examined using MTT method,and the growth curve was drawn.The cell-scaffold composite were then induced to differentiate towards cartilage by 3-D culturing,and then implanted into muscle pouches 2 weeks later.The result was observed 6 weeks later by HE staining,toluidine blue staining and type Ⅱ collagen immunohistochemistry.[Result]The scaffold possessed high porosity and proper pore size,the porosity was above 95%.BMSC could adhere onto the scaffold well,and the proliferation rate of the cells on the scaffolds was perfectly good.After in vitro induction,BMSC-scaffold composite can differentiate toward cartilage ectopicly.[Conclusion]The novel collagen I /chitosan /β-TCP bilayered scaffold possesses good pore structure and biocompatibility,and will possibly become a new biomaterial of TE used for osteochondral repair.