Abstract: Objective:To investigate the effect of cartilage tissue engineering scaffold PVA/ι-CA on the biological behavior of the ATDC-5 cells,and to evaluate its feasibility on constructing tissue engineering cartilage. Methods:The polyvinyl alcohol(PVA) and carrageenan were used to make the composite scaffold material PVA/ι-CA according to a certain proportion by physical blending technology and repeated freezing thawing method,and the porosity and pore size of PVA/ι-CA were detected.The ATDC-5 cells were seeded into the composite scaffold and its growth was observed; the expressions of collagen type Ⅱ in the ATDC-5 cells were tested by immunohistochemical staining and immunofluorescence staining;the morphology of the ATDC-5 cells was confirmed by Toluidine blue staining. The growth and secretion of extracellular matrix of the ATDC-5 cells were observed under scanning electron microscope(SEM);the proliferative rates of ATDC-5 cells in composite scaffold materials in negative control group (added with DMEM culture media) and experimental group(added with DMEM contain scaffold) were determined by MTT assay. The composite scaffolds were implanted subcutaneously in the SD rats.The histocompatibility and vascularization in vivo of the composite scaffolds were evaluated. Results:The average porosity of cartilage tissue engineering scaffold PVA/ι-CA was (86.88±3.88)%,and the average pore size was 20-40 μm.The HE staining results showed that the ATDC-5 cells grew well with the polygon and plumpness morphology. All the samples were stained positive for collagen type Ⅱ by immunohistochemistry and immunofluorescence staining, which verified the normal phenotype of chondrocytes on the scaffolds. All the sample were stained positive for toluidine blue staining, which verified ECM deposition of the ATDC-5 cells on the scaffolds.The number of the positive cells was significantly increased with the prolongation of time. After cultured for 7 d,few of the ATDC-5 cells presented polygonal; after cultured for 14 d,the ATDC-5 cells distributed more densely,and contacted with each other on the scaffold; after cultured for 21-28 d,the ATDC-5 cells filled the interconnected pores of the scaffolds, synthesizing a significant amount of neo-formed ECM. The proliferation of ATDC-5 cells in PVA/ι-CA grew fast during 7-14 d,and it became slow during 21-28 d;the difference was not statistically significant compared with control group(P>0.05).The subcutaneous implantation results showed the inflammatory reactions were slight at the early stage and eviated gradually,there was an increasing angiogenesis at the late stage,and the degradation and absorption of the meterial were slight. Conclusion:PVA/ι-CA composite material will be an ideal material for the cartilage tissue engineering.

Key words: cartilage tissue engineering, polyvinyl alcohol, carrageenan, biocompatibility