[Research on preparation and characters of decellularized cartilage matrix for tissue engineering].

OBJECTIVE: To produce a decellularized cartilage matrix (DCM) and investigate its possibility to be used as a scaffold for tissue engineering.

METHODS: Fresh bovine articular cartilage from knee joints was sliced, freeze-dried and freeze-ground into fine powder, and then was treated sequentially with Trypsin, Triton X-100 and hypotonic solution for decellularization. The decellularized matrix was freeze-dried for shaping and cross-linked by UV radiation. Histological, immunohistological, SEM, porosity assays and biomechanical assays were used to characterize the DCM. BMSCs were isolated from rabbit bone marrow aspirate and cultured in DCM extraction medium of different concentration (100%, 10% and 1%) for 0, 24, 48 and 72 hours, respectively, to detect the release rate of the lactate dehydrogenase (LDH). The DMEM medium (5% FBS) served as the control. Biocompatibility was evaluated using BMSCs (1 x 10(7)/mL) cultured with DCM.

RESULTS: The DCM showed white spongy appearances, and histological analysis showed that the material was constructed by cartilage particles without any cells or cell fragments left in the matrix. Immunohistology staining and alcian blue staining showed that DCM retained the collagen and glycosaminoglycan components of cartilaginous matrix. SEM scanning showed that DCM had a porous spongy-like structure with the aperture ranging 30-150 microm. The porosity assay showed that the average porosity was 89.37% and the average aperture was 90.8 microm. The mechanical assay showed that there was no difference for the compress module before and after the decellularization process, which was (17.91 +/- 0.98) MPa and (15.12 +/- 0.77) MPa, respectively (P > 0.05), but were both statistical different from normal articular cartilage [(26.30 +/- 1.98) MPa, P < 0.05]. The LDH release rate in the DCM extraction medium of different concentration was not significantly different from that in the normal DMEM medium (P > 0.05). The cell adhesion test showed BMSCs grew well on DCM without any signs of growth inhibition.

CONCLUSION: Articular cartilage can be decellularized and fabricated into a scaffold which retains the major components of cartilaginous matrix. DCM has good biochemical, biophysical characteristics and good biocompatibility with cultured BMSCs and may be used as a novel scaffold for tissue engineering studies.