Abstract: Objective To test the feasibility of in vitro generation of a full-sized and ear-shaped cartilage with remnant ear chondrocytes derived from individual microtia patient. Methods The initial cell yield of remnant ear chondrocytes was analyzed from 40 cases of microtia. Proliferation was tested by MTS and expansion efficiency was calculated. The chondrocytic phenotype altering after continuous passages was characterized by immunofluorence staining and PCR. P3~P4 chondrocytes were seeded onto the PGA/PLA scaffold with the shape and full size of adult human ear. The complex was cultured with a redifferentiation system composed of chondrogenic factors, alginate gel, and a rotating culture device. Results The initial cell yield from remnant ear tissue was（3.90±1.27）×106/g. The proliferative ability of remnant ear chondrocytes from P1~P4 passages was enhanced by adding bFGF, and the amplification of the cells expanded to P4 could reach around（328.4±50.4）folds. However, the COLII and ACAN expressions gradually declined with passages and became negative in P4 chondrocytes whereas COLI expression showed stronger. The neo-cartilage in the experimental group maintained the ear shape well and formed cartilaginous structure with positive staining of Safranin O, Toludine Blue, and COLII, while the control group failed to form cartilage tissue and only showed fibrous structure. Conclusion A full-sized and ear-shaped cartilage could be engineered in vitro by the passaged remnant ear chondrocytes derived from individual microtia under a redifferentiation culture system.

Key words: microtia, remnant ear chondrocyte, ear-shaped cartilage, tissue engineering