Abstract: Objective To investigate the application of tissue engineering cartilage using PKH26 and molecular light imaging system. Method Canine chondrocyte was labeled by fluorescent dye PKH26 and seeded at a density of 5×107 cells/ml into the porous cartilage acellular matrix scaffold. The cells/scaffold constructs were cultured in vitro for 1 week. After that the construct were implanted into the dorsal pocket of nude mice. We utilized a molecular light imaging system to macroscopically image cells/scaffold constructs in vivo with fluorescence at 4 weeks, and merged with X-rays got at the same position. The fluorescence images were compared with the histological and immunofluorosence results of tissue-engineered cartilage-like tissue in vivo. Results Luminescent images were acquired at the 4 weeks, a red color enhanced overlay of the luminescent image over x-ray photographic image demonstrated the location of the implants and that cell viability and cell growth on porous CACM scaffold in vivo was very well. Histological results show that the safranin O, tuoluidine blue and anti-coll II immunohistochemistry stain of tissue-engineered cartilage-like tissue is positive. Immunofluorescence examination demonstrated chondrocytes in the constructs showed red fluorescence, and anti-collogen II immunofluoresence staining was green fluorescence. Conclusion This study outlines a non-desturctive method to evaluate cell growing on tissue engineering constructs in vivo using PKH26 and molecular light imaging system.

Key words: cartilage tissue engineering, chondrocyte, fluorescence