Assessment of tissue-engineered cartilage tissues with soluble protein 100 and alpha-actin

Ji Ling1，Yang Lin2，Wu Yan-ge2，Wang Zheng2

1 Department of Laboratory Medicine, 2 Department of Thoracic Surgery, Shenzhen People's Hospital, the Second Clinical Medical College of Jinan University, Shenzhen 518020, Guangdong Province, China

Ji Ling☆, Doctor，Associate professor, Department of Laboratory Medicine, Shenzhen People's Hospital, the Second Clinical Medical College of Jinan University, Shenzhen 518020, Guangdong Province, China
Jilingdd@yahoo.com

Correspondence to: Yang Lin, Doctor, Associate chief physician, Department of Thoracic Surgery, Shenzhen People's Hospital, Second Clinical Medical College of Jinan University, Shenzhen  518020, Guangdong Province, China Yanglin70@yahoo. Com

Supported by: the National Natural Science Foundation of China, No.30500499*

Received: 2008-02-03

Abstract
BACKGROUND: Alcian blue staining protocol is usually used to identify cartilage tissues, however, it cannot show the secretion of extracellular matrix well in the early formation stage of tissue-engineered cartilage tissues.
OBJECTIVE: To observe the feasibility to identify artificial tissue-engineered cartilage with soluble protein 100 antigen and α-actin antigen immunohistochemical method.
DESIGN，TIME AND SETTING: A contrast observation was carried out between December 2006 and February 2008 in the Medical Science Research Center of Shenzhen People's Hospital, Shenzhen, Guangdong, China.
MATERIALS: Sprague-Dowly rats of SPF grade, aged 2 weeks, weighing 50-60 g, were used to culture xiphoid chondrocytes; DegraPol scaffolds, 20 mm long, 0.75 mm thickness, internal/outer diameter 2.5/4 mm, were provided by Swiss Federal Institute of Technology (Zurich).
METHODS: Passage 3 xiphoid chondrocytes were harvested and seeded onto DegraPol scaffolds to from chondrocyte-polymer composites, and were implanted in the greater omentum of homologous rats to culture in vivo for 1 week following 3-week in vitro static culture. The chondrocyte-polymer composites were harvested after 3-week in vitro static culture and 1-week in vivo culture, respectively, to perform HE staining and soluble protein 100 and α-actin immunohistochemical staining.
MAIN OUTCOME MEASURES: Changes of chondrocyte-polymer composite were observed under inverted microscope; identification of chondrocytes was performed by immunohistochemistry staining.
RUSULTS：After 3-week in vitro static culture, HE staining showed that chondrocytes were in cartilage lacunas and cartilage matrix was stained blue. After implanting chondrocytes and culturing for 3 weeks, the inner side of scaffold was soluble protein 100-positive and α-actin-negative, which indicates chondrocyte-polymer composite has formed new tissue-engineered cartilage layer before implanting in the greater omentum of homologous rats. After 1-week in vivo culture, the obtained tissues were mixed cell structures, soluble protein 100 positive reactions concentrated in the inner side of the scaffold and α-actin positive reactions concentrated in the outer side of the scaffold.
CONCLUSION: Cartilage tissue was soluble protein 100-positive and connective tissue was α-actin-positive, soluble protein 100 and α-actin can be used as indices of tissue-engineered cartilage tissues.

Ji L，Yang L，Wu YG，Wang Z. Assessment of tissue-engineered cartilage tissues with soluble protein 100 and alpha-actin.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(28):5554-5557
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