目的观察不同频率周期性压力对组织工程软骨的影响。方法将兔关节软骨细胞接种到PLGA支架上,随机分成4组。A、B、C组分别在频率为0.01、0.1、1Hz的周期性压力(强度0~200kPa)下培养;D组不加压,为对照组。2周后采用组织化学,免疫组织化学法观察四组工程软骨的细胞增殖及基质分泌。并定量检测硫酸糖氨多糖(GAG)含量。结果四组之间Ⅱ型胶原染色面积百分比及GAG含量差异均有统计学意义(分别F=478.379,P〈0.01;F=67.402,P〈0.01)。其中B组工程软骨细胞最多,排列规则,Ⅱ胶原染色面积百分比[(83.95±2.23)%]和GAG含量[(476.33±25.66)μg]最高(P〈0.01)。结论周期性压力对软骨细胞的新陈代谢具有促进作用,其中0~200kPa、0.1Hz频率的周期性压力能最好的促进软骨细胞增殖,合成Ⅱ胶原、GAG等细胞外基质。
Objective To explore the effects of cyclic pressure at different frequencies on the construction of tissue-engineering cartilage. Methods Chondrocytes were obtained from articular cartilages of freshly killed 3-day-old rabbits. Three-dimensional cartilage tissue was produced using PLGA scaffold as a carrier. All samples were cultured in bioreactor ( Celdyne HFB-40). Four different culture conditions were examined:group A (0-200 kPa,0.01 Hz) ,group B (0-200 kPa,0.1 Hz) ,group C (0-200 kPa, 1 Hz) ,group D ( no pressure). After culture for 2 weeks in each group,the level of GAG in each sample was measured. Macroscopical, histological and immunohistochemical analyses were performed. Results There were significant differences in type Ⅱ collagen and GAG among the 4 groups ( F = 478. 379, P 〈 0.01;F = 67. 402, P 〈 0.01 respectively). In the group B, tissue-engineering chondrocytes were the most, and produced the most type Ⅱ collagen [ ( 83.95 ± 2.23 ) % ) ] and GAG [ (476.33 ± 25.66) μg ] among 4 groups ( P 〈 0.01 ). Conclusion The cyclic pressure (0-200 kPa,0.1 Hz) effectively promotes chondroeytes to synthesize and secrete extracellular matrix just as GAG and type Ⅱ collagen in 4 groups, suggesting that cyclic pressure at different frequencies have important effects on metabolism of tissue-engineering cartilage.