保存时间对兔髌韧带压缩力学性能的影响

Effects of Storage Duration on Compressive Mechanical Properties of Rabbit Patellar Ligament

目的研究保存时间对兔髌韧带压缩力学性能的影响,以期为韧带的离体保存提供参考信息。方法通过万能拉伸试验机,测试兔髌韧带在-20℃下经不同保存时间(36 d内)后的压缩力学性能,通过扫描电镜观察胶原纤维的微观形态,差示扫描量热法检测胶原纤维的热焓和变性温度。结果随着保存时间的增加,髌韧带在40%应变下压应力由19 kPa增至112 kPa,随后降至57 kPa。扫描电镜下观察发现,胶原纤维交联先增强后减弱。差示扫描量热法结果显示,热焓由59.47 J/g增至67.10 J/g,随后降至54.43 J/g;而变性温度由67.62℃增至77.28℃,随后降至64.10℃。结论兔髌韧带在-20℃下保存,随着保存时间的增加,韧带的抗压强度先增强后减弱。该变化可能是胶原纤维的交联程度差异所致,胶原纤维的交联越强,压缩力学性能越强。

Objective To study the effect of storage duration on compressive mechanical properties of rabbit patellar,so as to provide references for in vitro ligament storage.Methods The compressive mechanical properties of rabbit patellar ligament storaged at-20℃at different storage durations(in 36 d)were tested with the universal tensile test machine.The microscopic morphology of collagen fibers was observed under the scanning electron microscopy(SEM).The enthalpy and denaturation temperature of collagen fibers were measured with differential scanning calorimetry(DSC).Results With the increase of storage duration,the compressive stress of the patellar ligament at 40%strain increased from 19 kPa to 112 kPa and then decreased to 57 kPa.SEM observation showed that the cross-linking of collagen fibers was initially strengthened and then weakened.DSC results showed that the enthalpy increased from 59.47 J/g to 67.10 J/g and then decreased to 54.43 J/g.The denaturation temperature increased from 67.62℃to 77.28℃and then decreased to 64.10℃.Conclusions When rabbit patellar ligament is stored at-20℃,with the increase of storage duration,the compressive stress of rabbit patellar ligament at 40%strain increases at first and then decreases.This change may be due to the variation of cross-linking level of collagen fibers.The stronger the cross-linking of collagen fibers,the stronger the compressive mechanical properties will be.