梯度乙醇脱脂对异体松质骨脱脂效果及力学性能的评估

Defatting effect of gradient alcohol treatment on cancellous bone allograft and the biomechanical properties of defatted cancellous bone allograft

背景:脱脂被认为是获取同种异体骨移植材料的首要程序,但当前的脱脂方法无法避免有机溶剂的残留问题。目的:观察梯度乙醇脱脂的脱脂效果及该方法是否会降低骨的力学性能。方法:从人的股骨髁中获取新鲜松质骨块60粒,根据脱脂处理的不同平均分为3组,分别是梯度乙醇组、丙酮组及新鲜组(对照组)。大体观察骨块的大体形状以及材料的形态和色泽;采用索氏提取法测定脱脂处理后骨块的剩余脂质含量;采用红外光谱法观察不同脱脂方法处理后骨块内各种成分的变化;最大应力和弹性模量用于评价脱脂处理对骨块力学性能的影响。研究方案的实施符合天津医院的相关伦理要求。结果与结论:①大体观察见新鲜骨块呈黄色且孔隙中含量大量脂肪,脱脂处理的骨块呈白色且多孔网状结构清晰;②梯度乙醇组和丙酮组骨块的剩余脂质含量差异无显著性意义(P=0.385);③红外光谱图显示,2种脱脂方法的脱脂效果相近,且对骨中其他成分,如PO43-、碳酸盐及羟基磷灰石等无影响;④力学性能检测显示,新鲜组、梯度乙醇组和丙酮组骨块分别进行两两比较,3组间的最大应力和弹性模量差异均无显著性意义;⑤结果表明,梯度乙醇脱脂与传统的丙酮溶剂萃取脱脂效果相似,且该方法不会降低骨的力学性能。

BACKGROUND:Defatting is considered to be the primary procedure for obtaining bone allograft.However,the current defatting method cannot avoid the problem of residual organic solvents.OBJECTIVE:To investigate the defatting effect of gradient alcohol treatment and whether this defatting method can reduce the mechanical properties of bone.METHODS:Sixty pieces of fresh cancellous bone mass were obtained from human femoral condyles.They were divided into three groups according to different defatting treatments:gradient alcohol group,acetone group,and fresh group(control group).The general shape of the bone mass and the morphology and color of the cancellous bone allograft were observed with the naked eye.Soxhlet extraction was used to determine the residual lipid content of the bone mass after defatting.Infrared spectroscopy was used to observe the changes of various components in the bone mass after different defatting treatments.The maximum stress and elastic modulus were used to evaluate the effect of defatting treatment on the biomechanical properties of bone mass.RESULTS AND CONCLUSION:(1)Gross observation revealed that fresh bone mass was yellow with a large amount of fat in the pores,and the defated bone mass was white with a clear porous network structure.(2)There was no statistical difference in residual lipid content between the gradient alcohol and the acetone groups(P=0.385).(3)Infrared spectroscopy showed that the defatting effects of the two defatting treatments were similar and had no effect on other components in the bone,such as PO43-,carbonate,and hydroxyapatite.(4)Biomechanical tests showed that there were no significant differences in the maximum stress and elastic modulus between groups.(5)These results suggest that the defatting effect of the gradient alcohol treatment is similar to that of the traditional acetone solvent extraction,and gradient alcohol treatment cannot reduce the biomechanical properties of bone.