携sialyl Lewis^X靶向微泡与P-选择素Fc段黏附特征的体外研究

In Vitro Evaluation of the Adhesive Characteristics of Microbubbles with sialyl Lewis^X Targeted to Fc Segment of P-selectin

目的探讨携sialylLewisX靶向超声微泡(MB-SLex)与P-选择素Fc段(PSFc)的结合和解离特征,并与携抗ICAM-1单抗靶向超声微泡(MB-ICAM)比较。材料与方法构建MB-SLex、MB-ICAM与携同型抗体IgG1微泡(MB-C)后,应用平行板流动腔装置,在结合实验中观测MB-Slex、MB-ICAM及MB-C通过小鼠PSFc、小鼠ICAM-1抗原包被培养皿时,在低剪切应力(0.5dyn/cm2)、高剪切应力(4.0dyn/cm2)和不同时间点各种微泡的结合数量、滚动数量,以及在解离实验中各测定种微泡达到半数解离的剪切应力。结果在0.5dyn/cm2剪切应力下,MB-Slex和PSFc每分钟微泡的结合数量(结合率)与MB-ICAM和ICAM-I抗原的结合率相比差异无统计学意义(P>0.05);而在4.0dyn/cm2剪切应力下MB-Slex的结合率明显大于MB-ICAM(P<0.05)。结合实验可见MB-Slex每分钟微泡的滚动数量无论在0.5dyn/cm2还是4.0dyn/cm2均明显大于MB-ICAM(P<0.05)。而MB-C与PSFc及ICAM-1抗原均未见明显结合,亦未见明显MB-C滚动现象。MB-Slex半数解离的剪切应力小于MB-ICAM(P<0.05)。结论 MB-SLex能与PSFc在高剪切应力下结合,应用sialylLewisX为靶向诱导分子可能构建出在高速血流下与血管内皮细胞的靶分子特异结合的靶向超声微泡。

Purpose To evaluate the adhesive characteristics of microbubbles with sialyl Lewis X（MB-SLex） targeted to Fc segment of P-selectin（PSFc） and compare with those of microbubbles with anti-ICAM-1 monoclone antibody（MBICAM） to ICAM-1 antigen in vitro.Materials and Methods MB-SLex,MB-ICAM and microbubbles with isotype IgG1（MB-C） were prepared.The attachment and detachment of MB-SLex to PSFc and MB-ICAM to ICAM-1 antigen in the shear stress of 0.5 dyn/cm 2 and 4.0 dyn/cm 2 were assessed in a parallel-plate flow chamber,meanwhile MB-C was served as a control.Results The attachment rate of MB-SLex targeted to PSFc in the shear stress of 0.5 dyn/cm 2 was similar to that of MB-ICAM targeted to ICAM-1 antigen.Only at the condition of 4.0 dyn/cm 2,the attachment rate was significantly higher in the MB-Slex group than the MB-ICAM group（P〈0.05）.However,the rolling number of MB-SLex on PSFc was greater than that of MBICAM on ICAM-1 antigen（P〈0.05） in both 0.5 and 4.0 dyn/cm 2.As compared with MB-SLex and MB-ICAM,the attachment and rolling number of MB-C targeted to ICAM-1 antigen were very limited（P 0.05）.The shear stress of half detachment in MB-SLex was smaller than that in MB-ICAM at the detaching test（P〈0.05）.Conclusion MB-SLex targeted to PSFc is quick but not firm at high shear stress.sialyl Lewis X can be used as adhesion-inducing molecules in the construction of sitetargeted microbubbles,which can have sufficient and specific adhesion efficacy in high-shear flow.