可吸收支架负载外泌体方法研究

Research on the method of loading exosomes onto absorbable stents

目的探讨一种将外泌体负载于可吸收支架的方法。方法应用化学连接法,通过建立支架-氨丙基三乙氧基硅烷-二硬脂酰磷脂酰乙酰胺-聚乙二醇5000-外泌体的连接使可吸收支架负载外泌体,构建外泌体洗脱可吸收支架。扫描电镜观察支架表面及外泌体吸收情况,飞行时间质谱对支架表面物质进行鉴定,原子力显微镜检测支架表面粗糙程度,体视显微镜观察支架外观及外径,径向力检测仪检测支架力学强度;以单纯可吸收支架作为对照。结果扫描电镜观察示外泌体洗脱可吸收支架表面有细小不规则裂纹以及许多外泌体颗粒。原子力显微镜示5μm2取样范围其表面粗糙程度为±70 nm,而可吸收支架为±20 nm。飞行时间质谱检测示外泌体洗脱可吸收支架与外泌体在质荷比(mass charge ratio,m/z)处均有峰值,而可吸收支架无此峰值;并且外泌体洗脱可吸收支架m/z73处峰值较可吸收支架明显降低。体视显微镜观察示外泌体洗脱可吸收支架外径在可吸收支架规格范围内且表面无明显裂纹、毛刺及凹陷;径向强度检测结果符合原可吸收支架径向强度标准。结论应用化学连接法可以将外泌体负载于可吸收支架表面,并且支架尺寸、径向强度均符合原可吸收支架标准。

Objective To explore a method of loading exosomes onto absorbable stents.Methods By building a stent-(3-aminopropyl)triethoxysilane-1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)5000]-exosomes connection,the exosomes were loaded onto absorbable stents to obtained the exosome-eluting absorbable stents.The surface conditions of the stents and absorption of exosomes were observed by scanning electron microscope and identified through the time-of-flight mass spectrometry;the roughness of the stents’surfaces was observed by atomic force microscope;the appearances and sizes of the stents were observed by stereomicroscope;and the radial force was tested by tensile test machine.The absorbable stents were used as control.Results The scanning electron microscope observation showed that the exosome-eluting absorbable stents had some small irregular cracks on the surface where many exosomes could be seen.The atomic force microscopy observation showed that within the range of 5μm2,the surface roughness of the absorbable stents was±20 nm,while the surface roughness of the exosome-eluting absorbable stents was±70 nm.In the results of time-of-flight mass spectrometry,both the exosome-eluting absorbable stents and exosomes had a peak at the mass charge ratio of 81(m/z 81),while the absorbable stents did not have this peak.The peak of exosome-eluting absorbable stents at m/z 73 showed a significant decrease compared to the absorbable stents.The stereomicroscope observation showed that the sizes of exosome-eluting absorbable stents met standards and the surfaces had no cracks,burrs,or depressions.The radial force results of the exosome-eluting absorbable stents met the strength standards of the original absorbable stent.Conclusion By applying the chemical connection method,the exosomes successfully loaded onto the absorbable stents.And the sizes and radial forces of this exosome-eluting absorbable stents meet the standards of the original absorbable stents.