人工脾脏:血液病原体“吸尘器” 快速清除细菌和病毒
2014/09/16
近日,科学家们发明了一种可快速清除血液中病原体的先进设备——“人工脾脏”。该设备不仅可以清除大鼠血液中90%以上的大肠杆菌和金黄色葡萄球菌,并且对清除HIV和埃博拉病毒同样有效。目前,研究人员正在猪身上测试“人工脾脏”,新技术有望在几年内进入临床应用。


“人工脾脏”上的纳米珠结合大肠杆菌(左)和金黄色葡萄球菌(右),并从血液中将它们清除。

近日,发表在《Nature Medicine》上的一项研究中,科学家发明了一种清除体内感染病病源(即便是连病原体都不知道的感染病)的高科技方法。这项先进的设备叫做“人工脾脏”,可快速清除血液中的一切有害物质,从大肠杆菌到埃博拉病毒。

血液感染非常难治疗,会导致一种致命的免疫反应——败血症。医生通常很难判断出引发败血症的具体原因,所以他们使用抗生素广泛对抗未知的病原体。这种方法并不总是奏效,很容易导致细菌的抗生素耐药性。

创新:MBL结合磁性纳米珠

波士顿怀斯生物工程研究所的生物工程师Donald Ingber领导的研究小组发明了一种可以清除任何病原体的新方法——“人工脾脏”。“人工脾脏”可对血液进行过滤,清除掉其中的有害物质。该设备使用了改版的甘露糖结合凝集素(MBL)。MBL,一种蛋白质,是人体中先天性免疫系统的重要成分之一,它能够结合超过90种细菌、病毒和真菌表面的糖分子以及引发败血症的细菌释放的毒素。

研究人员在MBL表面涂上有磁性的纳米珠( nanobeads,编者译),形成MBL结合纳米珠(MBL-NB)。当血液进入“人工脾脏”设备, MBL-NB会结合大多数的病原体。然后,“人工脾脏”上的一块磁铁将纳米珠和它们的“猎物”从血液中一起吸出来。


“人工脾脏”利用蛋白结合纳米珠以及磁铁净化血液中病原体。

效果:血液有害物质“吸尘器”

为了检测该设备, Ingber 和他的团队用大肠杆菌和金黄色葡萄球菌感染大鼠,随后用“人工脾脏”过滤被感染的动物的血液。感染5小时后,89%血液被过滤的大鼠依然存活着,而没接受血液过滤的大鼠只有14%存活。该设备清除了大鼠体内90%以上的细菌,血液被过滤的大鼠在肺部和其它器官只有轻微的炎症,表明它们不易患败血症。

研究人员还对“人工脾脏”能否处理一个成年人的平均血液体积(约5升)进行了测试,他们将含有细菌和真菌的人血以每小时1升的速度通过“人工脾脏”,发现该设备在5小时之内清除了血液中大多数的病原体。

“人工脾脏”清除了血液中大量的病原体后,抗生素和免疫系统就能够与剩下的少数病原体对抗,这就表明,“人工脾脏”清除病原体的效果将能够有效的控制感染。

Ingber 表示,“人工脾脏”同样可以帮助治疗病毒疾病,包括HIV和埃博拉病毒。只有清除患者血液中HIV和埃博拉病毒,使它们的含量达到可以忽略不计的水平,患者才能生存。研究小组目前正在猪身上测试这款“人工脾脏”。

伦敦大学的感染和免疫学专家Nigel Klein称,“人工脾脏”还可以从血液中收集病原体,从而测试哪种药物对这种病原体最有效。目前,输血和血液过滤已经是很常用的技术,这项设备有望在几年内进入临床应用。

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