世界首个塑料抗体在小鼠实验中获成功

World's first plastic antibody works in mice
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$ z7 z  f' N) M" s) m- kFor similar stories, visit the Nanotechnology Topic Guide
Antibodies made entirely from plastic have saved the lives of mice injected with bee venom – the first time such a strategy has worked in live animals.

Researchers developing the antibodies say it is the first step towards customised antibodies for a host of other medical applications, from treating people who have been poisoned to combating infection.
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Natural antibodies are made by the body's immune system to lock onto a specific "antigen". Likewise, the plastic antibodies contain cavities moulded in exactly the right shape to capture target molecules, in this case, melittin – the active agent in bee venom.

Faking it

Kenneth Shea of the University of California at Irvine led the team which made melittin antibodies through a process called molecular imprinting. They used a catalyst to stimulate polymers to form around molecules of bee venom, then dissolved away the venom itself, leaving empty cavities with the exact shape to trap melittin.

) J  U! C& b# }* [. K# HShea injected these tiny plastic nanoparticles into mice 20 seconds after they'd been injected with bee venom, 60 per cent survived whereas all the untreated mice died. The plastic antibodies were then destroyed by the liver.
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/ q8 s( Z0 H% @$ \"We conclude that imprinted polymer nanoparticles efficiently capture melittin in the bloodstream," say Shea and his colleagues in the paper.
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% ], T7 _3 u% T0 ~" q- k, p"We see this as a very significant paper, and the first demonstration in living things of these materials, effectively using them as a drug," says Mike Whitcombe, whose lab at Cranfield University in the UK develops imprinted polymers and runs a database of the polymers available.
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Plastic copycats

Philipp Holliger of the Laboratory of Molecular Biology in Cambridge, UK, said that the plastic antibodies do perform some of the functions of natural antibodies – capturing toxins and sending them to the liver for destruction. "These properties should make them attractive alternatives to antibodies in antidote anti-toxin treatments," he says.
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However, Holliger doubts whether they could perform other important functions of natural antibodies, such as priming the body's immune system to fight future infections. Unlike natural antibodies, they are not equipped to communicate with other cells and components of the immune system.

Journal reference: Journal of the American Chemical Society, DOI: 10.1021/ja102148f

$ a# f# n  B2 z1 u# @3 G. Hhttp://www.newscientist.com/arti ... -works-in-mice.html

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' w  r( Z* M2 B世界首个塑料抗体在小鼠实验中获成功

, `" k* y+ h3 ~  ^撰文：Andy Coghlan
《新科学家》2010年6月11日11:07报道

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# B- s" m; r1 n/ G! M# H完全由塑料构成的抗体已经挽救成功中了蜂毒的小白鼠性命 —— 这样一种治疗策略在活体动物起作用尚属首次。

开发这种抗体的研究者说，本实验的成功是定制抗体以提供其它方面的多种多样的医学用途所迈出的第一步， 包括治疗人类中毒、对抗感染等等。
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2 ^' N, v. O) m+ w8 p- _/ ^% T天然抗体是体内的免疫系统自动跟踪一特定“抗原”时产生的。与此相同，塑料抗体包含的空腔形态与要捕获的目标分子丝丝相扣、严密合一。在本实验中，目标分子是蜂毒肽，即蜂毒中的活性成分。

“剪径的李鬼”
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. X' b: T0 G0 H8 \' A4 Z* I+ K3 ^美国加州大学欧文分校的Kenneth Shea领导了这支通过“分子印记”过程制造出蜂毒肽抗体的研究团队。他们用了一种催化剂以促使高分子材料在蜂毒分子周围成型，然后将蜂毒本身溶解掉，这样就留下了空穴，其准确的形状可以诱捕蜂毒肽。
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( J! p0 z# d' L3 W3 ?! J4 m在小白鼠被注射蜂毒二十秒后，Shea 将这些微小的塑料纳米粒子注射进小鼠体内，60%的小鼠得以存活了下来，而未得到治疗的小鼠则全部死亡。接着塑料抗体被肝脏分解破坏。
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Shea及其同事在其论文中说：“我们由此得出结论：印记聚合纳米粒在血液中有效捕获了蜂毒肽。”
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“我们认为这是一篇非常重要的论文，首次显示了这些物质在活体内的表现， 事实上可以将它们作为药物来用。”英国克兰菲尔德大学实验室的Mike Whitcombe说。其实验室开发的是印记聚合物（高分子材料）并拥有一目前已投入使用并提供服务的聚合物数据库。

塑料复制机
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3 O6 Y  l& y; h0 U2 E英国分子生物学实验室剑桥实验分室的Philipp Holliger说，塑料抗体确实具有天然抗体的功能 —— 捕获毒素并传送到肝脏解毒。“这些性质应该使它们在解毒治疗中成为抗体的有魅力的替代物。”
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不过， Holliger 怀疑它们是否具有天然抗体的其它重要功能，比如让免疫系统为未来的感染作好备战工作。跟天然抗体不同，塑料抗体还没有与其它细胞与免疫系统成员进行交流的装备。”
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参考文献：
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" a- U* p6 S" m7 ?  C& pJournal reference: Journal of the American Chemical Society, DOI: 10.1021/ja102148f
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