Your body vs. implants - Kaitlyn Sadtler

翻译人员: Carol Wang 校对人员: Fanny C ai

Insulin pumps improve the lives

全球 4.15 亿糖尿病患者中，

of many of the 415 million people with diabetes around the world

很多人因胰岛素泵而改善了生活。

by monitoring blood sugar, delivering insulin,

胰岛素泵可监测 血糖并释放胰岛素，

and preventing the need for constant finger-pricking and blood testing.

避免了患者 频繁指尖取血检验的麻烦。

These small machines include a pump and a needle, which can sense glucose levels,

这个小机器包括一个泵、

感知血糖水平并将结果返给泵的针，

feed back to the pump,

and then calculate how much insulin to deliver through the needle.

然后计算出针头需注射的胰岛素量。

But they have a catch: they’re temporary.

但存在一个问题：它们是暂时的。

Within a few days, glucose sensors have to be moved and replaced.

几天后，就要更换血糖感应器。

And it’s not just glucose monitors and insulin pumps that have this problem,

并非只是血糖检测仪 和胰岛素泵存在这个问题，

but all bodily implants, at different time scales.

而是所有身体植入物都有， 只是时间不同而已。

Plastic prosthetic knees have to be replaced after about 20 years.

塑料假膝盖大约 20 年后就要更换，

Other implants, such as those used for cosmetic reasons,

其他植入物，如美容植入物，

can meet the same fate in about 10.

大约 10 后也要更换。

That isn’t just a nuisance: it can be expensive and risky.

这不仅仅是麻烦而已： 它既昂贵又有风险。

This inconvenience happens because of our bodies’ immune systems.

由于我们身体免疫系统的缘故， 才会产生这些不便。

Honed by several hundred million years of evolution,

经过数亿年的进化，

these defensive fronts

免疫系统作为防守前锋，

have become exceptionally good at identifying foreign objects.

特别精于发现外来物。

Our immune systems boast

我们的免疫系统

an impressive arsenal of tools to tackle, intercept, and destroy

以拥有强大的工具库而闻名，

anything they believe shouldn’t be there.

But the consequence of this constant surveillance

但这种不断监测的结果是，

is that our bodies treat helpful implants, like insulin pumps,

我们的身体把有用的植入物， 如胰岛素泵，

with the same suspicion as they would a harmful virus or bacteria.

当做有害病毒或细菌一样怀疑。

As soon as the insulin pump has been implanted in the skin,

一旦胰岛素泵植入皮下，

its presence triggers what’s known as a “foreign body response.”

会立刻触发身体的排异反应。

This starts with free-floating proteins

自由漂浮的蛋白质

that stick themselves to the surface of the implant.

开始粘在植入物表面。

Those proteins include antibodies,

这些蛋白质包括抗体，

which attempt to neutralize the new object

试图中和新物体，

and send out a signal that calls other immune cells to the site

并发出信号引来其它免疫细胞

to strengthen the attack.

以加强攻击。

Early-responding inflammatory cells,

早期反应的发炎细胞，

like neutrophils and macrophages,

如中性粒细胞和巨噬细胞，

respond to the emergency call.

在接警后会首先到达。

Neutrophils release little granules filled with enzymes

中性粒细胞释放出充满酶的小颗粒，

that try to break down the surface of the insulin pump’s needle.

试图破坏胰岛素泵针头的表面。

Macrophages secrete enzymes too,

巨噬细胞也会分泌酶，

together with nitric oxide radicals,

与一氧化氮自由基一起

which create a chemical reaction that degrades the object over time.

产生化学反应， 随着时间的推移会使物体降解。

If the macrophages are unable to dispatch the foreign body rapidly,

如果巨噬细胞 无法快速处理掉异物，

they fuse together, forming a mass of cells called a “giant cell.”

它们会融合在一起， 形成一团称为“巨细胞”的细胞。

At the same time, cells called fibroblasts

同时，纤维母细胞

travel to the site and begin to deposit layers of dense connective tissue.

前往该部位，并开始 沉积致密结缔组织层。

Those enclose the needle that the pump uses to deliver insulin

它们封闭了胰岛素泵中

and test for glucose levels.

用于输送胰岛素 并测试血糖水平的针头。

Over time this scaffolding builds up,

包围层逐渐形成，

forming a scar around the implant.

在植入物周围形成疤痕。

The scar functions as an almost impenetrable wall

疤痕就像一面几乎无法穿透的墙，

that might start to block vital interactions

开始阻止

between the body and the implant.

身体和植入物间的重要交互作用。

For example, scarring around pacemakers can interrupt

例如，心脏起搏器周围的疤痕，

the electrical transmission that’s crucial for their functioning.

可能会中断对其功能 至关重要的电传输。

Synthetic knee joints may give off particles as they’re worn down,

合成膝关节使用中磨损会产生颗粒，

causing immune cells to inflame around these fragments.

导致这些颗粒周围的 免疫细胞发炎。

Tragically, the immune system’s attack can even be life-threatening.

不幸的是，免疫系统的攻击 甚至可能危及生命。

However, researchers are finding ways to trick the immune system

然而，研究人员正在寻找方法

into accepting the new devices we introduce into our bodily tissues.

诱使免疫系统接受 我们引入身体组织的新设备。

We’ve discovered that coating implants with certain chemicals and drugs

我们发现通过在植入物表面 涂抹某些化学物质和药物，

can dampen the immune response.

可以抑制免疫反应。

Those basically make the implants invisible to the immune system.

这些基本上使植入物 对免疫系统不可见。

We’re also making more implants out of natural materials

我们正以直接模仿组织的形式，

and in forms that directly mimic tissues,

用天然材料制作更多的植入物，

so that the body launches a weaker attack

比起全人造材料的植入物，

than it would if it came across a completely artificial implant.

身体对它的攻击要弱得多。

Some medical treatments involve implants

有些医学治疗涉及植入物,

designed to regenerate lost or damaged tissues.

旨在重建失去或受损组织。

In those cases, we can design the implants to contain ingredients

这些情况下，我们可将植入物设计为

that will release specific signals,

含有能够释放特定信号的成分、

and carefully tailor our bodies’ immune reactions.

专为应对我们身体的 免疫反应而精心定制。

In the future, this way of working alongside the immune system

未来，这种与免疫系协作的方式

could help us develop completely artificial organs,

可以帮我们开发全人工器官，

totally integrative prostheses,

全集成假体

and self-healing wound therapies.

和自愈的伤口疗法。

These treatments might one day revolutionize medicine–

这些治疗方法可能有一天 会引发医学革命——

and transform, forever, the bodies we live in.

并永远改变我们赖以存在的身体。