to want to improve our health and minimize our suffering.

誰もが 健康を改善したり

Whatever life throws at us,

肉体的苦しみを最小限に留め

whether it's cancer, diabetes, heart disease,

我が身に起る事が

or even broken bones, we want to try and get better.

癌 糖尿病 心臓病または骨折と

Now I'm head of a biomaterials lab,

それが何であろうと 良くなりたいと思うものです

and I'm really fascinated by the way that humans

私は生体材料研究所の所長ですが

have used materials in really creative ways

過去 様々な材料が 独創的な方法で人体に

in the body over time.

使われてきたということに

Take, for example, this beautiful blue nacre shell.

とても感心させられます

This was actually used by the Mayans

例えば この貝の青い真珠層をご覧下さい

as an artificial tooth replacement.

これはマヤ族が歯のインプラントに

We're not quite sure why they did it.

実際 使っていました

It's hard. It's durable.

その理由はよく分かりませんが

But it also had other very nice properties.

硬く長持ちし

In fact, when they put it into the jawbone,

他にもとても良い特質があります

it could integrate into the jaw,

顎に入れると

and we know now with very sophisticated

顎骨と融合するのです

imaging technologies

高度画像技術で

that part of that integration comes from the fact

分かっている

that this material is designed

融合の理由は この材料の

in a very specific way, has a beautiful chemistry,

用途によく合ったデザイン

has a beautiful architecture.

そして素晴らしい化学的性質と

And I think in many ways we can sort of think

構造にありました

of the use of the blue nacre shell and the Mayans

あらゆる意味で

as the first real application

マヤ族の青い真珠層を持つ貝の使い道は

of the bluetooth technology.

まさしく最初の

(Laughter)

ブルートゥース技術だ なんて思ったりします

But if we move on and think throughout history

（笑）

how people have used different materials in the body,

先に進んで 歴史を通して

very often it's been physicians

人類が体に様々な種類の材料を 使ってきたことを考えてみると

that have been quite creative.

創意工夫をしてきたのは 医師の場合が多く

They've taken things off the shelf.

彼らが様々な発明をしてきました

One of my favorite examples

その中でも 私のお気に入りは

is that of Sir Harold Ridley,

サー・ハロルド・リドリーのものです

who was a famous ophthalmologist,

彼は有名な眼科医で—

or at least became a famous ophthalmologist.

少なくとも そうなったのですが—

And during World War II, what he would see

第２次世界大戦中 彼は

would be pilots coming back from their missions,

戦線から戻って来たパイロットを見て

and he noticed that within their eyes

彼らの目の中に

they had shards of small bits of material

小さな異物のかけらが 入っているのに気がつきました

lodged within the eye,

興味深いことに

but the very interesting thing about it

その物質は炎症反応を

was that material, actually, wasn't causing

全く引き起こしていなかったのでした

any inflammatory response.

調べて分かったことは

So he looked into this, and he figured out

その物質は 小さなプラスチックのかけらで

that actually that material was little shards of plastic

スピットファイア戦闘機の天蓋から 来る物でした

that were coming from the canopy of the Spitfires.

それで彼はこの物質を

And this led him to propose that material

新しい眼内レンズの素材 として提唱したのです

as a new material for intraocular lenses.

PMMAと呼ばれるもので

It's called PMMA, and it's now used

毎年 何百万人の人の目に

in millions of people every year

白内障を防ぐ為に使われています

and helps in preventing cataracts.

この例は

And that example, I think, is a really nice one,

昔は機械的機能をさせる為に

because it helps remind us that in the early days,

よく生体不活性材料が 選ばれ

people often chose materials

使われていた ということを 示しています

because they were bioinert.

生体不活性材料を体に入れても

Their very purpose was to perform a mechanical function.

拒絶反応はありません

You'd put them in the body

しかし ここで私が述べたい事は

and you wouldn't get an adverse response.

再生医療は

And what I want to show you is that

生体不活性材料から

in regenerative medicine,

全く離れたということです

we've really shifted away from that idea

我々が積極的に探している材料は

of taking a bioinert material.

生体と作用する 生体活性材料で

We're actually actively looking for materials

生体内に入れられると

that will be bioactive, that will interact with the body,

そこで機能し

and that furthermore we can put in the body,

時が経つにつれ 生体内に吸収されるものです

they'll have their function,

このチャートをご覧下さい

and then they'll dissolve away over time.

これが示しているのは

If we look at this schematic,

細胞組織工学の 典型的アプローチです

this is showing you what we think of

普通患者から細胞を取り

as the typical tissue-engineering approach.

それを材料に入れ

We have cells there, typically from the patient.

非常に複雑なものに することもでき—

We can put those onto a material,

実験室で増殖するか

and we can make that material very complex if we want to,

患者の体に直接 戻すか どちらでもできます

and we can then grow that up in the lab

これが世界中で そして

or we can put it straight back into the patient.

我々の実験室でも 行われている方法です

And this is an approach that's used all over the world,

幹細胞について 本当に大切なことの１つは

including in our lab.

幹細胞は あらゆる組織に分化でき

But one of the things that's really important

又 そうなる傾向にあるので

when we're thinking about stem cells

幹細胞を入れる環境に

is that obviously stem cells can be many different things,

我々が必要な情報を 確実に組み込むと

and they want to be many different things,

目的の特定の組織に なるという事です

and so we want to make sure that the environment

世界中の実験室で 再生が試みられている組織のタイプは

we put them into has enough information

殆ど考え得る全ての組織 と言っていい程です

so that they can become the right sort

そんな組織の構造は

of specialist tissue.

かなり多様で

And if we think about the different types of tissues

患者の他の 隠れた病気とか健康問題が

that people are looking at regenerating

組織の再生法や

all over the world, in all the different labs in the world,

材料の使用法や

there's pretty much every tissue you can think of.

生化学的性質､ 機能

And actually, the structure of those tissues

その他多くの特質に影響し それにより 我々の対処法も大きく変わってきます

is quite different, and it's going to really depend

組織は其々 異なる再生能力があります

on whether your patient has any underlying disease,

ここで思い出すのが 可哀想なプロメテウス

other conditions, in terms of how

危なっかしい決断をした彼は

you're going to regenerate your tissue,

ギリシャの神々に罰せられ

and you're going to need to think about the materials

岩に縛り付けられ 鷲が毎日

you're going to use really carefully,

彼の肝臓をついばみに来ます

their biochemistry, their mechanics,

彼の肝臓は毎日再生し

and many other properties as well.

そうやって来る日も来る日も

Our tissues all have very different abilities to regenerate,

永遠に神々に罰せられるのです

and here we see poor Prometheus,

肝臓はこのように 再生されることになるでしょうが

who made a rather tricky career choice

他の組織

and was punished by the Greek gods.

例えば軟骨は

He was tied to a rock, and an eagle would come

どんな些細な欠損でも

every day to eat his liver.

再生するのは とても難しいのです

But of course his liver would regenerate every day,

この様に組織により 違いが非常に大きく

and so day after day he was punished

骨の再生能力はその中間です

for eternity by the gods.

骨は我々の実験室で よく扱われる組織の１つで

And liver will regenerate in this very nice way,

自己修復能力は 実は かなり高いのです

but actually if we think of other tissues,

そうでなければ困ります たぶん我々はみな

like cartilage, for example,

骨折を経験しているでしょうし

even the simplest nick and you're going to find it

骨折治療の１つの方法は

really difficult to regenerate your cartilage.

「腸骨採取」と呼ばれる手法で

So it's going to be very different from tissue to tissue.

外科医が

Now, bone is somewhere in between,

腸骨から骨を採取し

and this is one of the tissues that we work on a lot in our lab.

ここにありますが—

And bone is actually quite good at repairing.

体の他の部分にそれを移植します

It has to be. We've probably all had fractures

これは本当にうまく行くのです

at some point or other.

本人の骨なので

And one of the ways that you can think

うまく血管新生化し

about repairing your fracture

血液の流れが とても良くなるのですが

is this procedure here, called an iliac crest harvest.

問題は採骨できる量に 限界があるという事です

And what the surgeon might do

その上 手術後 採骨した場所が

is take some bone from your iliac crest,

２年経っても

which is just here,

非常に痛む可能性があるのです

and then transplant that somewhere else in the body.

それで我々が考えた事は

And it actually works really well,

勿論 骨修復の需要は 非常に大きいのですが—

because it's your own bone,

腸骨タイプのアプローチでは

and it's well vascularized,

限界があまりにあるので

which means it's got a really good blood supply.

必要に応じ 生体内で

But the problem is, there's only so much you can take,

骨を再生し 移植したらどうだろう

and also when you do that operation,

それにより腸骨採取後のような

your patients might actually have significant pain

極度の痛みが伴わない移植が

in that defect site even two years after the operation.

出来るのではないだろうか？ ということです

So what we were thinking is,

その我々のやり方は

there's a tremendous need for bone repair, of course,

典型的な細胞組織工学の アプローチに戻ったのですが

but this iliac crest-type approach

かなり違った観点を取りました

really has a lot of limitations to it,

随分 簡素化して

and could we perhaps recreate

かなりステップを省きました

the generation of bone within the body

患者からの 細胞採取の必要性

on demand and then be able to transplant it

あらゆる高価な 化学薬品の必要性

without these very, very painful aftereffects

そして研究室で担体を

that you would have with the iliac crest harvest?

培養する必要性を なくしました

And so this is what we did, and the way we did it

我々が本当に 焦点を置いているのは

was by coming back to this typical tissue-engineering approach

材料系と それを簡素化する事ですが

but actually thinking about it rather differently.

よく考えられた方法で使用したので

And we simplified it a lot,

このアプローチによって

so we got rid of a lot of these steps.

膨大な量の骨を 再生できたのです

We got rid of the need to harvest cells from the patient,

それで我々は生体を

we got rid of the need to put in really fancy chemistries,

骨を大量に作る為の

and we got rid of the need

媒体として使いました

to culture these scaffolds in the lab.

そのアプローチを

And what we really focused on

「生体バイオリアクター」と呼び このやり方で

was our material system and making it quite simple,

とてつもない量の骨を 再生できるのです

but because we used it in a really clever way,

分かり易く説明すると

we were able to generate enormous amounts of bone

こうです

using this approach.

生体には幹細胞の層が

So we were using the body

長骨の外側にあり

as really the catalyst to help us

「骨膜」とよばれ

to make lots of new bone.

普段とても

And it's an approach that we call

しっかりと その下の骨に密着していて

the in vivo bioreactor, and we were able to make

幹細胞を含んでいます

enormous amounts of bone using this approach.

この幹細胞は

And I'll talk you through this.

胎芽の成長にとても重要で

So what we do is,

骨折すると

in humans, we all have a layer of stem cells

骨を修復しようと活性化します

on the outside of our long bones.

我々はその骨膜に目をつけ

That layer is called the periosteum.

その下に液体を 注入する方法を開発しました

And that layer is actually normally

その液体は注入後30秒内で

very, very tightly bound to the underlying bone,

固形のゲルになり