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  • As humans, it's in our nature

    翻訳: Reiko Bovee 校正: Eriko T

  • 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