JP3874205B2 - In vivo implant material and method for producing the same - Google Patents
In vivo implant material and method for producing the same Download PDFInfo
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- JP3874205B2 JP3874205B2 JP33472195A JP33472195A JP3874205B2 JP 3874205 B2 JP3874205 B2 JP 3874205B2 JP 33472195 A JP33472195 A JP 33472195A JP 33472195 A JP33472195 A JP 33472195A JP 3874205 B2 JP3874205 B2 JP 3874205B2
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Description
【0001】
【発明の属する技術分野】
本発明は、パッチ等の疾病あるいは傷害で失われた生体の構造物を代替する用途に用いられる生体内移植材料に関するものである。
【0002】
【従来の技術】
四弗化エチレン樹脂(以下、PTFEと記す)は、その化学的な安定性に基づく生体に対する無毒性、非炎症性、非分解性、抗血栓性などを有しているため、生体内に直接触れる用途には最適である。しかし、PTFEはそのままでは硬く脆いため、様々な生体内の形状に合わせて形状を変化させることが必要である。そこで柔軟性が必要な人工血管やパッチ材、カテーテル等の医療材料では、多孔質体に加工されて使用されている。特に延伸法で製造された延伸多孔質体は、非常に細い繊維とその繊維により互いに連結された結節からなる気孔率が高い微細構造状組織を有することから、柔軟性、可撓性、通過性に富み、好適に使用されている。このようなPTFE延伸多孔質体は、2、3倍から場合によっては数十倍にも昇る延伸を行って柔軟性をもたせ、70%を越える高い気孔率の多孔質構造を持ち、生体内では周囲の結合組織が侵入し、これと一体となって良好な治療状態を形成する。
【0003】
しかし、同じ生体内移植材料でも、生体内の隔壁として機能する心膜、胸膜、横隔膜、腹膜などを補修する用途で用いられるパッチ材では、柔軟性は同様に必要であるが、周囲組織の侵入や癒着は避ける必要がある。これは代替する生体器官である心膜、胸膜、横隔膜、腹膜などが結合組織から心臓や肺、消化器管といった臓器を隔てて、これら臓器の腔内での自由な動きを維持することを役割としているためである。
【0004】
また、結合組織の侵入は、多孔質体の形状変化にも影響する。これは先に述べた人工血管においても問題となるが、結合組織は新生されたのちに安定な組織として治癒する際に著しい収縮を起こすため、多孔質体内でこれが起こると特にシート状の多孔質体は様々な方向に収縮し、ひきつれ・湾曲することが知られている。例えば全くフリーの状態で気孔率70%のPTFE樹脂多孔質体のシートを皮下あるいは腹腔内に移植する動物実験では、数週間のちにはシートの面積は少なくとも1/3以下に収縮し、場合によっては丸まって塊状になってしまう。
【0005】
これらの問題を解決するためには、結合組織が侵入できないほどの小さな孔の大きさにする必要がある。一方、延伸多孔質体の場合、単純には延伸率を下げることになるが、これではせっかくの柔軟性を損なわれ移植先の周囲の生体組織の形状に沿わせることが困難になったり、あるいは生体組織を損傷するといった問題があった。
【0006】
また、今一つの問題点として、生体内移植材料として必要な強度であるスーチャ引裂強度がある。生体内移植材料は全くフリーな状態で移植されては先に述べた動物実験のように意味がないので、どこかにつなぎ止める必要がある。そのため通常は縫合糸によって生体に縫いつける。そこでこの縫合糸による引裂に対する耐性強度が必要になる。しかし、延伸多孔質体の場合、この引裂強度は延伸によって発生するPTFEの微細組織によって引裂強度を維持しているため、結合組織が侵入できないほど小さい孔を形成する低い延伸率では引裂強度が弱くなるといった問題があった。
【0007】
上記の問題を解決するために、延伸多孔質体の延伸率を下げることなく、その表面に結合組織が侵入できないほどの小さな孔を有する層を設けることが種々試みられている。例えば、多孔質のPTFEからなるチューブの外面または内面の少なくとも一面にフッ素ゴムを被覆することが知られている(特公昭60−3773号公報、特開昭59−160470号公報)。しかし、このフッ素ゴムを被覆した多孔質PTFEチューブは、細胞が孔を広げて入り込むため、上記の問題を解決することができない。
【0008】
また、上記の例と同じように、PTFE延伸多孔質チューブにフッ素樹脂等の樹脂またはエラストマー被覆を超音波を利用して設けることも知られている(特開昭60−38064号公報)。しかし、この樹脂またはエラストマー被覆は多孔性でないため、生体組織の進入は阻止できるが生体液の交通性が得られない。
【0009】
【発明が解決しようとする課題】
以上の問題を整理すると、生体移植材料であって特に隔壁の用途で用いられるPTFE多孔質体は、柔軟で高引裂強度を有し、かつ生体組織を侵入させないという相反する特性を具備しなければならない。しかし、従来かかる特性と同時に満たす生体移植材料が存在しなかった。すなわち、延伸多孔質体は延伸率を下げることによって結合組織が進入できないほどの小さい孔を設けることができるが、移植材料として必要な柔軟性が損なわれる。更に、生体移植材料は通常縫合糸によって生体に縫い付けられるから、この縫合糸による引き裂きに対する耐性強度すなわちスーチャ引裂強度が必要であるが、延伸多孔質体は延伸率を低くすると引裂強度が低くなる。本発明者は、この相反する特性を持つ生体移植材料を実現すべく鋭意研究の結果、十分に延伸し開孔させることによって柔軟性を与えられたPTFE多孔質体を、柔軟性を維持したままその過剰に開いた孔を塞ぎ生体組織の侵入を阻害することによって、移植後の組織癒着や収縮による形状変化がきわめて少ない生体移植材料を生み出すことに成功した。
【0010】
【課題を解決するための手段】
かくして、本発明によれば、繊維と該繊維によって互いに連結された結節とからなる微細繊維状組織を有する樹脂多孔質体において、孔径0.2μm〜1μmの四弗化エチレン樹脂多孔質体の外表面に、孔径が0.05μmの四弗化エチレン樹脂シートを貼り合わした樹脂多孔質体であることを特徴とする生体内移植材料が提供される。
【0011】
本発明の生体内移植材料の断面図を模式的に示せば図1のようになる。図1において、1はPTFE多孔質体、2は該多孔質体の外表面に設けられた被覆層、3は結節、4はPTFE繊維である。図1はフッ素樹脂層からなる被覆層2がPTFE多孔質体1の片面に設けられた生体内移植材料の一例である。本発明において、フッ素樹脂層のフッ素樹脂として、例えばPTFE、テトラフルオロエチレン−ヘキサフロオロプロピレン共重合体(FEP)、テトラフルオロエチレン−パーフルオロアルキルビニルエーテル共重合体(PFA)、弗化ビニリデン樹脂、テトラフルオロエチレン−エチレン共重合体(ETFE)が使用される。
【0012】
【発明の実施の形態】
本発明に係る生体内移植材料は以下の方法によって製造することができる。本発明の目的に供されるPTFE多孔質体は、例えば特公昭42−13560号公報に記載される方法によって製造することができる。まず、PTFEパウダーと潤滑剤を混合し、シート状あるいはチューブ状に押出し、これを少なくとも一方向に延伸することでパウダー同士が離れて裂けるようにしてできた亀裂状の孔間に糸を引くように繊維が延伸方向に形成され、PTFEの融点以上に加熱することで強度が向上したPTFE多孔質体が得られる。
【0013】
このように製造されたPTFE多孔質体は微細な繊維と繊維をつなぐ結節による微細多孔質構造をなしており、延伸率等の製造条件に応じて多様な繊維長、結節形状となり得るが、厚み方向を除けば基本的に均質なものである。従って、ある程度の改変の余地はあるものの、基本的には気孔率が高く柔軟なもの程、孔は大きいものとなる。つまり、本発明の目的の一つである柔軟性を保つことは可能である。しかしながら、このままでは生体組織が侵入しないような小さい孔とすることは事実上不可能である。
【0014】
柔軟性を保ったままPTFE多孔質体内に生体組織を侵入させないために、本発明者は、ごく表層の多孔質の孔のみを塞ぐ方法について鋭意研究した結果、以下の方法でPTFE多孔質体の表面の孔を塞ぐことが可能であることを見出した。
【0015】
移植に耐えうる強度を有する延伸PTFEの表面に、孔径0.05μmの延伸PTFEフィルムを圧力を加えながら、PTFEの融点以上の温度に加熱し接着させることで製造することができる。
【0016】
本発明者の検討では、生体組織が侵入させないためには、孔径が0.5μm以下あることが必要であり、生体移植に必要な柔軟性は形状にもよるが孔径0.2〜1μm以上のものが望ましい。従って、生体移植材料としては、通常孔径が0.2〜1μmのPTFE多孔質体を用いることが望ましい。孔径が0.5μm以下であれば、壁の透過性があまり低下しなくとも生体組織侵入の阻止効果があらわれると考えられる。一方、生体移植材料は、生体液の交通性を要求されるから、塗布層は0.05μm以上の孔径を構造を持つことが必要となる。従って、この第3の方法によって造孔のための物質の粒径を選ぶことで本発明の目的とする生体移植材料を製造することができる。
【0017】
このようにして加工される被覆層は、本発明の生体内移植材料の片面だけでなく、これらの加工を繰り返すことによって図2に示すように両面に施すことも可能である。しかし例えば、心膜の場合、癒着を防止するべきなのは心臓側の面であって胸腔内側は必ずしも癒着防止は必要ではない。逆に生体内移植材料の場合、生体内のどこかにつなぎ止めなければいけないため、全く癒着しない構造では生体と一体化して治癒することが不可能になる。したがって用途によって、癒着を防止する面を考慮し、片面のみに被覆層を設ける場合や、あるいは部分的に被覆層を設け、周囲のつなぎ止める部分は被覆層を設けないなどの措置を取ることが望ましい。
【0018】
以上のように本発明によると、従来の構造に比して、柔軟性を維持したまま、必要に応じて生体組織の侵入による癒着・収縮を起こさない部分を設けた生体内移植材料を得ることが可能であり、心膜パッチなど医療生体内移植材料用途における治癒性において有用性が高いものである。
【0019】
【実施例】
以下、本発明について実施例及び比較例を挙げて具体的に説明するが、本発明は、これらの実施例のみに限定されるものではない。なお、物性の測定方法は以下の通りである。
<平均孔径> 粒子を濾過させた後に、90%以上カットできる最小粒子径をシートの平均孔径とした。
【0020】
<スーチャ引裂強度> 手術用ナイロン糸付縫合針(協和時計工業社製、4−0・ナイロン、角針)をシートの縁より5mm離れたところを通し、シートがプルアウトするまでこの糸を引っ張った。このときの最大荷重をスーチャ引裂強度とした。
【0021】
<癒着強度> ラット背皮下にサンプルを埋植し、閉創後2週間後に周囲組織ごと摘出し、サンプル周囲の組織を平板に接着剤で固定し、サンプルの一部をつかんで、180°剥離方式にて引張試験機に配置し20cm/分の速度で引っ張ったときに生じる抗力の最大値を癒着強度とした。
【0022】
<収縮率> 同様に、ラット背皮下にサンプルを埋植し、閉創後2週間後に周囲組織ごと摘出したときの表面積の、埋植前の表面積に対して減少した面積の比率を収縮率とした。
【0023】
(実施例1) 平均孔径1μmの市販PTFE多孔質体シート(住友電気工業製ポアフロン(登録商標)WP−100、厚さ100μm)の片面に平均孔径0.05μmの市販PTFE多孔質体シート(住友電気工業製ポアフロンWP−005、厚さ80μm)を張り合わせ、形状が変化しないようにステンレス鋼板の板に挟んで固定し、340℃で20分加熱し、融着させた。このシートのスーチャ引裂強度は平均559gだった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごと摘出し、シート周囲の組織を引張試験機のクロスヘッドに取り付けた平板に接着剤で固定し、ロードセルに取り付けたグリップでシートの一部を掴んで、180℃剥離方式にて20cm/minの速度で引っ張った時の抗力の最大値より、癒着強度を測定した。測定の結果は平均0.39gf/mmであった。また、肉眼観察によるとシートの収縮はなくまた半透明に変化していることから体液の交通性があることが分かった。
【0024】
(参考例1) 平均孔径0.2μmの市販PTFE多孔質体シート(住友電気工業製ポアフロンWP−020、厚さ80μm)をガラス平板に密着固定し水平にした面上にPTFEパウダー(ダイキン工業製ルブランL−5)を10%分散させたエタノールを50ml/m2の割合で塗布した。ドクターナイフを使用して数回均層化する数分のうちにエタノールは蒸発してゆき、適度な粘度に達したところで放置して自然乾燥させた。このシートの樹脂の厚みは約3μmであった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごとに摘出し、実施例1と同様に癒着強度を測定した結果、平均0.66gf/mmであった。また肉眼観察より、シートの収縮はなく、また半透明に変色していることから体液の交通性があることが分かった。
【0025】
(参考例2) 参考例1においてPTFEパウダーの10%エタノール分散液を100ml/m 2 使用したこと以外は参考例1と同様にした。実施例1と同様の条件で癒着強度を測定した結果、平均0.39gf/mmであり、また肉眼観察により、シートの収縮はなく、また半透明に変色していることから体液の交通性があることが分かった。このシートの樹脂層の厚みは約7μmであった。
【0026】
(参考例3) 参考例1においてPTFEパウダーの10%エタノール分散液を200ml/m 2 使用したこと以外は参考例1と同様にした。実施例1と同様の条件で癒着強度を測定した結果、平均0.41gf/mmであり、また肉眼観察により、シートの収縮はなく、また半透明に変色していることから体液の交通性があることが分かった。このシートの樹脂層の厚みは約10μmであった。
【0027】
(参考例4) 平均孔径0.45μmの市販PTFE多孔質体シート(住友電気工業製ポアフロンWP−045、厚さ80μm)、PTFEパウダーの代わりにFEPパウダー(ダイキン工業製ネオフロンFEP(登録商標))を使用し、恒温槽温度を300℃としたこと以外は参考例1と同様にした。このシートの樹脂層の厚みは約5μmであった。
【0028】
(参考例5) 平均孔径1μmの市販PTFE多孔質体シート(住友電気工業製ポアフロンWP−100、厚さ100μm)、PTFEパウダーの代わりにPFAパウダー(ダイキン工業製ネオフロンPFA(登録商標))を使用し、恒温槽温度を300℃としたこと、及びこの操作を繰り返して被覆層をPTFE多孔質体シートの両面に設けた以外は参考例1と同様にした。このシートの樹脂層の厚みは約5μmであった。実施例1と同様の条件で癒着強度を測定した結果、平均0.75gf/mmであり、また肉眼観察より、シートの収縮はなく、また半透明に変色していることから体液の交通性があることが分かった。
【0029】
(参考例6) 参考例1と同様のPTFE多孔質シート(住友電気工業製ポアフロンWP−020、厚さ80μm)を、直径5cmの金属円筒2つを平行に並べ、一方の円筒面を滑らないように密着固定した。他方の円筒を表面温度400℃に加熱し、1回転/秒の速度で軸回りに回転させ、シートを固定した円筒を0.5回転/秒で他方の円筒と同方向に回転させた状態で、両円筒間の距離を狭めて加熱金属円筒面がシート表面を接触、摩擦するようにした。30秒後、接触を停止して金属円筒から取り外した。実施例1と同様の条件で癒着強度を測定した結果、平均0.5gf/mmであり、また肉眼観察より、シートの収縮はなく、また半透明に変色していることから体液の交通性があることが分かった。
【0030】
(参考例7) 参考例1と同様のPTFE多孔質シート(住友電気工業製ポアフロンWP−020、厚み80μm)をガラス平板に密着固定し水平にした面にPTFEディスパージョン(ダイキン工業製D1)8gに粒径5μm程度の塩化ナトリウムを16gを分散させたペースト状の液体を塗布した。ドクターナイフを使用して数回均層化した後、80℃恒温槽で乾燥させた。次いで、このPTFE多孔質シートを金属板固定した状態で、350℃恒温槽で15分間処理して塗布したPTFEパウダーを融解接着させて被覆層を形成した。その後、蒸留水で塩化ナトリウムを抽出した。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごと抽出し、実施例1と同様に癒着強度を測定した結果、平均0.55gf/mmであった。また肉眼観察により、シートの収縮はなく、また半透明に変色していることから体液の交通性があることが確認できた。
【0031】
(参考例8) 参考例7において、PTFEディスパージョン(ダイキン工業製D1)4gに蒸留水32gと界面活性剤(三洋化成製オクタポールNo.80(登録商標))16gを混合、撹拌して分散させた後、凍結乾燥によって水分を除去して作成したペースト状の液体を塗布したこと以外は参考例7と同様にしてPTFE多孔質シートを得た。これを350℃恒温槽で15分間処理して塗布したPTFEパウダーを接着させると共にポリブテンを蒸発と熱分解により揮散、除去した。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごと抽出し、実施例1と同様に癒着強度を測定した結果、平均0.65gf/mmであった。また肉眼観察により、シートの収縮はなく、また半透明に変色していることから体液の交通性があることが確認できた。
【0032】
(比較例1) 平均孔径0.05μmの市販PTFE多孔質シート(住友電気工業製ポアフロン、WP−005,厚み80μm)のスーチャ引裂強度は平均185gであった。
【0037】
(比較例2) 平均孔径0.1μmの市販PTFE多孔質シート(住友電気工業製ポアフロン、WP−010、厚み80μm)のスーチャ引裂強度は平均220gであった。
【0033】
(比較例3) 平均孔径0.2μmの市販PTFE多孔質シート(住友電気工業製ポアフロン、WP−020、厚み80μm)のスーチャ引裂強度は平均350gであった。
【0034】
(比較例4) 平均孔径0.45μmの市販PTFE多孔質シート(住友電気工業製ポアフロン、WP−045、厚み80μm)のスーチャ引裂強度は平均335gであった。
【0035】
(比較例5) 平均孔径1μmの市販PTFE多孔質シート(住友電気工業製ポアフロン、WP−100、厚み100μm)のスーチャ引裂強度は平均377gであった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごと抽出し、実施例1と同様に癒着強度を測定した結果、平均4.63gf/mmであった。また肉眼観察により、シートはしわが寄った形で収縮していた。
【0036】
(比較例6) 平均孔径3μmの市販PTFE多孔質シート(住友電気工業製ポアフロン、WP−300、厚み75μm)のスーチャ引裂強度は平均313gであった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごと摘出し、実施例1と同様に癒着強度を測定した結果、平均5.07gf/mmであった。また肉眼観察により、シートはしわが寄った形で収縮していた。
【0037】
(比較例7) 市販PTFE多孔質シートに平均孔径0.05μmのPTFE多孔質シート(住友電気工業製、ポアフロンWP005)を用いた以外は、参考例1と同様にシートを作成した。このフッ素樹脂層の厚みは、約4μmであった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごと摘出し、実施例1と同様に癒着強度を測定した結果、平均0.45gf/mmであった。また肉眼観察により、シートの収縮はないが変色しておらず、壁内に空気が残存していることから体液の交通性が消失していることが分かった。
【0038】
(比較例8) 市販PTFE多孔質シートに平均孔径0.05μmのPTFE多孔質シート(住友電気工業製、ポアフロンWP005)を用いた以外は、参考例2と同様にシートを作成した。このフッ素樹脂層の厚みは、約5μmであった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごと摘出し、実施例1と同様に癒着強度を測定した結果、平均0.37gf/mmであった。また肉眼観察により、シートの収縮はないが変色しておらず、壁内に空気が残存していることから体液の交通性が消失していることが分かった。
【0039】
(比較例9) 市販PTFE多孔質シートに平均孔径0.05μmのPTFE多孔質シート(住友電気工業製、ポアフロンWP005)を用いた以外は、参考例3と同様にシートを作成した。このフッ素樹脂層の厚みは、約10μmであった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごと摘出し、実施例1と同様に癒着強度を測定した結果、平均0.53gf/mmであった。また肉眼観察により、シートの収縮はないが変色しておらず、壁内に空気が残存していることから体液の交通性が消失していることが分かった。
【0040】
(比較例10) 平均孔径1μmの市販PTFE多孔質体シート(住友電気工業製ポアフロン(登録商標)WP−100、厚さ100μm)の片面に平均孔径0.1μmの市販PTFE多孔質体シート(住友電気工業製ポアフロンWP−010、厚さ80μm)を張り合わせ、形状が変化しないようにステンレス鋼板の板に挟
んで固定し、340℃で20分加熱し、融着させた。このシートのスーチャ引裂強度は平均512gであった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごと摘出し、実施例1と同様に癒着強度を測定した結果、平均1.07gf/mmであった。また、肉眼観察により、シートの収縮はなく、また半透明に変色していることから体液の交通性があることが分かった。
【0041】
(比較例11) 平均孔径1μmの市販PTFE多孔質シート(住友電気工業製ポアフロンWP−100、厚さ100μm)の片面に平均孔径0.2μmの市販PTFE多孔質シート(住友電気工業製ポアフロンWP−020、厚さ40μm)を張り合わせ、形状が変化しないようにステンレス鋼製の板に挟んで固定し、3
40℃で20分加熱し、融着させた。このシートのスーチャ引裂強度は平均556gであった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごとに摘出し、実施例1と同様に癒着強度を測定した結果、平均1.3gf/mmであった。また肉眼観察より、シートの収縮はなく、また半透明に変色していることから体液の交通性があることを確認できた。
【0042】
(比較例12) 平均孔径1μmの市販PTFE多孔質体シート(住友電気工業製ポアフロンWP−100、厚さ100μm)の片面に平均孔径0.45μmの市販PTFE多孔質体シート(住友電気工業製ポアフロンWP−045、厚さ40μm)を張り合わせ、形状が変化しないようにステンレス鋼製の板に挟んで固定し、340℃で20分加熱し融着させた。このシートのスーチャ引裂強度は平均534gであった。このシートをラット背皮下に埋植し、閉創後4週間後に周囲組織ごとに摘出し、実施例1と同様に癒着強度を測定した結果、平均1.9gf/mmであった。また肉眼観察より、シートの収縮はなく、また半透明に変色していることから体液の交通性があることを確認できた。
【0043】
また、実施例1のPTFE多孔質体シートを1分間手で揉んで、層の剥離を調べた結果、外観上変化はなく粉の発生などの不具合は見られなかった。また5cm×5cmの大きさで半分に折り畳んでいって何回折り畳めるかを調査したところ、実施例、参考例、比較例とも6回が限度と同等であった。
【0044】
【表1】
表中の特性値の測定方法は本文参照
【0045】
【発明の効果】
以上のように、本発明品は、PTFE多孔質体の柔軟性を保持し、その長所を損なうことなく、生体内で組織侵入しにくい構造であるため、生体内の隔壁などの用途に使用される生体内移植材料に好適である。さらに、本発明品のPTFE多孔質体の加工方法は、使用するPTFE多孔質体がどのような多孔質体構造でも適用が可能である。このことは、例えばスーチャ引裂強度や引張強度などの力学的強度や柔軟性がより必要な場合等、それらの特性を満たすPTFE多孔質体を加工する基材として選択すればよい。また、本発明品は、生体内移植材料の場合、生体組織のどこかに固定しないと目的の位置にとどめることができないため、縫合糸や接着剤で一時的に固定し、傷の治癒過程において生体と一体化する必要がある。したがって本発明の目的である非癒着性が向上すると、逆に固定した部分が治癒・一体化できずに解離して隔壁の役目を果たさなくなる。しかし、本発明の製造方法では、部分的に被覆することも容易である。したがって用途にあわせて生体と固定・縫合する部分と非癒着部分に設けることが可能であり、応用範囲が広い。
【図面の簡単な説明】
【図1】片面に被覆層を有する本発明の生体内移植材料の一例の断面を示す模式図である。
【図2】両面に被覆層を有する本発明の生体内移植材料の一例の断面を示す模式図である。
【図3】片面に被覆層を有する生体内移植材料の製造方法(参考例)の一例を示す模式図である。
【符号の説明】
1:PTFE多孔質体
2:PTFE多孔質体に設けた被覆層
3:結節
4:PTFE繊維
5:PTFE多孔質体が固定される第1の金属円筒
6:加熱される第2の金属円筒[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-vivo implant material used for a substitute for a living body structure lost due to a disease or injury such as a patch.
[0002]
[Prior art]
Tetrafluoroethylene resin (hereinafter referred to as PTFE) is non-toxic, non-inflammatory, non-degradable, antithrombotic, etc. to the living body based on its chemical stability, so it is directly in vivo. Ideal for touching applications. However, since PTFE is hard and brittle as it is, it is necessary to change the shape according to various in vivo shapes. Therefore, medical materials such as artificial blood vessels, patch materials, and catheters that require flexibility are used after being processed into a porous body. In particular, a stretched porous body produced by a stretching method has a microstructure with a high porosity composed of very thin fibers and nodules connected to each other by the fibers, so that flexibility, flexibility, and passability are obtained. It is rich and is used favorably. Such a PTFE-stretched porous body has a porous structure having a high porosity exceeding 70% by performing stretching that increases from a few times to several tens times in some cases, and has a porous structure exceeding 70%. The surrounding connective tissue invades and unites with it to form a good therapeutic state.
[0003]
However, patch materials used for repairing the pericardium, pleura, diaphragm, peritoneum, etc., which function as the in-vivo septum, require the same flexibility, but invasion of surrounding tissues It is necessary to avoid adhesions. This is because the pericardium, pleura, diaphragm, peritoneum, etc., which are alternative living organs, separate organs such as the heart, lungs, and digestive tract from connective tissues and maintain free movement within these organs. It is because it is doing.
[0004]
Further, the invasion of connective tissue also affects the shape change of the porous body. This is also a problem in the above-mentioned artificial blood vessels. However, since connective tissue undergoes significant contraction when healed as a stable tissue after being born, if this occurs in a porous body, it is particularly a sheet-like porous material. It is known that the body contracts in various directions and is pulled and bent. For example, in an animal experiment in which a porous sheet of PTFE resin having a porosity of 70% is transplanted subcutaneously or intraperitoneally in a completely free state, the area of the sheet shrinks to at least 1/3 or less in several weeks, and in some cases Will curl up and become a lump.
[0005]
In order to solve these problems, it is necessary to make the pore size so small that the connective tissue cannot enter. On the other hand, in the case of a stretched porous body, the stretch ratio is simply lowered, but this makes it difficult to conform to the shape of the living tissue around the transplant destination because the flexibility is impaired, or There was a problem of damaging living tissue.
[0006]
Another problem is Suture tear strength, which is a strength necessary for an in vivo transplant material. When transplanted in a completely free state, the in vivo transplant material is meaningless as in the animal experiment described above, and must be tied somewhere. Therefore, it is usually sewn to a living body with a suture thread. Therefore, resistance to tearing by this suture is required. However, in the case of a stretched porous body, the tear strength is maintained by the fine structure of PTFE generated by stretching, so that the tear strength is weak at a low stretch ratio that forms pores that are so small that the connective tissue cannot enter. There was a problem of becoming.
[0007]
In order to solve the above problems, various attempts have been made to provide a layer having pores that are so small that connective tissue cannot enter the surface thereof without reducing the stretch ratio of the stretched porous body. For example, it is known that at least one of the outer surface or inner surface of a tube made of porous PTFE is coated with fluoro rubber (Japanese Patent Publication No. 60-3773, Japanese Patent Application Laid-Open No. 59-160470). However, the porous PTFE tube coated with this fluororubber cannot solve the above-mentioned problem because the cells expand and enter the pores.
[0008]
As in the above example, it is also known that a PTFE stretched porous tube is provided with a resin such as a fluororesin or an elastomer coating using ultrasonic waves (Japanese Patent Laid-Open No. 60-38064). However, since this resin or elastomer coating is not porous, the invasion of living tissue can be prevented, but the fluidity of biological fluid cannot be obtained.
[0009]
[Problems to be solved by the invention]
To summarize the above problems, a porous PTFE material that is a biotransplant material, particularly for use as a partition wall, must be flexible, have high tear strength, and have the contradictory characteristics of not allowing living tissue to enter. Don't be. However, there has been no biological transplant material that satisfies the above properties at the same time. That is, the stretched porous body can be provided with pores that are so small that the connective tissue cannot enter by lowering the stretch rate, but the flexibility necessary for the transplant material is impaired. Furthermore, since the biological transplant material is usually sewn to the living body with sutures, resistance strength against tearing by sutures, that is , suture tear strength is necessary. However, if the stretched porous body has a low stretch ratio, the tear strength decreases. . As a result of diligent research to realize a biotransplant material having these contradictory characteristics, the present inventor has maintained the flexibility of the PTFE porous body given flexibility by sufficiently stretching and opening. By blocking the excessively open holes and inhibiting the invasion of living tissue, we succeeded in producing a living transplant material with very little shape change due to tissue adhesion and contraction after transplantation.
[0010]
[Means for Solving the Problems]
Thus, according to the present invention, in the resin porous body having a fine fibrous structure composed of fibers and nodules connected to each other by the fibers, the outer surface of the tetrafluoroethylene resin porous body having a pore diameter of 0.2 μm to 1 μm is used. There is provided an in vivo implant material characterized by being a resin porous body having a surface bonded with a tetrafluoroethylene resin sheet having a pore diameter of 0.05 μm .
[0011]
A cross-sectional view of the in vivo implant material of the present invention is schematically shown in FIG. In FIG. 1, 1 is a PTFE porous body, 2 is a coating layer provided on the outer surface of the porous body, 3 is a knot, and 4 is a PTFE fiber. FIG. 1 shows an example of an in vivo transplant material in which a
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The in vivo implant material according to the present invention can be produced by the following method. The PTFE porous material provided for the purpose of the present invention can be produced by, for example, a method described in Japanese Patent Publication No. 42-13560. First, PTFE powder and a lubricant are mixed, extruded into a sheet or tube, and stretched in at least one direction so that the powder is separated and the yarn is pulled between cracked holes. In this way, a porous PTFE body having improved strength is obtained by heating the fiber to the melting point of PTFE or higher.
[0013]
The PTFE porous body produced in this way has a fine porous structure with knots that connect the fine fibers to each other, and can have various fiber lengths and knot shapes depending on the production conditions such as the stretch ratio. It is basically homogeneous except for the direction. Accordingly, although there is room for modification to some extent, basically, the higher the porosity and the more flexible, the larger the hole. That is, it is possible to maintain the flexibility that is one of the objects of the present invention. However, in this state, it is practically impossible to make a small hole that does not allow living tissue to enter.
[0014]
In order to prevent the living tissue from invading into the PTFE porous body while maintaining flexibility, the present inventor has conducted intensive research on a method for closing only the porous pores on the surface layer, and as a result, the following method has been adopted for the PTFE porous body. It has been found that it is possible to close the surface holes.
[0015]
It can be produced by bonding a stretched PTFE film having a pore diameter of 0.05 μm to the surface of the stretched PTFE having a strength that can withstand transplantation while applying pressure to a temperature equal to or higher than the melting point of PTFE.
[0016]
According to the inventor's study, in order to prevent the living tissue from invading, the pore diameter needs to be 0.5 μm or less, and the flexibility required for living body transplantation depends on the shape, but the pore diameter is 0.2 to 1 μm or more. Things are desirable. Accordingly, it is desirable to use a PTFE porous body having a pore size of 0.2 to 1 μm as a biological transplant material. If the pore diameter is 0.5 μm or less, it is considered that the effect of preventing the invasion of living tissue appears even if the permeability of the wall does not decrease so much. On the other hand, since the biological transplant material is required to have the fluidity of the biological fluid, the coating layer needs to have a pore size of 0.05 μm or more. Therefore, it is possible to produce a biological graft material, which is an object of the present invention in this third method and this choose the particle size of the material for forming the hole.
[0017]
The coating layer processed in this way can be applied not only to one side of the in vivo implant material of the present invention but also to both sides as shown in FIG. 2 by repeating these processes. However, for example, in the case of the pericardium, it is the heart side surface that should prevent adhesion, and the inner side of the thoracic cavity does not necessarily require adhesion prevention. In contrast, in the case of an in-vivo transplant material, it must be tied to somewhere in the living body, and therefore a structure that does not adhere at all cannot be integrated with the living body and healed. Therefore, depending on the application, it is desirable to take measures such as providing a coating layer only on one side, or providing a coating layer on a part of the surface and not providing a coating layer on the surrounding joints, considering the surface that prevents adhesion. .
[0018]
As described above, according to the present invention, it is possible to obtain an in-vivo transplant material provided with a portion that does not cause adhesion / contraction due to invasion of a living tissue as necessary while maintaining flexibility as compared with a conventional structure. Therefore, it is highly useful in curability in medical in vivo graft material applications such as pericardial patches.
[0019]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited only to these Examples. In addition, the measuring method of a physical property is as follows.
<Average pore diameter> After filtering the particles, the minimum particle diameter capable of cutting 90% or more was defined as the average pore diameter of the sheet.
[0020]
<Suture tear strength> A suture needle with surgical nylon thread (Kyowa Watch Industry Co., Ltd., 4-0 nylon, square needle) was passed 5 mm away from the edge of the sheet, and this thread was pulled until the sheet was pulled out. . The maximum load at this time was taken as the suture tear strength.
[0021]
<Adhesion strength> Implant the sample subcutaneously in the back of the rat, remove the
[0022]
<Shrinkage ratio> Similarly, the ratio of the area of the surface area when the sample was implanted subcutaneously in the back of the rat and the whole surrounding tissue was excised 2 weeks after the wounding with respect to the surface area before implantation was taken as the shrinkage ratio. .
[0023]
Example 1 Commercial PTFE porous sheet with an average pore diameter of 0.05 μm on one side of a commercially available PTFE porous sheet with an average pore diameter of 1 μm (PORFLON (registered trademark) WP-100, thickness 100 μm manufactured by Sumitomo Electric Industries, Ltd.) Sumitomo Electric Co., Ltd. pore flon WP-005, thickness 80 μm) was bonded together and fixed between stainless steel plates so as not to change the shape, heated at 340 ° C. for 20 minutes, and fused. The average shear strength of this sheet was 559 g. The sheet was implanted subcutaneously in the back of the rat, and the surrounding tissue was removed 4 weeks after closing. The tissue around the sheet was fixed to the flat plate attached to the crosshead of the tensile tester with an adhesive, and the grip attached to the load cell. The adhesion strength was measured from the maximum value of the drag when a part of the sheet was grasped and pulled at a speed of 20 cm / min by a 180 ° C. peeling method. The measurement result averaged 0.39 gf / mm. In addition, it was found by the naked eye observation that there was no fluid contraction and there was a fluidity of the body fluid because it was changed to translucent.
[0024]
( Reference Example 1 ) A PTFE powder (manufactured by Daikin Industries, Ltd.) on a horizontal surface obtained by closely fixing a commercially available PTFE porous sheet having a mean pore diameter of 0.2 μm (Poreflon WP-020, thickness 80 μm, manufactured by Sumitomo Electric Industries, Ltd.) to a glass plate. Ethanol in which 10% of LeBlanc L-5) was dispersed was applied at a rate of 50 ml / m2. Ethanol evaporated within a few minutes of leveling several times using a doctor knife, and when it reached a suitable viscosity, it was left to dry naturally. The resin thickness of this sheet was about 3 μm. The sheet was implanted subcutaneously in the back of the rat, and after 4 weeks from the closing, each of the surrounding tissues was excised. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 0.66 gf / mm. From the naked eye observation, it was found that there was no fluid contraction and there was fluidity of the body fluid because it was discolored translucently.
[0025]
Reference Example 2 Reference Example 1 was carried out in the same manner as Reference Example 1 except that 100 ml / m 2 of a 10% ethanol dispersion of PTFE powder was used. The adhesion strength was measured under the same conditions as in Example 1. As a result, the average was 0.39 gf / mm, and there was no contraction of the sheet and the translucency was translucent by visual observation. I found out. The thickness of the resin layer of this sheet was about 7 μm.
[0026]
( Reference Example 3 ) Reference Example 1 was the same as Reference Example 1 except that 200 ml / m 2 of a 10% ethanol dispersion of PTFE powder was used. The adhesion strength was measured under the same conditions as in Example 1. As a result, the average was 0.41 gf / mm, and there was no contraction of the sheet by visual observation. I found out. The thickness of the resin layer of this sheet was about 10 μm.
[0027]
( Reference Example 4 ) Commercially available PTFE porous sheet having an average pore size of 0.45 μm (Pureflon WP-045, thickness 80 μm manufactured by Sumitomo Electric Industries), FEP powder (Neoflon FEP (registered trademark) manufactured by Daikin Industries) instead of PTFE powder Was used, and the temperature was set to 300 ° C. in the same manner as in Reference Example 1 . The thickness of the resin layer of this sheet was about 5 μm.
[0028]
( Reference Example 5 ) Commercially available PTFE porous material sheet (Pureflon WP-100 manufactured by Sumitomo Electric Industries, thickness 100 μm) having an average pore diameter of 1 μm, and PFA powder (Nephron PFA (registered trademark) manufactured by Daikin Industries) instead of PTFE powder And it was made to be the same as that of the reference example 1 except having set the thermostat temperature to 300 degreeC, and having provided the coating layer on both surfaces of the PTFE porous material sheet by repeating this operation. The thickness of the resin layer of this sheet was about 5 μm. The adhesion strength was measured under the same conditions as in Example 1. As a result, the average was 0.75 gf / mm, and there was no contraction of the sheet and the translucency of the body fluid was confirmed by visual observation. I found out.
[0029]
( Reference Example 6 ) PTFE porous sheet (Pureflon WP-020 manufactured by Sumitomo Electric Industries Co., Ltd., thickness 80 μm) similar to that of Reference Example 1 is arranged in parallel with two metal cylinders having a diameter of 5 cm, and one cylindrical surface is not slid. It was fixed tightly. The other cylinder is heated to a surface temperature of 400 ° C., rotated around the axis at a speed of 1 rotation / second, and the cylinder with the sheet fixed is rotated in the same direction as the other cylinder at 0.5 rotation / second. The distance between the two cylinders was narrowed so that the heated metal cylindrical surface contacted and rubbed the sheet surface. After 30 seconds, contact was stopped and removed from the metal cylinder. The adhesion strength was measured under the same conditions as in Example 1. As a result, the average was 0.5 gf / mm. From the naked eye observation, there was no contraction of the sheet, and the color of the body fluid was translucent. I found out.
[0030]
( Reference example 7 ) PTFE dispersion (D1 made by Daikin Industries, Ltd.) 8 g on the same surface as a PTFE porous sheet (Pureflon WP-020 manufactured by Sumitomo Electric Industries, thickness 80 μm) similar to that of Reference Example 1 was fixed to a glass plate. A pasty liquid in which 16 g of sodium chloride having a particle size of about 5 μm was dispersed was applied. After leveling several times using a doctor knife, it was dried in a constant temperature bath at 80 ° C. Next, with the PTFE porous sheet fixed to a metal plate, the coated PTFE powder was melted and bonded in a constant temperature bath at 350 ° C. for 15 minutes to form a coating layer. Thereafter, sodium chloride was extracted with distilled water. This sheet was implanted subcutaneously in the back of the rat, and the surrounding tissues were extracted 4 weeks after closing. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 0.55 gf / mm. In addition, it was confirmed by visual observation that there was no contraction of the sheet and that the body fluid was transported because it was discolored translucently.
[0031]
( Reference Example 8 ) In Reference Example 7 , 4 g of PTFE dispersion (D1 manufactured by Daikin Industries) was mixed with 32 g of distilled water and 16 g of a surfactant (Octapole No. 80 (registered trademark) manufactured by Sanyo Kasei) and dispersed by stirring. after, except that the application of the moisture pasty liquid created by removing in the same manner as in reference example 7 to obtain a PTFE porous sheet by lyophilization. This was treated in a constant temperature bath at 350 ° C. for 15 minutes to adhere the coated PTFE powder, and the polybutene was volatilized and removed by evaporation and thermal decomposition. This sheet was implanted subcutaneously in the back of the rat, and the entire surrounding tissue was extracted 4 weeks after closing. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 0.65 gf / mm. In addition, it was confirmed by visual observation that there was no contraction of the sheet and that the body fluid was transported because it was discolored translucently.
[0032]
(Comparative example 1) The suture tear strength of the commercially available porous PTFE sheet (Sumitomo Electric Co., Ltd., Poreflon, WP-005, thickness 80 μm) having an average pore diameter of 0.05 μm was 185 g on average.
[0037]
(Comparative example 2) The suture tear strength of the commercially available PTFE porous sheet (Sumitomo Electric Industries pore flon, WP-010, thickness 80 micrometers) with an average hole diameter of 0.1 micrometer was 220g on average.
[0033]
(Comparative example 3) The suture tear strength of the commercially available PTFE porous sheet (Sumitomo Electric Industries poreflon, WP-020, thickness 80 micrometers) with an average pore diameter of 0.2 micrometer was 350 g on average.
[0034]
(Comparative example 4) The suture tear strength of the commercially available PTFE porous sheet (Sumitomo Electric Industries poreflon, WP-045, thickness 80 micrometers) with an average pore diameter of 0.45 micrometer was 335 g on average.
[0035]
(Comparative example 5) The suture tear strength of the commercially available PTFE porous sheet (Sumitomo Electric Industries poreflon, WP-100, thickness of 100 μm) having an average pore diameter of 1 μm was 377 g on average. This sheet was implanted subcutaneously in the back of the rat, and the entire surrounding tissue was extracted 4 weeks after closing. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 4.63 gf / mm. Also, by visual observation, the sheet contracted in a wrinkled form.
[0036]
(Comparative example 6) The suture tear strength of the commercially available porous PTFE sheet (Sumitomo Electric Industries poreflon, WP-300, thickness 75 μm) having an average pore diameter of 3 μm was 313 g on average. This sheet was implanted subcutaneously in the back of the rat, and the whole surrounding tissue was removed 4 weeks after closing. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 5.07 gf / mm. Also, by visual observation, the sheet contracted in a wrinkled form.
[0037]
(Comparative example 7) The sheet | seat was created similarly to the reference example 1 except having used the PTFE porous sheet (Sumitomo Electric Industries make, pore Freon WP005) with an average hole diameter of 0.05 micrometer for the commercially available PTFE porous sheet. The thickness of this fluororesin layer was about 4 μm. This sheet was implanted subcutaneously in the back of the rat, and the entire surrounding tissue was excised 4 weeks after closing, and the adhesion strength was measured in the same manner as in Example 1. As a result, the average was 0.45 gf / mm. In addition, it was found by visual observation that the fluidity of the body fluid was lost because the sheet was not contracted but was not discolored and air remained in the wall.
[0038]
(Comparative example 8) The sheet | seat was created similarly to the reference example 2 except having used the PTFE porous sheet (Sumitomo Electric Industries make, pore fron WP005) with an average hole diameter of 0.05 micrometer for the commercially available PTFE porous sheet. The thickness of this fluororesin layer was about 5 μm. This sheet was implanted subcutaneously in the back of the rat, and the entire surrounding tissue was removed 4 weeks after closing. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 0.37 gf / mm. In addition, it was found by visual observation that the fluidity of the body fluid was lost because the sheet was not contracted but was not discolored and air remained in the wall.
[0039]
(Comparative example 9) The sheet | seat was created similarly to the reference example 3 except having used the PTFE porous sheet (Sumitomo Electric Industries make, pore fron WP005) with an average hole diameter of 0.05 micrometer for the commercially available PTFE porous sheet. The thickness of this fluororesin layer was about 10 μm. This sheet was implanted subcutaneously in the back of the rat, and the whole surrounding tissue was removed 4 weeks after closing. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 0.53 gf / mm. In addition, it was found by visual observation that the fluidity of the body fluid was lost because the sheet was not contracted but was not discolored and air remained in the wall.
[0040]
( Comparative Example 10 ) A commercially available PTFE porous sheet having an average pore diameter of 0.1 μm on one side of a commercially available PTFE porous sheet having an average pore diameter of 1 μm (PORFLON (registered trademark) WP-100, thickness 100 μm manufactured by Sumitomo Electric Industries, Ltd.) Poreflon WP-010 (80 μm thickness) manufactured by Denki Kogyo Co., Ltd. was bonded together, fixed by being sandwiched between stainless steel plates so that the shape did not change, heated at 340 ° C. for 20 minutes, and fused. The suture tear strength of this sheet was 512 g on average. This sheet was implanted subcutaneously in the back of the rat, and the entire surrounding tissue was removed 4 weeks after closing. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 1.07 gf / mm. In addition, it was found by visual observation that there was no contraction of the sheet and that the body was transported due to the translucent discoloration.
[0041]
( Comparative Example 11 ) A commercially available PTFE porous sheet having a mean pore diameter of 0.2 μm on one side of a commercially available PTFE porous sheet having a mean pore diameter of 1 μm (poreflon WP-100, thickness 100 μm, manufactured by Sumitomo Electric Industries, Ltd.) 020, 40 μm thick) and sandwiched between stainless steel plates so that the shape does not change.
Heating was carried out at 40 ° C. for 20 minutes for fusing. The suture tear strength of this sheet averaged 556 g. This sheet was implanted subcutaneously in the back of the rat, and after 4 weeks after closure, the tissue was removed for each surrounding tissue. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 1.3 gf / mm. From the naked eye observation, it was confirmed that there was no fluid contraction and that the body fluid was transported from the translucent discoloration.
[0042]
( Comparative Example 12 ) A commercially available PTFE porous sheet having a mean pore diameter of 0.45 μm on one side of a commercially available PTFE porous sheet having a mean pore diameter of 1 μm (Poreflon WP-100, thickness 100 μm manufactured by Sumitomo Electric Industries, Ltd.) WP-045, thickness 40 μm) was bonded together and fixed between stainless steel plates so as not to change the shape, and heated at 340 ° C. for 20 minutes for fusion. The suture tear strength of this sheet averaged 534 g. The sheet was implanted subcutaneously in the back of the rat, and after 4 weeks from the closing, each of the surrounding tissues was excised. The adhesion strength was measured in the same manner as in Example 1. As a result, the average was 1.9 gf / mm. From the naked eye observation, it was confirmed that there was no fluid contraction and that the body fluid was transported from the translucent discoloration.
[0043]
Further, the porous PTFE sheet of Example 1 was held by hand for 1 minute, and the peeling of the layers was examined. As a result, there was no change in appearance and no problems such as generation of powder were observed. In addition, when the number of folds that were folded in half with a size of 5 cm × 5 cm was investigated, the number of folds in the examples , reference examples , and comparative examples was equal to the limit of six.
[0044]
[Table 1]
Refer to the text for the measurement method of characteristic values in the table.
【The invention's effect】
As described above, the product of the present invention retains the flexibility of the PTFE porous body, and does not impair the advantages thereof, and has a structure that prevents tissue from entering in vivo. Therefore, the product of the present invention is used for applications such as in vivo partition walls. This is suitable for in vivo transplantation materials. Furthermore, the PTFE porous material processing method of the present invention can be applied to any porous structure of PTFE porous material to be used. This may be selected as a base material for processing a PTFE porous body satisfying these properties, for example, when mechanical strength such as suture tear strength and tensile strength and flexibility are required. In addition, in the case of an in-vivo transplant material, the product of the present invention cannot be kept at the target position unless it is fixed somewhere in the living tissue. It needs to be integrated with the living body. Therefore, when the non-adhesion property, which is the object of the present invention, is improved, the fixed portion cannot be healed and integrated and dissociates and does not serve as a partition wall. However, in the manufacturing method of the present invention, partial coating is easy. Therefore, it can be provided in a portion to be fixed / sutured with a living body and a non-adhesion portion according to the use, and the application range is wide.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a cross section of an example of an in vivo implant material of the present invention having a coating layer on one side.
FIG. 2 is a schematic view showing a cross section of an example of the biomedical material of the present invention having coating layers on both sides.
FIG. 3 is a schematic view showing an example of a method (reference example) for producing an in vivo transplant material having a coating layer on one side.
[Explanation of symbols]
1: PTFE porous body 2: Coating layer provided on the PTFE porous body 3: Nodule 4: PTFE fiber 5: First metal cylinder 6 on which the PTFE porous body is fixed 6: Heated second metal cylinder
Claims (2)
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JP33472195A JP3874205B2 (en) | 1995-12-22 | 1995-12-22 | In vivo implant material and method for producing the same |
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JP33472195A JP3874205B2 (en) | 1995-12-22 | 1995-12-22 | In vivo implant material and method for producing the same |
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US20040024448A1 (en) * | 2002-08-05 | 2004-02-05 | Chang James W. | Thermoplastic fluoropolymer-coated medical devices |
CN101501113B (en) | 2006-08-09 | 2013-03-13 | 住友电工超效能高分子股份有限公司 | Fluororesin membrane, fluororesin composite, porous fluororesin composite, processes for production of them, and separation membrane element |
JP5830782B2 (en) | 2012-01-27 | 2015-12-09 | 住友電工ファインポリマー株式会社 | Method for producing modified polytetrafluoroethylene microporous membrane and method for producing modified polytetrafluoroethylene porous resin membrane composite |
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US4051848A (en) * | 1976-03-01 | 1977-10-04 | Levine Norman S | Synthetic skin wound dressing |
JPS5490897A (en) * | 1977-12-27 | 1979-07-18 | Hiroshi Matsumoto | Medical prosthetics |
JPS61151245A (en) * | 1984-12-25 | 1986-07-09 | Sumitomo Electric Ind Ltd | Method for treating surface of porous thin membrane material |
SE8802414D0 (en) * | 1988-06-27 | 1988-06-28 | Astra Meditec Ab | NEW SURGICAL MATERIAL |
JP2932611B2 (en) * | 1990-05-26 | 1999-08-09 | 住友電気工業株式会社 | Polytetrafluoroethylene resin porous tube |
EP0560934B2 (en) * | 1990-12-06 | 1999-11-10 | W.L. Gore & Associates, Inc. | Implantable bioabsorbable article |
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