Name: fabrication of small caliber stent-grafts using electrospinning and balloon expandable bare metal stents
Uploaded: 2016-10-26T15:00:00.000+00:00
Duration: 6 min 55 s
Description: Watch this Scientific Journal Video about Fabrication of Small Caliber Stent-grafts Using Electrospinning and Balloon Expandable Bare Metal Stents at JoVE.com

We would like to thank the Division of Engineering, Mayo Clinic for their technical support. This study was financially supported by European Regional Development Fund - FNUSA-ICRC (No. CZ.1.05/1.100/02.0123), National Institutes of Health (T32 HL007111), American Heart Association Scientist Development Grant (AHA #06-35185N), and The Grainger Innovation Fund - Grainger Foundation.

マンドレルコレクター上のポリウレタンの1エレクトロスピニング<ol><li> エレクトロスピニングのためのマンドレルを準備 <ol><li>オーブンを用いて155℃でメスシリンダー（約9ミリメートルの直径、深さ110 mm）の生体適合性、食品グレード、水溶性担体材料の約8ミリリットルメルト。 </li><li>マンドレルの表面上に支持材料のコーティングを得るために、直径3mm及び長さ100mmのステンレス鋼マンドレルを浸し。浸漬前に、溶融した担体材料で表面を濡らすのに役立つマンドレル表面の温度を上昇させるために、約15分間155℃のオーブンでマンドレルを配置します。 </li><li>溶融した支持材料がマンドレル表面上に均一な薄いコーティングを形成する固化しながら浸したマンドレルは、約140℃に冷却してみましょう。重力がオフに滴下する過剰な支持材を引き起こすように、冷却プロセスの間に、垂直方向にマンドレルを掛けます。このコーティングは、容易に可能マンドレルから完成したステント移植片の除去。 </li></ol></li><li> エレクトロスピニングシステムのマンドレルコレクタの設定（図1に示すように） <ol><li>水平に実験室用ミキサーを合わせ、ヒュームフード内部の反対側の端部にステンレス製の心棒を保持するプラスチック製の棒を接続します。 </li><li>マンドレルの端部にプラスチック製の支持ロッドを収容するために、水にマンドレルの先端のみを浸漬することによって、マンドレルの先端から支持材を溶解します。マンドレルコレクタの均一な回転を補助するために、マンドレルの自由端にプラスチック支持棒を支持します。 </li><li>ステンレス製の心棒を確保し、エレクトロスピニングの間に滑りを回避するために、プラスチック製の支持ロッドにセットネジを使用してください。 </li><li>ステンレス鋼のマンドレルにU字状のアース線を取り付けることにより、マンドレルコレクタを接地してください。マンドレルの側面にアース線を保持するためにゴム製のOリングを使用してください。 </li></ol></li><li> セッティエレクトロスピニング装置の液体ポリウレタン押出システムをngの<ol><li> 15％を得るために、25％（メートル/ v）のポリウレタン（PU）原液とジメチルアセトアミド（DMA）をミックス（メートル/ v）のPU DMA溶液（ 例えば 、9ミリリットルの25％PU溶液にDMAの6ミリリットルを追加します）。 注意！適切な個人用保護具とヒュームフード内部の作業を行います。 </li><li> 15％PU溶液で平滑末端ステンレス鋼針（口金）に5ミリリットルのガラスシリンジを埋めます。 </li><li>シリンジの内径に対して0.01 ml /分で押し出すシリンジポンプをプログラムします。 </li><li>マンドレルコレクタから約20cm針の先端に水平にシリンジポンプの口金にシリンジをマウントします。電気アーク放電を回避するためにゴムシートを用いて、シリンジポンプの導電性部分から注射器を絶縁します。 </li><li>ワニ口クリップを使用して、注射器の口金に高電圧発生器を接続します。 </li></ol></li><li> 0.01ミリリットル/分であり、ロタでシリンジポンプを実行します。低速（ 例えば 、50 rpm）で実行されている実験室用ミキサーでマンドレルをTE。 </li><li>口金全体の20キロボルトの電圧差とコレクタマンドレルを適用します。 PUナノファイバーは、回転マンドレル上に堆積開始され、薄層が数分以内に表示されます。ヒュームフードがオフになっていると排気が電気紡績ナノファイバーの損失を回避するために閉じていることを確認してください。 </li></ol> 2.ステントグラフトをエレクトロスピニング<ol><li> （ステップ1で説明したように）2時間回転マンドレル上にエレクトロスピニングPUナノファイバーは、均一なチューブを作成します。 </li><li>ベアメタルステントをインストールするには、実験室用ミキサーに接続されたプラスチック製の棒からマンドレルを削除します。前溶剤ヒュームが除去され、その名残を確実にするために、マンドレルを除去するヒュームフードやオープン排気をオンにします。 </li><li>目的の場所にエレクトロスピニングされたチューブにバルーン拡張ステンレス鋼ステント26をスライドさせます。 SLIので少しステントを拡張する必要があるかもしれませんpsの電界紡糸管を損傷することなく上。 </li><li>ステントをしっかりとマンドレル上にチューブ材料に設定し、スライドするのに十分な緩みされていないことを確認するために、ステントを圧着します。また、これは、内側と外側の層の剥離を防止するのに役立つであろう。 </li><li>ステントグラフトの外側の層をエレクトロスピニングするための実験室用ミキサーのプラスチック棒に再びチューブおよびステントとマンドレルをロードします。 </li><li>ステップ1で説明したように3時間エレクトロスピニングナノ繊維は、ステントグラフトの外側層を作製しました。 </li><li>後で外側をエレクトロスピニングした後、円周方向にPU素材にメスを用いて、ステントの端から約1ミリメートルを切りました。 </li><li>マンドレルからステント移植片を放出するマンドレルから支持材料を溶解し、脱イオン水でステントグラフトとマンドレルを浸します。完全に支持材料を溶解するために、必要に応じて新鮮な水と交換してください。 </li><li>支持材料が溶解したら、優しくトンからステントグラフトを削除彼はマンドレルと乾燥させます。空気乾燥に許可する前に、残りの支持材を溶解するために、脱イオン水で除去されたステントグラフトを浸すことを検討してください。 </li></ol>製造ステントグラフトの3試験<ol><li> 3ミリメートルのつ折りバルーン上のステント移植片をスライドさせます。 </li><li>圧着工具、手持ちを使用してバルーン上にステント移植片を圧着します。 </li><li>ステントの変形に均一に圧着するための顕微鏡とカバー材の剥離やパンクなどの故障の任意の他の徴候を使用してクリンプステントグラフトを点検します。 </li><li>膨張装置および水でつ折りバルーンを加圧することにより、3ミリメートルの設計直径にステントグラフトを展開します。ここでも、均一な膨張と故障の兆候が拡大ステントグラフトを調べます。 </li></ol>

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著者は、彼らが競合する金融利害関係を持たないことを宣言します。

We have developed a fabrication technique for a small caliber stent-graft which can be deployed using a standard percutaneous coronary intervention (PCI) procedure. Stent-grafts currently available are limited in their ability to maintain a low profile and flexibility for deployment. Bare metal stents developed by our group in our previous studies have proven to assist in rapid healing of the stented artery24,26. Various polymers have been electrospun by other groups and polyurethane has been proven biostable ...

冠動脈インターベンションの手順は、プラークの破壊および血管壁に起因する重大な血管壁の損傷を引き起こします。これは、再狭窄、静脈グラフトの末梢塞栓症、および冠状動脈内腔1-4の不連続が生じます。これらの合併症を回避するために、有望な戦略は、血管形成部位における血管表面を覆うように、潜在的に再狭窄を阻害するであろう、血管内腔の不連続のリスクを軽減、および末梢塞栓症を防止するであろう。これまでの研究では、ステントグラフト5のための肯定的な結果とステントグラフトにベアメタルステントを比較しました。研究者は、ステントをカバーするために膜を製造するためにいくつかの材料を使用しました。これは、ポリエチレンtetraphthalate（PET）、ポリテトラフルオロエチレン（PTFE）、ポリウレタン（PU）、及びシリコン又は覆われたステント6-9を製造するための自家血管組織のような合成材料を含んでいます。ステントを被覆するために使用される理想的な移植片材料は、抗血栓性、非biodegrであるべきですadable、および過度の増殖や炎症10せずに天然の組織と統合する必要があります。ステントを被覆するために使用される移植片材料はステント移植片の治癒を促進すべきです。 ステントグラフトが広く頚動脈の擬似動脈瘤、動静脈瘻は、静脈グラフトを縮退、大動脈縮窄の治療のために使用され、巨大な脳動脈瘤の大きさです。しかし、小口径のステント移植片の開発は、ステントグラフトの展開11-14に役立つロープロファイルと柔軟性を維持する能力によって制限されます。 PUは、ロープロファイルおよび良好な柔軟性15,16を達成するための所望の形質である良好な機械的強度と弾性ポリマーです。良好なデリバリーを有することに加えて、ステントグラフトはまた、迅速な治癒および内皮化を促進すべきです。 PUは、ステント移植片は、より良い生体適合性を実証し、内皮17を強化してい覆った。研究者は持っています以前PUは内皮細胞17でそれらを播種することによりステントグラフトを覆われた内皮化しようとしました。ナノファイバーマトリックスを作成するためにPUのエレクトロスピニングは、血管移植片18,19を製造するための貴重な技術であることが示されています。天然の細胞外マトリックスの構造を模倣するナノファイバーの存在はまた、内皮細胞増殖20,21を促進することが知られています。エレクトロスピニングは、材料22の厚さを制御することができます。 PUで作られた小口径血管移植片は、表面コーティング、抗凝固剤、及び細胞増殖抑制剤としての修飾を使用して、治癒を促進するために研究されています。すべてのこれらの変更は、ホスト受け入れを媒介グラフト治癒23を促進するように設計されています。 当社グループは、動物モデル24-26で展開することができるバルーン拡張ベアメタルステントを開発しました。エレクトロポリウレタンメッシュとボールの組み合わせキューン拡張型ステントは、小口径のバルーン拡張型ステント移植片を生成することができました。現在利用可能なステント移植片のほとんどは、介入手順中に大腿動脈を介して導入されているが、わずか数商業覆われたステントは非膨張バルーン27のために必要とされるよりも大きい1フレンチサイズを導入することができます。本研究では、経皮的インターベンションの手順で標準8-9フランスのガイドカテーテルを使用して冠状動脈に送達することができるエレクトロPUの2つの層の間のバルーン拡張型ステントをカプセル化することにより、小口径血管ステントグラフトを開発しました。

<table><tbody><tr><td>Glass syringe</td><td>Air Tite</td><td>7.140-33</td><td>Syringe for spinneret</td></tr><tr><td>Graduated cylinder 5 ml</td><td>Fisher Scientific</td><td>08-552-4G</td><td>5 ml pyrex graduated cylinder about 9 mm diameter and 11 cm long</td></tr><tr><td>High voltage generator</td><td>Bertan Accociates, Inc.</td><td>205A-30P</td><td>Used to apply voltage difference across spinneret and collector</td></tr><tr><td>Laboratory mixer with rpm control</td><td>Scilogex</td><td>SCI-84010201</td><td>Available from various laboratory equipment suppliers</td></tr><tr><td>Polyurethane</td><td>DSM</td><td>BioSpan SPU</td><td>Biospan Segmented Polyurethane</td></tr><tr><td>Rubber sheet</td><td>McMaster Carr</td><td>1370N11</td><td>Used to insulate syringe during electrospinning</td></tr><tr><td>Stainless steel mandrel</td><td>N/A</td><td>N/A</td><td>Manufactured&amp;nbsp;</td></tr><tr><td>Stainless steel needle</td><td>Hamilton</td><td>91018</td><td>Used as spinneret in electrospinning</td></tr><tr><td>Support material</td><td>EnvisionTec</td><td>B04-HT-DEMOMAT</td><td>Biocompatible water soluble material</td></tr><tr><td>Syringe Pump</td><td>Harvard Apparatus</td><td>55-3333</td><td></td></tr></tbody></table>

fabrication of small caliber stent-grafts using electrospinning and balloon expandable bare metal stents

Stent-grafts are widely used for the treatment of various conditions such as aortic lesions, aneurysms, emboli due to coronary intervention procedures and perforations in vasculature. Such stent-grafts are manufactured by covering a stent with a polymer membrane. An ideal stent-graft should have a biocompatible stent covered by a porous, thromboresistant, and biocompatible polymer membrane which mimics the extracellular matrix thereby promoting injury site healing. The goal of this protocol is to manufacture a small caliber stent-graft by encapsulating a balloon expandable stent within two layers of electrospun polyurethane nanofibers. Electrospinning of polyurethane has been shown to assist in healing by mimicking native extracellular matrix, thereby promoting endothelialization. Electrospinning polyurethane nanofibers on a slowly rotating mandrel enabled us to precisely control the thickness of the nanofibrous membrane, which is essential to achieve a small caliber balloon expandable stent-graft. Mechanical validation by crimping and expansion of the stent-graft has shown that the nanofibrous polyurethane membrane is sufficiently flexible to crimp and expand while staying patent without showing any signs of tearing or delamination. Furthermore, stent-grafts fabricated using the methods described here are capable of being implanted using a coronary intervention procedure using standard size guide catheters.

<html>我々のelectrospinnerセットアップ（ 図1）は、高品質のポリウレタンナノファイバー（ 図2）をもたらしました。ステントグラフトは、マンドレル上にポリウレタンの内部層をエレクトロスピニングこの層の上にベアメタルステントを滑り、及びポリウレタンの第二の外側層（ 図3）をエレクトロスピニングすることによって製造されます。ポリウレタ?...

Watch this Scientific Journal Video about Fabrication of Small Caliber Stent-grafts Using Electrospinning and Balloon Expandable Bare Metal Stents at JoVE.com

Fabrication of Small Caliber Stent-grafts Using Electrospinning and Balloon Expandable Bare Metal Stents

In the protocol, we present a method to manufacture a small caliber stent-graft by sandwiching a balloon expandable stent between two electrospun nanofibrous polyurethane layers.

エレクトロとバルーン拡張ベアメタルステントを使用した小口径ステントグラフトの作製

Stent-grafts are widely used for the treatment of various conditions such as aortic lesions, aneurysms, emboli due to coronary intervention procedures and ...

fabrication-small-caliber-stent-grafts-using-electrospinning-balloon

Research

JoVE Journal

Medicine

8.8K ビュー.  Mayo Clinic. In the protocol, we present a method to manufacture a small caliber stent-graft by sandwiching a balloon expandable stent between two electrospun nanofibrous polyurethane layers.

ビデオ: Fabrication of Small Caliber Stent-grafts Using Electrospinning and Balloon Expandable Bare Metal Stents

Postproduction Processing of Electrospun Fibres for Tissue Engineering

Electrospinning is a commonly used and versatile method to produce scaffolds (often biodegradable) for 3D tissue engineering.1, 2, 3 Many tissues in vivo undergo biaxial distension to varying extents such as skin, bladder, pelvic floor and even the hard palate as children grow. In producing scaffolds for these purposes there is a need to develop scaffolds of appropriate biomechanical properties (whether achieved without or with cells) and which are sterile for clinical use. The focus of this paper is not how to establish basic electrospinning parameters (as there is extensive literature on electrospinning) but on how to modify spun scaffolds post production to make them fit for tissue engineering purposes - here thickness, mechanical properties and sterilisation (required for clinical use) are considered and we also describe how cells can be cultured on scaffolds and subjected to biaxial strain to condition them for specific applications.
Electrospinning tends to produce thin sheets; as the electrospinning collector becomes coated with insulating fibres it becomes a poor conductor such that fibres no longer deposit on it. Hence we describe approaches to produce thicker structures by heat or vapour annealing increasing the strength of scaffolds but not necessarily the elasticity. Sequential spinning of scaffolds of different polymers to achieve complex scaffolds is also described. Sterilisation methodologies can adversely affect strength and elasticity of scaffolds. We compare three methods for their effects on the biomechanical properties on electrospun scaffolds of poly lactic-co-glycolic acid (PLGA).
Imaging of cells on scaffolds and assessment of production of extracellular matrix (ECM) proteins by cells on scaffolds is described. Culturing cells on scaffolds in vitro can improve scaffold strength and elasticity but the tissue engineering literature shows that cells often fail to produce appropriate ECM when cultured under static conditions. There are few commercial systems available that allow one to culture cells on scaffolds under dynamic conditioning regimes - one example is the Bose Electroforce 3100 which can be used to exert a conditioning programme on cells in scaffolds held using mechanical grips within a media filled chamber.4 An approach to a budget cell culture bioreactor for controlled distortion in 2 dimensions is described. We show that cells can be induced to produce elastin under these conditions. Finally assessment of the biomechanical properties of processed scaffolds cultured with or without cells is described.

Electrospun scaffolds can be processed post production for tissue engineering applications. Here we describe methods for spinning complex scaffolds (by consecutive spinning), for making thicker scaffolds (by multi-layering using heat or vapour annealing), for achieving sterility (aseptic production or sterilisation post production) and for achieving appropriate biomechanical properties.

組織工学のためのエレクトロ繊維のポスト処理

Electrospinning is a commonly used and versatile method to produce  scaffolds (often biodegradable) for 3D tissue engineering.1, 2, 3 Many tissues in vivo ...

生物工学

A Murine Model of Stent Implantation in the Carotid Artery for the Study of Restenosis

Despite the considerable progress made in the stent development in the last decades, cardiovascular diseases remain the main cause of death in western countries. Beside the benefits offered by the development of different drug-eluting stents, the coronary revascularization bears also the life-threatening risks of in-stent thrombosis and restenosis. Research on new therapeutic strategies is impaired by the lack of appropriate methods to study stent implantation and restenosis processes. Here, we describe a rapid and accessible procedure of stent implantation in mouse carotid artery, which offers the possibility to study in a convenient way the molecular mechanisms of vessel remodeling and the effects of different drug coatings.

A model of stent implantation in mouse carotid artery is described. Compared to other similar methods, this procedure is very rapid, simple and accessible, offering the possibility to study in a convenient way the vascular wall reaction to different drug-eluting stents and the molecular mechanisms of restenosis.

再狭窄の研究のための頸動脈内ステント留置のマウスモデル

Despite  the considerable progress made in the stent development in the last decades,  cardiovascular diseases remain the main cause of death in western ...

医学

Combination of Microstereolithography and Electrospinning to Produce Membranes Equipped with Niches for Corneal Regeneration

Corneal problems affect millions of people worldwide reducing their quality of life significantly. Corneal disease can be caused by illnesses such as Aniridia or Steven Johnson Syndrome as well as by external factors such as chemical burns or radiation. Current treatments are (i) the use of corneal grafts and (ii) the use of stem cell expanded in the laboratory and delivered on carriers (e.g., amniotic membrane); these treatments are relatively successful but unfortunately they can fail after 3-5 years. There is a need to design and manufacture new corneal biomaterial devices able to mimic in detail the physiological environment where stem cells reside in the cornea. Limbal stem cells are located in the limbus (circular area between cornea and sclera) in specific niches known as the Palisades of Vogt. In this work we have developed a new platform technology which combines two cutting-edge manufacturing techniques (microstereolithography and electrospinning) for the fabrication of corneal membranes that mimic to a certain extent the limbus. Our membranes contain artificial micropockets which aim to provide cells with protection as the Palisades of Vogt do in the eye.

We report a technique for the fabrication of micropockets within electrospun membranes in which to study cell behavior. Specifically, we describe a combination of microstereolithography and electrospinning for the production of PLGA (Poly(lactide-co-glycolide)) corneal biomaterial devices equipped with microfeatures.

角膜再生のためのニッチを装備膜を製造するためのマイクロ光とエレクトロスピニングの組み合わせ

Corneal problems affect millions of people worldwide reducing their quality of life significantly. Corneal disease can be caused by illnesses such as ...

Ferromagnetic Bare Metal Stent for Endothelial Cell Capture and Retention

Rapid endothelialization of cardiovascular stents is needed to reduce stent thrombosis and to avoid anti-platelet therapy which can reduce bleeding risk. The feasibility of using magnetic forces to capture and retain endothelial outgrowth cells (EOC) labeled with super paramagnetic iron oxide nanoparticles (SPION) has been shown previously. But this technique requires the development of a mechanically functional stent from a magnetic and biocompatible material followed by in-vitro and in-vivo testing to prove rapid endothelialization. We developed a weakly ferromagnetic stent from 2205 duplex stainless steel using computer aided design (CAD) and its design was further refined using finite element analysis (FEA). The final design of the stent exhibited a principal strain below the fracture limit of the material during mechanical crimping and expansion. One hundred stents were manufactured and a subset of them was used for mechanical testing, retained magnetic field measurements, in-vitro cell capture studies, and in-vivo implantation studies. Ten stents were tested for deployment to verify if they sustained crimping and expansion cycle without failure. Another 10 stents were magnetized using a strong neodymium magnet and their retained magnetic field was measured. The stents showed that the retained magnetism was sufficient to capture SPION-labeled EOC in our in-vitro studies. SPION-labeled EOC capture and retention was verified in large animal models by implanting 1 magnetized stent and 1 non-magnetized control stent in each of 4 pigs. The stented arteries were explanted after 7 days and analyzed histologically. The weakly magnetic stents developed in this study were capable of attracting and retaining SPION-labeled endothelial cells which can promote rapid healing.

Our goals were to design, manufacture and test ferromagnetic stents for endothelial cell capture. Ten stents were tested for fracture and 10 more stents were tested for retained magnetism. Finally, 10 stents were tested in-vitro and 8 more stents were implanted in 4 pigs to show cell capture and retention.

内皮細胞捕捉および保持のための強磁性ベアメタルステント

Rapid endothelialization of cardiovascular stents is needed to reduce stent thrombosis and to avoid anti-platelet therapy which can reduce bleeding risk. ...

4D Printed Bifurcated Stents with Kirigami-Inspired Structures

Branched vessels, typically in the form of the letter &#34;Y,&#34;&#160;can be narrowed or blocked, resulting in serious health problems. Bifurcated stents, which are hollow in the interior and exteriorly shaped to the branched vessels, surgically inserted inside the branched vessels, act as a supporting structure so that bodily fluids can freely travel through the interior of the stents without being obstructed by the narrowed or blocked vessels. For a bifurcated stent to be deployed at the target site, it needs to be injected inside the vessel and travel within the vessel to reach the target site. The diameter of the vessel is much smaller than the bounding sphere of the bifurcated stent; thus, a technique is required so that the bifurcated stent remains small enough to travel through the vessel and expands at the targeted branched vessel. These two conflicting conditions, that is, small enough to pass through and large enough to structurally support narrowed passages, are extremely difficult to satisfy simultaneously. We use two techniques to fulfill the above requirements. First, on the material side, a shape memory polymer (SMP) is used to self-initiate shape changes from small to large, that is, being small when inserted and becoming large at the target site. Second, on the design side, a kirigami pattern is used to fold the branching tubes into a single tube with a smaller diameter. The presented techniques can be used to engineer structures that can be compacted during transportation and return to their functionally adept shape when activated. Although our work is targeted on medical stents, biocompatibility issues need to be solved before actual clinical use.

Using a 3D printer, a shape memory polymer filament is extruded to form a branched tubular structure. The structure is patterned and shaped such that it can contract into a compact form once folded and then return to its formed shape when heated.

キリガミ風構造の4Dプリント分岐ステント

Branched vessels, typically in the form of the letter &#34;Y,&#34;&#160;can be narrowed or blocked, resulting in serious health problems. Bifurcated ...

工学

<meta charset="utf8"></head><body>犠牲銅固定具を使用したNiTiワイヤーの費用対効果の高い形状設定

Rapid Formation and Testing of Self-expanding NiTi Frames with a Small Form Factor Suitable for Minimally Invasive Implants

NiTiNOL (commonly referred to as nitinol or NiTi) wires feature exceptional shape memory and super-elastic characteristics, while shape-setting is often a costly process. Among the steps in&#160;this process, heat treatment requires exposure to high temperatures for shape-setting. Traditionally, metal fixtures are used for this purpose.&#160;However, their manufacturing costs can be significant, which is unideal&#160;for iterating prototypes. This work demonstrates a recently introduced approach using sacrificial fixtures made of copper tubes, which eliminates the need for expensive fixtures. These copper tubes allow for the formation of complex geometries, and they offer a scaffold for various phases of the fabrication process. Moreover, ammonium persulfate is used&#160;for selective copper etching, which simplifies the production of NiTi frames. This work&#39;s findings confirm the effectiveness of this technique and&#160;demonstrate&#160;the successful shape-setting of NiTi wires for self-expanding frames. This methodology paves the way for future research, allowing for rapid prototyping of NiTi wireframes for various applications, especially those in medical devices.

<meta charset="utf8"></head><body>著者スポットライト:経カテーテル埋め込み型デバイス用の自己拡張型ニチノールフレームのラピッドプロトタイピングとテスト

This work illustrates a low-cost fabrication technique for shape-setting nitinol wires/frames with a small form factor using sacrificial fixtures. The technique is demonstrated for the fabrication of self-expanding frames designed for minimally invasive implants with complex shapes.

低侵襲インプラントに適した小型フォームファクタの自己拡張型NiTiフレームの迅速な形成と試験

NiTiNOL (commonly referred to as nitinol or NiTi) wires feature exceptional shape memory and super-elastic characteristics, while shape-setting is often a ...

Biodegradable Magnesium Stent Treatment of Saccular Aneurysms in a Rat Model - Introduction of the Surgical Technique

The steady progess in the armamentarium of techniques available for endovascular treatment of intracranial aneurysms requires affordable and reproducable experimental animal models to test novel embolization materials such as stents and flow diverters. The aim of the present project was to design a safe, fast, and standardized surgical technique for stent assisted embolization of saccular aneurysms in a rat animal model.
Saccular aneurysms were created from an arterial graft from the descending aorta.The aneurysms were microsurgically transplanted through end-to-side anastomosis to the infrarenal abdominal aorta of a syngenic male Wistar rat weighing &#62;500 g. Following aneurysm anastomosis, aneurysm embolization was performed using balloon expandable magnesium stents (2.5 mm x 6 mm). The stent system was retrograde introduced from the lower abdominal aorta using a modified Seldinger technique.
Following a pilot series of 6 animals, a total of 67 rats were operated according to established standard operating procedures. Mean surgery time, mean anastomosis time, and mean suturing time of the artery puncture site were 167 &#177; 22 min, 26 &#177; 6 min and 11 &#177; 5 min, respectively. The mortality rate was 6% (n=4). The morbidity rate was 7.5% (n=5), and in-stent thrombosis was found in 4 cases (n=2 early, n=2 late in stent thrombosis).
The results demonstrate the feasibility of standardized stent occlusion of saccular sidewall aneurysms in rats - with low rates of morbidity and mortality. This stent embolization procedure combines the opportunity to study novel concepts of stent or flow diverter based devices as well as the molecular aspects of healing.

Reproducable experimental animal models are needed for the testing of novel embolization materials, which have been designed to treat endovascular occlusion of intracranial aneurysms (IA). The present study aims to develop a safe and standardized surgical technique for stent assisted embolization of saccular aneurysms in a rat animal model.

ラットのモデル - 手術手技の導入における嚢状脳動脈瘤のステント治療を生分解性マグネシウム

The steady progess in the armamentarium of techniques available for endovascular treatment of intracranial aneurysms requires affordable and reproducable ...

神経科学

Combining 3D-Printing and Electrospinning to Manufacture Biomimetic Heart Valve Leaflets

Electrospinning has become a widely used technique in cardiovascular tissue engineering as it offers the possibility to create (micro-)fibrous scaffolds with adjustable properties. The aim of this study was to create multilayered scaffolds mimicking the architectural fiber characteristics of human heart valve leaflets using conductive 3D-printed collectors.
Models of aortic valve cusps were created using commercial computer-aided design (CAD) software. Conductive polylactic acid was used to fabricate 3D-printed leaflet templates. These cusp negatives were integrated into a specifically designed, rotating electrospinning mandrel. Three layers of polyurethane were spun onto the collector, mimicking the fiber orientation of human heart valves. Surface and fiber structure was assessed with a scanning electron microscope (SEM). The application of fluorescent dye additionally permitted the microscopic visualization of the multilayered fiber structure. Tensile testing was performed to assess the biomechanical properties of the scaffolds.
3D-printing of essential parts for the electrospinning rig was possible in a short time for a low budget. The aortic valve cusps created following this protocol were three-layered, with a fiber diameter of 4.1 &#177; 1.6 &#181;m. SEM imaging revealed an even distribution of fibers. Fluorescence microscopy revealed individual layers with differently aligned fibers, with each layer precisely reaching the desired fiber configuration. The produced scaffolds showed high tensile strength, especially along the direction of alignment. The printing files for the different collectors are available as Supplemental File 1, Supplemental File 2, Supplemental File 3, Supplemental File 4, and Supplemental File 5.
With a highly specialized setup and workflow protocol, it is possible to mimic tissues with complex fiber structures over multiple layers. Spinning directly on 3D-printed collectors creates considerable flexibility in manufacturing 3D shapes at low production costs.

The presented method offers an innovative way for engineering biomimetic fiber structures in three-dimensional (3D) scaffolds (e.g., heart valve leaflets). 3D-printed, conductive geometries were used to determine shape and dimensions. Fiber orientation and characteristics were individually adjustable for each layer. Multiple samples could be manufactured in one setup.

3Dプリンティングとエレクトロスピニングを組み合わせて、生体模倣心臓弁リーフレットを製造

Electrospinning has become a widely used technique in cardiovascular tissue engineering as it offers the possibility to create (micro-)fibrous scaffolds ...

エレクトロとバルーン拡張ベアメタルステントを使用した小口径ステントグラフトの作製

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組織工学のためのエレクトロ繊維のポスト処理

再狭窄の研究のための頸動脈内ステント留置のマウスモデル

角膜再生のためのニッチを装備膜を製造するためのマイクロ光とエレクトロスピニングの組み合わせ

内皮細胞捕捉および保持のための強磁性ベアメタルステント

キリガミ風構造の4Dプリント分岐ステント

低侵襲インプラントに適した小型フォームファクタの自己拡張型NiTiフレームの迅速な形成と試験

低侵襲インプラントに適した小型フォームファクタの自己拡張型NiTiフレームの迅速な形成と試験

低侵襲インプラントに適した小型フォームファクタの自己拡張型NiTiフレームの迅速な形成と試験

ラットのモデル - 手術手技の導入における嚢状脳動脈瘤のステント治療を生分解性マグネシウム

3Dプリンティングとエレクトロスピニングを組み合わせて、生体模倣心臓弁リーフレットを製造