Name: molecular entanglement and electrospinnability of biopolymers
Uploaded: 2014-09-03T15:45:00.000+00:00
Duration: 7 min 59 s
Description: Watch this Scientific Journal Video about Molecular Entanglement and Electrospinnability of Biopolymers at JoVE.com

この作品は、食料農業USDA国立研究所、国立競争補助金プログラム、国家研究イニシアティブプログラム71.1 2007年度によって部分的に資金を供給されているアレルギー感染病に対する認可番号2007-35503-18392、および国立衛生研究所、研究所など、R33AI94514-03。

1スピニングドープ準備<ol><li>調査されるべき生体高分子濃度の範囲を準備します（0.1％〜30％、w / v）の、これらの計算では、バイオポリマー粉末の含水率を考慮してください。各濃度について50mlの試験管にバイオポリマー（デンプン、プルラン）粉末の重量を量る。水性ジメチルスルホキシド（DMSO）溶液と撹拌棒を加える。 </li><li>マグネチックスターラーホットプレート上で一定に攪拌しながら沸騰したお湯にチューブを置きます。 </li><li>約1時間後、加熱をオフにし、分散液が室温に冷却させる。次に、分散液をレオロジーテストやエレクトロスピニングの準備ができています。 </li></ol> 2定常せん断レオロジー<ol><li>レオメーターをウォームアップし、20℃のステージ温度を設定します。プローブ（使用25mmのコーン）とステージ（プレート）の間のギャップを校正します。 </li><li>ステージの中央への生体高分子分散の荷重0.41ミリリットルとPOSITIを設定するためのプローブを下げる（25mmのコーンのための0.053ミリメートルギャップ）について。分散が均等にギャップ内に広がっていることを確認します。 </li><li>掃引モード：ログインし、初期速度：100秒-1、最終速度：0.1秒-1、十年ごとのポイント：10、対策前の遅延：5秒、小節時間：10秒、以下の実験パラメータでレオロジー試験を行う拍子や方向：2（反時​​計回りの両方）。 </li><li>試験をエレクトロスピニングするための適切な分散濃度を推定するレオロジーデータを分析します。 <ol><li>ポリマー濃度の関数としてせん断速度に対する見掛けのせん断粘度をプロットします。 0.1秒での見かけの粘度（低せん断速度のデータは信頼性が低い低濃度で、 例えば ）実際の、または外挿した値で、各フローカーブ、おおよそのゼロせん断粘度、η0、の場合- 1。 </li><li>比粘度を計算し、ηSP =（η0 - η 秒 ）ηsは溶媒の粘度である/ηsで、。 </li><li>濃度の関数として特定の粘度をプロットします。 semidilute交絡と絡み合った体制を識別します。 semidilute交絡政権は、小さな傾きで低濃度端から始まり、semidiluteもつれ政権は交絡政権、次のより大きな傾斜を有する。双方の体制に合わせるべき乗則回帰モデル。電力値は、両対数プロット上semidilute交絡と絡み合った体制での斜面（濃度依存性）である。 2近似直線の交点が絡み合い濃度はC eは 。 </li></ol></li></ol> 3エレクトロスピニングパラメータ変動<ol><li> 図1に示すように電界紡糸セットアップを組み立てます。シリンジポンプ上に、100％のDMSO中の15％（w / v）のデンプンまたはプルラン、 たとえば 、適切な組成の分散体と注射器をロードします。 POSIT（高電圧ワイヤークリップ針にIVE）。浴にアース線（マイナス）を浸漬することによって地面に純粋なエタノールを含む凝固槽を接続します。注射針と凝固浴との間の距離を調整するためにラボジャッキを使用してください。エレクトロスピニング後に繊維マットを収集する浴中に金属メッシュを浸す。 </li><li>次のパラメータに生体高分子をスピン範囲：0〜15 kVの0.1〜0.4ミリリットル/時間から速度、5〜10センチメートルスピニング距離、電圧を養う。 <ol><li> 5cmのスピニング距離から始めます。最初の送り速度（0.1ミリリットル/時）の場合は、0 V針の先端で押し出し、分散液の形状に注意を払い、滴下分散が加速した後、伸長した際に注意してから、ゆっくりと電圧が上昇します。 </li><li>小さなジェットは、溶液のelectrospinnabilityを示す、落下面から開始する電圧に注意してください。もしあれば、継続的なジェットが開始する電圧を記録します。 </li><li> 3 parameteのそれぞれのための完全な範囲を調べRSとノート成功紡糸条件。先端から連続ジェットがある場合にのみ繊維を収集します。 </li></ol></li><li>収集の数分後、純粋なエタノールで繊維マットをすすぐ。真空下で乾燥剤入りデシケーター中に繊維マットを置きます。 </li><li>完全な特性のために、各生体高分子濃度について繰り返します。 </li></ol><img alt="図1" fo:content-width="5in" src="/files/ftp_upload/51933/51933fig1highres.jpg" width="500" /> エレクトロ湿式紡糸セットアップの図1概念図。バイオポリマー分散液をシリンジポンプから押し出される。高電圧DC電源は、鈍針を接地凝固浴に高電圧を提供する。針の先端からのポリマージェットはまっすぐな道を通って移動した後、急速なホイップ·パス（別名​​泡立て不安定）を開発しています。 4。形態学的特性評価<ol><li>乾燥した繊維マットの部分をカットし、カーボンテープを使用したSEMスタブの上に固定化する。 </li><li> SEM装置内に試料スタブをロードし、分析のための画像を取得する。 </li></ol>

<ol>
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E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlation+of+Chitosan&#8217;s+Rheological+Properties+and+Its+Ability+to+Electrospin.">Correlation of Chitosan&#8217;s Rheological Properties and Its Ability to Electrospin.</a> Biomacromolecules. 9 (10), 2947-2953 (2008).</li><li>McKee, M. G., Wilkes, G. L., Colby, R. H., Long, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlations+of+Solution+Rheology+with+Electrospun+Fiber+Formation+of+Linear+and+Branched+Polyesters.">Correlations of Solution Rheology with Electrospun Fiber Formation of Linear and Branched Polyesters.</a> Macromolecules. 37 (5), 1760-1767 (2004).</li><li>McKee, M. G., Hunley, M. T., Layman, J. M., Long, T. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solution+rheological+behavior+and+electrospinning+of+cationic+polyelectrolytes.">Solution rheological behavior and electrospinning of cationic polyelectrolytes.</a> Macromolecules. 39 (2), 575-583 (2006).</li><li>Kong, L., Ziegler, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+pure+starch+fibers+by+electrospinning.">Fabrication of pure starch fibers by electrospinning.</a> Food Hydrocolloids. 36, 20-25 (2014).</li><li>Singh, R. S., Saini, G. K., Kennedy, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pullulan:+microbial+sources,+production+and+applications.">Pullulan: microbial sources, production and applications.</a> Carbohydrate Polymers. 73 (4), 515-531 (2008).</li><li>Leathers, T. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biotechnological+production+and+applications+of+pullulan.">Biotechnological production and applications of pullulan.</a> Applied Microbiology and Biotechnology. 62 (5), 468-473 (2003).</li><li>Karim, M. R., Lee, H. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+characterization+of+electrospun+pullulan/montmorillonite+nanofiber+mats+in+aqueous+solution.">Preparation and characterization of electrospun pullulan/montmorillonite nanofiber mats in aqueous solution.</a> Carbohydrate Polymers. 78 (2), 336-342 (2009).</li><li>Stijnman, A. C., Bodnar, I., Hans Tromp, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrospinning+of+food-grade+polysaccharides.">Electrospinning of food-grade polysaccharides.</a> Food Hydrocolloids. 25 (5), 1393-1398 (2011).</li><li>Kong, L., Ziegler, G. 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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Fiber Spinning Rheology and Processing of Polymeric Materials: Volume 2: Polymer Processing. , 257-304 (2007).</li><li>Morris, E. R., Cutler, A. N., Ross-Murphy, S. B., Rees, D. A., Price, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Concentration+and+shear+rate+dependence+of+viscosity+in+random+coil+polysaccharide+solutions.">Concentration and shear rate dependence of viscosity in random coil polysaccharide solutions.</a> Carbohydrate Polymers. 1 (1), 5-21 (1981).</li><li>Thompson, C. J., Chase, G. G., Yarin, A. L., Reneker, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+parameters+on+nanofiber+diameter+determined+from+electrospinning+model.">Effects of parameters on nanofiber diameter determined from electrospinning model.</a> Polymer. 48 (23), 6913-6922 (2007).</li></ol>

著者らは、開示することは何もないことを宣言します。

レオロジーは、従来の紡糸やエレクトロスピニング13を含むポリマーの加工を、研究するための不可欠なツールです。定常せん断レオロジー研究、ポリマーコンフォメーションと異なる溶媒でのそれらの相互作用から解決することができる（ 図2および3）。バイオポリマー分子が互いに重なるために十分ではない高濃度で、それらの濃度依存性は、良溶媒...

エレクトロスピニングは、多種多様な材料からナノスケールの繊維に連続したマイクロを生成することができる技術である。これは、増加し、学術および産業の関心1を得ています。セットアップとエレクトロスピニングの実施は簡単なように見えるが、繊維特性をelectrospinnabilityを予測し、制御する能力は、課題である。その理由は、多くのエレクトロスピニング工程2に影響を与える要因、プロセス、繊維が移動特にパスが存在するという事実にあるのかもしれない、カオス1である。しばしば経験的な「クック·アンド·ルック」アプローチは、潜在的electrospinnable物質をスクリーニングするために使用される。しかしながら、電界紡糸プロセス及び結果として得られる繊維の特性より良好な制御を得るために、electrospinnabilityを支配するメカニズムのより完全な理解が必要である。いくつかの研究者は、紡糸原液中のポリマーの分子の絡み合いは、エッセンであることを見出した成功したエレクトロスピニング3〜5はLの前提条件。 レオロジーは、ポリマー分散液中の分子の立体配座との相互作用を調査するための強力なツールです。例えば、マッキーら 。クロロホルム/ジメチルテレフタレート（7/3、v / v）を含む溶媒中で線形の分子配座および分枝状ポリ（エチレンテレフタレート - コ - エチレンテレフタレート）共重合体を調査し、ポリマー濃度が2-2.5xをする必要があったと判断さ成功したエレクトロスピニング4用の絡み合い濃度。 なぜなら、生分解性、生体適合性、および気力それらの合成対応更新性におけるそれらの利点のバイオポリマーからの繊維で現在新たな関心がある。しかし、専門家は、その構造の複雑さ、熱加工と劣る機械的性質の困難さから、一般的に発生する多くの課題に直面する。植物組織に見られるデンプンは、アモンですgの地球上で最も豊富で安価なバイオポリマー。最近6に記載された純粋な澱粉繊維は、電気湿式紡糸装置を使用して製造。プルランは、ある種の細菌によって細胞外に生産さ線状多糖類である。 （1→4）および（1→6） ​​の規則的な交互のグルコシド結合は機能7,8を形成する優れた繊維/フィルムを含むプルランのいくつかの独特の特性の原因であると考えられている。水性分散液からプルラン繊維の電界紡糸は、研究者9,10の数で報告されている。われわれの以前の出版物では、2つのバイオポリマー、デンプン11及びプルラン12のelectrospinnabilityは、議論されている。このレポートは、これらの2つの生体高分子のelectrospinnabilityの調査にレオロジーの原則を利用するためのプロトコルを示すに焦点を当てています。

<table><tbody><tr><td>Gelose 80 starch</td><td>Ingredion</td><td></td><td>Used as it is</td></tr><tr><td>Pullulan</td><td>Hayashibara Co. Ltd</td><td></td><td>Used as it is</td></tr><tr><td>Dimethyl sulfoxide</td><td>BDH Chemicals</td><td>BDH1115-4LP</td><td></td></tr><tr><td>Ethanol</td><td>VWR International</td><td>89125-172</td><td>200 proof</td></tr><tr><td>Rheometer</td><td>TA Instruments</td><td>ARES&amp;nbsp;</td><td>50 mm cone and plate geometry</td></tr><tr><td>Syringe (10 ml)</td><td>Becton, Dickinson and Company</td><td>309604</td><td>Syringe with Luer-Lok&amp;reg; Tip</td></tr><tr><td>High voltage generator</td><td>Gamma High Voltage Research, Inc.</td><td>ES40P</td><td></td></tr><tr><td>Syringe pump</td><td>Hamilton Company</td><td>81620</td><td></td></tr><tr><td>Environmental scanning electron microscope</td><td>FEI Company</td><td>Quanta 200</td><td>for starch fibers</td></tr><tr><td>Environmental scanning electron microscope</td><td>Phenom-World</td><td>Phenom G2 Pro</td><td>for pullulan fibers</td></tr></tbody></table>

molecular entanglement and electrospinnability of biopolymers

エレクトロスピニングは、多種多様な材料からナノスケールの繊維にマイクロ作製する魅力的な技術である。バイオポリマーは、紡糸原液中の成分ポリマーの分子絡み合いが成功したエレクトロスピニングのための必須の前提条件であることが見出された。レオロジーは、生体高分子の分子コンフォメーションとの相互作用を調査するための強力なツールです。本稿では、それらのジメチルスルホキシド（DMSO）/水分散液から、2の生体高分子、デンプンおよびプルランのelectrospinnabilityを評価するためにレオロジーを利用するためのプロトコルを示しています。ミクロン範囲にサブミクロンの平均直径を持つ整形式デンプン及びプルラン繊維が得られた。 Electrospinnabilityが形成された繊維の視覚的な顕微鏡観察により評価した。彼らのelectrospinnabilityに分散液のレオロジー特性を相関させることによって、私たちは、分子の立体配座は、分子の絡み合い、せん断粘度はすべて当選者に影響を与えることを実証しているrospinning。レオロジーは、溶媒系の選択およびプロセスの最適化において有用であるだけでなく、分子レベルで繊維形成のメカニズムを理解していない。

バイオポリマーの濃度や溶媒中のDMSO濃度の関数としてのバイオポリマー分散液の流動曲線が得られた。二つの代表的な数値は、純粋なDMSO溶媒中のそれらの濃度の関数として澱粉（ 図2A）およびプルラン（ 図2B）の流動曲線を示す。具体的な粘度は、バイオポリマーの濃度（プルラン用デンプンおよび図3Bは図3A）に対してプロットした。こ?...

Watch this Scientific Journal Video about Molecular Entanglement and Electrospinnability of Biopolymers at JoVE.com

Molecular Entanglement and Electrospinnability of Biopolymers

エレクトロスピニングは、多種多様な材料からナノスケールの繊維にミクロを製造するために使用される魅力的な技術である。紡糸原液中の成分ポリマーの分子絡み合いが成功エレクトロスピニングのために必須である。私たちは、2つの生体高分子、デンプンおよびプルランのelectrospinnabilityを評価するためにレオロジーを利用するためのプロトコルを提示する。

生体高分子の分子エンタングルメントとElectrospinnability

Electrospinning is a fascinating technique to fabricate micro- to nano-scale fibers from a wide variety of materials. For biopolymers, molecular ...

molecular-entanglement-and-electrospinnability-of-biopolymers

Research

JoVE Journal

Bioengineering

13.8K ビュー.  Pennsylvania State University. エレクトロスピニングは、多種多様な材料からナノスケールの繊維にミクロを製造するために使用される魅力的な技術である。紡糸原液中の成分ポリマーの分子絡み合いが成功エレクトロスピニングのために必須である。私たちは、2つの生体高分子、デンプンおよびプルランのelectrospinnabilityを評価するためにレオロジーを利用するためのプロトコルを提...

ビデオ: Molecular Entanglement and Electrospinnability of Biopolymers

Electrospinning Fundamentals: Optimizing Solution and Apparatus Parameters

Electrospun nanofiber scaffolds have been shown to accelerate the maturation, improve the growth, and direct the migration of cells in vitro. Electrospinning is a process in which a charged polymer jet is collected on a grounded collector; a rapidly rotating collector results in aligned nanofibers while stationary collectors result in randomly oriented fiber mats. The polymer jet is formed when an applied electrostatic charge overcomes the surface tension of the solution. There is a minimum concentration for a given polymer, termed the critical entanglement concentration, below which a stable jet cannot be achieved and no nanofibers will form - although nanoparticles may be achieved (electrospray). A stable jet has two domains, a streaming segment and a whipping segment. While the whipping jet is usually invisible to the naked eye, the streaming segment is often visible under appropriate lighting conditions. Observing the length, thickness, consistency and movement of the stream is useful to predict the alignment and morphology of the nanofibers being formed. A short, non-uniform, inconsistent, and/or oscillating stream is indicative of a variety of problems, including poor fiber alignment, beading, splattering, and curlicue or wavy patterns. The stream can be optimized by adjusting the composition of the solution and the configuration of the electrospinning apparatus, thus optimizing the alignment and morphology of the fibers being produced. In this protocol, we present a procedure for setting up a basic electrospinning apparatus, empirically approximating the critical entanglement concentration of a polymer solution and optimizing the electrospinning process. In addition, we discuss some common problems and troubleshooting techniques.

Electrospinning techniques can create a variety of nanofibrous scaffolds for tissue engineering or other applications. We describe here a procedure to optimize the parameters of the electrospinning solution and apparatus to obtain fibers with the desired morphology and alignment. Common problems and troubleshooting techniques are also presented.

エレクトロスピニングの基礎：最適化ソリューションと装置のパラメータ

Electrospun nanofiber scaffolds have been shown to accelerate the maturation, improve the growth, and direct the migration of cells in vitro. ...

生物工学

Air Filter Devices Including Nonwoven Meshes of Electrospun Recombinant Spider Silk Proteins

Based on the natural sequence of Araneus diadematus Fibroin 4 (ADF4), the recombinant spider silk protein eADF4(C16) has been engineered. This highly repetitive protein has a molecular weight of 48kDa and is soluble in different solvents (hexafluoroisopropanol (HFIP), formic acid and aqueous buffers). eADF4(C16) provides a high potential for various technical applications when processed into morphologies such as films, capsules, particles, hydrogels, coatings, fibers and nonwoven meshes. Due to their chemical stability and controlled morphology, the latter can be used to improve filter materials. In this protocol, we present a procedure to enhance the efficiency of different air filter devices, by deposition of nonwoven meshes of electrospun recombinant spider silk proteins. Electrospinning of eADF4(C16) dissolved in HFIP results in smooth fibers. Variation of the protein concentration (5-25% w/v) results in different fiber diameters (80-1,100 nm) and thus pore sizes of the nonwoven mesh.
Post-treatment of eADF4(C16) electrospun from HFIP is necessary since the protein displays a predominantly &alpha;-helical secondary structure in freshly spun fibers, and therefore the fibers are water soluble. Subsequent treatment with ethanol vapor induces formation of water resistant, stable &beta;-sheet structures, preserving the morphology of the silk fibers and meshes. Secondary structure analysis was performed using Fourier transform infrared spectroscopy (FTIR) and subsequent Fourier self-deconvolution (FSD).
The primary goal was to improve the filter efficiency of existing filter substrates by adding silk nonwoven layers on top. To evaluate the influence of electrospinning duration and thus nonwoven layer thickness on the filter efficiency, we performed air permeability tests in combination with particle deposition measurements. The experiments were carried out according to standard protocols.

Spider silk fibers display extraordinary mechanical properties. Engineered Araneus diadematus Fibroin 4 (eADF4) can be processed into nonwoven meshes using electrospinning. Here, the eADF4 nonwoven meshes are used to improve the performance of air filtering devices.

エレクトロ組換えスパイダーシルクタンパク質の不織布メッシュを含むエアフィルターデバイス

Based on the natural sequence of Araneus diadematus Fibroin 4 (ADF4), the recombinant spider silk protein eADF4(C16) has been engineered. This highly ...

Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial applications. Here we describe how electrospinning or electrospraying a polymer mixture containing a biodegradable, biocompatible aliphatic polyester (e.g., polycaprolactone and poly(lactide-co-glycolide)), as the major component, doped with a hydrophobic copolymer composed of the polyester and a stearate-modified poly(glycerol carbonate) affords a superhydrophobic biomaterial. The fabrication techniques of electrospinning or electrospraying provide the enhanced surface roughness and porosity on and within the fibers or the particles, respectively. The use of a low surface energy copolymer dopant that blends with the polyester and can be stably electrospun or electrosprayed affords these superhydrophobic materials. Important parameters such as fiber size, copolymer dopant composition and/or concentration, and their effects on wettability are discussed. This combination of polymer chemistry and process engineering affords a versatile approach to develop application-specific materials using scalable techniques, which are likely generalizable to a wider class of polymers for a variety of applications.

Two- and three-dimensional superhydrophobic polymeric materials are prepared by electrospinning or electrospraying biodegradable polymers blended with a lower surface energy polymer of similar composition.

バイオメディカル応用のための超疎水性高分子材料を製造します

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial ...

Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning

While various smart materials have been explored for a variety of biomedical applications (e.g., drug delivery, tissue engineering, bioimaging, etc.), their ultimate clinical use has been hampered by the lack of biologically-relevant degradation observed for most smart materials. This is particularly true for temperature-responsive hydrogels, which are almost uniformly based on polymers that are functionally non-degradable (e.g., poly(N-isopropylacrylamide) (PNIPAM) or poly(oligoethylene glycol methacrylate) (POEGMA)). As such, to effectively translate the potential of thermoresponsive hydrogels to the challenges of remote-controlled or metabolism-regulated drug delivery, cell scaffolds with tunable cell-material interactions, theranostic materials with the potential for both imaging and drug delivery, and other such applications, a method is required to render the hydrogels (if not fully degradable) at least capable of renal clearance following the required lifetime of the material. To that end, this protocol describes the preparation of hydrolytically-degradable hydrazone-crosslinked hydrogels on multiple length scales based on the reaction between hydrazide and aldehyde-functionalized PNIPAM or POEGMA oligomers with molecular weights below the renal filtration limit. Specifically, methods to fabricate degradable thermoresponsive bulk hydrogels (using a double barrel syringe technique), hydrogel particles (on both the microscale through the use of a microfluidics platform facilitating simultaneous mixing and emulsification of the precursor polymers and the nanoscale through the use of a thermally-driven self-assembly and cross-linking method), and hydrogel nanofibers (using a reactive electrospinning strategy) are described. In each case, hydrogels with temperature-responsive properties similar to those achieved via conventional free radical cross-linking processes can be achieved, but the hydrazone cross-linked network can be degraded over time to re-form the oligomeric precursor polymers and enable clearance. As such, we anticipate these methods (which may be generically applied to any synthetic water-soluble polymer, not just smart materials) will enable easier translation of synthetic smart materials to clinical applications.

Protocols are described for the fabrication of degradable thermoresponsive hydrogels based on hydrazone cross-linking of polymeric oligomers on the bulk scale, microscale, and nanoscale, the latter for preparation of both gel nanoparticles and nanofibers.

自己組織化反応押出、マイクロフルイディクス, 経由で複数の長さスケールでの分解性感温ハイドロゲルを加工・ エレクトロスピニング

While various smart materials have been explored for a variety of biomedical applications (e.g., drug delivery, tissue engineering, bioimaging, etc.), ...

Methods for the Self-integration of Megamolecular Biopolymers on the Drying Air-LC Interface

Living organisms that use water are always prone to drying in the environment. Their activities are driven by biopolymer-based micro- and macro-structures, as seen in the cases of moving water in vascular bundles and moisturizing water in skin layers. In this study, we developed a method for assessing the effect of aqueous liquid crystalline (LC) solutions composed of biopolymers on drying. As LC biopolymers have megamolecular weight, we chose to study polysaccharides, cytoskeletal proteins, and DNA. The observation of biopolymer solutions during drying under polarized light reveals milliscale self-integration starting from the unstable air-LC interface. The dynamics of the aqueous LC biopolymer solutions can be monitored by evaporating water from a one-side-open cell. By analyzing the images taken using cross-polarized light, it is possible to recognize the spatio-temporal changes in the orientational order parameter. This method can be useful for the characterization of not only artificial materials in various fields, but also natural living tissues. We believe that it will provide an evaluation method for soft materials in the biomedical and environmental fields.

A method for the drying-induced self-integration of megamolecular biopolymers on the air-liquid crystalline interface is provided here. This methodology will be useful not only for understanding the macroscopic potentials of biopolymers, but also as an evaluation method for soft materials in biomedical and environmental fields.

乾燥風-LCインターフェイス上Megamolecular生体高分子の自己統合するための方法

Living organisms that use water are always prone to drying in the environment. Their activities are driven by biopolymer-based micro- and ...

DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers

Mechanical properties of complex, polymer-based soft matter, such as cells or biopolymer networks, can be understood in neither the classical frame of flexible polymers nor of rigid rods. Underlying filaments remain outstretched due to their non-vanishing backbone stiffness, which is quantified via the persistence length (lp), but they are also subject to strong thermal fluctuations. Their finite bending stiffness leads to unique, non-trivial collective mechanics of bulk networks, enabling the formation of stable scaffolds at low volume fractions while providing large mesh sizes. This underlying principle is prevalent in nature (e.g., in cells or tissues), minimizing the high molecular content and thereby facilitating diffusive or active transport. Due to their biological implications and potential technological applications in biocompatible hydrogels, semiflexible polymers have been subject to considerable study. However, comprehensible investigations remained challenging since they relied on natural polymers, such as actin filaments, which are not freely tunable. Despite these limitations and due to the lack of synthetic, mechanically tunable, and semiflexible polymers, actin filaments were established as the common model system. A major limitation is that the central quantity lp cannot be freely tuned to study its impact on macroscopic bulk structures. This limitation was resolved by employing structurally programmable DNA nanotubes, enabling controlled alteration of the filament stiffness. They are formed through tile-based designs, where a discrete set of partially complementary strands hybridize in a ring structure with a discrete circumference. These rings feature sticky ends, enabling the effective polymerization into filaments several microns in length, and display similar polymerization kinetics as natural biopolymers. Due to their programmable mechanics, these tubes are versatile, novel tools to study the impact of lp on the single-molecule as well as the bulk scale. In contrast to actin filaments, they remain stable over weeks, without notable degeneration, and their handling is comparably straightforward.

Semiflexible polymers display unique mechanical properties that are extensively applied by living systems. However, systematic studies on biopolymers are limited since properties such as polymer rigidity are inaccessible. This manuscript describes how this limitation is circumvented by programmable DNA nanotubes, enabling experimental studies on the impact of filament rigidity.

セミフレキシブル高分子を研究する多目的ツールとして DNA ナノチューブ

Mechanical properties of complex, polymer-based soft matter, such as cells or biopolymer networks, can be understood in neither the classical frame of ...

Melt Electrospinning Writing of Three-dimensional Poly(&#949;-caprolactone) Scaffolds with Controllable Morphologies for Tissue Engineering Applications

This tutorial reflects on the fundamental principles and guidelines for electrospinning writing with polymer melts, an additive manufacturing technology with great potential for biomedical applications. The technique facilitates the direct deposition of biocompatible polymer fibers to fabricate well-ordered scaffolds in the sub-micron to micro scale range. The establishment of a stable, viscoelastic, polymer jet between a spinneret and a collector is achieved using an applied voltage and can be direct-written. A significant benefit of a typical porous scaffold is a high surface-to-volume ratio which provides increased effective adhesion sites for cell attachment and growth. Controlling the printing process by fine-tuning the system parameters enables high reproducibility in the quality of the printed scaffolds. It also provides a flexible manufacturing platform for users to tailor the morphological structures of the scaffolds to their specific requirements. For this purpose, we present a protocol to obtain different fiber diameters using melt electrospinning writing (MEW) with a guided amendment of the parameters, including flow rate, voltage and collection speed. Furthermore, we demonstrate how to optimize the jet, discuss often experienced technical challenges, explain troubleshooting techniques and showcase a wide range of printable scaffold architectures.

This protocol serves as a comprehensive guideline to fabricate scaffolds via electrospinning with polymer melts in a direct writing mode. We systematically outline the process and define the appropriate parameter settings for achieving targeted scaffold architectures.

組織工学的応用の制御可能な形態の三次元 Poly(ε-caprolactone) 足場のエレクトロスピニング記述を溶かす

This tutorial reflects on the fundamental principles and guidelines for electrospinning writing with polymer melts, an additive manufacturing technology ...

Vapor Phase Deposition of Electroactive Poly(3,4-ethylenedioxythiophene) onto Electrospun Commodity Polymer Nanofibers

This study investigates the preparation of polyacrylonitrile (PAN) nanofibers through electrospinning to create highly porous and strong materials for applications in water purification, electrocatalysis, and biomedicine. The uniformly white PAN nanofiber mats were cut into 2 cm x 2 cm coupons to ensure consistency. After electrospinning, these nanofibers were coated with an electroactive polymer (EAP) using chemical vapor deposition, with iron (III) chloride (FeCl3) serving as an oxidant for polymerizing 3,4-ethylenedioxythiophene (EDOT) into poly(3,4-ethylenedioxythiophene) (PEDOT). The study examined the impact of different FeCl3 concentrations on PEDOT deposition on the PAN coupons. PEDOT deposition led to an increase in coupon weight. Scanning electron microscopy (SEM) revealed increases in the diameter of the nanofibers treated with increasing FeCl3 oxidant concentration, although higher FeCl3&#160;concentrations caused inter-fiber bridging, implying a concomitant decrease in inter-fiber spacing. Energy dispersive X-ray spectroscopy (EDS) was used to confirm the presence of Fe, Cl, and S in the nanofibers, with sulfur content rising with FeCl3&#160;concentration used, suggesting increased PEDOT deposition efficiency with increasing oxidant concentration. Mechanical testing showed that PEDOT-coated PAN fibers had improved tensile strength and toughness in the hydrated state compared to pure PAN nanofibers. These results highlight the crucial role of FeCl3&#160;concentration in influencing the morphology and properties of PAN-PEDOT composites, enhancing their suitability for applications such as water purification, tissue engineering, biosensing, catalysis, and energy storage.

This paper describes a simple technique for coating electrospun PAN nanofibers with electroactive polymers using vapor deposition. The effects of the oxidant FeCl&#8323; on the deposition of poly(3,4-ethylenedioxythiophene) coatings on PAN were investigated to understand and optimize polymer growth, fiber diameter, and overall mechanical strength of the nanofiber mats.

エレクトロスピニング商品ポリマーナノファイバー上への電気活性ポリ(3,4-エチレンジオキシチオフェン)の気相堆積

This study investigates the preparation of polyacrylonitrile (PAN) nanofibers through electrospinning to create highly porous and strong materials for ...

化学

Controlling Electrospun Polymer Morphology for Tissue Engineering Demonstrated Using hepG2 Cell Line

Electrospinning affords researchers the opportunity to fabricate reproducible micro to nanoscale polymer fibers. The 3D fibrous architecture of electrospun polymers is regarded as a structural imitation of the extracellular matrix (ECM). Hence, electrospun fibers fabricated from biocompatible polymers have been widely investigated by tissue engineering researchers for their potential role as an artificial ECM for guiding tissue growth both in vitro and in vivo. All cells are acutely sensitive to their mechanical environment. This has been demonstrated by the discovery of multiple mechanotransduction pathways intrinsically linked to the cytoskeletal actin filaments. The cytoskeleton acts as a mechanical sensor that can direct the functionality and differentiation of the host cell depending on the stiffness and morphology of its substrate. Electrospun fibers can be tuned both in terms of fiber size and morphology to easily modulate the mechanical environment within a fibrous polymer scaffold. Here, methods for electrospinning polycaprolactone (PCL) for three distinct morphologies at two different fiber diameters are described. The morphological fiber categories consist of randomly oriented fibers, aligned fibers, and porous cryogenically spun fibers, with 1 &#181;m and 5 &#181;m diameters. The methods detailed within this study are proposed as a platform for investigating the effect of electrospun fiber architecture on tissue generation. Understanding these effects will allow researchers to optimize the mechanical properties of electrospun fibers and demonstrate the potential of this technology more thoroughly.

This method provides the means to test different polycaprolactone fiber morphologies and topographies for the purpose of tissue engineering. Small and large fibers are fabricated with random orientations, aligned orientations, and also porous cryogenically electrospun structures and used as platforms for cell culture.

Electrospinning affords researchers the opportunity to fabricate reproducible micro to nanoscale polymer fibers. The 3D fibrous architecture of ...

Procedure for Fabricating Biofunctional Nanofibers

Electrospinning is an effective processing method for preparing nanofibers decorated with functional groups. Nanofibers decorated with functional groups may be utilized to study material-biomarker interactions i.e. act as biosensors with potential as single molecule detectors. We have developed an effective approach for preparing functional polymers where the functionality has the capacity of specifically binding with a model protein. In our model system, the functional group is 2,4-dinitrophenyl (DNP) and the protein is anti-DNP IgE (Immunoglobulin E). The functional polymer, &alpha;,&omega;-bi[2,4-dinitrophenyl caproic][poly(ethylene oxide)-b-poly(2-methoxystyrene)-b-poly(ethylene oxide)] (CDNP-PEO-P2MS-PEO-CDNP), is prepared by anionic living polymerization. The difunctional initiator utilized in the polymerization was prepared by electron transfer reaction of &alpha;-methylstyrene and potassium (mirror) metal. The 2-methoxystyrene monomer was added first to the initiator, followed by the addition of the second monomer, ethylene oxide, and finally the living polymer was terminated by methanol. The &alpha;,&omega;-dihydroxyl polymer [HO-PEO-P2MS-PEO-OH] was reacted with N-2,4-DNP-&isin;-amino caproic acid, by DCC coupling, resulting in the formation of &alpha;,&omega;-bi[2,4-dinitrophenylcaproic][poly(ethyleneoxide)-b-poly(2-methoxystyrene)-b-poly(ethylene oxide)] (CDNP-PEO-P2MS-PEO-CDNP). The polymers were characterized by FT-IR, 1H NMR and Gel Permeation Chromatography (GPC). The molecular weight distributions of the polymers were narrow (1.1-1.2) and polymers with molecular weights greater than 50,000 was used in this study. The polymers were yellow powders and soluble in tetrahydrofuran. A water soluble CDNP-PEO-P2MS-PEO-CDNP/ DMEG (dimethoxyethylene glycol) complex binds and achieves steady state binding with solution IgE within a few seconds. Higher molecular weight (water insoluble i.e. around 50,000) CDNP-PEO-P2MS-PEO-CDNP polymers, containing 1% single wall carbon nanotubes (SWCNT) were processed into electroactive nanofibers (100 nm to 500 nm in diameter) on silicon substrate. Fluorescence spectroscopy shows that anti-DNP IgE interacts with the nanofibers by binding with the DNP functional groups decorating the fibers. These observations suggest that appropriately functionalized nanofibers hold promise for developing biomarker detection device.

An efficient approach for preparing nanofibers decorated with functional groups capable of specifically interacting with proteins is described. The approach first requires the preparation of a polymer functionalized with the appropriate functional group. The functional polymer is fabricated into nanofibers by electrospinning. The effectiveness of the binding of the nanofibers with a protein is studied by confocal microscopy.

バイオ機能ナノファイバーを製造するための手順

Electrospinning is an effective processing method for preparing nanofibers decorated with functional groups. Nanofibers decorated with functional groups ...

生体高分子の分子エンタングルメントとElectrospinnability

要約

さらに動画を探す

この動画の章

エレクトロスピニングの基礎：最適化ソリューションと装置のパラメータ

エレクトロ組換えスパイダーシルクタンパク質の不織布メッシュを含むエアフィルターデバイス

バイオメディカル応用のための超疎水性高分子材料を製造します

自己組織化反応押出、マイクロフルイディクス, 経由で複数の長さスケールでの分解性感温ハイドロゲルを加工・エレクトロスピニング

乾燥風-LCインターフェイス上Megamolecular生体高分子の自己統合するための方法

セミフレキシブル高分子を研究する多目的ツールとして DNA ナノチューブ

組織工学的応用の制御可能な形態の三次元 Poly(ε-caprolactone) 足場のエレクトロスピニング記述を溶かす

エレクトロスピニング商品ポリマーナノファイバー上への電気活性ポリ(3,4-エチレンジオキシチオフェン)の気相堆積

Controlling Electrospun Polymer Morphology for Tissue Engineering Demonstrated Using hepG2 Cell Line

バイオ機能ナノファイバーを製造するための手順

生体高分子の分子エンタングルメントとElectrospinnability

要約

さらに動画を探す

この動画の章

エレクトロスピニングの基礎：最適化ソリューションと装置のパラメータ

エレクトロ組換えスパイダーシルクタンパク質の不織布メッシュを含むエアフィルターデバイス

バイオメディカル応用のための超疎水性高分子材料を製造します

自己組織化反応押出、マイクロフルイディクス, 経由で複数の長さスケールでの分解性感温ハイドロゲルを加工・ エレクトロスピニング

乾燥風-LCインターフェイス上Megamolecular生体高分子の自己統合するための方法

セミフレキシブル高分子を研究する多目的ツールとして DNA ナノチューブ

組織工学的応用の制御可能な形態の三次元 Poly(ε-caprolactone) 足場のエレクトロスピニング記述を溶かす

エレクトロスピニング商品ポリマーナノファイバー上への電気活性ポリ(3,4-エチレンジオキシチオフェン)の気相堆積

Controlling Electrospun Polymer Morphology for Tissue Engineering Demonstrated Using hepG2 Cell Line

バイオ機能ナノファイバーを製造するための手順

自己組織化反応押出、マイクロフルイディクス, 経由で複数の長さスケールでの分解性感温ハイドロゲルを加工・エレクトロスピニング