This study was supported by a Singapore National Research Foundation (NRF) Grant NRF2012NRF-POC001-043.

1.フォトマスク製造<ol><li>石英槽に浸漬し、120℃で20分間：ピラニア溶液（1比2でH 2 SO 4 / H 2 O 2）を用いて4 &quot;のガラスウェハをきれい。 </li><li>電子ビーム蒸発器7（ 図1A）を使用して、ガラスウェハ上にクロム/金（AuのCR /1μmの30 nm）の層の層を堆積させます。 <ol><li>電子ビーム蒸発器でウェーハを配置します。真空が5×10 -6トルに達すると、高電圧源（10キロボルト）をオンにしてください。モニターコントロールパネルにより厚さを制御します。 </li><li>電子ビーム銃を用いて30秒（ウエハ上への堆積を回避するために）シャッター「OFF」に維持するため、各材料プリクリーン。 </li></ol></li><li>ガラスの深いウェットエッチング用のCr / Auのフォトレジストマスキング層を生成します。 <ol><li>スピンスプレーコーターシステムを用いて3000rpmで30秒間溶液5mlを回転させることにより厚さ2μmのフォトレジストを適用します。1.5分間、100℃のホットプレート上にフォトレジストをベーキング。 </li><li>公開とハードホットプレート上で30分間120℃でフォトレジストを焼きます。これは、疎水性表面と金属層にフォトレジストの強い接着力を発生させることが重要です。パターンフォトレジストマスク8,9を介してCr及びAuのエッチング液を使用してのCr / Au層。 </li></ol></li><li>非パターン化ガラス表面の保護のため、一時的にダミーシリコンウエハ、ガラスウエハを接合。9 <ol><li> 110℃のホットプレート上でガラスウエハを配置し、（ウェハの全表面をワックスで被覆されているように）ガラスウエハの反対側に、ワックスを溶融します。 </li><li>ガラスウェハに接触してダミーのシリコンウェハを置き、余分なワックスを除去するために押します。ワックスのこぼれを回避するために、ホットプレート上でクリーンルームティッシュペーパーを置きます。 </li></ol></li><li>最適化されたフッ酸を用いたレンズの等方性エッチングを行う（49％v / v）の8.5磁気スターラー分のHCl 10プレゼンス生成レンズの良好な表面品質を達成するために重要である：（1〜10の体積比で）と塩酸（37％v / v）の溶液。 <ol><li>エッチングレートが7ミクロン/分であることを確認してください。エッチング液を200mlの全容量を使用します。プラスチック容器にエッチングを行い、この処理ステップのための安全対策を取ります。 </li><li> RTですすぎ、さらに乾燥することにより、脱イオン（DI）水でウェハを清掃してください。 </li></ol></li><li>処理完了後、ダミーのシリコンウェハからガラスウェハを分離し、15秒間100℃のホットプレートを用いてワックスを温めます。ワックスはこの温度で​​溶融するように、ダミーのシリコンウェハからガラスウェハを取り外します。 </li><li>超音波タンク内の80℃の溶媒としてのNメチル-2-ピロリドンを用いて、1時間超音波を使用して、レンズの端に残っているワックス、フォトレジストオーバーハングのCr / Au層を削除します。</li><li>フォトマスク11上に製造されたマイクロレンズのPDMS型レプリカを作成します。 </li><li>フォトマスクの寸法（長さおよび幅）を特徴づけるとマイクロレンズPDMS型（深さと直径）は、それぞれ、走査型電子顕微鏡および実体顕微鏡を用いてレプリカ。12-14 </li></ol> 2. MNのシャフト製作<ol><li>ガラスの両側に取り付けられたガラススライドを使用して0.9センチメートル×2.5センチメートルの空洞を作成します。いずれかの側に積層ガラススライドの数は、スペーサの厚さ（ 図1B）と呼ばれるキャビティの高さを決定します。 </li><li> 0.5％w / wの2-ヒドロキシ-2-メチル - プロピオフェノン（HMP）を有するポリ含有プレポリマー溶液（エチレングリコール）ジアクリレート（PEGDA、MW = 258 Da）での薄層を適用することにより、スライドガラスの各層を確保します2秒間高強度の紫外線を設定（UV）光を照射することにより、その後、スライドガラス。 </li><li> photomaを配置SK空洞の内部に面するのCr / Auをコーティングした表面に（以前に製造されました）。空洞壁の側面は、フォトマスクに埋め込まれたレンズを曖昧にされていないことを確認してください。 </li><li> Cr / Auをコーティングした表面は、目に見える気泡ない溶液と接触するまでプレポリマー溶液を用いて空洞を満たします。 </li><li> 320から500 nmでのUVフィルターの範囲を有するUV硬化ステーションを使用して、UV光源から3.5センチ間隔で1秒間、所望の強度の高強度のUV光を照射してセットアップ。 UV光プローブでコリメートアダプターを使用してください。 </li><li>放射計を用いて使用されるUV光の強度を測定します。 </li><li>紫外線露光後、MNのの配列を使用してフォトマスクを削除します。再利用のために、その元の容器に戻し工程で重合されていない過剰プレポリマー溶液を注ぎます。 </li><li>製造業者の指示に従って実体顕微鏡を用いてのMNの長さおよび先端の直径を定量化します。 </li></ol><pクラス= &quot;jove_title&quot;&gt; 3。 MNバッキング層の作製<ol><li> 図1Cに示すように鉗子のMNを配置して（以前に製造された）24ウェルプレートのウェルに、フォトマスク上に取り付けられています。 </li><li>針が所望の高さに水没するまで十分にプレポリマー溶液の - （400μL300）指定されたボリュームを追加します。この量は、得られたバッキング層の厚さを決定します。 </li><li> 10.5センチメートル離れて1秒の持続時間のための紫外線源から、高強度のUV光（15.1 W / cm 2）としてセットアップを照射。 </li><li>鋭い刃を使用してフォトマスクからMNアレイ上にバッキング層を分離します。 </li><li>製造業者の指示に従って実体顕微鏡を用いて、バッキング層とのMNの長さ、先端の直径とベース直径を定量化します。 </li></ol>

<ol><li>Zhou, C. P., Liu, Y. L., Wang, H. L., Zhang, P. X., Zhang, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Transdermal+delivery+of+insulin+using+microneedle+rollers+in+vivo%5BTitle%5D)+AND+%22International+journal+of+pharmaceutics%22%5BJournal%5D)">Transdermal delivery of insulin using microneedle rollers in vivo.</a> International journal of pharmaceutics. 392, 127-133 (2010).</li>
<li>Lee, J. W., Choi, S. O., Felner, E. I., Prausnitz, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Dissolving+microneedle+patch+for+transdermal+delivery+of+human+growth+hormone%5BTitle%5D)+AND+%22Small%22%5BJournal%5D)">Dissolving microneedle patch for transdermal delivery of human growth hormone.</a> Small. 7, 531-539 (2011).</li>
<li>Raphael, A. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((needle-free+vaccinations+in+skin+using+multi+layered%2C+densely-packed+dissolving+microprojection+arrays%5BTitle%5D)+AND+%22Small%22%5BJournal%5D)">needle-free vaccinations in skin using multi layered, densely-packed dissolving microprojection arrays.</a> Small. 6, 1785-1793 (2010).</li>
<li>Lee, J. W., Han, M. R., Park, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Polymer+microneedles+for+transdermal+drug+delivery%5BTitle%5D)+AND+%22Journal+of+drug+targeting%22%5BJournal%5D)">Polymer microneedles for transdermal drug delivery.</a> Journal of drug targeting. 21, 211-223 (2012).</li>
<li>Kochhar, J. S., Goh, W. J., Chan, S. Y., Kang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+simple+method+of+microneedle+array+fabrication+for+transdermal+drug+delivery%5BTitle%5D)+AND+%22Drug+development+and+industrial+pharmacy%22%5BJournal%5D)">A simple method of microneedle array fabrication for transdermal drug delivery.</a> Drug development and industrial pharmacy. 39, 299-309 (2013).</li>
<li>Kochhar, J. S., Zou, S., Chan, S. Y., Kang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Protein+encapsulation+in+polymeric+microneedles+by+photolithography%5BTitle%5D)+AND+%22International+journal+of+nanomedicine%22%5BJournal%5D)">Protein encapsulation in polymeric microneedles by photolithography.</a> International journal of nanomedicine. 7, 3143-3154 (2012).</li>
<li>Tay, F. E. H., Iliescu, C., Jing, J., Miao, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Defect-free+wet+etching+through+pyrex+glass+using+Cr%2FAu+mask%5BTitle%5D)+AND+%22Microsystem+Technologies%22%5BJournal%5D)">Defect-free wet etching through pyrex glass using Cr/Au mask.</a> Microsystem Technologies. 12, 935-939 (2006).</li>
<li>Iliescu, C., Chen, B., Miao, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((On+the+wet+etching+of+Pyrex+glass%5BTitle%5D)+AND+%22Sensors+and+Actuators%2C+A%3A+Physical%22%5BJournal%5D)">On the wet etching of Pyrex glass.</a> Sensors and Actuators, A: Physical. 143, 154-161 (2008).</li>
<li>Iliescu, C., Taylor, H., Avram, M., Miao, J., Franssila, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+practical+guide+for+the+fabrication+of+microfluidic+devices+using+glass+and+silicon%5BTitle%5D)+AND+%22Biomicrofluidics%22%5BJournal%5D)">A practical guide for the fabrication of microfluidic devices using glass and silicon.</a> Biomicrofluidics. 6, 16505-16516 (2012).</li>
<li>Iliescu, C., Jing, J., Tay, F. E. H., Miao, J., Sun, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Characterization+of+masking+layers+for+deep+wet+etching+of+glass+in+an+improved+HF%2FHCl+solution%5BTitle%5D)+AND+%22Surface+and+Coatings+Technology%22%5BJournal%5D)">Characterization of masking layers for deep wet etching of glass in an improved HF/HCl solution.</a> Surface and Coatings Technology. 198, 314-318 (2005).</li>
<li>Pan, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Fabrication+of+a+3D+hair+follicle-like+hydrogel+by+soft+lithography%5BTitle%5D)+AND+%22Journal+of+biomedical+materials+research.+Part+A%22%5BJournal%5D)">Fabrication of a 3D hair follicle-like hydrogel by soft lithography.</a> Journal of biomedical materials research. Part A. 101, 3159-3169 (2013).</li>
<li>Jay, T. R., Stern, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Preshaping+photoresist+for+refractive+microlens+fabrication%5BTitle%5D)+AND+%22P+Soc+Photo-Opt+Ins%22%5BJournal%5D)">Preshaping photoresist for refractive microlens fabrication.</a> P Soc Photo-Opt Ins. 1992, 275-282 (1993).</li>
<li>Friedman, G. B., Sandhu, H. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Longitudinal+Spherical+Aberration+of+a+Thin+Lens%5BTitle%5D)+AND+%22Am+J+Phys%22%5BJournal%5D)">Longitudinal Spherical Aberration of a Thin Lens.</a> Am J Phys. 35, 628(1967).</li>
<li>Xu, Q. A., Li, J., Zhang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Collimated+the+laser+diode+beam+by+the+focus+lens%5BTitle%5D)+AND+%22Semiconductor+Lasers+and+Applications+IV%22%5BJournal%5D)">Collimated the laser diode beam by the focus lens.</a> Semiconductor Lasers and Applications IV. 7844, (2010).</li>
<li>Lin, T. W., Chen, C. F., Yang, J. J., Liao, Y. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+dual-directional+light-control+film+with+a+high-sag+and+high-asymmetrical-shape+microlens+array+fabricated+by+a+UV+imprinting+process%5BTitle%5D)+AND+%22J+Micromech+Microeng%22%5BJournal%5D)">A dual-directional light-control film with a high-sag and high-asymmetrical-shape microlens array fabricated by a UV imprinting process.</a> J Micromech Microeng. 18, (2008).</li>
<li>Dunne, S. M., Millar, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Effect+of+distance+from+curing+light+tip+to+restoration+surface+on+depth+of+cure+of+composite+resin%5BTitle%5D)+AND+%22Prim+Dent+Care%22%5BJournal%5D)">Effect of distance from curing light tip to restoration surface on depth of cure of composite resin.</a> Prim Dent Care. 15, 147-152 (2008).</li>
<li>Kochhar, J. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microneedle+integrated+transdermal+patch+for+fast+onset+and+sustained+delivery+of+lidocaine%5BTitle%5D)+AND+%22Molecular+pharmaceutics%22%5BJournal%5D)">Microneedle integrated transdermal patch for fast onset and sustained delivery of lidocaine.</a> Molecular pharmaceutics. 10, 4272-4280 (2013).</li>
<li>Kochhar, J. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Direct+microneedle+array+fabrication+off+a+photomask+to+deliver+collagen+through+skin%5BTitle%5D)+AND+%22Pharmaceutical+research%22%5BJournal%5D)">Direct microneedle array fabrication off a photomask to deliver collagen through skin.</a> Pharmaceutical research. 31, 1724-1734 (2014).</li>
</ol>

The authors declare no conflict of Interest.

MNのアレイの製造について上記したプロトコルは、約1 cm 2のMNのアレイを製造するために提示されています。アレイは、大きなサイズの空洞を作成することによって、より大きなフォトマスクを用いてスケールアップすることができます。増加した空洞の大きさは、両側のスペーサの幅を増加させることによって作成することができます。プロトコルでMNアレイを作製するために、各?...

経皮薬物送達は、特にほぼ独占的に皮下注射によって投与された生体分子のために、薬剤投与のための魅力的な代替的なアプローチを提供しています。しかし、皮膚、特に最上層（角質層）は、人体に侵入する外来性分子を防止手ごわい障壁です。最近では、MNのデバイスは、皮膚を介して薬物を送達するためのツールを有効にするとして浮上しています。 MNデバイスは、薬物分子の通過が改善された患者のコンプライアンスと利便1-3で所望の生理学的活性を達成できるように、角質層内部に一時的な空孔を作成します。 様々な製造方法は、ポリマーのMN 4を製造するために採用されています。しかし、それらは通常のMNのアレイを製造するために長い時間および/ ​​または高い温度を必要とする、複雑で多段階のプロセスを伴う。4製造工程を簡略化するために、単一工程モールドフリープロセスを使用してフォトマスクは5,6、最近開発されました。しかし、この方法では、メカニズムは、フォトリソグラフィに関係する紫外線（UV）光路を変更するための場所ではなかったとしてのMNは、鈍針のヒントを持っていた製作。 本研究では、フォトマスクに埋め込まれたマイクロレンズのMNのジオメトリを定義するために提案されています。埋め込まれたマイクロレンズからなり、その後、フォトマスクを用いて、鋭い先端が報告されていると製作をMNのフォトマスクを製造するためのプロトコル。

<table><tbody><tr><td>Poly(ethylene glycol) diacrylate (PEGDA Mn=258)</td><td>SIGMA&amp;nbsp;</td><td>475629-500ML</td><td></td></tr><tr><td>2-hydroxy-2-methyl-propiophenone (HMP)</td><td>SIGMA&amp;nbsp;</td><td>405655-50ML</td><td></td></tr><tr><td>Bovine collagen type 1, FITC conjugate&amp;nbsp;</td><td>SIGMA&amp;nbsp;</td><td>C4361</td><td></td></tr><tr><td>UV curing station&amp;nbsp;&amp;nbsp;&amp;nbsp;</td><td>EXFO Photonic Solutions Inc., Canada</td><td>OmniCure S2000-XL</td><td></td></tr><tr><td>Collimating Adaptor&amp;nbsp;</td><td>EXFO Photonic Solutions Inc., Canada</td><td>EXFO 810-00042</td><td></td></tr><tr><td>24-well plate</td><td>Thermo Fisher Scientific, USA</td><td></td><td></td></tr><tr><td>Nikon SMZ 1500 stereomicroscope&amp;nbsp;</td><td>Nikon, Japan</td><td></td><td></td></tr><tr><td>Dillon GL-500 digital force gauge&amp;nbsp;</td><td>Dillon, USA</td><td></td><td></td></tr><tr><td>A-1R confocal microscope&amp;nbsp;</td><td>Nikon, Japan</td><td></td><td></td></tr></tbody></table>

polymeric microneedle array fabrication by photolithography

本稿では、フォトリソグラフィ法により、高分子マイクロニードル（MN）アレイの製造を説明しています。これは、埋め込まれたマイクロレンズからなるフォトマスクを用いて、単純な鋳型を含まないプロセスを含みます。埋め込まれたマイクロレンズは​​、MNジオメトリ（鋭さ）に影響することが見出されました。二つの異なる長さ（193ミクロンと171ミクロン±957ミクロン±1336ミクロン）を作製したと41.5ミクロン±8.4ミクロンと71.6ミクロン±13.7ミクロンの間の範囲の先端径の堅牢MNアレイ、。これらMNアレイは、皮膚を介して、低分子および高分子の治療薬の送達の潜在的なアプリケーションを提供してもよいです。

MNの形状は大きくフォトマスクの特性及び埋め込みマイクロレンズによって影響を受けることができます。屈折度は、MNの幾何形状（ 図2A）の影響紫外線の伝送路に影響を与えます。各マイクロレンズは350μmの直径を有することが見出された、130ミクロンの凸面を平坦化し、62.3μmの深さ（ 図2B-D）。ピタゴラスの定理を用いて、第1の表面の曲率半径は、272.89マイクロ...

Watch this Scientific Journal Video about Polymeric Microneedle Array Fabrication by Photolithography at JoVE.com

Polymeric Microneedle Array Fabrication by Photolithography

Here, we present a protocol describing a mold-free fabrication process of the polymeric microneedles by photolithography.

フォトリソグラフィ法により高分子マイクロニードルアレイの作製

This manuscript describes the fabrication of polymeric microneedle (MN) arrays by photolithography. It involves a simple mold-free process by using a ...

polymeric-microneedle-array-fabrication-by-photolithography

Research

JoVE Journal

Bioengineering

12.0K ビュー.  National University of Singapore. Here, we present a protocol describing a mold-free fabrication process of the polymeric microneedles by photolithography. 

ビデオ: Polymeric Microneedle Array Fabrication by Photolithography

Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates

Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 19771. They offer the advantages of low weight, easy tailoring of properties and a wide spectrum of applications2,3. Due to sensitivity of conducting polymers to environmental conditions (e.g., air, oxygen, moisture, high temperature and chemical solutions), lithographic techniques present significant technical challenges when working with these materials4. For example, current photolithographic methods, such as ultra-violet (UV), are unsuitable for patterning the conducting polymers due to the involvement of wet and/or dry etching processes in these methods. In addition, current micro/nanosystems mainly have a planar form5,6. One layer of structures is built on the top surfaces of another layer of fabricated features. Multiple layers of these structures are stacked together to form numerous devices on a common substrate. The sidewall surfaces of the microstructures have not been used in constructing devices. On the other hand, sidewall patterns could be used, for example, to build 3-D circuits, modify fluidic channels and direct horizontal growth of nanowires and nanotubes.
A macropunching method has been applied in the manufacturing industry to create macropatterns in a sheet metal for over a hundred years. Motivated by this approach, we have developed a micropunching lithography method (MPL) to overcome the obstacles of patterning conducting polymers and generating sidewall patterns. Like the macropunching method, the MPL also includes two operations (Fig. 1): (i) cutting; and (ii) drawing. The "cutting" operation was applied to pattern three conducting polymers4, polypyrrole (PPy), Poly(3,4-ethylenedioxythiophen)-poly(4-styrenesulphonate) (PEDOT) and polyaniline (PANI). It was also employed to create Al microstructures7. The fabricated microstructures of conducting polymers have been used as humidity8, chemical8, and glucose sensors9. Combined microstructures of Al and conducting polymers have been employed to fabricate capacitors and various heterojunctions9,10,11. The "cutting" operation was also applied to generate submicron-patterns, such as 100- and 500-nm-wide PPy lines as well as 100-nm-wide Au wires. The "drawing" operation was employed for two applications: (i) produce Au sidewall patterns on high density polyethylene (HDPE) channels which could be used for building 3D microsystems12,13,14, and (ii) fabricate polydimethylsiloxane (PDMS) micropillars on HDPE substrates to increase the contact angle of the channel15.

A micropunching lithography approach is developed to generate micro- and submicron-patterns on top, sidewall and bottom surfaces of polymer substrates. It overcomes the obstacles of patterning conducting polymers and generating sidewall patterns. This method allows rapid fabrication of multiple features and is free of aggressive chemistry.

ポリマー基板上へのマイクロ·サブミクロンのパターンを生成するためのリソグラフィMicropunching

Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 19771. They offer the advantages of ...

工学

Fabrication of Micropatterned Hydrogels for Neural Culture Systems using Dynamic Mask Projection Photolithography

Increasingly, patterned cell culture environments are becoming a relevant technique to study cellular characteristics, and many researchers believe in the need for 3D environments to represent in vitro experiments which better mimic in vivo qualities 1-3. Studies in fields such as cancer research 4, neural engineering 5, cardiac physiology 6, and cell-matrix interaction7,8have shown cell behavior differs substantially between traditional monolayer cultures and 3D constructs.
Hydrogels are used as 3D environments because of their variety, versatility and ability to tailor molecular composition through functionalization 9-12. Numerous techniques exist for creation of constructs as cell-supportive matrices, including electrospinning13, elastomer stamps14, inkjet printing15, additive photopatterning16, static photomask projection-lithography17, and dynamic mask microstereolithography18. Unfortunately, these methods involve multiple production steps and/or equipment not readily adaptable to conventional cell and tissue culture methods. The technique employed in this protocol adapts the latter two methods, using a digital micromirror device (DMD) to create dynamic photomasks for crosslinking geometrically specific poly-(ethylene glycol) (PEG) hydrogels, induced through UV initiated free radical polymerization. The resulting "2.5D" structures provide a constrained 3D environment for neural growth. We employ a dual-hydrogel approach, where PEG serves as a cell-restrictive region supplying structure to an otherwise shapeless but cell-permissive self-assembling gel made from either Puramatrix or agarose. The process is a quick simple one step fabrication which is highly reproducible and easily adapted for use with conventional cell culture methods and substrates.
Whole tissue explants, such as embryonic dorsal root ganglia (DRG), can be incorporated into the dual hydrogel constructs for experimental assays such as neurite outgrowth. Additionally, dissociated cells can be encapsulated in the photocrosslinkable or self polymerizing hydrogel, or selectively adhered to the permeable support membrane using cell-restrictive photopatterning. Using the DMD, we created hydrogel constructs up to ~1mm thick, but thin film (&lt;200 &mu;m) PEG structures were limited by oxygen quenching of the free radical polymerization reaction. We subsequently developed a technique utilizing a layer of oil above the polymerization liquid which allowed thin PEG structure polymerization.
In this protocol, we describe the expeditious creation of 3D hydrogel systems for production of microfabricated neural cell and tissue cultures. The dual hydrogel constructs demonstrated herein represent versatile in vitro models that may prove useful for studies in neuroscience involving cell survival, migration, and/or neurite growth and guidance. Moreover, as the protocol can work for many types of hydrogels and cells, the potential applications are both varied and vast.

Simple techniques are described for the rapid production of microfabricated neural culture systems using a digital micromirror device for dynamic mask projection lithography on regular cell culture substrates. These culture systems may be more representative of natural biological architecture, and the techniques described could be adapted for numerous applications.

動的なマスク投影リソグラフィーを用いたニューラル培養システムのためのマイクロパターンハイドロゲルの作製

Increasingly, patterned cell culture environments are becoming a relevant technique to study cellular characteristics, and many researchers believe in the ...

生物工学

Polymer Microarrays for High Throughput Discovery of Biomaterials

The discovery of novel biomaterials that are optimized for a specific biological application is readily achieved using polymer microarrays, which allows a combinatorial library of materials to be screened in a parallel, high throughput format1. Herein is described the formation and characterization of a polymer microarray using an on-chip photopolymerization technique 2. This involves mixing monomers at varied ratios to produce a library of monomer solutions, transferring the solution to a glass slide format using a robotic printing device and curing with UV irradiation. This format is readily amenable to many biological assays, including stem cell attachment and proliferation, cell sorting and low bacterial adhesion, allowing the ready identification of 'hit' materials that fulfill a specific biological criterion3-5. Furthermore, the use of high throughput surface characterization (HTSC) allows the biological performance to be correlated with physio-chemical properties, hence elucidating the biological-material interaction6. HTSC makes use of water contact angle (WCA) measurements, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). In particular, ToF-SIMS provides a chemically rich analysis of the sample that can be used to correlate the cell response with a molecular moiety. In some cases, the biological performance can be predicted from the ToF-SIMS spectra, demonstrating the chemical dependence of a biological-material interaction, and informing the development of hit materials5,3.

A description of the formation of a polymer microarray using an on-chip photopolymerization technique. The high throughput surface characterization using atomic force microscopy, water contact angle measurements, X-ray photoelectron spectroscopy and time of flight secondary ion mass spectrometry and a cell attachment assay is also described.

バイオマテリアルのハイスループット検出用高分子マイクロアレイ

The discovery of novel biomaterials that are optimized for a specific biological application is readily achieved using polymer microarrays, which allows a ...

Hollow Microneedle-based Sensor for Multiplexed Transdermal Electrochemical Sensing

The development of a minimally invasive multiplexed monitoring system for rapid analysis of biologically-relevant molecules could offer individuals suffering from chronic medical conditions facile assessment of their immediate physiological state. Furthermore, it could serve as a research tool for analysis of complex, multifactorial medical conditions. In order for such a multianalyte sensor to be realized, it must be minimally invasive, sampling of interstitial fluid must occur without pain or harm to the user, and analysis must be rapid as well as selective.
Initially developed for pain-free drug delivery, microneedles have been used to deliver vaccines and pharmacologic agents (e.g., insulin) through the skin.1-2 Since these devices access the interstitial space, microneedles that are integrated with microelectrodes can be used as transdermal electrochemical sensors. Selective detection of glucose, glutamate, lactate, hydrogen peroxide, and ascorbic acid has been demonstrated using integrated microneedle-electrode devices with carbon fibers, modified carbon pastes, and platinum-coated polymer microneedles serving as transducing elements.3-7,8
This microneedle sensor technology has enabled a novel and sophisticated analytical approach for in situ and simultaneous detection of multiple analytes. Multiplexing offers the possibility of monitoring complex microenvironments, which are otherwise difficult to characterize in a rapid and minimally invasive manner. For example, this technology could be utilized for simultaneous monitoring of extracellular levels of, glucose, lactate and pH,9 which are important metabolic indicators of disease states7,10-14 (e.g., cancer proliferation) and exercise-induced acidosis.15

This article details the construction of a multiplexed microneedle-based sensor. The device is being developed for in situ sampling and electrochemical analysis of multiple analytes in a rapid and selective manner. We envision clinical medicine and biomedical research uses for these microneedle-based sensors.

多重経皮電気化学センシングのための中空マイクロニードルベースの​​センサ

The development of a minimally invasive multiplexed monitoring system for rapid analysis of biologically-relevant molecules could offer individuals ...

Capillary Force Lithography for Cardiac Tissue Engineering

Cardiovascular disease remains the leading cause of death worldwide1. Cardiac tissue engineering holds much promise to deliver groundbreaking medical discoveries with the aims of developing functional tissues for cardiac regeneration as well as in vitro screening assays. However, the ability to create high-fidelity models of heart tissue has proven difficult. The heart&#8217;s extracellular matrix (ECM) is a complex structure consisting of both biochemical and biomechanical signals ranging from the micro- to the nanometer scale2. Local mechanical loading conditions and cell-ECM interactions have recently been recognized as vital components in cardiac tissue engineering3-5.
A large portion of the cardiac ECM is composed of aligned collagen fibers with nano-scale diameters that significantly influences tissue architecture and electromechanical coupling2. Unfortunately, few methods have been able to mimic the organization of ECM fibers down to the nanometer scale. Recent advancements in nanofabrication techniques, however, have enabled the design and fabrication of scalable scaffolds that mimic the in vivo structural and substrate stiffness cues of the ECM in the heart6-9.
Here we present the development of two reproducible, cost-effective, and scalable nanopatterning processes for the functional alignment of cardiac cells using the biocompatible polymer poly(lactide-co-glycolide) (PLGA)8 and a polyurethane (PU) based polymer. These anisotropically nanofabricated substrata (ANFS) mimic the underlying ECM of well-organized, aligned tissues and can be used to investigate the role of nanotopography on cell morphology and function10-14.
Using a nanopatterned (NP) silicon master as a template, a polyurethane acrylate (PUA) mold is fabricated. This PUA mold is then used to pattern the PU or PLGA hydrogel via UV-assisted or solvent-mediated capillary force lithography (CFL), respectively15,16. Briefly, PU or PLGA pre-polymer is drop dispensed onto a glass coverslip and the PUA mold is placed on top. For UV-assisted CFL, the PU is then exposed to UV radiation (&#955; = 250-400 nm) for curing. For solvent-mediated CFL, the PLGA is embossed using heat (120 &#176;C) and pressure (100 kPa). After curing, the PUA mold is peeled off, leaving behind an ANFS for cell culture. Primary cells, such as neonatal rat ventricular myocytes, as well as human pluripotent stem cell-derived cardiomyocytes, can be maintained on the ANFS2.

In this protocol, we demonstrate the fabrication of biomimetic cardiac cell culture substrata made from two distinct polymeric materials using capillary force lithography. The described methods provide a scalable, cost-effective technique to engineer the structure and function of macroscopic cardiac tissues for in vitro and in vivo applications.

心臓組織工学のためのキャピラリーフォースリソグラフィ

Cardiovascular disease remains the leading cause of death worldwide1. Cardiac tissue engineering holds much promise to deliver groundbreaking medical ...

High-Density DNA and RNA microarrays - Photolithographic Synthesis, Hybridization and Preparation of Large Nucleic Acid Libraries

Photolithography is a powerful technique for the synthesis of DNA oligonucleotides on glass slides, as it combines the efficiency of phosphoramidite coupling reactions with the precision and density of UV light reflected from micrometer-sized mirrors. Photolithography yields microarrays that can accommodate from hundreds of thousands up to several million different DNA sequences, 100-nt or longer, in only a few hours. With this very large sequence space, microarrays are ideal platforms for exploring the mechanisms of nucleic acid&#183;ligand interactions, which are particularly relevant in the case of RNA. We recently reported on the preparation of a new set of RNA phosphoramidites compatible with in situ photolithography and which were subsequently used to grow RNA oligonucleotides, homopolymers as well as mixed-base sequences. Here, we illustrate in detail the process of RNA microarray fabrication, from the experimental design, to instrumental setup, array synthesis, deprotection and final hybridization assay using a template 25mer sequence containing all four bases as an example. In parallel, we go beyond hybridization-based experiments and exploit microarray photolithography as an inexpensive gateway to complex nucleic acid libraries. To do so, high-density DNA microarrays are fabricated on a base-sensitive monomer that allows the DNA to be conveniently cleaved and retrieved after synthesis and deprotection. The fabrication protocol is optimized so as to limit the number of synthetic errors and to that effect, a layer of &#946;-carotene solution is introduced to absorb UV photons that may otherwise reflect back onto the synthesis substrates. We describe in a step-by-step manner the complete process of library preparation, from design to cleavage and quantification.

In this article, we present and discuss new developments in the synthesis and applications of nucleic acid microarrays fabricated in situ. Specifically, we show how the protocols for DNA synthesis can be extended to RNA and how microarrays can be used to create retrievable nucleic acid libraries.

高密度DNAおよびRNAマイクロアレイ - 光リソグラフィー合成、ハイブリダイゼーション、大型核酸ライブラリーの調製

Photolithography is a powerful technique for the synthesis of DNA oligonucleotides on glass slides, as it combines the efficiency of phosphoramidite ...

遺伝学

Assembly and Tracking of Microbial Community Development within a Microwell Array Platform

The development of microbial communities depends on a combination of complex deterministic and stochastic factors that can dramatically alter the spatial distribution and activities of community members. We have developed a microwell array platform that can be used to rapidly assemble and track thousands of bacterial communities in parallel. This protocol highlights the utility of the platform and describes its use for optically monitoring the development of simple, two-member communities within an ensemble of arrays within the platform. This demonstration uses two mutants of Pseudomonas aeruginosa, part of a series of mutants developed to study Type VI secretion pathogenicity. Chromosomal inserts of either mCherry or GFP genes facilitate the constitutive expression of fluorescent proteins with distinct emission wavelengths that can be used to monitor community member abundance and location within each microwell. This protocol describes a detailed method for assembling mixtures of bacteria into the wells of the array and using time-lapse fluorescence imaging and quantitative image analysis to measure the relative growth of each member population over time. The seeding and assembly of the microwell platform, the imaging procedures necessary for the quantitative analysis of microbial communities within the array, and the methods that can be used to reveal interactions between microbial species area all discussed.

The development of microbial communities depends on a combination of factors, including environmental architecture, member abundance, traits, and interactions. This protocol describes a synthetic, microfabricated environment for the simultaneous tracking of thousands of communities contained in femtoliter wells, where key factors such as niche size and confinement can be approximated.

マイクロウェルアレイプラットフォーム内での微生物コミュニティ開発の組み立てと追跡

The development of microbial communities depends on a combination of complex deterministic and stochastic factors that can dramatically alter the spatial ...

Large-area Scanning Probe Nanolithography Facilitated by Automated Alignment and Its Application to Substrate Fabrication for Cell Culture Studies

Scanning probe microscopy has enabled the creation of a variety of methods for the constructive (&#39;additive&#39;) top-down fabrication of nanometer-scale features. Historically, a major drawback of scanning probe lithography has been the intrinsically low throughput of single probe systems. This has been tackled by the use of arrays of multiple probes to enable increased nanolithography throughput. In order to implement such parallelized nanolithography, the accurate alignment of probe arrays with the substrate surface is vital, so that all probes make contact with the surface simultaneously when lithographic patterning begins. This protocol describes the utilization of polymer pen lithography to produce nanometer-scale features over centimeter-sized areas, facilitated by the use of an algorithm for the rapid, accurate, and automated alignment of probe arrays. Here, nanolithography of thiols on gold substrates demonstrates the generation of features with high uniformity. These patterns are then functionalized with fibronectin for use in the context of surface-directed cell morphology studies.

Here we present a protocol for wide-area scanning probe nanolithography enabled by the iterative alignment of probe arrays, as well as the utilization of lithographic patterns for cell-surface interaction studies.

広域走査型プローブ ナノリソグラフィ自動配置と細胞培養研究用基板作製への応用

Scanning probe microscopy has enabled the creation of a variety of methods for the constructive (&#39;additive&#39;) top-down fabrication of ...

Fabrication of a Multiplexed Artificial Cellular MicroEnvironment Array

Cellular microenvironments consist of a variety of cues, such as growth factors, extracellular matrices, and intercellular interactions. These cues are well orchestrated and are crucial in regulating cell functions in a living system. Although a number of researchers have attempted to investigate the correlation between environmental factors and desired cellular functions, much remains unknown. This is largely due to the lack of a proper methodology to mimic such environmental cues in vitro, and simultaneously test different environmental cues on cells. Here, we report an integrated platform of microfluidic channels and a nanofiber array, followed by high-content single-cell analysis, to examine stem cell phenotypes altered by distinct environmental factors. To demonstrate the application of this platform, this study focuses on the phenotypes of self-renewing human pluripotent stem cells (hPSCs). Here, we present the preparation procedures for a nanofiber array and the microfluidic structure in the fabrication of a Multiplexed Artificial Cellular MicroEnvironment (MACME) array. Moreover, overall steps of the single-cell profiling, cell staining with multiple fluorescent markers, multiple fluorescence imaging, and statistical analyses, are described.

This article describes the detailed methodology to prepare a Multiplexed Artificial Cellular MicroEnvironment (MACME) array for high-throughput manipulation of physical and chemical cues mimicking in vivo cellular microenvironments and to identify the optimal cellular environment for human pluripotent stem cells (hPSCs) with single-cell profiling.

多重の人工細胞の微小環境配列の作製

Cellular microenvironments consist of a variety of cues, such as growth factors, extracellular matrices, and intercellular interactions. These cues are ...

Fabrication of Fine Electrodes on the Tip of Hypodermic Needle Using Photoresist Spray Coating and Flexible Photomask for Biomedical Applications

We have introduced a fabrication method for electrical impedance spectroscopy (EIS)-on-a-needle (EoN: EIS-on-a-needle) to locate target tissues in the body by measuring and analyzing differences in the electrical impedance between dissimilar biotissues. This paper describes the fabrication method of fine interdigitated electrodes (IDEs) at the tip of a hypodermic needle using a photoresist spray coating and flexible film photomask in the photolithography process. A polyethylene terephthalate (PET) heat shrink tube (HST) with a wall thickness of 25 &#181;m is employed as the insulation and passivation layer. The PET HST shows a higher mechanical durability compared with poly(p-xylylene) polymers, which have been widely used as a dielectric coating material. Furthermore, the HST shows good chemical resistance to most acids and bases, which is advantageous for limiting chemical damage to the EoN. The use of the EoN is especially preferred for the characterization of chemicals/biomaterials or fabrication using acidic/basic chemicals. The fabricated gap and width of the IDEs are as small as 20 &#181;m, and the overall width and length of the IDEs are 400 &#181;m and 860 &#181;m, respectively. The fabrication margin from the tip (distance between the tip of hypodermic needle and starting point of the IDEs) of the hypodermic needle is as small as 680 &#181;m, which indicates that unnecessarily excessive invasion into biotissues can be avoided during the electrical impedance measurement. The EoN has a high potential for clinical use, such as for thyroid biopsies and anesthesia drug delivery in a spinal space. Further, even in surgery that involves the partial resection of tumors, the EoN can be employed to preserve as much normal tissue as possible by detecting the surgical margin (normal tissue that is removed with the surgical excision of a tumor) between the normal and lesion tissues.

The fabrication method for fine interdigitated electrodes (gap and width: 20 &#181;m) at the tip of a hypodermic needle (diameter: 720 &#181;m) is demonstrated using a spray coating and flexible film photomask in the photolithography process.

医用フォトレジスト スプレー塗装と柔軟なフォトマスクを使用して皮下注射針の先端の微細電極の作製

We have introduced a fabrication method for electrical impedance spectroscopy (EIS)-on-a-needle (EoN: EIS-on-a-needle) to locate target tissues in the ...

フォトリソグラフィ法により高分子マイクロニードルアレイの作製

要約

さらに動画を探す

ポリマー基板上へのマイクロ·サブミクロンのパターンを生成するためのリソグラフィMicropunching

動的なマスク投影リソグラフィーを用いたニューラル培養システムのためのマイクロパターンハイドロゲルの作製

バイオマテリアルのハイスループット検出用高分子マイクロアレイ

多重経皮電気化学センシングのための中空マイクロニードルベースのセンサ

心臓組織工学のためのキャピラリーフォースリソグラフィ

高密度DNAおよびRNAマイクロアレイ - 光リソグラフィー合成、ハイブリダイゼーション、大型核酸ライブラリーの調製

マイクロウェルアレイプラットフォーム内での微生物コミュニティ開発の組み立てと追跡

広域走査型プローブナノリソグラフィ自動配置と細胞培養研究用基板作製への応用

多重の人工細胞の微小環境配列の作製

医用フォトレジストスプレー塗装と柔軟なフォトマスクを使用して皮下注射針の先端の微細電極の作製

フォトリソグラフィ法により高分子マイクロニードルアレイの作製

要約

さらに動画を探す

ポリマー基板上へのマイクロ·サブミクロンのパターンを生成するためのリソグラフィMicropunching

動的なマスク投影リソグラフィーを用いたニューラル培養システムのためのマイクロパターンハイドロゲルの作製

バイオマテリアルのハイスループット検出用高分子マイクロアレイ

多重経皮電気化学センシングのための中空マイクロニードルベースの​​センサ

心臓組織工学のためのキャピラリーフォースリソグラフィ

高密度DNAおよびRNAマイクロアレイ - 光リソグラフィー合成、ハイブリダイゼーション、大型核酸ライブラリーの調製

マイクロウェルアレイプラットフォーム内での微生物コミュニティ開発の組み立てと追跡

広域走査型プローブ ナノリソグラフィ自動配置と細胞培養研究用基板作製への応用

多重の人工細胞の微小環境配列の作製

医用フォトレジスト スプレー塗装と柔軟なフォトマスクを使用して皮下注射針の先端の微細電極の作製

多重経皮電気化学センシングのための中空マイクロニードルベースのセンサ

広域走査型プローブナノリソグラフィ自動配置と細胞培養研究用基板作製への応用

医用フォトレジストスプレー塗装と柔軟なフォトマスクを使用して皮下注射針の先端の微細電極の作製