Name: gradient strain chip for stimulating cellular behaviors in cell-laden hydrogel
Uploaded: 2017-08-08T12:30:00
Description: Watch this Scientific Journal Video about Gradient Strain Chip for Stimulating Cellular Behaviors in Cell-laden Hydrogel at JoVE.com

このプロジェクトで、大学院学生研究留学プログラム (NSC-101-2917-I-007-010); をサポートされていた生体医用工学プログラム (NSC-101-2221-E-007-032-MY3);国立ナノテクノロジー プログラム (NSC-101-2120-M-007-001-) は、中華民国、台湾の国立科学評議会。著者は、ハイドロゲルとセル封止技術を共有するため教授アリ Khademhosseini、Unal-Gulden Camci、タントラ文献に見ポールとハーバード大学医学部で Ronglih 遼を感謝したいです。

1. GelMA Synthesis
<ol>
	<li>Weigh 10 g of gelatin powder and add it to a glass flask with 100 mL ofDulbecco&#39;s phosphate-buffered saline (DPBS). Put a magnetic stir bar into the flask and place the flask on a stirring hot plate.</li>
	<li>Cover the flask with aluminum foil to avoid water evaporation. Set the hot plate temperature to 50-60 &#176;C and the stirrer at 100 rpm for 1 h to dissolve the gelatin powder well.</li>
	<li>After the gelatin has dissolved, add 8 mL of methacrylic anhydride very slowly (one drop ...

<ol>
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本稿でハイドロゲル図形指導及び引張ストレッチ後細胞の配向挙動を比較する単純なアプローチについて報告する.柔軟な PDMS 膜は、同心の円形ヒドロゲルの高さ別の生成のためのドームの曲率を作成します。圧力を解放した後 PDMS 膜は自動的にセンターで最大と外側の境界で最小勾配ひずみ/伸長を形成するマイクロ パターンのヒドロゲルに力を適用します。グラデーションの歪みの形成は?...

ネイティブの微小環境を模したブロック素材として、ゲルの細胞外マトリックス (ECM) を含む再細胞の成長をサポートする生体模倣組織足場を構築できます。組織の機能を所有するには、組織のセルの配置は必須要件です。さまざまな 2 D (すなわち表面上で培養した細胞) と 3 D (すなわちハイドロゲルにカプセル化細胞) セルの配置は、培養または細胞またはマイクロ フレキシブル基板上にカプセル化することによって達成されている- またはナノ パターン1。マイクロ アーキテクチャの 3 D セルの配置はより魅力的な微小環境は、ネイティブの組織構築2,3,4に近いです。3 D のセルの配置のための一般的なアプローチは、ハイドロゲル形2,3の幾何学的なキューです。短軸方向に細胞増殖の制限された空間のため細胞はマイクロ パターン化ハイドロゲルの長軸方向に沿って配置を目指しています。別のアプローチは、ストレッチ方向4,5並列セルの配置を達成するためにゲルに引張のストレッチを適用することです。
圧縮ひずみなどの ECM ゲル上生物物理刺激または電気のフィールドは、適切な組織統合、増殖および分化1,2,3の細胞機能を調整できます。多くの研究は、複数機械制御ユニット4,6,7,8,9を使用して、一度に 1 つのひずみ条件を適用することによって細胞の挙動を調査するために行われています。たとえば、機械式ステップ モーターの使用は圧迫や共通のアプローチ7,10されている 3 D セルでカプセル化されたコラーゲンのゲルの上に伸ばし。しかし、そのような制御装置は余分なスペースを必要とする、インキュベーター7,9,11,12の汚染の問題に直面しています。さらに、大型の楽器は、再現性の高い13を提供する正確に制御環境を与えることはできません。
細胞を含んだヒドロゲルは、医用マイクロ スケールで通常用いられることを考えると、同時に 3 D 模倣構造体外2,14,15,16,17,18細胞の挙動を調査するためのひずみ/ストレッチ刺激の範囲を生成する MEMS 技術を組み合わせることが有利です。たとえば、マイクロ流体チップの PDMS 膜を変形するガス圧を使用して、異なる系統9,16に細胞の分化を運転系統に上昇を与えることができます。ただし、クリーン ルームやモーター、ポンプ、バルブ、圧縮ガスのソフトウェア管理の統合で複雑なチップ製造プロセスなど、多くの技術的課題があります。
この作品は、同心の円形ハイドロゲル パターンと柔軟な PDMS 膜を用いた自律的勾配の静的ひずみマイクロ流体チップを取得する単純なアプローチを紹介します。異なり、既存のアプローチのほとんどは、当社のプラットフォームは黄色い部屋の外を作製できるし、孵化の間に外部機器なしの携帯カプセルのヒドロゲルを同心円のグラデーションの系統を自己生成所有しているポータブルと使い捨ての小型デバイスです。ハイドロゲル形状の組み合わせによって影響を受けた 3T3 繊維芽細胞の挙動と 3 日間のグラデーションひずみチップで 3 D の ECM 模倣環境内セルの配置の観察の間に様々 な引張ストレッチ指導の手がかりを示した。

<table border="0" cellpadding="0" cellspacing="0" width="1383">
	<tbody>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">1.5-mL black microcentrifuge tube</td>
			<td style="width:225px;">Argos Technologies&#160;</td>
			<td style="width:156px;">03-391-161</td>
			<td style="width:665px;">This one can be replaced with a neutral color of 1.5-mL tube covered with aluminun foil</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">10X DPBS</td>
			<td style="width:225px;">Sigma-Aldrich</td>
			<td style="width:156px;">56064C</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Alexa Fluor 488 phalloidin&#160;</td>
			<td style="width:225px;">Invitrogen</td>
			<td style="width:156px;">A12379&#160;</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">BSA</td>
			<td style="width:225px;">Sigma</td>
			<td style="width:156px;">A1595</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Calcein</td>
			<td style="width:225px;">Molecular Probe</td>
			<td style="width:156px;">C1430</td>
			<td style="width:665px;">For labeling viable cells</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">CCD</td>
			<td style="width:225px;">PCO. Imaging</td>
			<td style="width:156px;">Pixelfly qe</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Cell membrane permeating solution</td>
			<td style="width:225px;">Sigma-Aldrich</td>
			<td style="width:156px;">X100</td>
			<td style="width:665px;">0.5% Triton X-100 for permeating cell membrane</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">DAPI</td>
			<td style="width:225px;">Sigma-Aldrich</td>
			<td style="width:156px;">D8417</td>
			<td style="width:665px;">Cell nucleus staining</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Dialysis membrane</td>
			<td style="width:225px;">Sigma-Aldrich</td>
			<td style="width:156px;">D9527</td>
			<td style="width:665px;">Molecular weight cut-off = 14,000</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">DMEM</td>
			<td style="width:225px;">Gibco</td>
			<td style="width:156px;">11995-065</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Double-side tape</td>
			<td style="width:225px;">3M</td>
			<td style="width:156px;">8003</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">FBS</td>
			<td style="width:225px;">Hyclone</td>
			<td style="width:156px;">SH30071.03</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Gelatin</td>
			<td style="width:225px;">Sigma-Aldrich</td>
			<td style="width:156px;">G2500</td>
			<td style="width:665px;">gel strength 300, type A, from porcine skin</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">High frequency electronic corona generator</td>
			<td style="width:225px;">Electro-technic products</td>
			<td style="width:156px;">MODEL BD-20</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Methacrylic Anhydride</td>
			<td style="width:225px;">Sigma-Aldrich</td>
			<td style="width:156px;">276685</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Micro syringe</td>
			<td style="width:225px;">Hamilton</td>
			<td style="width:156px;">80501</td>
			<td style="width:665px;">50 &#956;L&#160;</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Microscope</td>
			<td style="width:225px;">Olympus</td>
			<td style="width:156px;">IX71</td>
			<td style="width:665px;">Include two filter sets: LF405/LP-B-000 and LF488/LP-C-000 from Semrock</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Oxygen plasma machine</td>
			<td style="width:225px;">Harrick plasma</td>
			<td style="width:156px;">PDC-001</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Paraformaldehyde</td>
			<td style="width:225px;">Sigma-Aldrich</td>
			<td style="width:156px;">P6148</td>
			<td style="width:665px;">For fixing cell</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">PDMS</td>
			<td style="width:225px;">DOW CORNING</td>
			<td style="width:156px;">Sylgard 184</td>
			<td style="width:665px;">Mixture for PDMS chip cast-molding fabrication</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Pen-Strep</td>
			<td style="width:225px;">Gibco</td>
			<td style="width:156px;">10378-016</td>
			<td style="width:665px;">penicillin/streptomycin</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Photoinitiator</td>
			<td style="width:225px;">CIBA</td>
			<td style="width:156px;">Irgacure 2959</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Propidium iodide</td>
			<td style="width:225px;">Sigma-Aldrich</td>
			<td style="width:156px;">P4170</td>
			<td style="width:665px;">For labeling dead cells</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Sterile Filtration cup</td>
			<td style="width:225px;">Millipore</td>
			<td style="width:156px;">SCGPT05RE</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">TMSPMA</td>
			<td style="width:225px;">Sigma-Aldrich</td>
			<td style="width:156px;">440159</td>
			<td style="width:665px;">For hydrogel immobilization</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Ultrasonicator</td>
			<td style="width:225px;">Delta</td>
			<td style="width:156px;">D150H</td>
			<td style="width:665px;">150W, 43kHz</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">UV light</td>
			<td style="width:225px;">DAIHAN</td>
			<td style="width:156px;">WUV-L10</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">Freeze Dryer</td>
			<td style="width:225px;">FIRSTEK</td>
			<td style="width:156px;">150311025</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">NIH3T3(fibroblast)</td>
			<td style="width:225px;">Food Industry Research and Development Institute(FIRDI)</td>
			<td style="width:156px;">08C0011</td>
			<td style="width:665px;"></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:337px;">MOXI Z Mini Automated Cell Counter</td>
			<td style="width:225px;">ORFLO</td>
			<td style="width:156px;">MXZ001</td>
			<td style="width:665px;"></td>
		</tr>
	</tbody>
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gradient strain chip for stimulating cellular behaviors in cell-laden hydrogel

人工細胞の配置については、組織工学の分野でのホットな話題です。過去の研究のほとんどは、複雑な実験的プロセスおよび汚染の問題に通常関連付けられている質量システム制御、使用して細胞を含んだハイドロゲルのひずみ誘起細胞の単一の位置合わせを調査しました。したがって、この記事では PDMS のプラスチック カバー、UV 透明なガラス基板 3 D ゲルの細胞挙動の刺激のため流体チップを用いた勾配静的ひずみを構築するシンプルなアプローチを提案する.流体の商工会議所でのオーバー ロードの写真パターン形成可能なセル プレポリマーは、カバーの凸曲面 PDMS 膜を生成できます。UV 架橋後湾曲した PDMS 膜とバッファー洗浄、調査細胞の微小環境下で同心円形パターンをさまざまなグラデーションの株の下で動作は外部機器なしの単一の流体チップで自己確立です。NIH3T3 細胞をゲル上 15-65% から様々 なひずみの刺激との連携で、ジオメトリの指導の下で細胞の配置の傾向の変化を観察した後示した。3 日間培養後ハイドロゲル ジオメトリは、細胞が高圧縮ひずみハイドロゲル伸長方向に沿って整列低圧縮ひずみ, セルの配置を支配しました。これらの間は、細胞は、ハイドロゲルの伸長とパターン化ハイドロゲルの幾何学指導の根本的な指導の逸散によるランダムな配置を示した。

完成したグラデーションひずみ刺激チップの各円形のハイドロゲルの機械的変化を比較するためは 0 μ L (図 4 a) の注入量と 40 μ L (図 4 b) では、同じチップの 2 つの各円形のハイドロゲルの線幅をそれぞれ測定しました。各サークルでパーセントの伸びを 0 μ L 注入チップ (図 4 c) に対応するハイドロ?...

Watch this Scientific Journal Video about Gradient Strain Chip for Stimulating Cellular Behaviors in Cell-laden Hydrogel at JoVE.com

Gradient Strain Chip for Stimulating Cellular Behaviors in Cell-laden Hydrogel

組織工学用セルの配置を調整する同心円状細胞を含んだハイドロゲルの非連続的なグラデーション静的系統を提供する単純なアプローチを紹介します。

細胞を含んだハイドロゲルの刺激細胞挙動のひずみ勾配チップ

Artificial guidance for cellular alignment is a hot topic in the field of tissue engineering. Most of the previous research has investigated single ...

The overall goal of this gradient strain chip is to provide a simple approach to generate non continuous gradient static strains on a 3D hydrogel for the investigation of cell behaviors under a series of strain conditions. This method can help answer key questions in the bioengineering field such as the stimulations of a stem cell differentiation and the regulation of cellular alignment for artificial tissue organ development. The main advantage of this technique is that various strains can be applied on the cell layer and hydrogels in the same micro environment for comparison of cell behavior.Visual demonstration of this method is critical as the chip preparation steps are difficult to learn since the light should be complete in three to four hours for base of experiment to ensure high cell variability. Weigh 10 grams of gelatin powder and add it to a glass flask with 100 milliliters of Dulbecco's phosphate buffered saline, or DPBS. Put a magnetic stir bar into the flask and place the flask on a stirring hot plate.Cover the flask with aluminum foil to avoid water evaporation. Set the hot plate temperature to 50 to 60 degrees and the stirrer at 100 RPM for one hour to dissolve the gelatin powder. After the gelatin has dissolved, add eight milliliters of methacrylic anhydride very slowly using a pipette.Let it react at 60 degrees Celsius for three hours. Then add prewarmed DPBS into the flask to a final volume of 500 milliliters. Allow the solution to mix well for 15 minutes to stop the reaction.Meanwhile cut a dialysis membrane into several 25 millimeter long tubes. Immerse them in deionized water for 15 minutes. And make a knot to close one end of the dialysis tubes.Load the appropriate amount of the polymer solution into the dialysis tubes and close the other end. Then place the filled tubes in a five liter plastic beaker with deionized water for a week. Renew the deionized water twice a day and maintain the solution at 40 to 50 degrees Celsius during the dialysis process.Following dialysis collect the solution from the tubes into a 500 milliliter glass bottle. Pour approximately 450 to 500 milliliters of solution into a 500 milliliter filter cup. And apply a vacuum to force the solution to pass through the filter membrane for sterilization.Then transfer the sterilized polymer into several 50 milliliter sterilized tubes. Transfer the sterilized polymer into several 50 milliliter sterilized tubes and store them in a minus 80 degrees Celsius freezer for three to five days. Freeze dry the minus 80 degrees Celsius polymer for one week using a freeze drier to form GelMA which can then be stored in a minus 80 degree Celsius freezer.For chip fabrication first prepare the polymethacrylate or PMMA, played and molded as described in the text protocol. Then prepare the PTMS cover and PTMS plug by properly mixing 30 grams of PTMS elastomer and three grams of PTMS curing agent. Degas the mixture under a vacuum chamber for one hour.Cast 1.8 to two grams of the mixture into the PMMA mold for the PTMS cover. Also use the appropriate amount to fill each cavity for the PMMA mold for the PTMS plug. In addition cast 10 grams of uncured PTMS mixture in a blank 10 centimeter plastic plate.Put these molds in a vacuum chamber to degas for 30 minutes. Cure the PTMS for two hours at 80 degrees Celsius. After cooling down the cured PTMS on the mold, detach the PTMS covers and the PTMS plugs from the PMMA molds.Next punch two holes with diameters of about three millimeters at the ends of the flow channels of the PTMS covers. Cut the PTMS sheet molded from the 10 centimeter plastic plate into many one centimeter by one centimeter cubes. And punch a three millimeter hole in each PTMS cube.Glue two uncured one centimeter by one centimeter PTMS cubes onto the openings of the PTMS cover to serve as medium reservoirs and to aid in the curing process of the gradient circular hydrogel patterns. Then cure for one hour at 80 degrees Celsius. Next bond the PTMS covers with the two PTMS reservoirs onto a TMSPMA coated slide.To do so, pretreat the bonding side of the PTMS cover and the TMSPMA coated slide under an oxygen plasma machine for 90 seconds of oxygen plasma treatment. Contact the plasma treated surface of the PTMS covers and the TMSPMA slide and press them closely for permanent bonding through the formation of the silicon oxygen silicon bond. Print a photomask by printing the established layout on a transparent film.Then cut the printed photomask to 25 millimeters by 37.5 millimeters in size. Weigh 25 milligrams of freeze dried GelMA into 0.3 milliliters of prewarmed cell culture medium in a 1.5 milliliter black microcentrifuge tube. Put the microcentrifuge tube on a laboratory stirrer hot plate until the GelMA dissolves in the medium.Add 50 milligrams of photoinitiator to one milliliters of DPBS in a microcentrifuge tube. And place it in an 80 degree Celsius oven for 15 minutes or until the photoinitiator has dissolved. Add 25 microliters of the 10%photoinitiator to the microcentrifuge tube.Pipette several times to mix well. Next count three million NIH3T3 cells using an automated cell counter. After centrifuging the suspension at 200 Gs for five minutes discard the supernatant and resuspend the cells in 175 microliters of cell culture medium.Add the cell solution to the microcentrifuge tube to get a pre polymer cell solution of 5%GelMA, 0.5%photoinitiator and about six million 3T3 cells per milliliter. After mixing load 100 microliters of cell prepolymer into a 100 microliter microsyringe. Manually align a piece of the photomask onto the bottom slide of the sterilized gradient strain chip.And simply fix the position using a small drop of deionized water in between. Connect the 100 microliter microsyringe, loaded with prepolymer cell solution to the inlet of the chip. Then place 50 microliters of prepolymer cell solution in the flow channel using the microsyringe and plug the outlet using a PTMS plug.Inject an extra 40 microliters of solution to create a convex bulge in the circular PTMS membrane. Move the chip with the photomask, microsyringe, and PTMS plug to under a UV lamp. And expose it for 30 to 45 seconds to cross link the concentric circular hydrogel in the fluidic chamber.After cross linking remove the PTMS plug and the microsyringe to release the liquid pressure. Use a one milliliter syringe loaded with prewarmed DPBS to wash out uncrosslinked resins three times by flushing from the inlet to the outlet. Next fill the flow channel with about 100 microliters of cell culture medium.Place the chip in a sterilized culture dish and culture in a 5%carbon dioxide atmosphere at 37 degrees Celsius for a week. Refresh the medium every day. Take images of three chips on day zero after four hours of incubation as the control group.And three chips on day three as the experimental set using a microscope with a 20 times objective. Measure the line width of each hydrogel from line one to line 12 using software to calculate the compress stains. Shown here are representative results of hydrogel patterns with zero microliter and 40 microliters over injection, after UV cross linking and four hour incubation.The line width of the 3D hydrogel in the non over injection control looks uniform as expected. However the hydrogel patterns with 40 microliters over injection gives a gradient line width of hydrogels decreasing from line one to line 12. After three days of incubation, the cells in the hydrogel extend to different directions.The cells in line one align along the radial direction due to the stimulation of hydrogel elongation. On the contrary the cells in line 12 align along the hydrogel shape where the geometry cue dominates the cellular alignment. There is no specific cell alignment in line 7 where the two cellular alignment cues of line one and line 12 balance each other out.Once measuring the micro environment of gradient strains on 3D hydrogel can be done by the gradient strain chip in two hours if it's performed properly. While attempting this procedure, it is important to remember to sterilize the gradient strain chip before loading the cell prepolymer solution. Also thoroughly wipe the surface of the chip with 75%ethanol before placing the chips into the cell culture incubator.After watching this video you should have a very good understanding of how to generate a gradient strain chip to investigate cell behaviors under different strains imperial.

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