著者らは、この仕事をサポートして資金調達のためにアクロン大学を承認したいと思います。

著者らは、開示することは何もありません。

組換えタンパク質工学は多くの分野にまたがる非常に強力な技術である。これは、カスタム設計のタンパク質の高収量の産生を可能にする、費用対効果の高い、調整可能な比較的簡単な手順である。これは、設計および標的タンパク質を発現することは必ずしも容易ではないことに留意することが重要である。基底発現および組換えタンパク質の安定性を、ベクターの特定の選択に依存E.?...

タンパク質は、最終的に適切な組織形成、組織を導く、多くの生物学的機能に関与している生体分子の広い範囲をカバーする。これらの分子は、人体内の均衡を維持し、規制アップ及び/またはダウンレギュレーション遺伝子および他のタンパク質を制御するシグナル伝達経路の数千を開始する。単一のタンパク質の破壊は、壊滅的な障害または疾患の発症につながることができた信号のこのウェブ全体に影響します。ラボで個々のタンパク質を設計することは、これらの悪影響に対処するための一つの解決策を提供しており、低分子薬物に代わるものを提供しています。 1977年には、14個のアミノ酸ソマトスタチン配列をコードする遺伝子は、E.を使用して作成された第一の操作されたポリペプチドの一つであった大腸菌 1。まもなく1979年の後、インスリンは、形質転換、プラスミドpBR322にクローニングし、発現させ、精製した2。それ以来、組換えタンパク質は、解像度の複数のフィールドに自分の影響力を拡大しているearch などの生体材料、ドラッグデリバリー、組織工学、バイオ医薬品、農業、産業用酵素、バイオ燃料として（レビューは参考文献3-8を参照してください）。これは、技術には、目的のために、化学的部分またはタンパク質配列の特定のアプリケーションの添加を介して提供し、これらに限定されないが、タンパク質同定、安定化および精製を標的とすることが汎用性によるところが大きい。 組換えDNA技術によって、組換えタンパク質は、哺乳動物、植物、昆虫、酵母、真菌、または細菌を含む真核生物および原核生物宿主系の種々の発現させることができる。各ホストは異なる利点を提供し、通常は最高のシステムは、タンパク質機能、収率、安定性、全体的なコスト、および拡張性に基づいて決定される。細菌細胞は、多くの場合、真核生物宿主（ すなわちグリコシル化、ジスルフィドブリッジ、Eを提供する翻訳後修飾のメカニズムを欠いている<html> TC。）5。しかしながら、これらのホストは、典型的にはより高価で時間のかかる09であり、その結果、哺乳動物および昆虫システムは、通常、真核生物のタンパク質のより良好な相溶性および発現をもたらす。従って、E.細胞は、安価な増殖条件および遺伝子発現機構において急速に拡大しているため、大腸菌は、よく理解されている5,9は、我々の発現システムのための好まれる宿主である。さらに、このシステムは、翻訳後修飾10の欠如にもかかわらず、機能的なタンパク質の生産を目的とし、その結果のためのスケールアップが容易である。 E.この株は、高い形質転換効率に基づいた優れたプラスミド収量を提供していますので、 大腸菌 K12株は、クローニングのために、このプロトコルで選択される。さらに、E.この宿主株は、制御されたタンパク質の発現および安定性11を提供するT7 RNAポリメラーゼ遺伝子が含まれているため、 大腸菌 BL21株は、発現のために利用される。 10トン &quot;&gt;ホスト選択後、さらなる注意が組換えタンパク質を合成することは、バクテリオファージT7転写および翻訳シグナルの指示の下でクローン化され、標的DNA配列で始まる。選択され、制御されたタンパク質の発現を促進するために理想的な発現ベクターを選択する際に注意しなければならず発現は、T7 RNAポリメラーゼ遺伝子12の染色体コピーを含有する宿主細胞において誘導される。プラスミドベクターpBR322に由来するこれらのベクターは、（レビューのためには、13を参照する参照）、しっかりと最初にStudierら14によって開発されたT7プロモーターによって制御され、付加的に提供されているlacオペレーター 、およびlacリプレッサー（LAC1）15,16の包含を介して制御組換えタンパク質工学では、この発現系は、異なる標的DNA配列を挿入することにより、所望のタンパク質の特定のアミノ酸配列を調整するまたは融合タンパク質を作成する機能を提供合わせたドメインから構成されるシングルタンパク質からのS。さらに、いくつかのベクターシリーズはN又はC末端上に配置するペプチドタグ修飾を含む。我々の設計のために、ヒスチジン（His）タグは、精製の ​​ためのDNA標的配列に加え、15個のアミノ酸配列は、ビオチン化biotinylatable 17,18のために含めた。このプロトコルでは、アンピシリン耐性遺伝子を含むプラスミドは、我々のbiotinylatable融合タンパク質配列を運ぶために選択した。発現はT7のlacプロモーターを介してこのベクター中に制御され、容易にイソプロピルβ-D-1-チオガラクトピラノシド（IPTG）で誘導される。 テスト式（小スケールの培養物）を、精製手順のいずれかを処方するために可溶性または不溶性の形態で発現することができる標的タンパク質の存在および溶解度を決定するために使用される。細菌細胞内で発現される可溶性タンパク質は、その天然の構造体19を維持するために自発的なフォールディングを受けることになる。通常、ネイティブ構造は熱力学的に有利である。多くの場合、宿主の代謝活性は、不溶性タンパク質産生および不溶性タンパク質凝集体からなる封入体の形成をもたらすシステムにストレスを与え、標的タンパク質に資するものである。従って、標的タンパク質は20生物学的に不活性な、一般的にそれらをレンダリングする、変性させる。両方のテスト式は、アップスケーリングされ、および単離手順は、標的タンパク質の溶解度によって決定される。追加の再生またはリフォールディングステップは不溶性タンパク質のために必要である。得られた組換えタンパク質は、サイズ排除クロマトグラフィーを用いて精製することができる。 家の中での組換えタンパク質産生は、標的タンパク質のミリグラム本培養のリットルあたり単離することができるので、市販品よりもコストの利点を提供する。必要な機器のほとんどは、一般的な生物学的または化学実験室で提供されています。タンパク質工学の作成を可能に常に市販されていない追加された機能を持つカスタムの融合タンパク質の。 図1は、組換えタンパク質を工学に関わる主な手順を示している。この発現系では、我々は、インターフェロン-γ、血小板由来増殖因子、および骨形成タンパク質21〜23のような多くのbiotinylatableタンパク質を、作成しているが、我々は我々が軸索ガイダンス、NGF（29 kDaのために設計された二つのタンパク質に焦点を当てます）とのSema3A（91 kDa）の10（レビューのための基準24を参照）。ビオチン化はよく知られているビオチン-ストレプトアビジン相互作用を利用して25-27標識タンパク質の同定、単離および固定化のための一般的な技術である。生物物理学的なプローブ28,29、バイオセンサ30と、量子ドット31は、10 27 -15 MのオーダーのK dで、ビオチン-ストレプトアビジン結合の高い親和性を利用するシステムのいくつかの例である。 E.大腸菌バイオスズリガーゼ、BirAをは、ビオチンタグの付いたシーケンス18,32内で見つかったリジン側鎖へのビオチンの共有結合を助ける。材料や生体分子へのテザリングビオチンは、複数の組織工学適用21,33-35用セルに成長因子の持続性送達を生産している。したがって、これらのカスタム設計biotinylatableタンパク質を設計することは複数の研究の利益を超越することができる強力なツールです。

<table border="0" cellpadding="0" cellspacing="0" width="849">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:299px;">1,4-dithio--DL-threitol, DTT, 99.5%</td>
			<td style="width:191px;">Chem-Impex International</td>
			<td style="width:121px;">127</td>
			<td style="width:239px;">100 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:299px;">2-Hydroxyethylmercaptan &#946;-Mercaptoethanol</td>
			<td>Chem-Impex International</td>
			<td>642</td>
			<td>250 ml</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Acetic acid, glacial</td>
			<td>EMD</td>
			<td>AX0073-9</td>
			<td>2.5 L</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Agar</td>
			<td>Bioshop</td>
			<td>AGR001.500</td>
			<td>500 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Ampicillin sodium salt&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>A9518</td>
			<td>25 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Antifoam 204</td>
			<td>Sigma-Aldrich</td>
			<td>A6426</td>
			<td>500 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Barstar-NGF pET-21a(+)</td>
			<td>GenScript USA Inc.</td>
			<td></td>
			<td>4 &#181;g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">BL21(DE3) Competent Cells</td>
			<td>Novagen</td>
			<td>69450</td>
			<td>1 ml; Expression Host</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Bradford reagent</td>
			<td>Sigma-Aldrich</td>
			<td>B6916</td>
			<td>500 ml</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">BugBuster</td>
			<td>Novagen</td>
			<td>70922-3</td>
			<td>100 ml</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Gel filtration standard</td>
			<td>Bio-Rad</td>
			<td>151-1901</td>
			<td>6 vials</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Glycerol</td>
			<td>Bioshop</td>
			<td>GLY001.1</td>
			<td>1 L</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:299px;">Guanidine hydrodioride amioformamidine hydrochloride</td>
			<td>Chem-Impex International</td>
			<td>152</td>
			<td>1 kg</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:299px;">His-Pur Ni-NTA Resin</td>
			<td>Thermo Scientific</td>
			<td>88222</td>
			<td>100 ml</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Hydrochloric acid</td>
			<td>EMD&#160;</td>
			<td>HX0603-3</td>
			<td>2.5 L</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Imidazole&#160;</td>
			<td>Chem-Impex International</td>
			<td>418</td>
			<td>250 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">IPTG</td>
			<td>Chem-Impex International</td>
			<td>194</td>
			<td>100 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Laemmli sample buffer</td>
			<td>Bio-Rad</td>
			<td>161-0737</td>
			<td>30 ml</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:299px;">Lauryl sulfate sodium salt, Sodium dodecyl surface</td>
			<td>Chem-Impex International</td>
			<td>270</td>
			<td>500 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">LB Broth&#160;&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>L3022</td>
			<td>1 kg</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">NovaBlue Competent Cells</td>
			<td>Novagen</td>
			<td>69825</td>
			<td>1 ml; Cloning Host</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Phosphate buffered saline</td>
			<td>Sigma-Aldrich</td>
			<td>P5368-10PAK</td>
			<td>10 pack</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Potassium Chloride</td>
			<td>Chem-Impex International</td>
			<td>01247</td>
			<td>1 kg</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sema3A-pET-21a(+)</td>
			<td>GenScript USA Inc.</td>
			<td></td>
			<td>4 &#181;g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">SimplyBlue SafeStain</td>
			<td>Invitrogen</td>
			<td>LC6060</td>
			<td>1 L</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sodium chloride</td>
			<td>Sigma-Aldrich</td>
			<td>S5886-1KG</td>
			<td>1 kg</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sodium hydroxide</td>
			<td>Fisher Scientific</td>
			<td>S318-500</td>
			<td>500 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sodium phosphate diabasic</td>
			<td>Sigma-Aldrich</td>
			<td>S5136-500G</td>
			<td>500 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sodium phosphate monobasic</td>
			<td>Sigma-Aldrich</td>
			<td>S5011</td>
			<td>500 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Terrific Broth</td>
			<td>Bioshop</td>
			<td>TER409.5</td>
			<td>5 kg</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Tetracycline hydrochloride</td>
			<td>Chem-Impex International</td>
			<td>667</td>
			<td>25 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Tris/Glycine/SDS Buffer, 10X</td>
			<td>Bio-Rad</td>
			<td>1610732</td>
			<td>1 L</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Trizma Base</td>
			<td>Sigma-Aldrich</td>
			<td>T1503</td>
			<td>1 kg</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Tryptone, pancreatic</td>
			<td>EMD</td>
			<td>1.07213.1000</td>
			<td>1 kg</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Yeast extract, granulated</td>
			<td>EMD</td>
			<td>1.03753.0500</td>
			<td>500 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="56">
			<td height="56" style="height:56px;width:299px;">Name of Kits/ Equipment</td>
			<td style="width:191px;">Company</td>
			<td style="width:121px;">Catalog Number</td>
			<td>Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">&#160;&#196;KTApurifier10</td>
			<td style="width:191px;">GE Healthcare</td>
			<td style="width:121px;">28-4062-64&#160;</td>
			<td>Includes kits and accessories</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Benchtop Orbital Shaker</td>
			<td style="width:191px;">Thermo Scientific</td>
			<td style="width:121px;">SHKE4000</td>
			<td>MAXQ 4000</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:299px;">BirA500</td>
			<td style="width:191px;">Avidity</td>
			<td style="width:121px;">BirA500</td>
			<td style="width:239px;">Enzyme comes with reaction buffers and biotin solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Dialysis Casette</td>
			<td style="width:191px;">Thermo Scientific</td>
			<td style="width:121px;">66380</td>
			<td>Slide-A-Lyzer (Extra Strength)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Dialysis Tubing</td>
			<td style="width:191px;">Spectrum Laboratories&#160;</td>
			<td style="width:121px;">132127, 132129</td>
			<td style="width:239px;">MWCO: 25,000 and 50,000</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Flow Diversion Valve FV-923</td>
			<td style="width:191px;">GE Healthcare</td>
			<td style="width:121px;">11-0011-70</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:299px;">FluoReporter Biotin Quantification Assay Kit</td>
			<td style="width:191px;">Invitrogen</td>
			<td style="width:121px;">1094598</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Frac-950 Tube Racks, Rack C</td>
			<td style="width:191px;">GE Healthcare</td>
			<td style="width:121px;">18-6083-13</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Fraction Collector Frac-950</td>
			<td style="width:191px;">GE Healthcare</td>
			<td style="width:121px;">18-6083-00</td>
			<td>Includes kits and accessories</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Heated/Refrigerated Circulator&#160;</td>
			<td style="width:191px;">VWR</td>
			<td style="width:121px;">13271-102</td>
			<td>Model 1156D</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">Heating Oven FD Series</td>
			<td style="width:191px;">Binder</td>
			<td style="width:121px;"></td>
			<td>Model FD 115</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;">HiLoad 16/60 Superdex 200 pg</td>
			<td style="width:191px;">GE Healthcare</td>
			<td style="width:121px;">17-1069-01</td>
			<td style="width:239px;">Discontinued--Replacement Product: HiLoad 16/600 Superdex 200 pg</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">J-26 XPI Avanti Centrifuge</td>
			<td style="width:191px;">Beckman Coulter</td>
			<td style="width:121px;">393126</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">JA 25.50 Rotor</td>
			<td style="width:191px;">Beckman Coulter</td>
			<td style="width:121px;">363055</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:299px;">JLA 8.1 Rotor</td>
			<td style="width:191px;">Beckman Coulter</td>
			<td style="width:121px;">969329</td>
			<td>Includes 1 L polyporpylene bottles</td>
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			<td style="width:191px;">Beckman Coulter</td>
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			<td>infinite M200</td>
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			<td style="width:121px;">165-8004</td>
			<td style="width:239px;">4-gel vertical electrophoresis system</td>
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			<td height="21" style="height:21px;width:299px;">Mini-PROTEAN TGX Precast Gels</td>
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			<td style="width:239px;">Any kDa, 15-well comb</td>
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			<td>737-2512</td>
			<td>49 ml&#160;volume ECONO-Column</td>
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			<td height="21" style="height:21px;width:299px;">Plasmid Miniprep Kit</td>
			<td style="width:191px;">OMEGA bio-tek</td>
			<td style="width:121px;">D6943-01</td>
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			<td height="21" style="height:21px;width:299px;">PowerPac HC Power Supply</td>
			<td>Bio-Rad</td>
			<td style="width:121px;">164-5052</td>
			<td>250 V, 3 A, 300 W</td>
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		<tr height="42">
			<td height="42" style="height:42px;width:299px;">Round Bottom Polypropylene Copolymer Tubes</td>
			<td style="width:191px;">VWR</td>
			<td style="width:121px;">3119-0050</td>
			<td>50 ml&#160;tubes for JA 25.50 rotor</td>
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			<td height="21" style="height:21px;width:299px;">Spin-X UF Concentrators</td>
			<td style="width:191px;">Corning</td>
			<td style="width:121px;">431488, 431483</td>
			<td>&#160;20 and 6 ml; MWCO: 10,000 Da</td>
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			<td height="21" style="height:21px;width:299px;">Subcloning Service</td>
			<td style="width:191px;">GenScript USA Inc.</td>
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			<td height="21" style="height:21px;width:299px;">Ultrasonic Processor&#160;</td>
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			<td style="width:121px;">18910445A</td>
			<td>Model CV18</td>
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			<td height="21" style="height:21px;width:299px;">Vortex-Genie 2</td>
			<td style="width:191px;">Scientific Industries</td>
			<td>SI-0236</td>
			<td>Model G560</td>
		</tr>
	</tbody>
</table>

expression, isolation, and purification of soluble and insoluble biotinylated proteins for nerve tissue regeneration

組換えタンパク質工学は、 大腸菌（E.coli）発現ほぼ40年のためのシステム、今日Eを利用している大腸菌はまだ最も広く使用されている宿主生物である。システムの柔軟性は、（ストレプトアビジン相互作用のための）ビオチンタグなどの部分と緑色蛍光タンパク質またはチェリーレッドのタンパク質のような大きな機能性タンパク質を付加することができます。また、翻訳後修飾を付与する金属イオンキレート剤、一意的に反応性官能基、分光学的プローブ、および分子などの非天然アミノ酸の組込みは、タンパク質の特性及び機能のより良好な操作を可能にした。その結果、この技術は研究の様々な分野のための重要なユーティリティを提供し、カスタマイズ可能な融合タンパク質を作成します。具体的には、biotinylatableタンパク質配列が原因アビジンおよびストレプトアビジンとビオチンとの間の高親和性相互作用の多くの標的タンパク質に組み込まれている。この追加により、タグ付けされたタンパク質の検出および精製を強化するだけでなく、このような細胞選別などの二次アプリケーションのための道を開くことに支援しています。このように、ビオチン標識分子がbioindustrialおよび生物医学分野で増加し、広範な影響力を示している。本研究の目的のために、我々は、神経成長因子（NGF）およびsemaphorin3A（Sema3Aの）機​​能的領域を含む組換えビオチン化融合タンパク質を設計している。我々は、これらのビオチン化融合タンパク質は、他の活性なタンパク質配列と共に、組織工学および再生の目的のための生体材料に繋留することができる方法を以前に報告した。このプロトコルは、T7 LAC誘導ベクターおよびEを利用し、ミリグラム規模でエンジニアリングbiotinylatableタンパク質の基礎を概説形質転換からのスケールアップおよび精製を開始大腸菌発現宿主、。

<html> クローニングとテスト式 めっきが適切に行われると、単一の単離されたコロニーをクローン形質転換された細菌細胞（ 図2A）プラッキングの可能性を高めるために形成すべきである。あまりにも多くの細胞を播種する場合は、プレートを37℃以下で変態が長すぎるインキュベートし、コロニーを寒天プレートを被覆または細胞の大きな凝集?...

Watch this Scientific Journal Video about Expression, Isolation, and Purification of Soluble and Insoluble Biotinylated Proteins for Nerve Tissue Regeneration at JoVE.com

Expression, Isolation, and Purification of Soluble and Insoluble Biotinylated Proteins for Nerve Tissue Regeneration

biotinylatable融合タンパク質を開発することは、研究の様々な分野で多くの潜在的な用途がある。組換えタンパク質工学は、カスタム設計されたタンパク質を高収率で提供する、費用対効果のある単純な手順である。

神経組織再生のための可溶性および不溶性ビオチン化タンパク質の発現、分離、および精製

Recombinant protein engineering has utilized Escherichia coli (E. coli) expression systems for nearly 4 decades, and today E. coli is still the most ...

expression-isolation-purification-soluble-insoluble-biotinylated

Research

JoVE Journal

Bioengineering

33.4K ビュー.  University of Akron.  biotinylatable融合タンパク質を開発することは、研究の様々な分野で多くの潜在的な用途がある。組換えタンパク質工学は、カスタム設計されたタンパク質を高収率で提供する、費用対効果のある単純な手順である。 

ビデオ: Expression, Isolation, and Purification of Soluble and Insoluble Biotinylated Proteins for Nerve Tissue Regeneration

Use of Human Perivascular Stem Cells for Bone Regeneration

Human perivascular stem cells (PSCs) can be isolated in sufficient numbers from multiple tissues for purposes of skeletal tissue engineering1-3. PSCs are a FACS-sorted population of 'pericytes' (CD146+CD34-CD45-) and 'adventitial cells' (CD146-CD34+CD45-), each of which we have previously reported to have properties of mesenchymal stem cells. PSCs, like MSCs, are able to undergo osteogenic differentiation, as well as secrete pro-osteogenic cytokines1,2. In the present protocol, we demonstrate the osteogenicity of PSCs in several animal models including a muscle pouch implantation in SCID (severe combined immunodeficient) mice, a SCID mouse calvarial defect and a femoral segmental defect (FSD) in athymic rats. The thigh muscle pouch model is used to assess ectopic bone formation. Calvarial defects are centered on the parietal bone and are standardly 4 mm in diameter (critically sized)8. FSDs are bicortical and are stabilized with a polyethylene bar and K-wires4. The FSD described is also a critical size defect, which does not significantly heal on its own4. In contrast, if stem cells or growth factors are added to the defect site, significant bone regeneration can be appreciated. The overall goal of PSC xenografting is to demonstrate the osteogenic capability of this cell type in both ectopic and orthotopic bone regeneration models.

Human perivascular stem cells (PSCs) are a novel stem cell class for skeletal tissue regeneration similar to mesenchymal stem cells (MSCs). PSCs can be isolated by FACS (fluorescence activated cell sorting) from adipose tissue procured during standard liposuction procedures, then combined with an osteoinductive scaffold to achieve bone formation in vivo.

骨再生のための人間の血管周囲の幹細胞の使用

Human perivascular stem cells (PSCs) can be isolated in sufficient numbers from multiple tissues for purposes of skeletal tissue engineering1-3. PSCs are ...

生物工学

Non-contact, Label-free Monitoring of Cells and Extracellular Matrix using Raman Spectroscopy

Non-destructive, non-contact and label-free technologies to monitor cell and tissue cultures are needed in the field of biomedical research.1-5 However, currently available routine methods require processing steps and alter sample integrity. Raman spectroscopy is a fast method that enables the measurement of biological samples without the need for further processing steps. This laser-based technology detects the inelastic scattering of monochromatic light.6 As every chemical vibration is assigned to a specific Raman band (wavenumber in cm-1), each biological sample features a typical spectral pattern due to their inherent biochemical composition.7-9 Within Raman spectra, the peak intensities correlate with the amount of the present molecular bonds.1 Similarities and differences of the spectral data sets can be detected by employing a multivariate analysis (e.g. principal component analysis (PCA)).10
Here, we perform Raman spectroscopy of living cells and native tissues. Cells are either seeded on glass bottom dishes or kept in suspension under normal cell culture conditions (37 &deg;C, 5% CO2) before measurement. Native tissues are dissected and stored in phosphate buffered saline (PBS) at 4 &deg;C prior measurements. Depending on our experimental set up, we then either focused on the cell nucleus or extracellular matrix (ECM) proteins such as elastin and collagen. For all studies, a minimum of 30 cells or 30 random points of interest within the ECM are measured. Data processing steps included background subtraction and normalization.

Raman spectroscopy is a suitable technique for the non-contact, label-free analysis of living cells, tissue-engineered constructs and native tissues. Source-specific spectral fingerprints can be generated and analyzed using multivariate analysis.

ラマン分光法を用いた細胞と細胞外マトリックスの非接触、ラベルフリーの監視

Non-destructive, non-contact and label-free technologies to monitor cell and tissue cultures are needed in the field of biomedical research.1-5 However, ...

Creating Adhesive and Soluble Gradients for Imaging Cell Migration with Fluorescence Microscopy

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as growth factors. Here, we outline a method to create opposing gradients of adhesive and soluble cues in a microfluidic chamber, which is compatible with live cell imaging. A copolymer of poly-L-lysine and polyethylene glycol (PLL-PEG) is employed to passivate glass coverslips and prevent non-specific adsorption of biomolecules and cells. Next, microcontact printing or dip pen lithography are used to create tracks of streptavidin on the passivated surfaces to serve as anchoring points for the biotinylated peptide arginine-glycine-aspartic acid (RGD) as the adhesive cue. A microfluidic device is placed onto the modified surface and used to create the gradient of adhesive cues (100% RGD to 0% RGD) on the streptavidin tracks. Finally, the same microfluidic device is used to create a gradient of a chemoattractant such as fetal bovine serum (FBS), as the soluble cue in the opposite direction of the gradient of adhesive cues.

A method for the assembly of adhesive and soluble gradients in a microscopy chamber for live cell migration studies is described. The engineered environment combines antifouling surfaces and adhesive tracks with solution gradients and therefore allows one to determine the relative importance of guidance cues.

蛍光顕微鏡を用いたイメージング細胞遊走用接着剤及び可溶性グラデーションを作成する

Cells can sense and migrate towards higher concentrations of adhesive cues such as the glycoproteins of the extracellular matrix and soluble cues such as ...

Engineering 3D Cellularized Collagen Gels for Vascular Tissue Regeneration

Synthetic materials are known to initiate clinical complications such as inflammation, stenosis, and infections when implanted as vascular substitutes. Collagen has been extensively used for a wide range of biomedical applications and is considered a valid alternative to synthetic materials due to its inherent biocompatibility (i.e., low antigenicity, inflammation, and cytotoxic responses). However, the limited mechanical properties and the related low hand-ability of collagen gels have hampered their use as scaffold materials for vascular tissue engineering. Therefore, the rationale behind this work was first to engineer cellularized collagen gels into a tubular-shaped geometry and second to enhance smooth muscle cells driven reorganization of collagen matrix to obtain tissues stiff enough to be handled.
The strategy described here is based on the direct assembling of collagen and smooth muscle cells (construct) in a 3D cylindrical geometry with the use of a molding technique. This process requires a maturation period, during which the constructs are cultured in a bioreactor under static conditions (without applied external dynamic mechanical constraints) for 1 or 2 weeks. The &#8220;static bioreactor&#8221; provides a monitored and controlled sterile environment (pH, temperature, gas exchange, nutrient supply and waste removal) to the constructs. During culture period, thickness measurements were performed to evaluate the cells-driven remodeling of the collagen matrix, and glucose consumption and lactate production rates were measured to monitor the cells metabolic activity. Finally, mechanical and viscoelastic properties were assessed for the resulting tubular constructs. To this end, specific protocols and a focused know-how (manipulation, gripping, working in hydrated environment, and so on) were developed to characterize the engineered tissues.

In this work, we present a technique for the rapid fabrication of living vascular tissues by direct culturing of collagen, smooth muscle cells and endothelial cells. In addition, a new protocol for the mechanical characterization of engineered vascular tissues is described.

エンジニアリング3D細胞化血管組織再生のためのコラーゲンゲル

Synthetic materials are known to initiate clinical complications such as inflammation, stenosis, and infections when implanted as vascular substitutes. ...

Design and Construction of Artificial Extracellular Matrix (aECM) Proteins from Escherichia coli for Skin Tissue Engineering

Recombinant technology is a versatile platform to create novel artificial proteins with tunable properties. For the last decade, many artificial proteins that have incorporated functional domains derived from nature (or created de novo) have been reported. In particular, artificial extracellular matrix (aECM) proteins have been developed; these aECM proteins consist of biological domains taken from fibronectin, laminins and collagens and are combined with structural domains including elastin-like repeats, silk and collagen repeats. To date, aECM proteins have been widely investigated for applications in tissue engineering and wound repair. Recently, Tjin and coworkers developed integrin-specific aECM proteins designed for promoting human skin keratinocyte attachment and propagation. In their work, the aECM proteins incorporate cell binding domains taken from fibronectin, laminin-5 and collagen IV, as well as flanking elastin-like repeats. They demonstrated that the aECM proteins developed in their work were promising candidates for use as substrates in artificial skin. Here, we outline the design and construction of such aECM proteins as well as their purification process using the thermo-responsive characteristics of elastin.

Design and Construction of Artificial Extracellular Matrix aECM Proteins from Escherichia coli for Skin Tissue Engineering

Recombinant technologies have enabled material designers to create novel artificial proteins with customized functionalities for tissue engineering applications. For example, artificial extracellular matrix proteins can be designed to incorporate structural and biological domains derived from native ECMs. Here, we describe the construction and purification of aECM proteins containing elastin-like repeats.

人工細胞外マトリックス（AECM）タンパク質からの設計と構築<em&gt;エシェリヒア·コリ</em&gt;皮膚組織工学のための

Recombinant technology is a versatile platform to create novel artificial proteins with tunable properties. For the last decade, many artificial proteins ...

A Microfluidic Platform for High-throughput Single-cell Isolation and Culture

Studying the heterogeneity of single cells is crucial for many biological questions, but is technically difficult. Thus, there is a need for a simple, yet high-throughput, method to perform single-cell culture experiments. Here, we report a microfluidic chip-based strategy for high-efficiency single-cell isolation (~77%) and demonstrate its capability of performing long-term single-cell culture (up to 7 d) and cellular heterogeneity analysis using clonogenic assay. These applications were demonstrated with KT98 mouse neural stem cells, and A549 and MDA-MB-435 human cancer cells. High single-cell isolation efficiency and long-term culture capability are achieved by using different sizes of microwells on the top and bottom of the microfluidic channel. The small microwell array is designed for precisely isolating single-cells, and the large microwell array is used for single-cell clonal culture in the microfluidic chip. This microfluidic platform constitutes an attractive approach for single-cell culture applications, due to its flexibility of adjustable cell culture spaces for different culture strategies, without decreasing isolation efficiency.

Here, we present a protocol for isolating and culturing single cells with a microfluidic platform, which utilizes a new microwell design concept to allow for high-efficiency single cell isolation and long-term clonal culture.

ハイスループットシングルセルの単離および培養のためのマイクロ流体プラットフォーム

Studying the heterogeneity of single cells is crucial for many biological questions, but is technically difficult. Thus, there is a need for a simple, yet ...

Isolation of Murine Adipose Tissue-derived Microvascular Fragments as Vascularization Units for Tissue Engineering

A functional microvascular network is of pivotal importance for the survival and integration of engineered tissue constructs. For this purpose, several angiogenic and prevascularization strategies have been established. However, most cell-based approaches include time-consuming in vitro steps for the formation of a microvascular network. Hence, they are not suitable for intraoperative one-step procedures. Adipose tissue-derived microvascular fragments (ad-MVF) represent promising vascularization units. They can be easily isolated from fat tissue and exhibit a functional microvessel morphology. Moreover, they rapidly reassemble into new microvascular networks after in vivo implantation. In addition, ad-MVF have been shown to induce lymphangiogenesis. Finally, they are a rich source of mesenchymal stem cells, which may further contribute to their high vascularization potential. In previous studies we have demonstrated the remarkable vascularization capacity of ad-MVF in engineered bone and skin substitutes. In the present study, we report on a standardized protocol for the enzymatic isolation of ad-MVF from murine fat tissue.

We present a protocol to isolate adipose tissue-derived microvascular fragments that represent promising vascularization units. They can be rapidly isolated, do not require in vitro processing and, thus, may be used for one-step prevascularization in different fields of tissue engineering.

組織工学のための血管新生単位としてマウスの脂肪組織由来の微小血管フラグメントの単離

A functional microvascular network is of pivotal importance for the survival and integration of engineered tissue constructs. For this purpose, several ...

Three-dimensional Tissue Engineered Aligned Astrocyte Networks to Recapitulate Developmental Mechanisms and Facilitate Nervous System Regeneration

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to replace lost neurons and regenerate axonal pathways. However, during nervous system development, neuronal migration and axonal extension often occur along pathways formed by other cells, referred to as &#34;living scaffolds&#34;. Seeking to emulate these mechanisms and to design a strategy that circumvents the inhibitory environment of the CNS, this manuscript presents a protocol to fabricate tissue engineered astrocyte-based &#34;living scaffolds&#34;. To create these constructs, we employed a novel biomaterial encasement scheme to induce astrocytes to self-assemble into dense three-dimensional bundles of bipolar longitudinally-aligned somata and processes. First, hollow hydrogel micro-columns were assembled, and the inner lumen was coated with collagen extracellular-matrix. Dissociated cerebral cortical astrocytes were then delivered into the lumen of the cylindrical micro-column and, at a critical inner diameter of &#60;350 &#181;m, spontaneously self-aligned and contracted to produce long fiber-like cables consisting of dense bundles of astrocyte processes and collagen fibrils measuring &#60;150 &#181;m in diameter yet extending several cm in length. These engineered living scaffolds exhibited &#62;97% cell viability and were virtually exclusively comprised of astrocytes expressing a combination of the intermediate filament proteins glial-fibrillary acidic protein (GFAP), vimentin, and nestin. These aligned astrocyte networks were found to provide a permissive substrate for neuronal attachment and aligned neurite extension. Moreover, these constructs maintain integrity and alignment when extracted from the hydrogel encasement, making them suitable for CNS implantation. These preformed constructs structurally emulate key cytoarchitectural elements of naturally occurring glial-based &#34;living scaffolds&#34; in vivo. As such, these engineered living scaffolds may serve as test-beds to study neurodevelopmental mechanisms in vitro or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding following CNS degeneration in vivo.

We showcase the development of self-assembled, three-dimensional bundles of longitudinally aligned astrocytic somata and processes within a novel biomaterial encasement. These engineered &#34;living scaffolds&#34;, exhibiting micron-scale diameter yet extending centimeters in length, may serve as test-beds to study neurodevelopmental mechanisms or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding.

三次元組織配置に発達メカニズムを要約し、神経系の再生を容易にするアストロ サイト ネットワーク

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to ...

Isolation of Mesenchymal Stem Cells from Human Alveolar Periosteum and Effects of Vitamin D on Osteogenic Activity of Periosteum-derived Cells

Mesenchymal stem cells (MSCs) are present in a variety of tissues and can be differentiated into numerous cell types, including osteoblasts. Among the dental sources of MSCs, the periosteum is an easily accessible tissue, which has been identified to contain MSCs in the cambium layer. However, this source has not yet been widely studied.
Vitamin D3 and 1,25-(OH)2D3 have been demonstrated to stimulate in vitro differentiation of MSCs into osteoblasts. In addition, vitamin C facilitates collagen formation and bone cell growth. However, no study has yet investigated the effects of Vitamin D3 and Vitamin C on MSCs.
Here, we present a method of isolating MSCs from human alveolar periosteum and examine the hypothesis that 1,25-(OH)2D3 may exert an osteoinductive effect on these cells. We also investigate the presence of MSCs in the human alveolar periosteum and assess stem cell adhesion and proliferation. To assess the ability of vitamin C (as a control) and various concentrations of 1,25-(OH)2D3 (10&#8722;10, 10&#8722;9, 10&#8722;8, and 10&#8722;7 M) to alter key mRNA biomarkers in isolated MSCs mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), core binding factor alpha-1 (CBFA1), collagen-1, and osteocalcin (OCN) are measured using real-time polymerase chain reaction (RT-PCR).

We present a protocol to investigate the mRNA expression biomarkers of periosteum-derived cells (PDCs) induced by vitamin C (vitamin C) and 1,25-dihydroxy vitamin D [1,25-(OH)2D3]. In addition, we evaluate the ability of PDCs to differentiate into osteocytes, chondrocytes, and adipocytes.

人間歯槽骨膜から骨膜由来細胞の骨形成促進活性に及ぼすビタミン D の間葉系幹細胞の分離

Mesenchymal stem cells (MSCs) are present in a variety of tissues and can be differentiated into numerous cell types, including osteoblasts. Among the ...

Wet-spinning-based Molding Process of Gelatin for Tissue Regeneration

This article presents an inexpensive method to fabricate gelatin, as a natural polymer, into monofilament fibers or other appropriate forms. Through the wet spinning method, gelatin fibers are produced by smooth extrusion in a suitable coagulation medium. To increase the functional surface of these gelatin fibers and their ability to mimic the features of tissues, gelatin can be molded into a tube form by referring to this concept. Examined by in vitro and in vivo tests, the gelatin tubes demonstrate a great potential for application in tissue engineering. Acting as a suitable filling gap material, gelatin tubes can be used to substitute the tissue in the damaged area (e.g., in the nervous or cardiovascular system), as well as to promote regeneration by providing a direct replacement of stem cells and neural circuitry. This protocol provides a detailed procedure for creating a biomaterial based on a natural polymer, and its implementation is expected to greatly benefit the development of correlative natural polymers, which help to realize tissue regeneration strategies.

We developed and describe a protocol based on the wet spinning concept, for the construction of gelatin-based biomaterials used for the application of tissue engineering.

組織再生用ゼラチンのウェット ベース回転成形プロセス

This article presents an inexpensive method to fabricate gelatin, as a natural polymer, into monofilament fibers or other appropriate forms. Through the ...