著者らは、貴重な援助のためにビョン哲リー、フィリップ崔とサミュエルHoを感謝したいと思います。この作業は、番号DE - AC02 - 05CH11231と国防脅威削減契約の下、米国エネルギー省の科学局によってサポートされているローレンスバークレー国立研究所、基礎エネルギー科学局、少なくとも分子ファウンドリーで実施された契約番号の下に代理店：IACRO - B0845281。

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我々は、開示することは何もない。

アプリケーションと意義 このプロトコルは、ペプトイド合成とナノシートへのペプトイドの水性自己組織化を簡単かつ効率的な方法を説明します。安価な材料、基本的な専門知識と簡単なテクニックは、4を利用しているので、ほとんどの研究室では合成ペプトイドの容易に可能である。同様に、超薄型、高秩序 ​​のナノシートの自己組織化は、単に希釈水溶液ペプトイドの溶液2の傾斜バイアルを繰り返す必要があります。彼らは堅牢で総合的に柔軟な、まだ5配列-特異的かつ高調整可能なので、ペプトイドは、生物医学およびナノサイエンス研究のための材料を約束してください。ペプトイドは、階層的ナノ構造3、11月14日に生物学的活性（治療6,7、診断8、細胞内デリバリー9-10）と折りたたみを実証している。そのモジュラー合成、コンビナトリアルペプトイドLIBRのため牡羊座15から19は、容易に合成され、活動またはプロパティの広範な一連のためにスクリーニングすることができる。特に、ナノシートは、2次元表示の足場、細胞膜模倣体、生物学的センサー、タンパク質の模倣体およびデバイス製造のための潜在的なプラットフォームとして機能する。可能な限り実質的に無尽蔵の別のシーケンスで、ペプトイド研究の領域は急速に拡大しています。 polypeptoidsの固相submonomer合成における変数 理由モノマー20の信じられないほど大規模かつ多様なアルファベットから選択する機能を、submonomerメソッドは、各ステップの結合効率を増加させると、全体的な製品の歩留まりを向上させるケースで、時折変更が必要。保護されていない複素環側鎖の取り込みは、クロロ酢酸の代わりにブロモ酢酸21を使用する必要があります。拡張変位倍と高いアミンの濃度は通常約20長いペプトイドシーケンスのためのカップリング、または以下の求核アミンの後に採用されている。 35に反応容器を加熱℃で、水ジャケット反応容器を使用して、反応を駆動するのに役立ちます。例えば、イソプロピルなどの揮発性の高いアミンの場合は、注意が蒸発を避けるように注意する必要があります。 例えば、t -ブチルβ-アラニンHClなどの塩酸塩の形態のアミンは、置換反応で導入される前にフリーベースである必要があります。これは、溶解または懸濁アミンをDCM（〜5グラムamine/25 mLのDCM）で、そして分液漏斗に水酸化ナトリウム水溶液のモル溶液を中和することによって達成することができます。 DCM層を集め、水層は、追加のDCMで洗浄する。複合DCM層を硫酸ナトリウムで乾燥し、事前に計量した丸底フラスコに濾過されています。油を得るためにロータリーエバポレーターにより溶媒を除去し、製品の重量を記録する。 ドゥリングラム切断ステップ、TFAの開裂のカクテルと切断時間は、使用される保護基の数と種類に依存しています。開裂のカクテルのためのガイドラインは、従来のペプチドの脱保護の切断を1に似ています。一般的に、10分のインキュベーションはいくつかの非常に酸に不安定な保護基（例えばBOC、トリチル）でグループまたはシーケンスを保護せずにシーケンスに必要です。 2時間のインキュベーションは、より困難な保護基（例えば、t -ブチルエステル、MTR、PBF）とシーケンスまたは各チェーンの完全な脱保護を確保するために多くの保護基を持つシーケンスを推奨します。原油ペプトイド製品は、一般的にアセトニトリルに溶解するであろう：水1:1（v / v）の、しかしより高いアセトニトリルの割合が高く、全体の疎水性側鎖と共通です。

<table border="1"><tbody><tr><td> 試薬の名前 </td><td> 会社 </td><td> カタログ番号 </td><td> コメント </td></tr><tr><td>ジメチルホルムアミド</td><td> EMD </td><td> EM - DX1726P - 1 </td><td> 99 +％ </td></tr><tr><td> N -メチルピロリジノン</td><td> BDH </td><td> BDH1141 - 4LP </td><td> 99パーセント</td></tr><tr><td>ブロモ酢酸</td><td>アクロスオーガニック</td><td> 200000-106 </td><td> 99パーセント</td></tr><tr><td> 4 - メチルピペリジン</td><td>シグマアルドリッチ</td><td> M73206 </td><td> 96パーセント</td></tr><tr><td> N、N&#39; -ジイソプロピルカルボジイミド</td><td>化学 - IMPEX </td><td> 001100 </td><td> 99.5パーセント</td></tr><tr><td>ジクロロメタン</td><td> EMD </td><td> EMD - DX0835 </td><td> ACSグレード</td></tr><tr><td>アセトニトリル</td><td> EMD </td><td> EM - AX0145P - 1 </td><td> 99.8パーセント</td></tr><tr><td>トリフルオロ酢酸</td><td>シグマアルドリッチ</td><td> T6508 </td><td> 99パーセント</td></tr><tr><td>トリイソプロピルシラン</td><td>シグマアルドリッチ</td><td> 233781 -10G </td><td> TFA開裂のための</td></tr><tr><td> 1,2 - ジクロロエタン</td><td> JTベーカー</td><td> JTH076 - 33 </td><td>ガラス製反応容器のシリコーンのための</td></tr><tr><td>フェネチルアミン</td><td>シグマアルドリッチ</td><td> 407267 - 100ML </td><td> &gt; 99.5％の疎水性側鎖アミン</td></tr><tr><td> BOC - エチレンジアミン</td><td> CNHテクノロジーズ</td><td> C - 1112 </td><td>カチオン性側鎖アミン</td></tr><tr><td> t -ブチルβ-アラニン塩酸</td><td>化学 - IMPEXインターナショナル</td><td> 04407 </td><td>陰イオン性側鎖アミン</td></tr><tr><td> α-シアノ-4 - ヒドロキシ桂皮酸</td><td>シグマアルドリッチ</td><td> C8982 - 10X10MG </td><td> MALDIマトリックスのための</td></tr><tr><td>ナイルレッド</td><td>シグマアルドリッチ</td><td> 19123 - 10mgの</td><td>蛍光イメージングのための</td></tr><tr><td>ジクロロジメチルシラン</td><td>シグマアルドリッチ</td><td> 80430 - 500G - F </td><td>ガラス製反応容器のシリコーンのための</td></tr><tr><td>使い捨てPPフリットカート尾根</td><td>適用された分離</td><td> 2416 </td><td> 20ミリメートルPEフリットと6 mLのポリプロピレンカートリッジ</td></tr><tr><td>使い捨ての3ウェイルアーアダプター</td><td>コー​​ルパーマー</td><td> 31200〜80 </td><td>使い捨て手動合成反応容器用栓</td></tr><tr><td>ルアーロックリング</td><td>コー​​ルパーマー</td><td> 45503〜19 </td><td>使い捨て手動合成反応容器の¼&quot;フィッティング</td></tr><tr><td>ルアーフィッティング</td><td>コー​​ルパーマー</td><td> 45500〜20 </td><td>使い捨て手動合成反応容器の¼&quot;フィッティング</td></tr><tr><td>使い捨てPPピペット</td><td> VWR </td><td> 16001-194 </td><td> TFA転送のための</td></tr><tr><td>ルアーロックのプラスチック注射器</td><td>国立科学</td><td> S7515 - 5 </td><td> 6 mLのシリンジ</td></tr><tr><td> 1 DRAMのガラスバイアル</td><td> VWR </td><td> 66011-041 </td><td>ポリビニル顔のパルプライナー付きフェノール成形スクリューキャップ付き</td></tr><tr><td> 20 mLのSCINtillationバイアル</td><td> VWR </td><td> 66022-060 </td><td>付属のPPキャップパルプ箔ライナー付き</td></tr><tr><td>セキュアシールの接着剤のスペーサー</td><td>インビトロジェン</td><td> S - 24736 </td><td>蛍光イメージングのための</td></tr><tr><td>スライドガラス</td><td>電子顕微鏡学</td><td> 63411 </td><td>蛍光イメージングのための</td></tr><tr><td>スリップカバー</td><td> VWR </td><td> 48366-067 </td><td>蛍光イメージングのための</td></tr><tr><td> 4&quot;シリコンウェーハ</td><td>テッドペラ</td><td> 16007 </td><td> 5 × 7 mmのチップでプレサイコロ</td></tr><tr><td> 0.45フィルタ</td><td> VWR、アクロディスク</td><td> 28143-924 </td><td> HPLC用。 PTFEメンブレン</td></tr><tr><td>アガロース</td><td> BD </td><td> 212272 </td><td>蛍光イメージングのための</td></tr><tr><td> SPE吸引マニホールド</td><td>シグマアルドリッチ</td><td> 57044 </td><td> SPE吸引マニホールドの例</td></tr><tr><td>フリットガラス容器</td><td>エースガラス</td><td> 6402〜12 </td><td>空隙率Cフリット</td></tr><tr><td>プラズマクリーナー/滅菌</td><td> Harrickプラズマ</td><td> PDC - 32G </td><td> SEM用シリコンチップを準備するためにプラズマクリーナーの例</td></tr></tbody></table>

solid-phase submonomer synthesis of peptoid polymers and their self-assembly into highly-ordered nanosheets

ペプトイドは、より高次のナノ構造への新たなバイオミメティック、非天然、のクラスの配列特異的タンパク質分解に抵抗heteropolymers、強力な生物学的活性を示す、と倍です。ペプチドと構造的に類似した、ペプトイドは、側鎖がα-炭素ではなく窒素に接続されているポリN -置換グリシン、です。合成と構造の多様性の容易さは、基本的な設計原則のテストは新たな生物学的活性とナノ構造物質のde novo設計とエンジニアリングを駆動することができます。 ここで、簡単なマニュアルペプトイド合成プロトコルは、優れた収率で長鎖polypeptoidsの合成（最大50mersまで）できるようにその表示されます。唯一の基本的な設備、簡単なテクニック（例えば、液体の転送、ろ過）、および市販の試薬は、ペプトイド多くの研究者のツールキットにアクセスできるだけでなくなり、要求される。ペプトイドバックボーンは、一度vで一つのモノマーを成長させ、アシル化および変位：二段モノマー添加のサイクルで構成されてsubmonomerメソッドをアイオワ。 Nとその場でアクティブに最初に、ブロモ酢酸、N&#39; -ジイソプロピルカルボジイミド、樹脂結合型二級アミンをアシル。第一級アミンによる臭化第二に、求核置換は、側鎖を導入するに従います。目的の鎖長に到達するまで二段階のサイクルが繰り返されます。この二段階サイクルの結合効率は、日常的に98％を超え、50残基限り、ペプトイドの合成が可能になります。非常に、調整可能な精密かつ化学的に多様な配列が容易に利用できる第一級アミンの何百ものとしてsubmonomerの方法で達成可能です直接組み込むことができます。 ペプトイドため、その合成柔軟性、堅牢性のnanobioscience研究のための多目的なバイオミメティック材料として浮上し、及び原子レベルで発注されています。単鎖、両親媒性、情の折り畳み高秩序ナノシートに組み込んでリッチなpolypeptoidが最近実証された。このペプトイドは、3つの異なる市販のモノマーから構成される36 - merのです：疎水性、カチオン性及びアニオン性。イオン性アミンとカルボキシル側鎖は親水性の面で揃えるのに対して、疎水性のフェニルエチル側鎖は、ナノシートのコアに埋め込まれている。ペプトイドナノシートは、膜の模倣物、タンパク質の模倣体、デバイスの製造、およびセンサーのための潜在的なプラットフォームとして機能する。ペプトイド合成、シートの形成、および顕微鏡イメージングのための方法を説明し、将来のペプトイドナノシートのデザインを可能にする簡単な方法を提供している。

Watch this Scientific Journal Video about Solid-phase Submonomer Synthesis of Peptoid Polymers and their Self-Assembly into Highly-Ordered Nanosheets at JoVE.com

Solid-phase Submonomer Synthesis of Peptoid Polymers and their Self-Assembly into Highly-Ordered Nanosheets

基本的な機器と市販の試薬を含む単純で一般的なマニュアルペプトイド合成法は、簡単に多くのラボで合成されるペプトイドを可能にする、概説されています。両親媒性ペプトイドの36merの合成、精製および特徴は、同様に高秩序のナノシートに、その自己組織化として、記述されています。

高秩序のナノシートにペプトイドポリマーおよびそれらの自己組織化の固相Submonomer合成

Peptoids are a novel class of biomimetic, non-natural, sequence-specific heteropolymers that resist proteolysis, exhibit potent biological activity, and ...

solid-phase-submonomer-synthesis-peptoid-polymers-their-self-assembly

Research

JoVE Journal

Bioengineering

29.1K ビュー.  Lawrence Berkeley National Laboratory. 基本的な機器と市販の試薬を含む単純で一般的なマニュアルペプトイド合成法は、簡単に多くのラボで合成されるペプトイドを可能にする、概説されています。両親媒性ペプトイドの36merの合成、精製および特徴は、同様に高秩序のナノシートに、その自己組織化として、記述されています。

ビデオ: Solid-phase Submonomer Synthesis of Peptoid Polymers and their Self-Assembly into Highly-Ordered Nanosheets

Shape Memory Polymers for Active Cell Culture

Shape memory polymers (SMPs) are a class of "smart" materials that have the ability to change from a fixed, temporary shape to a pre-determined permanent shape upon the application of a stimulus such as heat1-5. In a typical shape memory cycle, the SMP is first deformed at an elevated temperature that is higher than its transition temperature, Ttrans [either the melting temperature (Tm) or the glass transition temperature (Tg)]. The deformation is elastic in nature and mainly leads to a reduction in conformational entropy of the constituent network chains (following the rubber elasticity theory). The deformed SMP is then cooled to a temperature below its Ttrans while maintaining the external strain or stress constant. During cooling, the material transitions to a more rigid state (semi-crystalline or glassy), which kinetically traps or "freezes" the material in this low-entropy state leading to macroscopic shape fixing. Shape recovery is triggered by continuously heating the material through Ttrans under a stress-free (unconstrained) condition. By allowing the network chains (with regained mobility) to relax to their thermodynamically favored, maximal-entropy state, the material changes from the temporary shape to the permanent shape.
Cells are capable of surveying the mechanical properties of their surrounding environment6. The mechanisms through which mechanical interactions between cells and their physical environment control cell behavior are areas of active research. Substrates of defined topography have emerged as powerful tools in the investigation of these mechanisms. Mesoscale, microscale, and nanoscale patterns of substrate topography have been shown to direct cell alignment, cell adhesion, and cell traction forces7-14. These findings have underscored the potential for substrate topography to control and assay the mechanical interactions between cells and their physical environment during cell culture, but the substrates used to date have generally been passive and could not be programmed to change significantly during culture. This physical stasis has limited the potential of topographic substrates to control cells in culture.
Here, active cell culture (ACC) SMP substrates are introduced that employ surface shape memory to provide programmed control of substrate topography and deformation. These substrates demonstrate the ability to transition from a temporary grooved topography to a second, nearly flat memorized topography. This change in topography can be used to control cell behavior under standard cell culture conditions.

A method for developing cell culture substrates with the ability to change topography during culture is described. The method makes use of smart materials known as shape memory polymers that have the ability to memorize a permanent shape. This concept is adaptable to a wide range of materials and applications.

アクティブな細胞培養のための形状記憶ポリマー

Shape memory polymers (SMPs) are a class of "smart" materials that have the ability to change from a fixed, temporary shape to a pre-determined permanent ...

生物工学

Directed Cellular Self-Assembly to Fabricate Cell-Derived Tissue Rings for Biomechanical Analysis and Tissue Engineering

Each year, hundreds of thousands of patients undergo coronary artery bypass surgery in the United States.1 Approximately one third of these patients do not have suitable autologous donor vessels due to disease progression or previous harvest. The aim of vascular tissue engineering is to develop a suitable alternative source for these bypass grafts. In addition, engineered vascular tissue may prove valuable as living vascular models to study cardiovascular diseases. Several promising approaches to engineering blood vessels have been explored, with many recent studies focusing on development and analysis of cell-based methods.2-5 Herein, we present a method to rapidly self-assemble cells into 3D tissue rings that can be used in vitro to model vascular tissues.
To do this, suspensions of smooth muscle cells are seeded into round-bottomed annular agarose wells. The non-adhesive properties of the agarose allow the cells to settle, aggregate and contract around a post at the center of the well to form a cohesive tissue ring.6,7 These rings can be cultured for several days prior to harvesting for mechanical, physiological, biochemical, or histological analysis. We have shown that these cell-derived tissue rings yield at 100-500 kPa ultimate tensile strength8 which exceeds the value reported for other tissue engineered vascular constructs cultured for similar durations (&lt;30 kPa).9,10 Our results demonstrate that robust cell-derived vascular tissue ring generation can be achieved within a short time period, and offers the opportunity for direct and quantitative assessment of the contributions of cells and cell-derived matrix (CDM) to vascular tissue structure and function.

This article outlines a versatile method to create cell-derived tissue rings by cellular self-assembly. Smooth muscle cells seeded into ring-shaped agarose wells aggregate and contract to form robust three-dimensional (3D) tissues within 7 days. Millimeter-scale tissue rings are conducive to mechanical testing and serve as building blocks for tissue assembly.

生体力学的解析と組織工学のための細胞由来の組織のリングを製作する監督セルラーセルフアセンブリ

Each year, hundreds of thousands of patients undergo coronary artery bypass surgery in the United States.1 Approximately one third of these patients do ...

Optical Control of Living Cells Electrical Activity by Conjugated Polymers

Hybrid interfaces between organic semiconductors and living tissues represent a new tool for in-vitro and in-vivo applications. In particular, conjugated polymers display several optimal properties as substrates for biological systems, such as good biocompatibility, excellent mechanical properties, cheap and easy processing technology, and possibility of deposition on light, thin and flexible substrates. These materials have been employed for cellular interfaces like neural probes, transistors for excitation and recording of neural activity, biosensors and actuators for drug release. Recent experiments have also demonstrated the possibility to use conjugated polymers for all-optical modulation of the electrical activity of cells. Several in-vitro study cases have been reported, including primary neuronal networks, astrocytes and secondary line cells. Moreover, signal photo-transduction mediated by organic polymers has been shown to restore light sensitivity in degenerated retinas, suggesting that these devices may be used for artificial retinal prosthesis in the future. All in all, light sensitive conjugated polymers represent a new approach for optical modulation of cellular activity.
In this work, all the steps required to fabricate a bio-polymer interface for optical excitation of living cells are described. The function of the active interface is to transduce the light stimulus into a modulation of the cell membrane potential. As a study case, useful for in-vitro studies, a polythiophene thin film is used as the functional, light absorbing layer, and Human Embryonic Kidney (HEK-293) cells are employed as the biological component of the interface. Practical examples of successful control of the cell membrane potential upon stimulation with light pulses of different duration are provided. In particular, it is shown that both depolarizing and hyperpolarizing effects on the cell membrane can be achieved depending on the duration of the light stimulus. The reported protocol is of general validity and can be straightforwardly extended to other biological preparations.

A method for stimulation of in-vitro cell cultures electrical activity with visible light, based on the use of organic semiconducting polymers is described.

生細胞共役ポリマーにより電気的活動の光制御

Hybrid interfaces between organic semiconductors and living tissues represent a new tool for in-vitro and in-vivo applications. In particular, conjugated ...

Fabrication of a Dipole-assisted Solid Phase Extraction Microchip for Trace Metal Analysis in Water Samples

This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water samples. A brief overview of the evolution of chip-based SPE techniques is provided. This is followed by an introduction to specific polymeric materials and their role in SPE. To develop an innovative dipole-assisted SPE technique, a chlorine (Cl)-containing SPE functionality was implanted into a poly(methyl methacrylate) (PMMA) microchip. Herein, diverse analytical techniques including contact angle analysis, Raman spectroscopic analysis, and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis were employed to validate the utility of the implantation protocol of the C-Cl moieties on the PMMA. The analytical results of the X-ray absorption near-edge structure (XANES) analysis also demonstrated the feasibility of the Cl-containing PMMA used as an extraction medium by virtue of the dipole-ion interactions between the highly electronegative C-Cl moieties and the positively charged metal ions.

The fabrication protocol of a dipole-assisted solid phase extraction microchip for the trace metal analysis is presented.

水試料中の微量金属分析のためのダイポールアシスト固相抽出マイクロチップの作製

This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water ...

Synthesis of Gold Nanoparticle Integrated Photo-responsive Liposomes and Measurement of Their Microbubble Cavitation upon Pulse Laser Excitation

Photo-responsive nanoparticles (NPs) have received considerable attention because of their potential in providing spatial, temporal, and dosage control over the drug release. However, most of the relevant technologies are still in the development process and are unprocurable by clinics. Here, we describe a facile fabrication of these photo-responsive NPs with commercially available gold NPs and thermo-responsive liposomes. Calcein is used as a model drug to evaluate the encapsulation efficiency and the release kinetic profile upon heat/light stimulation. Finally, we show that this photo-triggered release is due to the membrane disruption caused by microbubble cavitation, which can be measured with hydrophone.

This protocol describes a simple preparation method for gold nanoparticle integrated photo-responsive liposomes with the commercially available materials. It also shows how to measure the microbubble cavitation process of the synthesized liposomes upon the treatment of pulsed laser.

パルスレーザー励起時の金ナノ粒子の統合フォト応答性リポソームとそのマイクロバブルキャビテーションの測定の合成

Photo-responsive nanoparticles (NPs) have received considerable attention because of their potential in providing spatial, temporal, and dosage control ...

High-throughput Identification of Bacteria Repellent Polymers for Medical Devices

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as contributing to antimicrobial resistance. One possible avenue for the reduction of device-associated infections is the identification of bacteria-repellent polymer coatings for these devices, which would prevent bacterial binding at the initial attachment step. A method for the identification of such repellent polymers, based on the parallel screening of hundreds of polymers using a microarray, is described here. This high-throughput method resulted in the identification of a range of promising polymers that resisted binding of various clinically relevant bacterial species individually and also as multi-species communities. One polymer, PA13 (poly(methylmethacrylate-co-dimethylacrylamide)), demonstrated significant reduction in attachment of a number of hospital isolates when coated onto two commercially available central venous catheters. The method described could be applied to identify polymers for a wide range of applications in which modification of bacterial attachment is important.

A high-throughput microarray method for the identification of polymers which reduce bacterial surface binding on medical devices is described.

医療機器のための細菌撥ポリマーのハイスループット同定

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as ...

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

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

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

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

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

Aqueous Droplets Used as Enzymatic Microreactors and Their Electromagnetic Actuation

For the successful implementation of microfluidic reaction systems, such as PCR and electrophoresis, the movement of small liquid volumes is essential. In conventional lab-on-a-chip-platforms, solvents and samples are passed through defined microfluidic channels with complex flow control installations. The droplet actuation platform presented here is a promising alternative. With it, it is possible to move a liquid drop (microreactor) on a planar surface of a reaction platform (lab-in-a-drop). The actuation of microreactors on the hydrophobic surface of the platform is based on the use of magnetic forces acting on the outer shell of the liquid drops which is made of a thin layer of superhydrophobic magnetite particles. The hydrophobic surface of the platform is needed to avoid any contact between the liquid core and the surface to allow a smooth movement of the microreactor. On the platform, one or more microreactors with volumes of 10 &#181;L can be positioned and moved simultaneously. The platform itself consists of a 3 x 3 matrix of electrical double coils which accommodate either neodymium or iron cores. The magnetic field gradients are automatically controlled. By variation of the magnetic field gradients, the microreactors' magnetic hydrophobic shell can be manipulated automatically to move the microreactor or open the shell reversibly. Reactions of substrates and corresponding enzymes can be initiated by merging the microreactors or bringing them into contact with surface immobilized catalysts.

Lab-in-a-drop reaction systems allow the versatile implementation of complex reactions in a microfluidic scale. An automated actuation platform consisting of a 3 x 3 matrix of electromagnetic coils was developed and successfully used to merge two 10 &#181;L microreactors and thereby initiate an enzymatic reaction in the resulting liquid marbles.

マイクロリアクター及び、電磁作動に水滴が酵素として使用

For the successful implementation of microfluidic reaction systems, such as PCR and electrophoresis, the movement of small liquid volumes is essential. In ...

Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells

Many important biomedical applications, such as cell imaging and remote manipulation, can be achieved by labeling cells with superparamagnetic iron oxide nanoparticles (SPIONs). Achieving sufficient cellular uptake of SPIONs is a challenge that has traditionally been met by exposing cells to elevated concentrations of SPIONs or by prolonging exposure times (up to 72 hr). However, these strategies are likely to mediate toxicity. Here, we present the synthesis of the protein-based SPION magnetoferritin as well as a facile surface functionalization protocol that enables rapid cell magnetization using low exposure concentrations. The SPION core of magnetoferritin consists of cobalt-doped iron oxide with an average particle diameter of 8.2 nm mineralized inside the cavity of horse spleen apo-ferritin. Chemical cationization of magnetoferritin produced a novel, highly membrane-active SPION that magnetized human mesenchymal stem cells (hMSCs) using incubation times as short as one minute and iron concentrations as lows as 0.2 mM.

A protocol for the synthesis and cationization of cobalt-doped magnetoferritin is presented, as well as a method to rapidly magnetize stem cells with cationized magnetoferritin.

細胞の超高速磁化のためのカチオン化Magnetoferritinの合成

Many important biomedical applications, such as cell imaging and remote manipulation, can be achieved by labeling cells with superparamagnetic iron oxide ...

Engineering Molecular Recognition with Bio-mimetic Polymers on Single Walled Carbon Nanotubes

Semiconducting single-wall carbon nanotubes (SWNTs) are a class of optically active nanomaterial that fluoresce in the near infrared, coinciding with the optical window where biological samples are most transparent. Here, we outline techniques to adsorb amphiphilic polymers and polynucleic acids onto the surface of SWNTs to engineer their corona phases and create novel molecular sensors for small molecules and proteins. These functionalized SWNT sensors are both biocompatible and stable. Polymers are adsorbed onto the nanotube surface either by direct sonication of SWNTs and polymer or by suspending SWNTs using a surfactant followed by dialysis with polymer. The fluorescence emission, stability, and response of these sensors to target analytes are confirmed using absorbance and near-infrared fluorescence spectroscopy. Furthermore, we demonstrate surface immobilization of the sensors onto glass slides to enable single-molecule fluorescence microscopy to characterize polymer adsorption and analyte binding kinetics.

We present a protocol for engineering the corona phase of near infrared fluorescent single walled carbon nanotubes (SWNTs) using amphiphilic polymers and DNA to develop sensors for molecular targets without known recognition elements.

単層カーボンナノチューブ上のバイオミメティックポリマーとエンジニアリング分子認識

Semiconducting single-wall carbon nanotubes (SWNTs) are a class of optically active nanomaterial that fluoresce in the near infrared, coinciding with the ...