親水性コーティングのためのグリアジンシアノアクリレートナノ粒子の製造のためのプロトコル
Summary
This article presents a protocol for the production of protein-based nanoparticles that changes the hydrophobic surface to hydrophilic. The produced nanoparticle is an assembly of gliadin-cyanoacrylate diblock copolymers. Spray coating with the produced nanoparticle changes the surface of target material to a hydrophilic surface.
Abstract
この記事では、単純なスプレーコーティングによって親水性に疎水性表面を変化させるタンパク質ベースのナノ粒子の製造のためのプロトコルを提示します。これらのナノ粒子は、穀物タンパク質（グリアジン）分子の表面上のアルキルシアノアクリレートの重合反応によって製造されます。アルキルシアノアクリレートは、それが材料の表面に適用した場合、即座に、室温で重合する単量体です。その重合反応は、水分を含む表面上に、弱塩基性または求核性種の微量によって開始されます。重合後ニトリル基は、ポリ（アルキルシアノアクリレート）のバックボーンにあるため、重合アルキルシアノアクリレートは、対象物質と強い親和性を示します。彼らはシアノアクリレートの重合を開始することができるアミン基を含有するためのタンパク質はまた、この重合のための開始剤として働きます。凝集タンパク質を開始剤として使用される場合、タンパク質凝集体は、疎水性で囲まれていますアルキルシアノアクリレートの重合反応後のポリ（アルキルシアノアクリレート）鎖。実験条件を制御することにより、ナノメートル範囲の粒子が生成されます。製造されたナノ粒子は、容易にガラス、金属、プラスチック、木材、皮革、及び織物を含むほとんどの物質の表面に吸着します。材料の表面を製造ナノ粒子懸濁液を噴霧し、水でリンスされた場合、ナノ粒子のミセル構造は、コンフォメーションが変化し、親水性タンパク質は、空気にさらされています。その結果、ナノ粒子コーティングされた表面は、親水性に変化します。
Introduction
The goal of this article is to show the protocol for the preparation of nanoparticle suspension that modifies the wetting property of materials by a simple spray. The presented nanoparticle suspension is made from alkyl cyanoacrylate1 and a cereal protein, gliadin2,3. During the manufacturing process, protein aggregates are formed in aqueous ethanol4. Subsequent reaction with monomer (alkyl cyanoacrylate) produces the nanoparticle that is comprised of a protein core surrounded by linear polymer chains [poly(alkyl cyanoacrylate)]5.
Poly(alkyl cyanoacrylate)s are biodegradable and have been used for the production of nanoparticles via emulsion polymerization6. This reaction is spontaneously initiated by the hydroxyl groups dissociated from water or by other nucleophilic groups in the reaction medium7. In the case of the reaction presented in this article, the amine groups on the surface of protein aggregates initiate the polymerization reaction of alkyl cyanoacrylate monomers5,8. As a result of this reaction, nanoparticles are formed in the reaction medium. The core of the nanoparticle is protein aggregates and the outer layer is poly(alkyl cyanoacrylate) (PACA) chains. The prepared nanoparticle has a strong affinity on most materials (more precisely, any material which PACA can adsorb to) and adheres onto their surface to form a thin coating on a nanometer scale. A simple spray coating instantly turns the surface of the materials hydrophilic.
Gliadin is one of the main fractions of gluten, which is in the endosperms of wheat. Gliadins are mainly monomeric proteins with molecular weights around 28,000 – 55,000. Non-covalent bonds such as hydrogen bonds, ionic bonds and hydrophobic bonds are responsible for the aggregation of gliadins2. Although gliadin is chosen as a reactant in this article, many other proteins can also be used for the same purpose. However, the reaction condition needs to be modified accordingly because the condition for inducing aggregation is dependent on the type of protein to be employed8. Compared with other proteins, gliadin is more readily available, purification is simple, and production cost is low. Although ethyl cyanoacrylate (ECA) is chosen as a monomer for the presented reaction, other alkyl cyanoacrylates can also be used for the same reaction. The reason for choosing ECA is that it is readily available at low cost.
Protocol
Representative Results
Discussion
There are several critical steps in the production of the nanoparticle suspension. If the purified gliadin contains impurities, the reaction with ECA will produce side products. Although these unwanted products can be removed from the reaction medium during the centrifugation stage, it lowers the yield of the major product. If the gliadin solution prepared during experimental step 2.3) does not show clear separation between supernatant and precipitate after two days, the solution needs to stand for longer time. Using fre…
Offenlegungen
The authors have nothing to disclose.
Acknowledgements
専門家の技術支援のための氏ジェイソン・アドキンスに感謝します。
Materials
| Ethyl cyanoacrylate (ECA) monomer | K&R International (Laguna Niguel, CA) | I-1605 | Any pure ECA can be used. |
| Gliadin | MGP Ingredients, Inc (Atchison, KS) | Gift from the company | Gliadin can be purchased from Sigma-Aldrich (cat #: G3375-25G). Instead of gliadin, any commercial gluten can be used. |
| HCl | Any | Any reagent grade chemical can be used. | |
| Acetone | Any | Any reagent grade chemical can be used. | |
| Methanol | Any | Any reagent grade chemical can be used. | |
| Ethanol (100%) | Any | Any reagent grade chemical can be used. | |
| Filter paper | Any | Any grade filter paper larger than 10 cm can be used. | |
| Cell culture square dish | Any | Any dish larger than 20 cm x 20 cm can be used. | |
| Coffee grinder | Any | Any coffee grinder can be used. | |
| Rotary evaporator | Any | Any rotary evaporator can be used. | |
| Freeze Dryer | Any | Any freeze dryer that can reach – 70°C can be used. | |
| Centrifuge | Any | Any centrifuge that can apply 1000 x g can be used. | |
| Magnetic stirrer | Any | Any magnetic stirrer that can turn spin bar to 1000 RPM can be used. | |
| Dynamic Light Scattering (DLS) | Brookhaven Instruments Corporation | NanoBrook Omni Zeta Potential Analyzer | DLS from any company can be used. |
| Scanning Electron Microscope (SEM) | Carl Zeiss Inc. | Any SEM can be used. | |
| Dynamic Contact Angle (DCA) | Thermo Cahn Instruments | Any DCA can be used. |
Referenzen
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