半フッ素化ジャヌス型デンドリマーでデンドロニズされたポリマーから組み立てられた自己組織性の膀状柱は,逆熱アクチュエータとして作用する
Virgil Percec1, Mohammad R Imam, Mihai Peterca
1Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA. percec@sas.upenn.edu
Journal of the American Chemical Society
|February 7, 2012
まとめ
研究者らは,ジャヌス・デンドリマーを使って新しいポリマーを合成し,ユニークな膀状の柱状構造を生み出しました. これらのポリマーは,逆熱アクチュエータとして機能し,加熱すると短縮します.
科学分野:
- ポリマー化学のポリマー化学について
- 超分子化学 超分子化学
- マテリアルサイエンス 材料科学
背景:
- ジャヌス・デンドリマー (Janus dendrimers) は,機能的に異なる末端を持つ分子であり,独自の自己組み立て特性を有しています.
- デンドロニゼーションされたポリマーは,ポリマーの骨格にデンドリート構造を組み込み,材料の性質に影響を与えます.
- デンドロニズドポリマーの構造を制御することは,高度な機能性材料の設計の鍵です.
研究 の 目的:
- 自己組み立てのジャヌス型デンドリマーでデンドロニズされたポリマーを合成し,構造的に特徴づける.
- セルフアセンブリメカニズムと,その結果生じる超分子構造を調査する.
- これらの新種のデンドロニズドポリマーの熱的アクチュエーション行動を調査するために.
主な方法:
- ジャヌス・デンドリマーの合成と,ポリマーの骨格への結合.
- 微分スキャニング熱計 (DSC) とX線微分法 (XRD) を用いた構造分析.
- 超分子組織を解明するために電子密度マッピング.
主要な成果:
- ハイドロゲンとフッ素の両端から付着したヤヌス型デンドリマーでデンドロニゼーションされたポリマーの合成が成功しました.
- 周辺にフッ素アルキル基を持つ膀状の柱状構造の観察.
- 逆熱操作の実証:高分子柱の長さは温度上昇とともに減少する.
結論:
- ジャヌス・デンドリマーは,デンドロン化されたポリマーの独特の膀状の柱状構造の形成を可能にします.
- これらのポリマーは,温度変化に対する新しい反応である逆熱アクチュエーションを示します.
- この発見は,調節可能な熱反応特性を持つ新しい材料を開発するための道を開く.
関連する概念動画
Actin Polymerization and Cell Motility
Actin is a family of globular proteins that are highly abundant in eukaryotic cells. It makes up approximately 1-5% of total cell protein concentration. Actin monomers polymerize to form a complex network of polarized filaments, the actin cytoskeleton, that plays a crucial role in many cellular processes, including cell motility, division, endocytosis, and metastasis of cancer cells.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
Mechanism of Filopodia Formation
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Mechanism of Lamellipodia Formation
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
Formation of Higher-order Actin Filaments
The polymerization of G-actin monomers into filamentous F-actin is a multi-step process. Once the F-actins are formed, they can bundle together in different arrangements to form higher-order networks and regulate cellular functions. Common examples include the formation of lamellipodia and filopodia at the cell's leading edge by actin reorganization in a migrating cell. The microvilli on the brush border epithelial cells are also formed through the F-actin network.
The high-order actin networks...
The high-order actin networks...
Assembly of Cytoskeletal Filaments
Cytoskeletal filaments are polymeric forms of smaller protein subunits. However, individual cytoskeletal filaments may easily disassemble or associate with other similar filaments to form rigid structures. Microfilaments, made of actin monomers, rely on actin-binding proteins to form bundles and create networks of individual actin filaments. Microtubules rely on microtubule-associated proteins (MAPs) to form sturdy cylindrical structures. However, the proteins involved in forming complex...
The Movement of Organelles and Vesicles
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...


