Video Experimental Relacionado
Updated: Jan 13, 2026
06:48
Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops
Published on: July 11, 2025
839
Envoltura colectiva de filamentos y formación de espirales anidadas en sistemas polidispersos activos
Caterina Landi1, Giulia Janzen2, Francesco Sciortino3
1Department of Structure of Matter, Thermal Physics, and Electronics, Complutense University of Madrid, Madrid 28040, Spain. cvaleriani@ucm.es.
Soft matter
|January 9, 2026
Resumen
En materia activa polidispersa, las diferencias en la longitud de los filamentos impulsan el enrollamiento colectivo en espirales anidadas. El aumento de la actividad disuelve estas estructuras, revelando la disparidad de longitud como clave para el autoensamblaje jerárquico.
Área de la Ciencia:
- Física de Materia Blanda
- Sistemas de Materia Activa
- Termodinámica de No Equilibrio
Sus antecedentes:
- Los sistemas activos monodispersos exhiben espiralización de filamentos individuales.
- Los sistemas polidispersos introducen complejidad a través de tamaños de componentes variados.
- La comprensión del autoensamblaje en materia activa es crucial para el diseño de materiales novedosos.
Objetivo del estudio:
- Investigar el comportamiento colectivo en suspensiones bidimensionales polidispersas de filamentos semiflexibles autopulsados.
- Revelar nuevos mecanismos de autoensamblaje impulsados por la disparidad de longitud de los filamentos.
- Explorar el papel de los niveles de actividad en las estructuras y dinámicas emergentes.
Principales métodos:
- Simulaciones por computadora de una suspensión bidimensional polidispersa.
- Análisis de configuraciones de filamentos y dinámicas colectivas.
- Se utilizaron distribuciones de van Hove para caracterizar el movimiento de las partículas.
Principales resultados:
- Se descubrió un mecanismo de envoltura colectiva ausente en sistemas monodispersos.
- Se observaron estructuras de espirales anidadas formadas por filamentos largos que se enrollan alrededor de otros más cortos.
- Se identificaron transiciones estructurales y disolución de espirales con el aumento de la actividad.
- Se revelaron poblaciones de filamentos coexistentes, confinadas y móviles.
Conclusiones:
- La disparidad de longitud de los filamentos es un parámetro de control clave para el autoensamblaje de no equilibrio.
- La envoltura entre filamentos es un mecanismo mínimo para la organización jerárquica en materia activa.
- Este mecanismo modela el confinamiento cooperativo y la jerarquía estructural en sistemas biológicos y sintéticos.
Videos de Conceptos Relacionados
01:11Formation of Higher-order Actin Filaments
3.5K
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...
The high-order actin...
3.5K
00:57Formation of Intermediate Filaments
3.8K
Intermediate filaments are cytoskeletal proteins with higher tensile strength and flexibility than microfilaments and microtubules. Unlike the other two cytoskeletal proteins, intermediate filament formation lacks the enzymatic activity to hydrolyze nucleotides like ATP and GTP to generate energy for polymerization. Therefore, the formation of intermediate filaments is multistep self-assembly. The involvement of any accessory proteins in intermediate filament formation has not yet been...
3.8K
01:39Mechanism of Filopodia Formation
3.0K
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...
3.0K
01:14Generation of Straight or Branched Actin Filaments
3.7K
The straight or branched structure formation of actin filaments is controlled by nucleating proteins such as the formins and Arp2/3 complex. Formin-mediated assembly results in straight filaments, whereas Arp2/3 protein complex-mediated assembly results in branched actin filaments.
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
3.7K
01:18Assembly of Cytoskeletal Filaments
27.1K
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...
27.1K
01:42Actin Polymerization
8.3K
Actin polymerization occurs through the head-to-tail association of binding sites on monomeric actin or G-actin to form filamentous or F-actin. The polymerization can be divided into three phases ̶ nucleation, elongation, and steady-state phase.
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
8.3K