q&more
My watch list
my.chemie.de  
Login  

News

"Form is function"

Liquid-like tissue behavior is a key principle for the formation of structures in biological systems

MPI of Colloids and Interfaces/ Sebastian Ehrig

Composition of phase contrast images of a tissue grown on a capillary bridge taken at three different times in tissue culture (left). The skeleton of the cells was stained with a green fluorescent marker to visualize them in 3D using light-sheet microscopy (right). The 3D image shows that the cells rotate in a certain direction around the capillary bridge.

17-Sep-2019: Researchers at the Max Planck Institute of Colloids and Interfaces in Potsdam have shown that growing bone tissue behaves like a viscous liquid on long time scales, thereby accepting forms with minimal surface area. This cell behavior determines the shape of the tissue when it grows on a scaffold.

A particular strength and fascinating feature of living systems is their adaptability to changing environmental conditions. One such example being human bone which regularly regenerates itself by attaching and removing small bone packages. This conversion process is regulated by the mechanical environment, allowing bone to adapt its structure and its internal shape to changing loading requirements such as regular exercise. John Dunlop, former group leader at the Max Planck Institute of Colloids and Interfaces in Potsdam, and now Professor of Biophysics at the University of Salzburg was researching with his team the optimum conditions for generating bone tissue.

Biological structures are formed by cells, which are much smaller than the resulting shape. The cells are even able to sense the curvature of a surface that is much larger than themselves. How do the cells manage to create such complex macroscopic forms or restore the original shape during bone healing? "A partial answer to this question could be the insight of this work. Cells use surface energy for shaping in much the same way that complex structures can arise from soap bubbles due to surface energy," underlines Peter Fratzl, Director at the Max Planck Institute of Colloids and Interfaces and co-author of the study, in which also scientists from the Berlin Charité, from Würzburg, from Dresden and from the Montanuniversität Leoben were involved.

Forms of constant mean curvature

The researchers were able to show that tissue that grew on curved surfaces developed forms with outer boundaries of constant mean curvature. These structures are very similar to forms of liquid droplets that assume a minimal surface area. Curved plastic surfaces functioned as substrates for cell and tissue growth, which Sebastian Ehrig produced during his PhD. These surfaces were produced using a liquid polymer that solidified at high temperatures. It formed together with the substrate and different geometries on which the cells could grow and form new tissue. The amount of tissue formed depended on the shape of the substrate. The scientists noted that more tissue on strongly concave surfaces developed, indicating a mechanically induced biological feedback mechanism.

By inhibiting cell contractility it was shown that active cell forces are needed to produce sufficient surface tensions for fluid-like behavior and growth of the tissue. "This suggests that mechanical signal transduction between cells and their physical environment, along with the continuous reorganization of cells and matrix, is a key principle in tissue formation," emphasizes Sebastian Ehrig, first author and former PhD student at the MPI of Colloids and Interfaces, who is now researching at the Max-Delbrück Center in Berlin.

Chiral Structures

Furthermore light sheet microscopy provided insights into the spatial structure of the tissue, with another notable discovery: the cells clustered into extensive chiral structures that spiral around the capillary bridges. You find similar structures in osteons, the smallest functional unit of the bone. An osteon arises when bone-forming cells (osteoblasts) are concentrically stored in 4-20 layers around a blood vessel, become walled and become lamellar bones.

The study suggests that liquid-like tissue behavior is a key principle for the formation of structures in biological systems. This could have far-reaching importance in terms of understanding healing processes and organ development but also for medical applications such as the development of implants.

Original publication:
S. Ehrig, B. Schamberger, C. M. Bidan, A. West, C. Jacobi, K. Lam, P. Kollmannsberger, A. Petersen, P. Tomancak, K. Kommareddy, F. D. Fischer, P. Fratzl, John W. C. Dunlop; "Surface tension determines tissue shape and growth kinetics"; Sci. Adv.; 2019; 5: eaav9394

Facts, background information, dossiers

  • bones
  • cells
  • light sheet microscopy

More about MPI für Kolloid- und Grenzflächenforschung

  • News

    Put into the right light - Reproducible and sustainable coupling reactions

    A team of researchers reports in the journal Nature Catalysis that sustainable carbon-nitrogen cross-couplings can be performed using simple nickel salts, carbon nitrides and light. The chemists study the use of cost-effective and reproducible semiconductors as photocatalysts in coupling re ... more

    "Make two out of one" - Division of Artificial Cells

    The success of life on earth is based on the amazing ability of living cells to divide themselves into two daughter cells. During such a division process, the outer cell membrane has to undergo a series of morphological transformations that ultimately lead to membrane fission. Scientists at ... more

    Let’s build a cell

    Cells are the basic unit of life. They provide an environment for the fundamental molecules of life to interact, for reactions to take place and sustain life. However, the biological cell is very complicated, making it difficult to understand what takes place inside it. One way to tackle th ... more

  • q&more articles

    With Light in the Fight against Malaria

    Malaria represents a global threat to health, which is difficult to keep under control. Amongst more than 200 million sufferers, over 500,000 die each year of the disease, with the risk of a fatal outcome being particularly high in children [1]. more

  • Authors

    Dr. Daniel Kopetzki

    born 1983, studied chemistry at the University of Regensburg and received his doctorate from the Max Planck Institute of Colloids and Interfaces in Potsdam, in the Department of Colloid Chemistry. Since Sept. 2011, he has been working as a post-doctoral fellow for Prof. Dr. Seeberger at the ... more

    Prof. Dr. Peter Seeberger

    born 1966, studied chemistry at the University of Erlangen-Nuremberg, and received his doctorate in biochemistry from the University of Colorado. After holding a post-doctorate position at the Sloan-Kettering Institute for Cancer Research in New York City, he was Assistant Professor and Fir ... more

More about Max-Planck-Gesellschaft

  • News

    Green Chemistry: Sustainable p-xylene production

    Lemonade, juice and mineral water often come in PET bottles. While these are practical and functional, their production is complex and not necessarily sustainable. The starting material for terephthalic acid, which is used to produce saturated polyesters such as PET (Polyethylene terephthal ... more

    How to design more reliable nano- and micro-electro-mechanical systems

    Mobile phones, data storage for laptops, solar cells, power electronics for renewable energy, or sensors in cars are applications where silicon is the first-choice material despite that its mechanical behaviour at elevated temperature is not yet fully understood. To design efficient and rel ... more

    Bacteria leave signature in colon cancer cells

    Some bacterial pathogens cause damage in the genomes of their infected cells which could lead to the initiation of cancer. While it is difficult to link an infection with an onset of cancer that arises many years later in life, researchers have been looking for definitive proof that such li ... more

q&more – the networking platform for quality excellence in lab and process

The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.

> more about q&more

q&more is supported by:

 

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE