Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Form is function

12.09.2019

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

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.


Composition of phase contrast images of a tissue grown on a capillary bridge (left). Skeleton of cells stained with a green fluorescent marker to visualize them in 3D, light-sheet microscopy (right).

MPI of Colloids and Interfaces/ Sebastian Ehrig

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.

Originalpublikation:

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

Weitere Informationen:

http://www.mpikg.mpg.de/6167246/news_publication_13873017_transferred

Katja Schulze | Max-Planck-Institut für Kolloid- und Grenzflächenforschung

More articles from Life Sciences:

nachricht Turbo-charging pharmaceutical biotechnology simulations
12.09.2019 | Technische Universität Graz

nachricht Existing drug could treat aggressive brain cancer
11.09.2019 | University of Georgia

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Milestones on the Way to the Nuclear Clock

Two research teams have succeeded simultaneously in measuring the long-sought Thorium nuclear transition, which enables extremely precise nuclear clocks. TU Wien (Vienna) is part of both teams.

If you want to build the most accurate clock in the world, you need something that "ticks" very fast and extremely precise. In an atomic clock, electrons are...

Im Focus: Graphene sets the stage for the next generation of THz astronomy detectors

Researchers from Chalmers University of Technology have demonstrated a detector made from graphene that could revolutionize the sensors used in next-generation space telescopes. The findings were recently published in the scientific journal Nature Astronomy.

Beyond superconductors, there are few materials that can fulfill the requirements needed for making ultra-sensitive and fast terahertz (THz) detectors for...

Im Focus: Physicists from Stuttgart prove the existence of a supersolid state of matte

A supersolid is a state of matter that can be described in simplified terms as being solid and liquid at the same time. In recent years, extensive efforts have been devoted to the detection of this exotic quantum matter. A research team led by Tilman Pfau and Tim Langen at the 5th Institute of Physics of the University of Stuttgart has succeeded in proving experimentally that the long-sought supersolid state of matter exists. The researchers report their results in Nature magazine.

In our everyday lives, we are familiar with matter existing in three different states: solid, liquid, or gas. However, if matter is cooled down to extremely...

Im Focus: World record for tandem perovskite-CIGS solar cell

A team headed by Prof. Steve Albrecht from the HZB will present a new world-record tandem solar cell at EU PVSEC, the world's largest international photovoltaic and solar energy conference and exhibition, in Marseille, France on September 11, 2019. This tandem solar cell combines the semiconducting materials perovskite and CIGS and achieves a certified efficiency of 23.26 per cent. One reason for this success lies in the cell’s intermediate layer of organic molecules: they self-organise to cover even rough semiconductor surfaces. Two patents have been filed for these layers.

Perovskite-based solar cells have experienced an incredibly rapid increase in efficiency over the last ten years. The combination of perovskites with classical...

Im Focus: A molecular 'atlas' of animal development

Researchers from the University of Pennsylvania provide a molecular map of every cell in a developing animal embryo

In a paper in Science this week, Penn researchers report the first detailed molecular characterization of how every cell changes during animal embryonic...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

AI for Laser Technology Conference: optimizing the use of lasers with artificial intelligence

29.08.2019 | Event News

 
Latest News

Turbo-charging pharmaceutical biotechnology simulations

12.09.2019 | Life Sciences

"Flying fish" robot can dive and fly

12.09.2019 | Power and Electrical Engineering

Form is function

12.09.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>