Archive for the ‘M is for Mechanobiology’ Category

Tensegrity: The Architecture of Life

Saturday, August 21st, 2010

Photo via flickr by richard winchell

SPTNK’s conversation with biologist Donald Ingber on the topic of tensegrity is now included in Tensegrity Wiki, and featured on the Vimeo channel, Tensegrity.

According to Ingber, head of Ingber Laboratories at the Harvard Medical School Children’s Hospital in Boston, tensegrity, the shape-stabilizing structures made famous by Buckminster Fuller’s geodesic dome that balances compression with tension and yields to forces without breaking, is the guiding force of evolution, the architecture of life. Moreover, Ingber’s research has shown that tensegrity gives cells their shape with each cell having an inner-scaffolding or cytoskeleton, and if you change the shape of the cell, you also change its biochemistry and genetic expression. This discovery is fundamental to the future of medicine as it may cure diseases such as cancer.

For more SPTNK conversations with Don Ingber on tensegrity and mechanbiology, click here.

To learn more about the SPTNK cultural theme of mechanobiology, click here.

The Evolution of Evo-Devo Biology

Monday, May 24th, 2010

Developmental biology (‘devo’) and evolutionary studies (‘evo’), once seen as distinct, yet complementary disciplines, have recently merged into an exciting and fruitful relationship. The official union occurred in 1999 when evolutionary developmental biology, or “evo-devo,” was granted its own division in the Society for Integrative and Comparative Biology (SICB).

It was natural for evolutionary biologists and developmental biologists to find common ground. Evolutionary biologists seek to understand how organisms evolve and change their shape and form. The roots of these changes are found in the developmental mechanisms that control body shape and form. Developmental biologists try to understand how alterations in gene expression and function lead to changes in body shape and pattern. So although SICB only recently validated evo-devo as an independent research area, evo-devo really started over a decade ago when biologists began using an individual organism’s developmental gene expression patterns to explain how groups of organisms evolved.

To highlight this emerging field, the Proceedings of the National Academy of Sciences (PNAS) Editorial Board has sponsored a special feature on Evolutionary Developmental Biology. This evo-devo special feature contains eight Perspective articles and a review that examine evo-devo’s progress to date, as well as 15 research articles that add new information and focus on the most recent evo-devo biology trends. The majority of the research articles were submitted directly to the PNAS office through the Track II system, and were evaluated by an Editorial Board member. After the initial screening, papers were assigned to an Academy Member-editor who oversaw a process where research manuscripts were rigorously peer-reviewed by experts in the field.

via PNAS

Biologist Donald Ingber explains how tensegrity helps to understand the origins of life in a 2007 conversation with Sputnik Observatory:

There’s beautiful work from 1917. D’Arcy Thompson had a book where he had a picture of one fish or one face of one ethnic group on a grid. Then they deformed the grid. They pull it this way, they pull it this way, they stretch it that way, and you get all the different species from that form. It’s not saying they we’re physically deformed in that way, but it’s basically saying that physical alterations of the structure are how you get different forms. They could be from internal forces, the cells pulling differently in this area than that, or it could be in a different physical environment, adapting. And the reason that I thought tensegrity really helps to understand origin of life is that each time you go through a systems jump where you put many elements together, whether they’re molecules or cells or tissues, you now have something that when the environment changes, for example it gets very cold or if it gets very salty and you change the structure, most things might break and you lose them but tensegrity is resilient so it can change when it freezes and then come right back again. Those would be selected. Without genes there would be natural selection, environmental selection by physicality, by stability. I think that’s something that’s interesting because most people who work on evolution only think about DNA and RNA and selection by genetic selection. Basically, we’ve had geodesic forms in the inorganic world for millions of years before we had life. We see it in cells, we see it in subcellular components, we see it in our bodies. So that means that the same rules must have been driving evolution in the inorganic world before life and DNA came about.

Michael Hensel, architect, discusses the notion of ‘morpho-ecology’ and how we need to understand the process of formation:

The title Morpho-Ecology brings, in principle, two or three notions or concepts together. On the one hand, morphology or morphogenesis; on the other hand, ecology. This is basically saying that in the morphological part we’re looking at the material constituent, and in the ecological part we’re looking at how this is embedded in a given environment. The term “morphology” was originally coined by Goethe in his studies on botanics, and he basically stated that when we look at nature we cannot concern ourselves merely with gestalt, with shape. Because everything that acquires a shape immediately, in the next moment, changes it’s shape. And he was arguing through the growth of a plant that any time you try to describe a shape it’s only a snapshot in time, because the next day it’s bigger and distributed in a different way. So material is redistributed all the time. It’s a constant process of formation. So what he states is that, up to that point, maybe plant shape studies were merely focused on drawing these snapshots. And he said we need to understand something other than that – we need to understand the process of formation. What is driving plants to grow into a particular shape and into a next shape and next shape? He basically says once something has acquired a shape, it immediately transforms into another. So morphology in that sense, or morphogenesis, the way form comes into being, is a dynamic process. And this dynamic process can only be understood in relation to the environment with which the organism that develops is in contact.

So what we call “morpho-ecology” is probably unnecessary for a biologist, because a biologist would always understand that every organism unfolds and becomes a kind of individual material expression in permanent exchange with the environment. But architects don’t. First of all, because we build our buildings for long time spans. And we don’t think of a building as something that in and of itself will change unless it’s mechanically done. An example would be, for instance, the Schroder House by Rietveld where you have panels that you move around and you change the interior configuration of the house or, for instance, the facade for the Institute for the Arab World by Jean Nouvel which has camera-like apertures that close and open in relation to the sunlight. But this is, again, all mechanically enhanced. So the question is really how can we begin to think of buildings not just as temporary storages of material but also as something that is somehow, in someway, in exchange with the environment and that might also be affected by the environment, while in turn affecting the environment.

Cells ‘Feel’ Their Shape

Monday, September 21st, 2009

Photo via flickr by PROYECTO AGUA**

Johns Hopkins scientists, working with the simplest of organisms, have discovered the molecular sensor that lets cells not only “feel” changes to their neat shapes, but also to remodel themselves back into ready-to-split symmetry. In a study published September 15 in Current Biology, the researchers show that two force-sensitive proteins accumulate at the sites of cell-shape disturbances and cooperate first to sense the changes and then to resculpt the cells. The proteins — myosin II and cortexillin I — monitor and correct shape changes in order to ensure smooth division.

“What we found is an exquisitely tuned mechanosensory system that keeps the cells shipshape so they can divide properly,” says Douglas N. Robinson, Ph.D., an associate professor of Cell Biology, Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine.

Faulty cell division can put organisms, including people, on the pathway to diseases such as cancer, Robinson notes, and a better understanding of how cells respond to mechanical stress on their shapes could present new targets for both diagnosing and treating such diseases.

The research was funded by grants from the National Institutes of Health, the American Cancer Society and the National Science Foundation.

via Science Daily

In a conversation with Sputnik Observatory, biologist Donald Ingber explains why shape/structure is important to developing healthy tissues.

I don’t think we’ll ever see no disease, but we’ll see new types of therapies. Maybe ways of predicting diagnosing and reversing, rebooting, types of treatments for disease rather than having to cut out and replace with artificial parts. I think understanding how cells and tissues are built and how mechanical forces are into play, how structure contributes to healing and development of tissues, will allow us to develop artificial materials that truly have the physical properties and the biochemical processing properties in one that would smoothly mesh with our natural materials as opposed to right now where you have a hunk of titanium or artificial plastic or polymers that you put in and there’s a compliance, a flexibility mismatch – they’re basically a dumb material next to an incredibly brilliant, multifunctional material. So I think that, at one level, understanding complexity, physical and information processing complexity, will allow us to build biologically-inspired materials that will interface with the body and be able to, for example, create the right physical and chemical environment so that stem cells that are already in your body don’t have to be taken out, grown up and put some place – they give the right cues to say, come here and multiply and then turn into this cell type and in this pattern.

M is for Mechanobiology

Saturday, May 9th, 2009

We are not made of jelly. Our cells are not formless blobs. Now that the dynamic information processes of biology are being viewed as solutions for engineering problems, the study of mechanobiology, how mechanical forces affect biological behavior, has emerged to suggest revolutionary possibilities. According to Don Ingber, biologist at Harvard Medical School Children’s Hospital, tensegrity, the shape-stabilizing structures made famous by Buckminster Fuller’s geodesic dome that balances compression with tension and yields to forces without breaking, is the guiding force of evolution, the architecture of life. Tensegrity gives cells their shape, as each cell has an inner-scaffolding or cytoskeleton, and what Ingber’s research has shown is that if you change the shape of the cell, you also change its biochemistry and genetic expression. This discovery, fundamental to medicine, is said to possibly cure diseases such as cancer considering that unlike normal cells, cancer cells don’t physically feel their neighbors and therefore keep growing. Instead of drugs, the aim of mechanobiology, with the interplay of physical and chemical sciences, is that medicine will be able to send the right set of signals that will revert the behavior of cancerous cells and form normal tissues. Moreover, considering that all cells, whether nerve, muscle, bone, etc., have distinct shapes, it’s believed that stem cells will no longer have to be grown in the lab, but given the right signal, those already in the body will come to the site and multiply to transform the damaged cell into the right pattern or structure. And, of course, there’s aging, considering wrinkles are old cells that can no longer hold shape-stability when the cytoskeleton loses its elasticity and becomes stiff. In the world of objects, we find that mechanobiology and the 1912 book by biologist and mathematician D’Arcy Thompson, “On Growth and Form,” that illustrates physical deformations such as the tensegral nature of bone cells subjected to forces over time, is the inspiration behind the now-leading trend of parametric design that uses generative computation enabling architectural “cells” to change shape to improve performance by creating structures that are natural and responsive. In fact, it’s been suggested that moving forward we will discover that tensegrity is all around us, present in the organic world for millions of years before there was any life at all, even the structure of black holes, galaxies and the universe itself.