Metabolic Architecture & Protocells

Building technology is rooted in the industrial machine age. We build structures that consume resources voraciously to create inert objects. If you divide a building down to its base component parts you start getting smaller components, until you eventually reach your base materials like wood, stone and concrete. This is normally where architectural thinking stops, but why can’t we think about materials on the molecular level?

To do this we need to develop new tools and architectural language. This can only be achieved by integrating architecture with other disciplines and technologies.

One such field of research, which seeks to bridge some of these gaps, is the use of Protocells.

So what is a Protocell?

All forms of life are made from molecules that individually are not alive. How can a combination of non-living matter be transformed into something that is classified as alive?

The Protocell (prototype cell) is an artificial structure that represents the first simple working model of a synthetically designed cell that exhibits attributes of being alive. But, what is classified as alive?

A living system is operationally defined as a system that integrates three critical functionalities (outer ring). First, it maintains an identity over time by localizing all its components. Secondly, it uses energy from its environment to maintain itself, grow, and reproduce. Third, the cell’s attributes are inheritable and can be modified during reproduction.Three other functionalities must be displayed in three integrated chemical systems (inner triangle). A metabolism that harvests energy from the environment, genes that chemically control functionalities, all enclosed within a container (Hanczyc et al).

So how can these cells be produced synthetically? One method is to combine a mix of inert molecules, let them react and self-assemble into a living Protocell. This is considered a bottom up approach to building a Protocell. A complimentary technique to this is a top-down approach which utilises genomic research. This approach takes an existing living cell and reduces its genome by the successive removal of genes, to arrive at a minimal cell (Hutchison et al., 1999).

The Protocells developed by Hanczyc et al, are bottom up chemically engineered cells and can travel around and sense their environment. They have the ability to form solid skins that are shed into the environment where they become sedimentary components eventually forming artificial limestone. It has been shown that it is possible to programme Protocells to react to stimuli such as light. One species for instance is attracted to the light whilst another is attracted to the darkness.

One example that shows the potential of Protocells was put forward by Rachel Armstrong. To prevent Venice slipping into the sea, Protocells engineered to be light sensitive would be released into the canals, where they would prefer shady areas to sunlight. As a result of this the Protocells would be guided towards the darkened areas of the foundations, opposed to depositing their material in the light canals, thereby turning the foundations of Venice to stone, simultaneously creating a huge carbon sink.

Protocells have also stared in science fiction; the short story “Bio-Lime mock rock” by Rachel Armstrong documents the mineral-clad buildings of a “Mossville suburb” where Protocell technology is implemented to curb climate change.

This technology is still being developed but the possibilities for the future are very exciting. It is feasible that by manipulating the local environment the density and type of solid material produced by the Protocells in solution could be controlled. The environment could be manipulated by 3D printing a variety of chemical stimuli into the solution manipulating the growth of the Protocells.

By combining different species with different functions an organism could be created. Light sensitive photosynthesising cells could create partnerships with cells feeding on their waste product possibly operating like coral polyps. Bacteria have already been genetically engineered to create chemicals such as insulin and growth hormones for the pharmaceutical industry. It is conceivable with an enhanced knowledge of genetics we will be able to program cells genetically to self-replicate and build complicated structures similar to coral. This would open up a new avenue of chemical computing.

The use of metabolic materials within architecture is in its infancy but its potential is enormous. Forming a real link between nature, not just imitating or patching it onto our cities, which will create a new architecture for the 21st centaury.

By Stuart Maggs

References:

Protocells: Bridging Non-living and Living Matter. MIT Press (2 Dec 2008)

http://www.rachelarmstrong.me/

Armstrong, R. 2010. Biolime: Mock Rock, ISSP, Southern University of
Denmark, Denmark, Available at:

http://www.science-society-policy.org/downloads/file-archive/Biolime.pdf

Armstrong, R. 2009. Protocells & Plectic Systems Architecture, Available at: http://www.sophiamagazine.co.uk/