Ask the Expert

Professor Endy says: Synthetic biology is a broad field of research that brings together scientists and engineers who are interested in assembling and engineering living matter. For the engineering community, in particular, synthetic biology has focused attention on improving the process by which we design and build living organisms. Stated differently, can we make biology easy to engineer? 

This is a research question; there is no one right answer today. Practically, synthetic biologists are working to explore and adapt past lessons from other forms of engineering, such as standardization of components, to see if we might usefully impact the world of biotechnology. However, as we’ve made early and incremental improvements in the engineering process, we’ve often created surprising and significant changes in what can be made and who can make it. Thus, synthetic biology also focuses attention on how we organize ourselves, so that the ongoing development and future applications of biological technologies remains overwhelmingly constructive. 

Of course, researchers have been engaged in genetic engineering and biotechnology for decades. They have produced some amazing results, but their work has required much more art than engineering. Early pioneers, and also their followers decades later, have had to be become experts in everything from physical chemistry to clinical diseases in order to pursue a medical benefit. In a human lifetime of attempts to engineer organisms and their byproducts, our methods of doing so have not evolved much beyond an educated form of trial and error.

Synthetic biologists hope to make the process of composing useful sequences of DNA more akin to assembling an integrated circuit from well documented, standardized, and readily available components. You wouldn’t expect an electrical engineer to have to invent the resistor or the capacitor just to add a clock to a coffee maker. Similarly, you wouldn’t expect a contractor to custom-thread hundreds of nuts and bolts, and to hand mill dozens of two-by-fours from raw timber just to frame an addition to a house. Metaphorically speaking, that’s what many biotechnology researchers have been doing with genetic material as they’ve strived to synthesize biologically derived drugs for malaria and other diseases.

The people who can imagine an outcome—perhaps a virus that has been reprogrammed to deliver drugs to ailing cells—should be able to flip through a catalog of DNA snippets, snap them together and then try them out with some initial confidence that they’ll work. If synthetic biology is successful, that will eventually become routine.

To help enable that, I am working with colleagues around the world in the BioBricks Foundation and the BioBricks parts collection, a collective experiment to build a standardized, freely-available library of pre-built and well understood genetic parts. About seven years ago Tom Knight, a computer engineer turned biologist and biological engineer at MIT, built the first few BioBrick DNA segments. There are now 3,500 components in the collection—snippets that control gene expression and others that make structures such as a protein balloon that can control the buoyancy of a microbe—and the number of parts has been doubling roughly every year.

Tom’s efforts represented a significant advance in solving the problem of physically assembling DNA parts. Another challenge is figuring out how different genetic functions can be made to work together reliably once they are connected. Engineers call this “functional composition,” and we’re working on this intently.

Beyond helping to build the basic engineering infrastructure underlying biotechnology, we are also now excited to move towards applications here at Stanford. One of the projects in my lab is to develop the equivalent of a genetic memory stick that can be inserted into cells. For example, if we can insert just eight bits of genetic memory into a cell, we could create a counter that would increase every time a cell divides. Over time, as we periodically read out the memory, we could see how many times a cell has replicated and track how genes change and mutate as multiple divisions occur. Perhaps cells that are replicating at a cancerous, rather than normal, rate could be targeted for destruction.

I also spend a lot of time considering and working to address the social and ethical dimensions of making biology easier to engineer. Not everyone starts with the views that I hold, such as that we might best understand and interact with the living world by rebuilding parts of it. As a second example, there are serious puzzles to be addressed regarding the potential future misapplications of biological technologies.  Because Stanford is home to top medical, engineering, business, law, and humanities schools, we’ve a great responsibility to figure out how to explore and take these topics forward. It is very important that we analyze these complicated issues and find ways to ensure sustained and constructive conversations around what I hope people will view as a constructive new field called synthetic biology.