Ellington says molecular biologists can’t always predict outcomes of genetic manipulations. If the outcome of a simple genetic manipulation can’t be predicted with certainty, it’'s going to be “very difficult to predict the outcome of a complex engineered biological system within a human. It’s a fact we encounter regularly at a simpler level with the unanticipated consequences of gene therapies,” he says.
Synthetic biologists disagree. “Synthetic biology aims at creating new forms of life, genetic circuits and behaviors in cells. Systems biology looks at existing natural systems and tries to understand how they work,” says Weiss. Although the two may have some procedures in common, they have “very different perspectives but more importantly, different goals,” he says. Lu further expands by saying the modus operandi of synthetic biology is to have better quantitative control over “molecular engineering techniques that others have been doing over the last 20 years” with higher throughput and predictable and logical properties.
By any name, the endeavor to create artificial biological systems for clinical applications will raise some fundamental questions: What happens to engineered cells when they enter complex mammalian systems? How stable will these engineered entities be in complex environments, and how long will they last? Can parts engineered for one particular mammalian system be translated easily to another? And do the engineered components actually do what they are supposed to do and not unwittingly unleash more havoc? Because of these unanswered questions, synthetic biologists are taking it slowly, keenly aware of the possibility of a backlash suffered in related fields, like the one that followed early attempts in at gene therapy. Those interviewed for this story say it will be at least five years before there are clinical trials will be run using synthetic biology components.
But with all these questions hounding the field, one may very well ask if synthetic biology is even ready for clinical applications. Keasling says he has heard the criticism before. But his response is this: “Why wait?”
Keasling says there is enough knowledge in some areas of biology to have well-characterized components that can be used for initial synthetic biology applications. By pushing on the boundaries into of the unknown, both synthetic biology and its foundation, molecular biology, stand to benefit. For example, Lu says, by delving into the mechanics of how to solve certain disease states, “synthetic biology can help us understand disease processes more efficiently” at the molecular level.
But he and others say synthetic biologists will need time, investment and collaborative efforts to figure out the best means of delivering safe and effective therapeutics to patients. As Lu notes, “The road is going to be a long one.”
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Rajendrani Mukhopadhyay (firstname.lastname@example.org) is the senior science writer for ASBMB Today and technical editor for JBC.