Engineer Better Medicines

Human DNA contains more than 20,000 genes, all of which are stored in our cells' nuclei. A gene is a strand of chemical code, a sort of blueprint for proteins and other substances necessary for life. Cells make those molecules according to the genetic blueprints.

Each person’s overall blueprint is basically the same, made up of about 3 billion “letters” of code, each letter corresponding to a chemical subunit of the DNA molecule. But subtle variants in about 1 percent of our DNA — often the result of just a single chemical letter being different — give humans their individual identities.

Beyond physical appearance, genes give rise to distinct chemistries in various realms of the body and brain. Such differences sometimes predispose people to particular diseases, and some dramatically affect the way a person will respond to medical treatments.

Ideally, doctors would be able to diagnose and treat people based on those individual differences, a concept commonly referred to as “personalized medicine.” At its core, personalized medicine is about combining genetic information with clinical data to optimally tailor drugs and doses to meet the unique needs of an individual patient. Eventually, personalized medicine will be further informed by detailed understanding of the body’s distinct repertoire of proteins (proteomics) and complete catalog of biochemical reactions (metabolomics).

Engineering Challenges

One engineering challenge is developing better systems to rapidly assess a patient’s genetic profile; another is collecting and managing massive amounts of data on individual patients; and yet another is the need to create inexpensive and rapid diagnostic devices such as gene chips and sensors able to detect minute amounts of chemicals in the blood.

In addition, improved systems are necessary to find effective and safe drugs that can exploit the new knowledge of differences in individuals. The current “gold standard” for testing a drug’s worth and safety is the randomized controlled clinical trial -- a study that randomly assigns people to a new drug or to nothing at all, a placebo, to assess how the drug performs. But that approach essentially decides a drug’s usefulness based on average results for the group of patients as a whole, not for the individual.

New methods are also needed for delivering personalized drugs quickly and efficiently to the site in the body where the disease is localized. For instance, researchers are exploring ways to engineer nanoparticles that are capable of delivering a drug to its target in the body while evading the body’s natural immune response. Such nanoparticles could be designed to be sensitive to the body’s internal conditions, and therefore could, for example, release insulin only when the blood’s glucose concentration is high.

In a new field called “synthetic biology,” novel biomaterials are being engineered to replace or aid in the repair of damaged body tissues. Some are scaffolds that contain biological signals that attract stem cells and guide their growth into specific tissue types. Mastery of synthetic tissue engineering could make it possible to regenerate tissues and organs.