Engineers now have the tools to design biological products and processes at the molecular level.
Proteins are of particular therapeutic interest, because proteins mediate most biochemical processes both inside and outside cells. The ability to manipulate the strength and specificity of protein binding events provides tremendous leverage for the development of novel biopharmaceuticals. In the absence of predictive capabilities for protein design, a directed evolution or combinatorial library screening strategy can be effectively applied to alter protein properties in a desired fashion. We are engineering potential protein biopharmaceuticals in areas where molecular understanding of disease pathology is sufficient to hypothesize particular objective functions to target. For example, antibodies can be used to target cell-killing modalities to cancerous cells, given sufficiently strong and specific binding properties.