From the subcellular level to the level of the whole body, movement is made possible by proteins that transform chemical to mechanical energy. For many years now there has been the hope of creating synthetic systems capable of similar efficiency and control. Now that we are able to measure force and motion at the molecular level and now that the structure of the component proteins has been resolved, it may soon be possible to mimic these living structure and motility systems to create robust artificial devices such as molecular sorters, filters, concentrators, switches, and power sources.
The ability to diagnose major diseases has improved dramatically in the past two decades. Biomolecular materials have been key to these advances. It is now possible to design biomolecular materials that undergo large physical changes when they bind to a target molecule and to design systems that exploit the consequences of cooperative binding events.
There has been a longstanding interest in using biomolecular materials for the delivery of therapeutic agents. Nanometer-size particles show promise as vehicles for the targeted delivery of payloads such as siRNA and DNA and as labels to monitor such delivery.
The design, fabrication, and integration of functional biomaterials into prosthetic devices present a number of challenges. Next-generation prostheses will likely incorporate feedback loops that involve sensing and actuating components.
Cells can detect minute amounts of molecules with extraordinary sensitivity. However, because only very small physical changes occur when a sensor binds to its target, the problem has been translating such an event into a measurable