Nanomedicine

Many diseases originate from alterations in biologic processes at the molecular or nanoscale level. Mutated genes, misfolded proteins, and infections caused by viruses or bacteria can lead to cell malfunction or miscommunication, sometimes leading to life-threatening diseases. These molecules and infectious agents are nanometers in size and may be located in biologic systems that are protected by nanometer-size barriers, such as nuclear pores 9 nm in diameter. Their chemical properties, size, and shape appear to dictate the transport of molecules to specific biologic compartments and the interactions between molecules. \n \nNanotechnology is defined as the “intentional design, characterization, production, and applications of materials, structures, devices, and systems by controlling their size and shape in the nanoscale range (1 to 100 nm).” Because nanomaterials are similar in scale to biologic molecules and systems yet can be engineered to have various functions, nanotechnology is potentially useful for medical applications. The field of nanomedicine aims to use the properties and physical characteristics of nanomaterials for the diagnosis and treatment of diseases at the molecular level. \n \nNanomaterials are now being designed to aid the transport of diagnostic or therapeutic agents through biologic barriers; to gain access to molecules; to mediate molecular interactions; and to detect molecular changes in a sensitive, high-throughput manner. In contrast to atoms and macroscopic materials, nanomaterials have a high ratio of surface area to volume as well as tunable optical, electronic, magnetic, and biologic properties, and they can be engineered to have different sizes, shapes, chemical compositions, surface chemical characteristics, and hollow or solid structures. These properties are being incorporated into new generations of drug-delivery vehicles, contrast agents, and diagnostic devices, some of which are currently undergoing clinical investigation or have been approved by the Food and Drug Administration (FDA) for use in humans. This overview describes the properties of nanomaterials, their principal medical applications, and the future possibilities for this emerging field.