The field of nanotechnology is growing explosively and impinging on all walks of life. This is reflected in the appearance of nanotechnology in consumer products; in March 2011, the Project on Emerging Nanotechnologies, a partnership between the Woodrow Wilson International Center for Scholars and the Pew Charitable Trusts, reported more than 1300 consumer products containing nanotechnology on the market, a growth of 520% since March 2006.1 The health care field is also being affected; a search on “nanoparticle” in ClinicalTrials.gov pulls up more than 80 trials, primarily in the cancer field but also including such diverse areas as antibacterial agents, dental composites, wound dressings, imaging agents, and stent coatings. What does “nanotechnology” refer to? The National Nanotechnology Initiative defines nanotechnology as the understanding and control of matter at dimensions between approximately 1 and 100 nm, where unique phenomena enable novel applications. Encompassing nanoscale science, engineering, and technology, nanotechnology involves imaging, measuring, modeling, and manipulating matter at this length scale.” There are 2 approaches to nanotechnology, termed “top-down” and “bottom-up.” Top-down approaches involve the use of tools to make nanoscale features, for example, nanopatterning of surfaces on devices to change their surface properties. Bottom-up approaches involve self-assembly of small components to make nanoscale particles or structures. ### National Heart, Lung, and Blood Institute Programs of Excellence in Nanotechnology Early last decade, the National Heart, Lung, and Blood Institute (NHLBI) recognized the promise of nanotechnology for improving the diagnosis and treatment of heart, lung, and blood diseases, and in 2003 the institute organized a working group to give advice on how to harness this potential. The working group brought together physical scientists such as chemists and material scientists, along with biological scientists and clinicians from the heart, lung, and blood fields. The highest-priority recommendation of the working group was the formation of multidisciplinary centers that would promote collaborations between the biological and physical …