It is common for articles about nanotechnology to start by pointing out that the nanoscale is much smaller than the thickness of a human hair (about 80,000 nm) or a red blood cell (about 7,000 nm). Such comparisons unwittingly suggest that nanotechnology is divorced from the living world, but nothing could be further from the truth. The field of nanobiotechnology is thriving, as various articles in this issue make clear.

Of course biologists had been studying proteins, viruses, DNA and the like long before nanotechnology became fashionable and fundable, but that does not mean they were doing nanotechnology. The US National Institutes of Health (NIH) makes this distinction clear1: “While much of biology is grounded in nanoscale phenomena, NIH has not re-classified most of its basic research portfolio as nanotechnology”. The NIH identifies three broad areas that qualify as nanotechnology in its eyes: “studies that use nanotechnology tools and concepts to study biology; that propose to engineer biological molecules toward functions very different from those they have in nature; or that manipulate biological systems by methods more precise than can be done by using molecular biological, synthetic chemical, or biochemical approaches that have been used for years in the biology research community”.

On page 85 Richard Jones explores the relationship between biology and nanotechnology. One view, which he terms the engineer's view, is that nature shows what can be achieved with random materials and design methods, so imagine the improvements that should be possible with better materials and rational design principles. The other view is that evolution is an extremely effective way of exploring all the different possibilities, so nature's solutions are likely to be the best available.

One approach to solar cells involves designing photosynthetic molecules similar to those found in nature.

As this debate continues, nanoscientists are busy exploiting the properties of various biomolecules in man-made devices. Viruses have been used to make memory devices2, photosynthetic proteins have been integrated into photovoltaic devices3, and DNA has demonstrated potential as an intelligent nanoscale building block4. Although these systems have been studied for years, there is still much to learn. For instance, as Philip Nelson and co-workers report on page 137, the mechanical properties of DNA change significantly when measured on length scales of 5–10 nm.

The traffic is not all one way, and there is work in which bio and nano are equal partners, such as experiments that combine semiconductor devices and neural circuits5,6. Moreover, many nanotechnology labs are developing new biosensors based on nanowires, nanoelectromechanical systems (NEMS) and other approaches. At the University of Georgia, for instance, a professor of infectious diseases has collaborated with colleagues in physics and chemistry to develop a new way to detect viruses. This project is typical of the multidisciplinary spirit that characterizes nanobiotechnology, and is featured in the 'Top down bottom up' column (page 89), which will highlight collaborations like this every month. And on page 142 James McGinnis and co-workers report how ceria nanoparticles offer a promising approach to the treatment of diseases that affect the eyes and other parts of the body. Indeed, nanomedicine has become a massive area in its own right, even if it remains a tiny niche in the overall pharmaceutical and medical device market7.

The only cloud on the horizon is our lack of knowledge about the health and environmental impacts of nanoparticles. There is also some terminology that needs to be tidied up: should the field be called nanobiotechnology or bionanotechnology? Nature Nanotechnology prefers the former, and a quick search on Google confirms this by more than three-to-one. But which is correct? Are there subtle differences between the two? Your views are welcome at naturenano@nature.com.