Bengt Fadeel*
Nanosafety and Nanomedicine Laboratory, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden

George Whitesides remarked, in his excellent perspective on the “right” size in nanobiotechnology, that “there already exists a highly developed science concerned with biologically relevant nanostructures: this science is called chemistry” (Whitesides, 2003). To this, one may add that there also exists a scientific discipline dealing with host responses to foreign objects on the nano- and microscale—it is called immunology (Shvedova et al., 2010). Whitesides goes on to explain that “biology also provides unparalleled examples of functional nanostructures to excite the imagination of nanotechnologists of all persuasions” (Whitesides, 2003). Indeed, as pointed out by Bruce Alberts in another visionary perspective, “the entire cell can be viewed as a factory that contains an elaborate network of interlocking assembly lines, each of which is composed of a set of large protein machines” (Alberts, 1998). These protein “machines” are oftentimes of nanoscale dimensions (van den Heuvel and Dekker, 2007).

Nanomedicine holds tremendous promise, yet despite the huge number of basic and preclinical studies, few nanomedicines have reached the clinic (Chan, 2017). Perhaps we have underestimated the complexity of biological systems, and that of human disease? Perhaps, as pointed out in a recent review, we need to view organs and cells in the body as complicit in the actions of nanomedicines: the chemistry of a material is altered upon contact with a biological system, and these changes determine its fate and function in the body (Chan, 2017). The reciprocal nature of so-called nano-bio interactions could be exploited for therapeutic gain if the underlying mechanisms are understood. However, the same features that may prove useful in the context of a disease may also turn out to be involved in the unwanted effects of a nanomaterial; toxicology and medicine may, in some respects, be viewed as two sides of the same coin.

Full paper available here: https://www.frontiersin.org/articles/10....2019.00001/full