[Chapter 4. Risks and benefits of medical nanotechnologies: a balancing to be Reconsidered].

Nanomedicine opens new diagnostic and therapeutic perspectives. So far, even if few health nanoproducts are on the market, more than a hundred are in clinical trials, mainly in oncology. In fact, the uncertainty that characterizes the knowledge of risks related to nanoparticles, such as the difficulty of adapting evaluation methodologies to the singularity of each of them, in turn, affects the establishment of the benefit-risk balance, prior to any marketing. The objective of this study is to show that, facing the pitfall of risk assessment, the measurement of a global benefit, combining medical efficacity and life benefit for patients, from the very beginning of the nanoproduct design, becomes crucial for the construction of the balance and should be apprehended as the key normative condition of its development.