Question of the Week, 30.8.2011
Nanotechnology is a hot topic nowadays in science. Some applications areas are still under testing but already you can find nanoparticles present in a lot of products in your daily life: sun protecting lotions, fuel additives, filler materials, inks, lubrificants, batteries, etc.
Nanoparticles find interest in technology due to their unusual physicochemical properties like small size, high surface area, chemical composition, crystallinity, surface reactivity, solubility, aggregation behavior, etc. But these same properties that make them so useful can also have an adverse effect in the human body. Even when the same material that the nanoparticles are made from, is relatively inert when in bulk, when size is reduced they can become toxic. Nanoparticles can interact with proteins and enzymes in cells; enhance the formation of free radicals (like the case of catalytic materials as TiO2), which affects the defense mechanism. They can also induce inflammatory responses and lead to necrosis or apoptosis of the cells.
Still, we see more and more research made in biological applications of nanomaterials (drug delivery, cancer treatment, dynamic therapies, etc) but less data on their toxicity in vivo. Tests made in cell cultures unfortunately are not sufficient, as the behavior of isolated cells is very different of that on a tissue or organ. To what extend should nanobiotechnology research be allowed to evolved to applied materials before extensive knowledge of their effects in the human body at long term is determined?
For more information:
Schrand, A.M; Rahman, M.F.; Hussain, S.M.; Schlager, J.J.; Smith, D.A.; Syed, A.F. Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology 2010, 2 (5), 544-568
Dreher, K.L. Toxicological Sciences 2004, 77(1), 3-5
Rute Andre