August 19 2017 by Drew Haser

The results of a half-decade long study on nanomaterials are in, and the data favors new opportunities while acknowledging areas that need more investigation.


A project conducted by the National Research Programme (NRP) in Switzerland included 23 individual but interdisciplinary research studies to evaluate the impact of nanoparticles on human health and the environment. Results of several of the projects were published recently in a special issue of the Journal of Nanobiotechnology.


In an editorial feature Ueli Aebi and Peter Gehr, both members of the Steering Committee of the Swiss National Research Programme, state, “Overall, the programme has clearly shown that, for the nanomaterials investigated, the opportunities outweigh the risks.”1 


Among the various studies were evaluations of measurement tools and protocols, single cell surgery with nanomagnets, nanoparticles for drug delivery, novel tissue engineering scaffolds, transport across the human placenta, and a “lab-on-a-chip” tool to assess the safety of nanoscale materials for next-generation battery systems.


Additionally, published in the special journal issue are 3 reviews highlighting important findings from the program.

1) An overview on nanoparticle toxicity for aquatic microorganisms features a novel tool to measure extracellular H2O2. As a result, valuable information on the potency of nano-CuO and nano-TiO2 to generate reactive oxygen species (ROS) as well as on the mechanisms of toxicity could be evaluated in algae populations. 2
2) A review of the transformation of released nanoparticles from composite materials and their health impacts illustrates findings such as “thermal treatment can destroy the fibrous structure of asbestos and transform asbestos into non-hazardous phase” and “released [carbon nanotubes] CNTs are possibly less harmful than the virgin CNTs.” 3


3) Evaluating the interaction of nanoparticles with the pulmonary immune system showed specific nanoparticle properties such as material, size and surface modification can be used to stimulate or to inhibit a specific immune reaction.4

                  • Certain nanoparticles were shown to stimulate T-Cell activation including amine functionalized gold nanorods (AuNR@NH2) and  20 nm polystyrene (PS) nanoparticles.  AuNR@NH2 enhanced ovalbumin-specific CD4+ T cell stimulation in lung draining lymph nodes, and PS nanoparticles also demonstrated enhanced activation of antigen-specific T cells following intra-nasal instillation in mice.
                  • On the other hand, nanoparticles like 50 nm PS with glycine (PS50G) were shown to inhibit features of allergic airway inflammation. PS50G nanoparticles suppressed the ability of CD11bhi dendritic cells in the draining lymph nodes of allergen-challenged mice to induce proliferation of OVA-specific CD4+ T cells.  

            With these mixed findings caution is urged for careful design, characterization, and control throughout the entire nanoparticle synthesis procedure in order to assure high-quality with repeatedly reproducible and accurate results dependant on subtle nanoparticle characteristics.


            For the full summary of all 23 studies within the program you can download the final brochure here.


            While the results of this work are highly encouraging, it is noted that there is significantly more work to be done. As professors Aebi and Gehr write, “What is still lacking are long-term studies that clearly document how exposure to nanoparticles over a longer period affects our bodies and the environment. By the same token, we still know very little about the effects of indirect exposure to nanoparticles, e.g. through the accumulation of nanoparticles in plants or animals that will eventually end up in our food chain.”


            Hopefully, with more studies like this intensive Swiss program the answers to these, and other nanoparticle unknowns, will continue to come to light.



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            References:

            1. Aebi, Ueli, and Peter Gehr. "Swiss National Research Programme “Opportunities and Risks of Nanomaterials”(NRP 64): key findings." (2017): 47. DOI: 10.1186/s12951-017-0282-5
            2. Santschi, Christian, et al. "Non-invasive continuous monitoring of pro-oxidant effects of engineered nanoparticles on aquatic microorganisms." Journal of nanobiotechnology 15.1 (2017): 19. DOI: 10.1186/s12951-017-0253-x
            3. Wang, Jing, Lukas Schlagenhauf, and Ari Setyan. "Transformation of the released asbestos, carbon fibers and carbon nanotubes from composite materials and the changes of their potential health impacts." Journal of nanobiotechnology 15.1 (2017): 15. DOI: 10.1186/s12951-017-0248-7
            4. Blank, Fabian, et al. "Interaction of biomedical nanoparticles with the pulmonary immune system." Journal of nanobiotechnology 15.1 (2017): 6. DOI: 10.1186/s12951-016-0242-5