The challenge of making safe engineered nanomaterials

The challenge of making safe engineered nanomaterials

Interest in nanotechnology and problems that may arise.

Nowadays the emerging field of nanoscience appears to have captured the imagination of the public thorough its novelty and aesthetics. Nanotechnology is recognized as one of the most important new technologies of the 21stcentury and there is clearly a public expectation that will figure prominently in the future of economic landscape. The global investment in nanotechnology from all public sources for 2008 exceeds $7 billion. USA investment in nanotechnology for 2014 will be $1.7 billion.1 The market size for nanotechnology is expected to grow to over $3 trillion by 2015. Nanotechnology promises new materials for industrial applications by having new or enhanced physico-chemical properties that are different in comparison to their micron-sized counterparts. Moreover, nanotechnology focused into the new era of production societies based on knowledge.
The impact of nanotechnologies on every day products could be more tremendous than expected. Within the nearly limitless diversity of the nowadays commercialized nanoparticles, some happen to be toxic to biological systems, others are relatively benign, while others confer health benefits.6 It is possible to cite beneficial properties of the extended use of nanoparticles: UV filters in cosmetics; as antifungal and antibacterial for textile, packaging, appliances and toiletry; in the manufacturing of materials for polymer, cement or ceramic based materials; as antioxidant for medicine; nanoparticles as catalyst in chemical production and environmental remediation; as nanoencapsulation of flavors and aromas; nanofood; etc… the question that nobody can answer today is related to how the massive use nanoparticles will affect the living organism in a medium-large period?. Right now it is mandatory to think in how to avoid or minimize the harmful future impact and to strengthen the enormous benefit that nanoparticles could contribute to the society.
As nanotechnology enters into industrial applications, the potential exposure of humans and the environment to these materials (nanoparticles in particular) is inevitable.3-5 As nanoparticles go through their life-cycle (from development, to manufacture, to consumer usage, to final disposal) different human groups (workers, bystanders, users), animal species (e.g. worm, fish or human through secondary exposure) and natural environments (air, soil, sediment, water) will be exposed to them. Like viruses, some nanoparticles can penetrate lung or dermal skin barriers and enter the circulatory and lymphatic systems of humans and animals, reaching most bodily tissues and organs, and potentially disrupting cellular processes and causing disease.6 A growing body of evidence has shown a range of toxic effects from engineered nanomaterials, NM, suggesting that even their low mass exposure will result in a risk to human health or the environment. Living bodies are not face before the massive appearance of nanoparticles and its derivative effects. Therefore it is clear that there is a need for a better understanding of the relationship between NM’s properties and the adverse responses which they can potentially cause in short period of time. Nowadays, the governments take land of the industrial concern of NM use by restrictive policies. Within the actual situation, long term studies are not an option and it is compulsory to produce NM with reduction of the collateral adverse effects. To reduce nanomaterials potential risks represents firstly a challenge to the companies and secondly a tremendous business opportunity to take advantage over competitors.

NM ife cycle

Is there a way to obtain benefits from safe-by design NM’s?

Current direction in this field focused into the development of nanostructured particles and materials in order to have desirable characteristics for industrial applications. Large-scale programs, institutes and research networks have been initiated recently on these and other topics in the United States, Japan, EC, China and other countries. Some examples of materials which could resolve the problems of free-nanoparticles thorough the formation of nanostructured microparticles, are based in supramolecular chemistry. To overcome the complex and expensive procedures new more reliable and accessible technologies are required. Among them, sol-gel chemistry with an adapted processing technique (microfabrication, chemical solution deposition, spraying, etc.) appears as a straightforward approach to design advanced functional materials with perfect control over their structures and textures. Beautiful examples of these alternative “low-cost” routes are provided by combination of sol-gel process onto silicon support.8

The solution of the harmful collateral effect of nanotechnology must be addressed by using new safe by design nanostructured microparticles in which advantages of nanoparticles would be preserved but harmful effect eliminated.

A room temperature solid-state redox reaction accounts for the surface reduction of the oxide nanoparticles when approaching the surface of microparticles9 and form of hierarchically supported nanoparticles. Short range interactions between a nanoparticle and microparticles are non-symmetrical so are the responsible for the induced stress in the nanoparticle. The nanoparticle anchored in a microparticle takes advantage of proximity effects that modify the chemical response of the nanoparticle just at room temperature without complex processes. This patented process was extended to a wide variety of nanoparticles and supports allowing effective nanodispersion processes.10 The relevance of this innovative process is to maximize the nanoparticles effectiveness by hierarchical arrangement while substantially reducing the volume thereof to achieve the same effects. In this way, the final products have to use lower nanoparticle load to get the desired effect, reducing the cost of their use. Moreover, this method is cheaper than other processes for dispersion of nanoparticles thanks to a huge operative simplification.

The spin-off company ADParticles based in this technology launched a new product in 2015, EnhanceU®, as an inorganic UV filter for suncare cosmetics characterized because:

  • High level of security on formulation – Non-nanometric size
  • High SPF (Sun Protection Factor) and UVA PF (UVA Protection Factor)
  • Good Photo-Stability
  • Alumina Free
  • UVA/UVB<3.0 and Critical Wavelength > 370 nm

Generally speaking, the anchored titanium dioxide nanoparticles in EnhanceU filter are able to effectively trap UV radiation and the host microparticles support serve as a ground line to reduce the formation of free radicals.

To sum up, new solutions are provided to promote the safe use of nanotechnology essentially linked whit its commercial viability and long-term sustainability.

EnhanceU

References

  1. J. F. Sargent Jr., The National Nanotechnology Initiative: Overview, Reauthorization, and Appropriations Issues. Congressional Research Service Report for Congress, August 29, 2013.
  2. C. Buzea, I. I. Pacheco and K. Robbie, Nanomaterials and nanoparticles: Sources and toxicity; Biointerphases 2,4,MR17-MR71(2007).
  3. Committee to Develop a Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials; National Research Council. A Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials. The National Academies Press. Washington, D.C. 2012.
  4. M. Mullins, F. Murphy, L. Baublyte, E. M. McAlea, S. A. M. Tofail, The insurability of nanomaterial production risk. Nature Nanotechnology 8,222–224(2013).
  5. D. A. Scheufele, E. A. Corley2, S. Dunwoody, T. J. Shih, E. Hillback, D. H. Guston. Scientists worry about some risks more than the public. Nature Nanotechnology 2, 732 – 734 (2007)
  6. T. V. Duncan. The communication challenges presented by nanofoods. Nature Nanotechnology 6,683–688(2011).
  7. H. Gleiter, Nanostructured materials: basic concepts and microstructure, Acta mater. 48,1-29(2000).
  8. A. Carretero-Genevrier, M. Gich, L. Picas, J. Gazquez, G. L. Drisko, C. Boissiere, D. Grosso, J. Rodriguez-Carvajal, C. Sanchez, Soft-Chemistry–Based Routes to Epitaxial a-Quartz Thin Films with Tunable Textures, Science 340, 827-31 (2013).
  9. M. S. Martin-González, M. A. García, I. Lorite, J. L. Costa-Krämer, F. Rubio-Marcos, N. Carmona, and J. F. Fernández, A Solid-State Electrochemical Reaction as the Origin of Magnetism at Oxide Nanoparticle Interfaces, J. Electrochem. Soc., 157, 3,E31-E35(2010).

10. J. F. Fernández, I. Lorite, F. Rubio-Marcos, J. J. Romero, M. A. García, A. Quesada, M. S. Martín-González, J.L. Costa-Kramer. Method for dry dispersion of nanoparticles and production of hierarchical structures and coatings. Patent WO2010/010220 A1 de 28/01/2010

Profesor de Investigación del C.S.I.C. INSTITUTO DE CERAMICA Y VIDRIO

12 julio, 2015 | Aplicaciones prácticas