A nanoparticle is small, exceptionally small. Not as tiny as an atom, but down there. On a comparative scale, if a marble were a nanometer, then one meter would be the size of the Earth. One nanometer is a billionth of a meter, or 10-9 of a meter. There are 25,400,000 nanometers in an inch. A sheet of newspaper is about 100,000 nanometers thick. So yeah, small.

Nanotechnology is the understanding and control of matter at the nanoscale, at dimensions between approximately 1 and 100 nanometers, “where unique phenomena enable novel applications.” That’s what it says at nano.gov, where the uninitiated can get some science:

“Encompassing nanoscale science, engineering and technology, nanotechnology involves imaging, measuring, modeling and manipulating matter at this length scale. Matter such as gases, liquids and solids can exhibit unusual physical, chemical and biological properties at the nanoscale, differing in important ways from the properties of bulk materials and single atoms or molecules. Some nanostructured materials are stronger or have different magnetic properties compared to other forms or sizes of the same material. Others are better at conducting heat or electricity. They may become more chemically reactive or reflect light better or change color as their size or structure is altered.”

Specifically, such “nanofillers” are typically inorganic and organic materials such as metals (Al, Fe, Au, or Ag), metal oxides (ZnO, Al2O3, TiO2), mixed metal oxides, clays, and carbon nanotubes. They improve “the volume properties, surface properties, dimensional stability, chemical stability and other functional properties of the reinforced polymers, conferring photocatalytic, optical, electrical and thermal stability,” according to NanoSafePACK, a research group based in Europe.

The concepts behind the field were articulated in the late 1950s by Richard Feynman, a brilliant Nobel Prize winning scientist and raconteur whose lectures are well worth reading, even by the layperson. Norio Taniguchi coined the term nanotechnology in 1974.

Today, nanoparticles are used in technology everywhere, and that includes a significant presence in packaging. Active packaging dominated the global technology sector in 2015, valued at $14.2 billion, according to “Nano-enabled Packaging Market Analysis by Technology,” published last year by Grand View Research. Nanoscience in packaging is expected to grow at a healthy CAGR of 12.9% from 2016 to 2024 in terms of value. It is expected that the food and pharmaceutical sectors will provide the highest demand.

Such packaging uses nanoparticles to provide a barrier to outside influences, the report says. Some of the technologies are oxygen scavengers, water vapor removers, carbon dioxide producers, ethylene removers, and ethanol releasers.

“Intelligent and smart packaging is designed for detecting microbial or biochemical changes in the food: for example, sensing specific pathogens developing in the food, or specific gases which can result in food spoilage. This technology is also used as a tracking device to ensure food safety or to avoid product counterfeiting,” Grand View reports. “It acts as a barrier from light, UV rays and moisture in the food and beverage industries, and also provides stability, safety and durability, and improves the shelf life of products. Nano-enabled packaging provides chemical and physical stability to medicines by improving their shelf life and acting as an antimicrobial barrier. It protects medicines from environmental pollutants and helps restore its medicinal properties.”

Health and environmental concerns
All industries, including medicine, have benefited from nanotechnology, and the science has changed the packaging game, most significantly for products that must maintain freshness and stability. But because of what and how small they are, nanoparticles raise concerns that cannot be ignored and are the subject of intense scientific study worldwide. Why?

The reasons have been identified, and some answers have been found but questions remain. Green Facts, an environmental research nonprofit, states the main concerns plainly:

Nanoparticles can have the same dimensions as some biological molecules (such as proteins) and can interact with these. In humans and in other living organisms, they may move inside the body, reach the blood and organs, such as the liver or the heart, and may also cross cell membranes. Insoluble nanoparticles are a greater health concern because they can persist in the body for long periods of time.

Inhaled nanoparticles can deposit in the lungs and then potentially move to other organs such as the brain, the liver and the spleen, and possibly the fetus in pregnant women. Some materials could become toxic if they are inhaled in the form of nanoparticles. Inhaled nanoparticles may cause lung inflammation and heart problems.

The objective of nanoparticles used as drug carriers is to deliver more of the drug to the target cells, to reduce the harmful effects of the drug itself on other organs, or both. However, it is sometimes difficult to distinguish the toxicity of the drug from that of the nanoparticle.

With the exception of airborne particles reaching the lungs, information on the behavior of nanoparticles in the body is still minimal. Assessment of the health implications of nanoparticles should take into account the fact that age, respiratory tract problems and the presence of other pollutants can modify some of the health effects.

Information on the effects of nanoparticles on the environment is very scarce. However, it is likely that many conclusions drawn from human studies can be extrapolated to other species, but more research is needed.

As long ago as 2010, the US National Library of Medicine at the National Institutes of Health published a paper addressing the benefits, current and future, of nanotechnology alongside questions that should be answered before the industry explodes. The authors wrote: “Despite obvious benefits of the power of small materials, there are open questions about how the nanoparticles used for day-to-day life may affect the environment. One of the crucial issues that have to be addressed in the near future, before massive fabrication of nanomaterials, is their toxicity to humans and impact on the environment.

“There are considerable debates regarding how the novel properties of nanomaterials could lead to adverse biological effects, with the potential to cause toxicity. One needs to understand when nanoparticles undergo biodegradation in the cellular environment, what will the cellular responses be? For example, biodegraded nanoparticles may accumulate within cells and lead to intracellular changes such as disruption of organelle integrity or gene alternations.

“Some of the crucial questions are: 1) Are nanomaterials more toxic than their non-nano counterparts? 2) Will nanoparticles transform in the environment into more toxic forms? Before nanomaterials are allowed to be used in daily life activities, it is important for nanotoxicology research to uncover and understand how nanomaterials influence the environment so that their undesirable properties can be avoided.”

Seven years later we know many of the dangers involved, but some questions persist. This surely is a strange new world, and we are boldly going where no one has gone before.

Ancient nano history
Nanoscale materials were used for centuries. Alternate-sized gold and silver particles created colors in the stained glass windows of medieval churches hundreds of years ago. The artists back then just didn’t know that the process they used to create these beautiful works of art actually led to changes in the composition of the materials with which they were working.

Glowing, glittering ceramic glazes used in the Islamic world, and later in Europe, contained silver or copper or other metallic nanoparticles. Damascus saber blades contained carbon nanotubes and cementite nanowires – an ultra-high carbon steel formulation that gave them strength, resilience, the ability to hold a keen edge, and a visible moiré pattern in the steel that give the blades their name.
— National Nanotechnology Initiative (www.nano.gov)



The author is president of Jack Kenny Media, a communications firm specializing in the packaging industry, and is the former editor of L&NW magazine. He can be reached at
[email protected].