Tag Archives: E. Johan Foster

The shorter, the better for cellulose nanofibres

Cellulose nanomaterials can be derived from any number of plants. In Canada, we tend to think of our trees first but there are other sources such as cotton, bananas, hemp, carrots, and more.

In anticipation that cellulose nanofibres will become increasingly important constituents of various products and having noticed a resemblance to carbon nanotubes, scientists in Switzerland have investigated the possible toxicity issues according to a May 7, 2015 news item on Nanowerk,

Plant-based cellulose nanofibres do not pose a short-term health risk, especially short fibres, shows a study conducted in the context of National Research Programme “Opportunities and Risks of Nanomaterials” (NRP 64). But lung cells are less efficient in eliminating longer fibres.

Similar to carbon nanotubes that are used in cycling helmets and tennis rackets, cellulose nanofibres are extremely light while being extremely tear-resistant. But their production is significantly cheaper because they can be manufactured from plant waste of cotton or banana plants. “It is only a matter of time before they prevail on the market,” says Christoph Weder of the Adolphe Merkle Institute at the University of Fribourg [Switzerland].

A May 7, 2015 Swiss National Science Foundation (SNSF) press release, which originated the news item, provides more detail,

In the context of the National Research Programme “Opportunities and Risks of Nanomaterials” (NRP 64), he collaborated with the team of Barbara Rothen-Rutishauser to examine whether these plant-based nanofibres are harmful to the lungs when inhaled. The investigation does not rely on animal testing; instead the group of Rothen-Rutishauser developped a complex 3D lung cell system to simulate the surface of the lungs by using various human cell cultures in the test tube.

The shorter, the better

Their results (*) show that cellulose nanofibres are not harmful: the analysed lung cells showed no signs of acute stress or inflammation. But there were clear differences between short and long fibres: the lung cell system efficiently eliminated short fibres while longer fibres stayed on the cell surface.

“The testing only lasted two days because we cannot grow the cell cultures for longer,” explains Barbara Rothen-Rutishauser. For this reason, she adds, they cannot say if the longer fibre may have a negative impact on the lungs in the long term. Tests involving carbon nanotubes have shown that lung cells lose their equilibrium when they are faced with long tubes because they try to incorporate them into the cell to no avail. “This frustrated phagocytosis can trigger an inflammatory reaction,” says Rothen-Rutishauser. To avoid potential harm, she recommends that companies developing products with nanofibres use fibres that are short and pliable instead of long and rigid.

National Research Programme “Opportunities and Risks of Nanomaterials” (NRP 64)

The National Research Programme “Opportunities and Risks of Nanomaterials” (NRP 64) hopes to be able to bridge the gaps in our current knowledge on nanomaterials. Opportunities and risks for human health and the environment in relation to the manufacture, use and disposal of synthetic nanomaterials need to be better understood. The projects started their research work in December 2010.

I have a link to and a citation for the paper (Note: They use the term cellulose nanocrystals in the paper’s title),

Fate of Cellulose Nanocrystal Aerosols Deposited on the Lung Cell Surface In Vitro by Carola Endes, Silvana Mueller, Calum Kinnear, Dimitri Vanhecke, E. Johan Foster, Alke Petri-Fink, Christoph Weder, Martin J. D. Clift, and Barbara Rothen-Rutishauser. Biomacromolecules, 2015, 16 (4), pp 1267–1275 DOI: 10.1021/acs.biomac.5b00055 Publication Date (Web): March 19, 2015

Copyright © 2015 American Chemical Society

While tracking down the 2015 paper, I found this from 2011,

Investigating the Interaction of Cellulose Nanofibers Derived from Cotton with a Sophisticated 3D Human Lung Cell Coculture by Martin J. D. Clift, E. Johan Foster, Dimitri Vanhecke, Daniel Studer, Peter Wick, Peter Gehr, Barbara Rothen-Rutishauser, and Christoph Weder. Biomacromolecules, 2011, 12 (10), pp 3666–3673 DOI: 10.1021/bm200865j Publication Date (Web): August 16, 2011

Copyright © 2011 American Chemical Society

Both papers are behind a paywall.

Future biomedical applications for CNC (cellulose nanocrystals, aka NCC [nanocrystalline cellulose]) from Polytechnic Institute of New York University (NYU-Poly)

It’s good to see a project that might result in applications for CNC (aka, NCC). I commented briefly about the CNC situation earlier today in my Nov. 25, 2013 posting about Lomiko Metals (based in Surrey, BC, Canada) and its focus on developing markets for its product (graphite flakes/graphene). By contrast, Canada’s CelluForce plant (in Québec) has stopped production to avoid adding to its stockpile (as per my Oct. 3, 2013 posting), Alberta has launched a pilot CNC plant (my Nov. 19, 2013 posting), Blue Goose Biorefineries in Saskatchewan was ramping up production according to my May 7, 2013 posting and someone, in a blog posting comment, claimed that Pure Liganin in BC produces CNC (which I cannot confirm since the company mentions neither CNC nor NCC).,

Back to happier matters, a research team from Polytechnic Institute of New York University (NYU-Poly) has discovered information that could be helpful for scientists working with protein polymers (from the Nov. 22, 2013 news item on Azonano,,

A team of researchers has uncovered critical information that could help scientists understand how protein polymers interact with other self-assembling biopolymers. The research helps explain naturally occurring nano-material within cells and could one day lead to engineered bio-composites for drug delivery, artificial tissue, bio-sensing, or cancer diagnosis.

The Nov. 21, 2013 NYU-Poly press release, which originated the news item, goes on to explain the CNC connection to this work,

Bionanocomposites provide a singular area of research that incorporates biology, chemistry, materials science, engineering, and nanotechnology. Medical researchers believe they hold particular promise because—unlike the materials that build today’s medical implants, for example—they are biodegradable and biocompatible, not subject to rejection by the body’s immune defenses. As biocomposites rarely exist isolated from other substances in nature, scientists do not yet understand how they interact with other materials such as lipids, nucleic acids, or other organic materials and on a molecular level. This study, which explored the ways in which protein polymers interact with another biopolymer, cellulose, provides the key to better understanding how biocomposite materials would interact with the human body for medical applications.

The materials analyzed were composed of bioengineered protein polymers and cellulose nanocrystals and hold promise for medical applications including non-toxic, targeted drug delivery systems. [emphasis mine] Such bionanocomposites could also be used as scaffolding for tissue growth, synthetic biomaterials, or an environmentally friendly replacement for petroleum-derived polymers currently in use.

I wonder if the researchers obtained their CNC from the production plant in Wisconsin (US), assuming it has opened since my July 27, 2012 posting featuring an announcement of future plans. Getting back to this latest work, here’s a link to and a citation for the paper,

Bionanocomposites: Differential Effects of Cellulose Nanocrystals on Protein Diblock Copolymers by Jennifer S. Haghpanah, Raymond Tu, Sandra Da Silva, Deng Yan, Silvana Mueller, Christoph Weder, E. Johan Foster, Iulia Sacui, Jeffery W. Gilman, and Jin Kim Montclare. Biomacromolecules, Article ASAP DOI: 10.1021/bm401304w Publication Date (Web): October 18, 2013
Copyright © 2013 American Chemical Society

This paper is behind a paywall.

Offhand I can think of only one Canadian laboratory (although I’m certain there are others), which is working on applications for CNC and that’s Mark MacLaclan’s lab at the University of British Columbia (UBC). For example, there is this ‘in press’ paper,

Shopsowitz, K.E.; Kelly, J.A.; Hamad, W.Y.; MacLachlan, M.J. “Biopolymer Templated Glass with a Twist: Controlling the Chirality, Porosity, and Photonic Properties of Silica with Cellulose Nanocrystals” Adv. Funct. Mater. 2013, in press. DOI: 10.1002/adfm.201301737

You can find more about MacLachlan’s work here.