Tag Archives: Kristin Syverud

Preparing nanocellulose for eventual use in* dressings for wounds

Michael Berger writes about a medical application for wood-based nanocellulose in an April 10, 2014 Nanowerk Spotlight article by featuring some recent research from Norway (Note: Links have been removed),

Cellulose is a biopolymer consisting of long chains of glucose with unique structural properties whose supply is practically inexhaustible. It is found in the cell walls of plants where it serves to provide a supporting framework – a sort of skeleton. Nanocellulose from wood – i.e. wood fibers broken down to the nanoscale – is a promising nanomaterial with potential applications as a substrate for printing electronics, filtration, or biomedicine.

Researchers have now reported on a method to control the surface chemistry of nanocellulose. The paper appeared in the April 8, 2014 online edition of the Journal of Biomaterials Applications (“Pretreatment-dependent surface chemistry of wood nanocellulose for pH-sensitive hydrogels”).

Using a specific chemical pretreatment as example (carboxymethylation and periodate oxidation), a team from the Paper and Fibre Research Institute (PFI) in Norway demonstrated that they could manufacture nanofibrils with a considerable amount of carboxyl groups and aldehyde groups, which could be applied for functionalizing the material.

The Norwegian researchers are working within the auspices of PFI‘s NanoHeal project featured in my Aug. 23, 2012 posting. It’s good to see that progress is being made. From the Berger’s article,

A specific activity that the PFI researchers and collaborators are working with in the NanoHeal project is the production of an ultrapure nanocellulose which is important for biomedical applications. Considering that the nanocellulose hydrogel material can be cross-linked and have a reactive surface chemistry there are various potential applications.

“A concrete application that we are working with in this specific case is as dressing for wound healing, another is scaffolds,” adds senior research scientist and co-author Kristin Syverud.

“Production of an ultrapure nanocellulose quality is an activity that we are intensifying together with our research partners at the Institute of Cancer Research and Molecular Medicine in Trondheim,” notes Chinga-Carrasco [Gary Chinga-Carrasco, a senior research scientist at PFI]. “The results look good and we expect to have a concrete protocol for production of ultrapure nanocellulose soon, for an adequate assessment of its biocompatibility.”

“We have various groups working with assessment of the suitability of nanocellulose as a barrier against wound bacteria and also with the assessment of the cytotoxicity and biocompatibility,” he says. “However, as a first step we have intensified our work on the production of nanocellulose that we expect will be adequate for wound dressings, part of these activities are described in this paper.”

I suggest reading Berger’s article in its totality for a more detailed description of the many hurdles researchers still have to overcome. For the curious, here’s a link to and a citation for the paper,

Pretreatment-dependent surface chemistry of wood nanocellulose for pH-sensitive hydrogels by Gary Chinga-Carrasco & Kristin Syverud. Published online before print April 8, 2014, doi: 10.1177/0885328214531511 J Biomater Appl April 8, 2014 0885328214531511

This paper is behind a paywall.

I was hoping to find someone from this group in the list of speakers for 2014 TAPPI Nanotechnology conference website here (officially known as 2014 TAPPI [Technical Association of the Pulp and Paper Industry] International Conference on Nanotechnology for Renewable Materials) being held in Vancouver, Canada (June 23-26, 2014) but had no luck.

* ‘as’ changed to ‘in’ Apr.14.14 10:50 am PDT in headline

Paper and Fibre Research Institute holds nanocellulose party/seminar

My ears always prick up when I come across a nanocellulose story and this Sept. 26, 2012 news item on Nanowerk features a nanocellulose seminar hosted by the Paper and Fibre Institute (PFI) in Norway (Note: I have removed a link),

PFI has the pleasure to organize the 4th research seminar about cellulose and their nanomaterials. The seminar will take place at PFI in Norway, on November 14-15, 2012. This will be a follow-up of the successful seminars in Trondheim 2006, 2008, 2010. The seminar offers an excellent scientific program, including topics which reflect the most recent advances from basic research to practical applications.

During the last years it has been considerable interest in cellulose nanofibrils [emphasis mine] due to the wide range of potential areas of application. This includes replacement for plastics, reinforcement of composite materials, boosting paper properties, barrier material in packaging and bio-medical applications.

As per the term I highlighted, cellulose nanofibrils, KarenS very kindly dropped by my Aug. 2, 2012 posting on nanocellulose research to explain some of the terminology that gets tossed around,

From my understanding, nanocrystaline cellulose (NCC), cellulose nanocrystals (CNC), cellulose whiskers (CW) and cellulose nanowhiskers (CNW) are all the same stuff: cylindrical rods of crystalline cellulose (diameter: 5-10 nm; length: 20-1000 nm). Cellulose nanofibers or nanofibrils (CNF), on the contrary, are less crystalline and are in the form of long fibers (diameter: 20-50 nm; length: up to several micrometers).

There is still a lot of confusion on the nomenclature of cellulose nanoparticles, but nice explanations (and pictures!) are given here (and also in other papers from the same [TAPPI 2012 in Montréal] conference):

http://www.tappi.org/Downloads/Conference-Papers/2012/12NANO/12NANO49.aspx

Thank you KarenS, I really appreciate the clarification and the link to additional information.

Back to the main event, I went to the webpage for the 4th research seminar about cellulose and their nanomaterials and found a listing of the speakers,

Tsuguyuki Saito (University of Tokyo):  “Material Properties of TEMPO-Oxidized Cellulose Nanofibrils: In bulk and Individual Forms”
Lars Berglund (KTH): “Unexplored materials property space – does nanofibrillated cellulose provide new possibilities?”
Michel Schenker (Omya): “Toward Nano-fibrillated Pigmented Cellulose Composites”
Anette Hejnesson-Hulten (Eka):  “Chemically Pretreated  MFC – Process, Manufacturing and Application”
Kriistina Oksman (Luleå Univ.of Techn): “Nanocelluloses extracted from  bio residues and their use in composites”
J.M. Lagaron (CSIC): “Nanocellulose as a reinforcing material in packaging films”
Tomas Larsson (Innventia): “Determining the specific surface area of NFC by CP/MAS 13C-NMR”
Tekla Tammelin, (VTT): “Dense NFC films with several opportunities for additional functionalities”
Kristin Syverud (PFI): “A biocompatibility study of microfibrillated cellulose”
Øyvind Gregersen (NTNU): “The effect of microfibrillated cellulose on the pressability and paper properties of TMP and ground calcium carbonate (GCC) based sheets”
Gary Chinga Carrasco (PFI): “Characterization of the fibrillation degree of various MFC materials and its implication on critical properties”
Marianne Lenes (PFI): “MFC as barrier material – possibilities and challenges”
Laura Alexandrescu (NTNU): “MFC filters for environmental particle filtration”
Per Stenius (NTNU): “Nanofibrils – do they fulfill the promises?”

Dag Høvik (Research Council of Norway): “Strategic research programmes within Nanotechnology and Advanced Materials in Norway, 2002-2021”.

Interestingly given our work in this field, there don’t seem to be any Canadians on the speaker list.  I imagine that this is largely due to the fact that they have healthy and active research community in Norway and this is not really an international affair.