Tag Archives: NanoHeal

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

Norwegians weigh in with research into wood nanocellulose healing application

It’s not just the Norwegians but they certainly seem to be leading the way on the NanoHeal project. Here’s a little more about the intricacies of healing wounds and why wood nanocellulose is being considered for wound healing, from the Aug. 23, 2012 news item on Nanowerk,

Wound healing is a complicated process consisting of several different phases and a delicate interaction between different kinds of cells, signal factors and connective tissue substance. If the wound healing does not function optimally, this can result in chronic wounds, cicatrisation or contractures. By having an optimal wound dressing such negative effects can be reduced. A modern wound dressing should be able to provide a barrier against infection, control fluid loss, reduce the pain during the treatment, create and maintain a moist environment in the wound, enable introduction of medicines into the wound, be able to absorb exudates during the inflammatory phase, have high mechanical strength, elasticity and conformability and allow for easy and painless release from the wound after use.

Nanocellulose is a highly fibrillated material, composed of nanofibrils with diameters in the nanometer scale (< 100 nm), with high aspect ratio and high specific surface area (“Cellulose fibres, nanofibrils and microfibrils: The morphological sequence of MFC components from a plant physiology and fibre technology point of view” [open access article in Nanoscale Research Letters]). Cellulose nanofibrils have many advantageous properties, such as high strength and ability to self-assembly.

Recently, the suitability of cellulose nanofibrils from wood for forming elastic cryo-gels has been demonstrated by scientists from Paper and Fibre Research Institute (PFI) and Lund University (“Cross-linking cellulose nanofibrils for potential elastic cryo-structured gels”  [open access in Nanoscale Research Letters). Cryogelation is a technique that makes it possible to engineer 3-D structures with controlled porosity. A porous structure with interconnected pores is essential for use in modern wound healing in which absorption of exudates, release of medicines into the wound or exchange of cells are essential properties.

The Research Council of Norway recently awarded a grant to the NanoHeal project, from the project page on the PFI (Pulp and Fibre Research Institute) website,

This multi-disciplinary research programme will develop novel material solutions for use in advanced wound healing based on nanofibrillated cellulose structures. This proposal requires knowledge on the effective production and application of sustainable and innovative micro- and nanofibres based on cellulose. The project will assess the ability of these nanofibres to interact with complementary polymers to form novel material structures with optimised adhesion and moulding properties, absorbance, porosity and mechanical performance.  The NanoHeal proposal brings together leading scientists in the fields of nanocellulose technology, polymer chemistry, printing and nanomedicine, to produce biocompatible and biodegradable natural polymers that can be functionalized for clinical applications. As a prototype model, the project will develop materials for use in wound healing. However, the envisaged technologies of synthesis and functionalization will have a diversity of commercial and industrial applications.

The project is funded by the Research Council of Norway/NANO2021, and is a cooperation between several leading R&D partners.

  • PFI
  • NTNU [Norwegian University of Science and Technology], Faculty of medicine
  • Cardiff University
  • Swansea University
  • Lund University
  • AlgiPharma

Project period: 2012-2016

I wonder when I’m going to start hearing about Canadian research into wood nanocellulose  (nanocrystalline cellulose or otherwise) applications.