Bio-compatible cellulose nanostructures for advanced wound healing applications

During the project period (2012-2016) we have demonstrated that we can produce TEMPO nanocellulose with defined structural and surface chemical characteristics, which can be used for cross-linking the material and thus stabilize the mechanical properties of hydrogels. Toxicity aspects, immunogenic properties and the ability of nanocellulose to resist bacterial colonization have been verified. We have confirmed that TEMPO nanocellulose is a good candidate for wound dressings. The material can be produced ultrapure (endotoxin levels less than 50 endotoxin units/gram cellulose) and can form films and porous structures with good water absorption properties. The effect of the dressing structure (surface roughness and porosity) on bacterial growth and biofilm formation has been verified. In addition, it was demonstrated that nanocellulose gels have a dose-dependent effect on bacterial growth (P. aeruginosa). The application of polyethylene glycol (PEG) as a component in nanocellulose films improves the properties of the wound dressings. PEG is biocompatible, antimicrobial, and contributes to form films which are flexible and with good strength, appropriate water absorption and smooth surface. This is positive for functionalizing the films with OligoG, by printing. OligoG in nanocellulose-PEG film dressings show antimicrobial properties. Additionally, as part of the PhD study, we have implemented a new method for preparing skin wound models from abdominal surgery. The models are used to verify the wound healing effect of nanocellulose structures. Preliminary results, compared to commercial wound dressings, are promising.

This multi-disciplinary programme of research 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 sustainabl e and innovative micro- and nanofibres based on cellulose. The ability of these nanofibres to interact with complementary polymers to form novel material structures (e.g. wound dressings or skin graft matrices) with optimised adhesion and moulding propert ies, absorbance, porosity and mechanical performance will be assessed. Such ambitious goals require the cooperation and multi-national team of research institutes, academia and industry, which is established in this proposal. The novelty of this approach is that it brings together leading scientists in the fields of nanocellulose technology, polymer chemistry, printing and nanomedicine, to produce the first generation of biocompatible and biodegradable natural polymers, which can be functionalised for cli nical applications. As our prototypical model we will develop materials for use in wound healing, but the technologies of synthesis, functionalization and controlled biodegradability that can be envisaged, will have many diverse commercial and industrial applications. The proposed project has thus a high potential for technological and medical innovation; generating fundamental knowledge on the design and formulation of nanofibrils and polymer conjugates. Such knowledge will form the basis for the creati on of novel bio-based materials with innovative functional properties. The proposal also fulfils important areas mentioned in the NANO2021 program, in forming the basis for industrial development and addresses important society issues within medicine, hea lth and use of natural resources.