Translucent and ductile nanocellulose-PEG bionanocomposites-A novel substrate with potential to be functionalized by printing for wound dressing applications

There is potential that nanocellulose structures can act as a substrate for biomedical applications in which printing can expand its use as a functionalized biomaterial. Nanocellulose has a variety of advantages, which make the material suitable for use in biomedical devices that include wound dressings. The material does not promote bacterial growth, allows for production of translucent films and provides a moist wound-healing environment. However it is intrinsically brittle so research is needed to develop its flexibility and strength through the addition of plasticisers. In this work, we explore the effect of Polyethylene Glycol (PEG 400) as a plasticizer on nanocellulose film formation and performance. The nanocellulose used was prepared with TEMPO mediated oxidation. We also demonstrated different methods such as laser profilometry and atomic force microscopy to observe the topography and morphology of the films. FTIR, UV-vis spectroscopy was used to look at the characteristics of the nanocellulose films. In addition, the mechanical strength of the films with and without plasticizers was assessed. This led to the formulation of films that included PEG400 at 10-40% by weight. These demonstrated properties that are suitable for wound dressings. Additionally, the PEG modification yielded films that showed a surface morphology adequate for surface modification by printing. Importantly, a cytotoxicity test was performed using Human Dermal Fibroblasts and Human Epidermal Keratinocytes. The results showed no effect on the metabolic activity when fibroblasts were incubated in the presence of films containing 10 and 25% PEG. A reduction was measured in the presence of PEG at 40%. However, no significant cell death was detected in any of the cell-types. Hence, the nanocellulose-PEG films are not considered to be cytotoxic against human skin cells at the concentrations applied in this study. (C) 2016 Elsevier B.V. All rights reserved.