INVESTIGADORES
LASSALLE Veronica Leticia
congresos y reuniones científicas
Título:
Gelatin/nanocellulose hydrogels: A potential materials for biomedical applications
Autor/es:
ALDANA PIZZANO; MELINA BRANCONE; JIMENA GONZÁLEZ; VERA ALVAREZ; MARÍA FERNANDA HORST; VERÓNICA LASSALLE
Reunión:
Workshop; Workshop on Insights and Strategies Towards a Bio-Based Economy; 2016
Resumen:
Nanocellulose is an attractive emerging material for biomedical applications due to its renewable nature, anisotropic shape, excellent mechanical properties, and good biocompatibility, among others. Hydrogels are soft materials, capable of holding large amounts of water in their networks maintaining their shape. For all these features, they are ideal materials for many biomedical applications. In particular, gelatin hydrogels are biocompatible, natural, biodegradable and non-toxic. However they lack in mechanical properties. In this context, nanocellulose can be add to produce nanocomposites with improved mechanical stiffness and durability. Moreover, hydrogel composites with nanocellulose seems to be promising biomaterials. The aim of this study is to synthesize gelatin based hydrogels modified with nanocellulose for biomedical applications. The nanocellulose was obtained from commercial microcellulose (sourced by Sigma Aldrich) by a mechanical procedure using an ultrasound tip (an ecofriendly procedure). The gelatin/nanocellulose hydrogel was prepared from freeze-thawing technique. In brief, an amount of gelatin and gum arabic (crosslinked agent) were dispersed in distilled water. The addition of aqueous dispersion of nanocellulose was performed and the mixture was allowed swell at 6°C during 24 h. Then, the temperature was increased to 50°C and maintained for an hour. After that, the solution was filled in disposable molds, allowing the formation of the hydrogel. Different amounts of nanocellulose content from 2 to 10 wt.% were evaluated. In this study, cellulose nanowhiskers were obtained applying ultrasound in a microcellulose aqueous solution. The images obtained in a scanning electron microscopy (SEM) show an average diameter of nanowhiskers of 37.50 ± 6.09 nm and 240 nm lengths. Fourier transform IR (FTIR) spectroscopy showed the stretching vibration of free ? OH at 3320 cm-1 and the stretching vibration of C-H at 2892 cm-1. Thermogravimetric measurements (TGA) displayed a degradation temperature at 333 °C and the obtained nanocellulose has a crystallinity index, IC% of 64.95 (determined by X-Ray diffraction, XRD). The dispersion ability of nanocellulose was tested in water, ethanol/water, acetone/water and acetone. Besides, the average diameter determined by Dynamic Light Scattering was measured in those three media. The values of hydrodynamic diameter in aqueous dispersion were broad in the range of 1-2 and the nanocellulose was not well dispersed. Moreover diameters around 800 nm were obtained in acetone/water dispersion. Meanwhile for acetone dispersion the hydrodynamic values were in the range of 500 nm. It was found that the acetone was the appropriate media to disperse the nanocellulose. Furthermore z potential measurements resulted in negative values for all the dispersions analyzed. The hydrogel synthesized is being characterized by FTIR, XRD, swelling determinations, TGA and SEM. Moreover, adsorption assays of bovine serum albumin as model protein will be done in order to evaluate the nanocomposite as wound dressing.