Tannins are natural antioxidants with unique properties such as hydrogen
electron splitting and electron elimination, considered potential inhibitors
against reactive oxygen or nitrogen species and efficient antimicrobial activity.
Due to the unfavorable pharmacokinetics of conventional antioxidants, they
manifest a rapid metabolism with formation of secondary metabolites and a
considerable reduction in their time of action [1]. For the enhancement of its
antioxidant and antibacterial properties, entrapment of natural biocides into a
natural matrix can be used for prolongation of their biological activities.
Biopolymers such as chitosan (CS), cellulose, dextran are supramacromolecular
biocompatible compounds with low toxicity and biological recognized by the
cell entities [2].
The present work was undertaken to determine the detailed morphology
of the chitosan-based compositions (hydrogel, films), containing biocide Enoxil
and hydroxyethyl cellulose (HEC) and glycerin (Gly) as stabilizers and
enhancers, using atomic force microscopy, DSC, NMR, FT-IR and others.
The results showed that the addition of Enoxil into CS solution changed
the morphology (sizes of nanodomains and roughness of the free sample
surface), as well as the porosity of the bottom films surface. Moreover, DSC and
DMA analysis display that the Enoxil introduction changed the thermal and
relaxation properties of composite films, which can be explained via assemble at
the nanolevel. Moreover, entrapment of Enoxil into chitosan/HEC/Gly matrix
enhanced antioxidant capacity (AC, by 50%) as compared to Enoxil alone
determined by ABTS and DPPH assays. Microbiological investigations has
revealed that biomedical films chitosan/HEC – Enoxil are efficient for inhibition
of growth of P.aeruginosa (MIC 0.1% mg/ml) and B.cereus (MIC 0.1% mg/ml)
bacteria. Therefore, these bionanocomposites could be proposed for using in
open trauma infections and as post-operative surgery.
Acknowledgements
The research has received partial funding from the People Programme (Marie Curie Actions) of the
European Union‗s Seventh Framework Programme FP7 under REA grant agreement PIRSES-GA-
2013-612484 - NanoBioMat: Nanostructured Biocompati-ble/Bioactive Materials.
1. W. Bors, C. Michel, M. Saran, Methods in Enzymology, 234 (1994) 420.
2. J. Jansen, R. Cassano, S. Trombino, A. Cilea, N. Picci, E. Drioli, L. Giorno, Cellulose. 18
(2011) 359.