Assessment of chemically and enzymatically modified chitosan with eugenol as a coating for viscose functionalization for potential medical use

Abstract

The present work deals with the preparation of chemically and enzymatically eugenol-modified chitosan and its application as a green coating on viscose for the potential production of medical textiles. The elemental composition of chemically and enzymatically eugenol-modified chitosan was determined by attenuated total reflection Fourier transform infrared (ATR FT-IR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. Moreover, potentiometric titration was used to estimate the number of accessible amino groups. The chitosan–eugenol formulation possesses a high antioxidant capacity level, as shown by the high content of phenolic compounds analyzed by the following methods: (a) Folin–Ciocalteu; (b) reduction of Fe3+ ions; and (c) α, α-diphenyl-β-picrylhydrazyl (DPPH•). Viscose coated with chitosan–eugenol formulations was evaluated by ATR FT-IR spectroscopy and Acid Orange VII spectrophotometric methods, the results of which demonstrated the successful deposition of these formulations on the fibers. Scanning electron microscopy showed the presence of the functional coating on the viscose. Finally, antimicrobial testing was performed to determine inhibition of selected pathogenic micro-organisms using the ASTM E 2149-01 standard. The antioxidant activity of the functionalized viscose was investigated spectrophotometrically by the DPPH• method. It was found that the coatings of eugenol-modified chitosan impart antimicrobial activity to the viscose against Gram-positive and Gram-negative bacteria as well as fungi, and cause inhibition of free radicals by introducing an antioxidant character. The chemical and enzymatic modification of chitosan offers many opportunities for the incorporation of many natural active ingredients into the chitosan system, which provides a good basis for further work related to the functionalization of chitosan for sanitary and medical use.