Characterization of Epigallocatechin-Gallate-Grafted Chitosan Nanoparticles and Evaluation of Their Antibacterial and Antioxidant Potential.

María J Moreno-Vásquez,Idania E Quintero-Reyes,Abril Z Graciano-Verdugo,Saúl Sánchez-Valdes,Judith C Tanori-Córdova,Francisco J Castillo-Yañez,Maribel Plascencia-Jatomea

doi:10.3390/polym13091375

María J Moreno-Vásquez, Idania E Quintero-Reyes + Show 5 more

Open Access

https://doi.org/10.3390/polym13091375

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Journal: Polymers	Publication Date: Apr 23, 2021
Citations: 23	License type: CC BY 4.0

Affiliation: Universidad de Sonora

Abstract

Nanoparticles based on chitosan modified with epigallocatechin gallate (EGCG) were synthetized by nanoprecipitation (EGCG-g-chitosan-P). Chitosan was modified by free-radical-induced grafting, which was verified by Fourier transform infrared (FTIR). Furthermore, the morphology, particle size, polydispersity index, and zeta potential of the nanoparticles were investigated. The grafting degree of EGCG, reactive oxygen species (ROS) production, antibacterial and antioxidant activities of EGCG-g-chitosan-P were evaluated and compared with those of pure EGCG and chitosan nanoparticles (Chitosan-P). FTIR results confirmed the modification of the chitosan with EGCG. The EGCG-g-chitosan-P showed spherical shapes and smoother surfaces than those of Chitosan-P. EGCG content of the grafted chitosan nanoparticles was 330 μg/g. Minimal inhibitory concentration (MIC) of EGCG-g-chitosan-P (15.6 μg/mL) was lower than Chitosan-P (31.2 μg/mL) and EGCG (500 μg/mL) against Pseudomonas fluorescens (p < 0.05). Additionally, EGCG-g-chitosan-P and Chitosan-P presented higher Staphylococcus aureus growth inhibition (100%) than EGCG at the lowest concentration tested. The nanoparticles produced an increase of ROS (p < 0.05) in both bacterial species assayed. Furthermore, EGCG-g-chitosan-P exhibited higher antioxidant activity than that of Chitosan-P (p < 0.05) in 2,2′-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and ferric-reducing antioxidant power assays. Based on the above results, EGCG-g-chitosan-P shows the potential for food packaging and biomedical applications.

Highlights

Food loss and waste are some of the main problems facing the food industry
To verify that the particle synthesis method does not affect the functionalization of chitosan, epigallocatechin gallate (EGCG)-g-chitosan-P was characterized by Fourier transform infrared (FTIR) spectroscopy
In the FTIR spectra of the EGCG-g-chitosan-P (Figure 1), the bands at 1500–1640 cm−1 are broader than those for the Chitosan-P which could be attributed to the conjugation with the EGCG as well as to the C=C skeletal vibration in the aromatic ring

Summary

Introduction

Food loss and waste are some of the main problems facing the food industry. The main factor contributing to this problem is deterioration because of microbiological, enzymatic, and physicochemical reactions [2]. The deterioration process leads to changes in pH, formation of toxic compounds, gas production, slime formation, off-flavor production, and lipid oxidation. There are several preservation methods for increasing the shelf life of foods, such as the incorporation of synthetic active compounds, mainly synthetic antimicrobials and antioxidants. The increasing occurrence of new food-borne disease outbreaks has raised concerns about food safety. These concerns have led to numerous studies on the isolation, characterization, and evaluation of biologically active compounds from natural sources, such as animals, microorganisms, herbs, and plants [3]

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