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

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.

Evaluation on Structural Properties and Performances of Graphene Oxide Incorporated into Chitosan/Poly-Lactic Acid Composites: CS/PLA versus CS/PLA-GO

“…Chitin is the second most abundant natural polymer after cellulose [4], and CS is derived from chitin (exoskeletons such as prawns, crustacean shells) via deacetylation reaction; thus, it is normal that CS has received attention from many researchers. CS is easy to obtain and is also a very compatible and effective biomaterial usable for many applications, for example, in the biomedical field [5,6], where it serves as an alternative candidate for drug delivery because it has a regenerative effect on connective tissue [7]. CS is normally associated with a moisture-resistant polymer while maintaining the overall biodegradability of the product.…”

Chitooligosaccharide Conjugates Prepared Using Several Phenolic Compounds via Ascorbic Acid/H2O2 Free Radical Grafting: Characteristics, Antioxidant, Antidiabetic, and Antimicrobial Activities

“…In addition, EGCG possessed a higher number of -OH groups, followed by CAT. As a result, their bulky structures limited the solubility in the aqueous medium and caused steric hindrance, thus restricting hydrogen bonding with COS molecules [ 21 ]. This was supported by the lowest conjugation efficiency of EGCG and CAT at 10 mg/mL.…”

HPLC Characterization of Phytochemicals and Antioxidant Potential of Alnus nitida (Spach) Endl.

“…Therefore, it can be concluded that malic acid, chlorogenic acid, epigallocatechin gallate, quercetin, ellagic acid, and pyrogallol are the chief phenolic compounds that might be accountable for the observed antioxidant potential of the selected plant. In other studies, it has been reported that these compounds, chlorogenic acid [30], epigallocatechin gallate [31], quercetin [32], ellagic acid [33], pyrogallol [34] have potent antioxidant effects. A total of 273 compounds are reported from the seven Alnus species (A. japonica, A. hirsuta, A. glutinosa, A. incana, A. nepalensis, A. sieboldiana and A. firma), with very little or no attention being paid to alternative folks uses of those plants.…”