Antibacterial nanocomposite of chitosan/silver nanocrystals/graphene oxide (ChAgG) development for its potential use in bioactive wound dressings

Abstract

An adequate wound dressing reduces time of healing, provides cost-effective care, thereby improving patients' quality life. An antimicrobial bioactivity is always desired, for that reason, the objective of this work is to design an antimicrobial nanocomposite of chitosan/silver nanocrystals/graphene oxide (ChAgG). ChAgG nanostructured composite material is composed of chitosan from corn (Ch), and silver nanocrystals from garlic (Allium sativum). The nanocomposite obtained is the result of a series of experiments combining the graphene oxide (GrOx) with two members of the Amaryllidaceae family; garlic and onion (Allium cebae), which contain different sulfur materials. The characterization arrays confirmed the successful production of silver crystal, graphene oxidation and the blending of both components. The role of the chitosan as a binder between graphene and silver nanocrystals is proved. Moreover, the study discusses garlic as an optimal source that permits the synthesis of silver nanocrystals (AgNCs) (⁓ 2 to 10 nm) with better thermal and crystallinity properties. It was also confirmed the successful production of the ChAgG nanocomposite. Escherichia coli and Staphylococcus aureus were used to demonstrate the antibacterial bioactivity and L-929 fibroblast cells were utilized to visualize their biocompatibility. The proposed ChAgG nanomaterial will be useful for functionalizing specific fiber network that represents current challenging research in the fabrication of bioactive wound dressings.

Figure 1

XRD for the sample corresponding to ChAgG nanocomposite.

Figure 2

SEM for nanocrystals obtained from garlic (Allium Sativum). (A) A1 sample with 100 nm (×50,000) amplification; (B) A1 sample with 1 µm (×10,000) amplification; (C) A5 sample with 1 µm (×11,000) amplification; (D) A5 sample with 100 nm (×50,000) amplification.

Figure 3

High-resolution transmission electron micrographs for nanocrystals obtained from a garlic sample (Allium cebae). (A) with the highest amplification (10 nm measuring bar); (B) with the lowest amplification (50 nm measuring bar); (C) with the medium amplification (20 nm measuring bar).

Figure 4

Raman spectroscopy of graphene (Gr), oxidized graphene (GrOx) and the nanocomposite (ChAgG).

Figure 5

(A) XPS deconvolution of C1s and O1s of the Gr and GrOx. (B) XPS deconvolution of C1s and O1s of the Nanocomposite ChAgG (Ag3d).

Figure 6

MTT cell viability test of PCL/PVP/ChAgG fibers. Experiments were done by triplicated. Average and standard deviation are presented.