Preparation and Characterization of Eco-Friendly Transparent Antibacterial Starch/Polyvinyl Alcohol Materials for Use as Wound-Dressing

Abstract

In this study, eco-friendly and transparent starch-based/polyvinyl alcohol/citric acid composite films are evaluated for their efficacy as wound dressing materials. The starch/polyvinyl alcohol (PVA) materials with added citric acid (0.46-1.83 wt%) and glycerol were made and handled based on the modified casting method. This new formulation decreases the amount of PVA used in the conventional preparation method. Citric acid ensures an appropriate antibacterial environment for wound-dressing materials. The mechanical, chemical, and surface morphological properties of such films were assessed and analyzed by tensile strength tests, UV-Vis spectrometry, swelling index, and scanning electron microscopy (SEM). Furthermore, the water vapor transmission (WVT) quantity was measured for an ideal wound-healing process to investigate an optimal moisture environment around the wound bed. Moreover, the pH level of the dressings was measured to examine the possibility of bacterial growth around these starch-based films. Additionally, the films' in-vitro antibacterial activities were studied against the two most common Gram-positive and Gram-negative bacteria (Escherichia coli and Staphylococcus aureus). The new starch-based dressings demonstrated suitable degradation, antibacterial activity, fluid absorption, and adequate mechanical strength, representing wound-dressing materials' vital features.

Keywords: characterization; polyvinyl alcohol; starch-based films; surface morphology; transparent; ultrasound mixing; wound-dressing.

Figure 1

The effects of citric acid on the mechanical properties of biodegradable starch-based films [citric acid concentrations (0.46, 0.92, 1.38, and 1.83 wt%)].

Figure 2

The effects of various citric acid proportions (0.46, 0.92, 1.38, and 1.83 wt%) on the film elongation-at-break percentage.

Figure 3

The effects of different citric acid concentrations on starch-based materials swelling index.

Figure 4

The weight loss percentage for starch-based wound-dressing films.

Figure 5

Water vapor transmission rate for starch-based wound-dressing films.

Figure 6

A study of the antibacterial activity of different formulations of starch-based wound-dressings against E. coli (A) 0.46 wt% CA, (B) 0.92 wt% CA, (C) 1.38 wt% CA, (D) 1.83 wt% CA and against S. aureus (E) SPGC1, (F) SPGC2, (G) SPGC3, (H) SPGC4), (I) control zone.

Figure 6

A study of the antibacterial activity of different formulations of starch-based wound-dressings against E. coli (A) 0.46 wt% CA, (B) 0.92 wt% CA, (C) 1.38 wt% CA, (D) 1.83 wt% CA and against S. aureus (E) SPGC1, (F) SPGC2, (G) SPGC3, (H) SPGC4), (I) control zone.

Figure 7

UV–Vis transmittance percentage of starch-based/PVA wound dressings (SPGC1–SPGC4).

Figure 8

SEM images of starch-based/polyvinyl alcohol/citric acid/glycerol (SPGC) films, (a) 0.46 wt% CA (SPGC1), (b) 0.92 wt% CA (SPGC2), (c) 1.38 wt% CA (SPGC3), (d) 1.83 wt% CA (SPGC4); The analyzed ImageJ software images without changing the magnification of SEM images; (i) 0.46 wt% CA (SPGC1), (ii) 0.92 wt% CA (SPGC2), (iii) 1.38 wt% CA (SPGC3), (iv) 1.83 wt% CA (SPGC4).

Figure 8

SEM images of starch-based/polyvinyl alcohol/citric acid/glycerol (SPGC) films, (a) 0.46 wt% CA (SPGC1), (b) 0.92 wt% CA (SPGC2), (c) 1.38 wt% CA (SPGC3), (d) 1.83 wt% CA (SPGC4); The analyzed ImageJ software images without changing the magnification of SEM images; (i) 0.46 wt% CA (SPGC1), (ii) 0.92 wt% CA (SPGC2), (iii) 1.38 wt% CA (SPGC3), (iv) 1.83 wt% CA (SPGC4).

Figure 9

The number and size of starch granules cluster as the citric acid content of the solution increases, (A) 0.46 wt% CA (SPGC1), (B) 0.92 wt% CA (SPGC2), (C) 1.38 wt% CA (SPGC3), (D) 1.83 wt% CA (SPGC4).

Figure 9

The number and size of starch granules cluster as the citric acid content of the solution increases, (A) 0.46 wt% CA (SPGC1), (B) 0.92 wt% CA (SPGC2), (C) 1.38 wt% CA (SPGC3), (D) 1.83 wt% CA (SPGC4).

Figure 9

The number and size of starch granules cluster as the citric acid content of the solution increases, (A) 0.46 wt% CA (SPGC1), (B) 0.92 wt% CA (SPGC2), (C) 1.38 wt% CA (SPGC3), (D) 1.83 wt% CA (SPGC4).

Figure 10

The surface roughness of the starch-based dressings as the citric acid content of the solution increases, (A) 0.46 wt% CA (SPGC1), (B) 0.92 wt% CA (SPGC2), (C) 1.38 wt% CA (SPGC3), (D) 1.83 wt% CA (SPGC4).

Figure 10

The surface roughness of the starch-based dressings as the citric acid content of the solution increases, (A) 0.46 wt% CA (SPGC1), (B) 0.92 wt% CA (SPGC2), (C) 1.38 wt% CA (SPGC3), (D) 1.83 wt% CA (SPGC4).