Fabrication and Characterization of Electrospun Poly(Caprolactone)/Tannic Acid Scaffold as an Antibacterial Wound Dressing

Abstract

Antibacterial wound dressings are promising materials to treat infected skin wounds, which greatly affect the wound-healing process. In this study, tannic acid (TA), a natural antibacterial agent, was successfully loaded by electrospinning into poly(caprolactone) (PCL) fibers in a high concentration. It is suggested that the addition of TA was beneficial for producing uniform and continuous PCL nanofibers. Hydrogen bonds existed between the PCL and TA molecules based on the analysis of FTIR spectra and DSC results. The interactions and continuous network improved the mechanical properties of the scaffolds. Meanwhile, increasing the amount of TA also enhanced the hydrophilicity and water absorption capacity of the scaffold, both of which are beneficial for accelerating wound healing. Moreover, a burst release of the TA in the initial stage and a controlled, steady release behavior over time contributed to the highly antibacterial properties of the PCL/TA scaffolds. The fabrication of the composite scaffold supplies a facile, efficient, and controllable approach to address the issue of antibacterial treatment in wound dressing.

Keywords: antibacterial property; bio-composite; nanofibers; wound dressing.

Figure 1

Photos, SEM images, and fiber diameters of electrospun nanofiber scaffolds spun from pure PCL solution (a,d) and from solutions with PCL/TA weight ratios of 9.5:0.5 (b,e) and 9:1 (c,f); the fiber diameter of electrospun PCL/TA (9.5:0.5, 9:1) nanofiber scaffolds are significantly different from the pure PCL nanofiber scaffolds, p < 0.05.

Figure 2

FTIR spectra (a,b) and DSC curves (c) of electrospun nanofiber scaffolds spun from pure PCL and from solutions with different PCL/TA weight ratios (9.5:0.5 and 9:1).

Figure 3

TGA (a) and DTG (b) of electrospun nanofiber scaffolds spun from PCL from solutions with different PCL/TA weight ratios (9.5:0.5 and 9:1).

Figure 4

Stress-strain curves of electrospun nanofiber scaffolds spun from PCL and from solutions with different PCL/TA weight ratios (9.5:0.5 and 9:1).

Figure 5

Water contact angle (a) and swelling ratio (b) of electrospun nanofiber scaffolds spun from PCL and from solutions with different PCL/TA weight ratios (9.5:0.5 and 9:1) (* p < 0.05).

Figure 6

TA release from PCL/TA nanofiber scaffolds spun from solutions with different PCL/TA weight ratios (9.5:0.5 and 9:1) in deionized water.

Figure 7

Antibacterial properties of nanofiber scaffolds spun from PCL and from solutions with different PCL/TA weight ratios (9.5:0.5 and 9:1).