Electrospun Nanofibers with Pomegranate Peel Extract as a New Concept for Treating Oral Infections

Abstract

Pomegranate peel extract is known for its potent antibacterial, antiviral, antioxidant, anti-inflammatory, wound healing, and probiotic properties, leading to its use in treating oral infections. In the first stage of this work, for the first time, using the Design of Experiment (DoE) approach, pomegranate peel extract (70% methanol, temperature 70 °C, and three cycles per 90 min) was optimized and obtained, which showed optimal antioxidant and anti-inflammatory properties. The optimized extract showed antibacterial activity against oral pathogenic bacteria. The second part of this study focused on optimizing an electrospinning process for a combination of polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) nanofibers loaded with the optimized pomegranate peel extract. The characterization of the nanofibers was confirmed by using SEM pictures, XRPD diffractograms, and IR-ATR spectra. The composition of the nanofibers can control the release; in the case of PVP-based nanofibers, immediate release was achieved within 30 min, while in the case of PCL/PVP, controlled release was completed within 24 h. Analysis of the effect of different scaffold compositions of the obtained electrofibers showed that those based on PCL/PVP had better wound healing potential. The proposed strategy to produce electrospun nanofibers with pomegranate peel extract is the first and innovative approach to better use the synergy of biological action of active compounds present in extracts in a patient-friendly pharmaceutical form, beneficial for treating oral infections.

Keywords: anti-inflammatory; antibacterial; nanofibers; oral infections; pomegranate peel; wound healing.

Figure 1

SEM images of nanofibers N1–N6.

Figure 1

SEM images of nanofibers N1–N6.

Figure 2

XRPD diffractograms for extract and nanofibers N1–N6.

Figure 3

IR-ATR spectra for PVP, PCL, extract (a), and nanofibers N1–N6 (b).

Figure 4

Dissolution profiles of rutin from nanofibers N1, N3, and N5.

Figure 5

Mucoadhesive properties of nanofibers N1–N6.

Figure 6

Viability of human normal skin fibroblasts (Hs27 cells) exposed to 100 µg/mL of the extract and nanofibers N1–N6 for 24 h. ANOVA statistically analyzed the results of the MTT assay with a post hoc Dunnett’s test. Statistical significance (vs control cells) was designated as *** when p < 0.001.

Figure 7

The wound-healing effect of the extract and nanofibers N1–N6 was observed on two-dimensional cultures of normal human skin fibroblasts (representative images).

Figure 8

The wound-healing properties of the extract and nanofibers N1–N6 were examined on Hs27 cells after 24 h incubation. The samples were tested at a concentration of 100 µg/mL. ANOVA statistically analyzed results with a post hoc Tukey’s test. Statistical significance was designated as “*” when p < 0.05, “**” when p < 0.01, “***” when p < 0.001, and “****” when p < 0.0001 (vs. control cells or extract-treated cells); ns—not significant.

Figure 9

Principal component analysis (PCA) showing the factor loading plot considering the average diameter of nanofibers (=diameter), production efficiency, percentage of rutin release at 6 h (=dissolution), antioxidant activity (=DPPH), anti-inflammatory activity (=Hyal), mucoadhesive properties, and wound closure after 24 h (=wound closure); N1—nanofibers N1, N3—nanofibers N3, N5—nanofibers N5.