PVA-Based Films with Strontium Titanate Nanoparticles Dedicated to Wound Dressing Application

Abstract

Bioactive materials may be applied in tissue regeneration, and an example of such materials are wound dressings, which are used to accelerate skin healing, especially after trauma. Here, we proposed a novel dressing enriched by a bioactive component. The aim of our study was to prepare and characterize poly(vinyl alcohol) films modified with strontium titanate nanoparticles. The physicochemical properties of films were studied, such as surface free energy and surface roughness, as well as the mechanical properties of materials. Moreover, different biological studies were carried out, like in vitro hemo- and cyto-compatibility, biocidal activity, and anti-biofilm formation. Also, the degradation of the materials' utilization possibilities and enzymatic activity in compost were checked. The decrease of surface free energy, increase of roughness, and improvement of mechanical strength were found after the addition of nanoparticles. All developed films were cyto-compatible, and did not induce a hemolytic effect on the human erythrocytes. The PVA films containing the highest concentration of STO (20%) reduced the proliferation of Eschericha coli, Pseudomonas aeruginosa, and Staphylococcus aureus significantly. Also, all films were characterized by surface anti-biofilm activity, as they significantly lowered the bacterial biofilm abundance and its dehydrogenase activity. The films were degraded by the compost microorganism. However, PVA with the addition of 20%STO was more difficult to degrade. Based on our results, for wound dressing application, we suggest using bioactive films based on PVA + 20%STO, as they were characterized by high antibacterial properties, favorable physicochemical characteristics, and good biocompatibility with human cells.

Keywords: hydrogels; nanoparticles; polyvinyl alcohol; strontium titanate.

Figure 1

(A) the Young Modulus (E_mod), (B) maximum tensile strength (σ_max) and (C) elongation at break (dl) determined for films based on PVA, PVA + 5%STO, PVA + 10%STO, and PVA + 20%STO. * significantly different from PVA (p < 0.05).

Figure 2

3D images of films surface (A) PVA; (B) PVA + 5%STO; (C) PVA + 10%STO; (D) PVA + 20%STO.

Figure 3

The effect of developed films on cyto-compatibility of hFOB 1.19 cells (cell viability and lactate dehydrogenase release): (a) after 24 h and (b) after 72 h exposure to films extracts (n = 4; data are expressed as the mean ± SD, * statistical significance compared to the control–PVA (p < 0.05)).

Figure 4

The effect of developed films on hemo-compatibility of human erythrocytes (hemolysis rate and lactate dehydrogenase release) after 24 h exposure to films (n = 4, data are expressed as the mean ± SD, * significantly different from the negative control and ^# significantly different from the PVA (p < 0.05)).

Figure 5

Biocidal properties of PVA/STO films. Different letters over the bars indicate a significant difference between means (p < 0.05).

Figure 6

Biofilm abundance and respiratory activity on the surface of PVA/STO films. Columns were designated as biofilm and lines as dehydrogenase. Different letters over the bars indicate a significant difference between means (p < 0.05), ±SD (n = 3).

Figure 6

Biofilm abundance and respiratory activity on the surface of PVA/STO films. Columns were designated as biofilm and lines as dehydrogenase. Different letters over the bars indicate a significant difference between means (p < 0.05), ±SD (n = 3).

Figure 7

Biodegradation of PVA/STO as expressed in mgO₂/kg compost. Different letters over the bars indicate a significant difference between means (p < 0.05), ±SD (n = 3).