Preparing and Characterizing Novel Biodegradable Starch/PVA-Based Films with Nano-Sized Zinc-Oxide Particles for Wound-Dressing Applications

Abstract

Given recent worldwide environmental concerns, biodegradability, antibacterial activity, and healing properties around the wound area are vital features that should be taken into consideration while preparing biomedical materials such as wound dressings. Some of the available wound dressings present some major disadvantages. For example, low water vapor transmission rate (WVTR), inadequate exudates absorption, and the complex and high environmental cost of the disposal/recycling processes represent such drawbacks. In this paper, starch/polyvinyl alcohol (PVA) material with inserted nano-sized zinc-oxide particles (nZnO) (average size ≤ 100 nm) was made and altered using citric acid (CA). Both ensure an efficient antibacterial environment for wound-dressing materials. The film properties were assessed by UV–Vis spectrometry and were validated against the UV light transmission percentage of the starch/ polyvinyl alcohol (PVA)/ zinc-oxide nanoparticles (nZnO) composites. Analyses were conducted using X-ray Spectroscopy (EDX) and scanning electron microscopy (SEM) to investigate the structure and surface morphology of the materials. Moreover, to validate an ideal moisture content around the wound area, which is necessary for an optimum wound-healing process, the water vapor transmission rate of the film was measured. The new starch-based materials exhibited suitable physical and chemical properties, including solubility, gel fraction, fluid absorption, biodegradability, surface morphology (scanning electron microscopy imaging), and mechanical properties. Additionally, the pH level of the starch-based/nZnO film was measured to study the prospect of bacterial growth on this wound-dressing material. Furthermore, the in vitro antibacterial activity demonstrated that the dressings material effectively inhibited the growth and penetration of bacteria (Escherichia coli, Staphylococcus aureus).

Optimizing Biodegradable Starch-Based Composite Films Formulation for Wound-Dressing Applications

“…For the purposes of evaluating the fluid absorption capacity of these films, it is necessary to apply the swelling index methodology. As part of this method, samples (1 × 1 cm 2 ) were immersed in phosphate buffer saline (PBS) solution and incubated at 37 • C for 24 h. The swelling index (SI%) is calculated utilizing Equation (1); the test procedure followed that in our previous articles [3,16].…”

“…The weight-loss percentage value can be determined using Equation (2). Our previous articles outlined the procedure for conducting the test [3,16]:…”

“…In order to ensure that the prepared films are durable and flexible enough to be used as wound dressings and wearable electronics, we developed a high-resolution testing device [15]. The ASTM D882-10 test was conducted following the procedure in our previous article [16]. where the swelling index, called SI, is determined by PVA, starch, citric acid (CA), and glycerol concentration, respectively.…”

“…Hydrophilic, non-toxic, and easy-to-process, starch-based/PVA composite biomaterials are commonly used as scaffolding support materials for tissue engineering. Overall, the starch-based/PVA composite films exhibit superior biodegradability, mechanical and pH stability, flexibility, and semi-permeability, compared to all other synthetic polymer-derived materials [2,3,10,15,16], enabling oxygen and nutrients to be transported to the wound bed area for the critical survival of biological cells [17].…”

“…With the addition of zinc oxide nanoparticles (nZnO), Baghaie et al improved PVA/starch/chitosan hydrogels' healing characteristics and tensile strength [26]. Similarly, Delavari et al embedded nZnO particles into starch-based material, resulting in a novel biodegradable and antibacterial starch-based wound dressing, improving its physical and in vitro degradation characteristics [15,16]. To achieve the controlled release of erythromycin, Tavakoli et al prepared a PVA/honey hydrogel using a borax crosslinker [27].…”