Fabrication of Gelatin-ZnO Nanofibers for Antibacterial Applications.

Nataliya Babayevska,Ewa Janiszewska,Stefan Jurga,Martin Järvekülg,Marcin Jarek,Grzegorz Nowaczyk,Igor Iatsunskyi,Łucja Przysiecka,Triin Kangur

doi:10.3390/ma14010103

Abstract

In this study, GNF@ZnO composites (gelatin nanofibers (GNF) with zinc oxide (ZnO) nanoparticles (NPs)) as a novel antibacterial agent were obtained using a wet chemistry approach. The physicochemical characterization of ZnO nanoparticles (NPs) and GNF@ZnO composites, as well as the evaluation of their antibacterial activity toward Gram-positive (Staphyloccocus aureus and Bacillus pumilus) and Gram-negative (Escherichia coli and Pseudomonas fluorescens) bacteria were performed. ZnO NPs were synthesized using a facile sol-gel approach. Gelatin nanofibers (GNF) were obtained by an electrospinning technique. GNF@ZnO composites were obtained by adding previously produced GNF into a Zn2+ methanol solution during ZnO NPs synthesis. Crystal structure, phase, and elemental compositions, morphology, as well as photoluminescent properties of pristine ZnO NPs, pristine GNF, and GNF@ZnO composites were characterized using powder X-ray diffraction (XRD), FTIR analysis, transmission and scanning electron microscopies (TEM/SEM), and photoluminescence spectroscopy. SEM, EDX, as well as FTIR analyses, confirmed the adsorption of ZnO NPs on the GNF surface. The pristine ZnO NPs were highly crystalline and monodispersed with a size of approximately 7 nm and had a high surface area (83 m2/g). The thickness of the pristine gelatin nanofiber was around 1 µm. The antibacterial properties of GNF@ZnO composites were investigated by a disk diffusion assay on agar plates. Results show that both pristine ZnO NPs and their GNF-based composites have the strongest antibacterial properties against Pseudomonas fluorescence and Staphylococcus aureus, with the zone of inhibition above 10 mm. Right behind them is Escherichia coli with slightly less inhibition of bacterial growth. These properties of GNF@ZnO composites suggest their suitability for a range of antimicrobial uses, such as in the food industry or in biomedical applications.

Highlights

Among semiconductor materials, zinc oxide (ZnO) is a well-known wide-bandgap semiconductor with a bandgap energy (3.37 eV at room temperature) and a large exciton binding energy (60 meV) [1]
We describe a simple synthetic route for the preparation of composites, consisting of gelatin nanofibres obtained by an electrospinning technique and ZnO
The phase purity and composition of ZnO NPs obtained by a sol-gel method was examis known that due to their small1b size, nanoparticles relatively larger surface inedItby the X-ray diffraction (XRD)

Summary

Introduction

Zinc oxide (ZnO) is a well-known wide-bandgap semiconductor with a bandgap energy (3.37 eV at room temperature) and a large exciton binding energy (60 meV) [1]. Due to its good biocompatibility, low cytotoxicity, high surface to volume ratio with enhanced surface reactivity, and antistatic, antimicrobial, antibacterial, and antifungal properties, ZnO found broad application in biomedicine as a drug carrier, a biomarker for cell labelling, a biosensor, and an antibacterial agent [4,5,6]. Polymeric materials are good carriers for incorporating or covering the functional agents (nanofillers) for achieving new physicochemical properties [12]. They can enhance the optical and mechanical properties, biocompatibility, antibacterial activity, or water stability of the resulting materials [13]. Beek et al obtained composites based on ZnO nanoparticles and nanorods with conjugated polymer (MDMO-PPV) for potential application in solar cells [14]

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Results

Conclusion