Electrospun nanofibers incorporating lactobionic acid as novel active packaging materials: biological activities and toxicological evaluation

Discover Nano Research Electrospun nanofibers incorporating lactobionic acid as novel active packaging materials: biological activities and toxicological evaluation Aline Aniele Vencato1 · Naiara Jacinta Clerici1 · André Luiz Mendes Juchem2 · Flavio Fonseca Veras1 · Helena Campos Rolla2 · Adriano Brandelli1 Received: 14 May 2024 / Accepted: 16 August 2024 © The Author(s) 2024  OPEN Abstract In this study, lactobionic acid (LBA) was incorporated into poly(vinyl alcohol) (PVA) and poly(ε-caprolactone) (PCL) by electrospinning. The antimicrobial effects of the nanofibers were tested using the agar diffusion method. Only the PVA formulations showed antimicrobial activity against Staphylococcus aureus. The PVA and PCL nanofibers containing LBA showed antioxidant activity ranging from 690.33 to 798.67 µM TEAC when tested by the ABTS method. The characterization of nanofibers was performed by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and mechanical analysis. The nanofibers showed a uniform morphology and their average diameters ranged from 295.5 to 2778.2 nm. The LBA addition induced a decrease in the enthalpy of fusion (ΔHm) of PVA and PCL nanofibers, while the Young’s modulus was reduced from 20 to 10 MPa in PCL and PCL-LBA nanofibers, respectively. No relevant differences were observed between the FTIR spectra of the control nanofibers and the nanofibers containing LBA. All nanofibers presented hemolysis rate below 2%, thus can be considered as non-hemolytic materials. Further toxicological assessment was performed with the selected formulation PVA10 + LBA. The evaluations by mutagenicity assay, cell survival measurement, cell viability analysis and agar diffusion cytotoxicity test indicated that there are no significant toxic effects. Electrospun nanofibers PVA-LBA and PCL-LBA were successfully produced, showing good thermal and mechanical properties and non-toxic effects. Furthermore, the nanofibers showed antimicrobial activity and antioxidant activity. The findings of this study indicate that PVA and PCL electrospun nanofibers incorporating LBA are promising for use in packaging applications. Keywords Nanofibers · Lactobionic acid · Antibacterial activity · Antioxidant activity · Toxicological evaluation 1 Introduction Lactobionic acid (LBA) is a natural polyhydroxy acid, composed of a galactose linked to a gluconic acid moiety via an ether-like linkage. LBA is produced by the oxidation of the glucose component of lactose to gluconic acid, showing potential application as natural preservative with antibacterial and antioxidant effects [1, 2]. The antimicrobial Supplementary Information The online version contains supplementary material available at https://doi.org/10.1186/s11671-024- 04084-8. * Adriano Brandelli, | 1Laboratório de Nanobiotecnologia e Microbiologia Aplicada, Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Porto Alegre 91501‑970, Brazil. 2NSF International BR, Rua Palermo 257, Viamão 94480‑775, Brazil. Discover Nano (2024) 19:135 | https://doi.org/10.1186/s11671-024-04084-8 Vol.:(0123456789) Research Discover Nano (2024) 19:135 | https://doi.org/10.1186/s11671-024-04084-8 activity of LBA has been attributed to the breakdown of structural integrity of the bacterial cell wall and membrane, releasing cellular contents and inhibiting protein synthesis, which causes cell death [3–5]. Lipid oxidation and microbial growth are the main causes of spoilage of a great variety of foods, causing important losses on sensorial and nutritional quality. Active packaging has been studied as an advanced technology to control the growth of spoilage and pathogenic microorganisms and to maintain the quality and safety of food products [2, 4]. However, there is interest to create active packaging materials that are not only antimicrobial, but also antioxidant. In this regard, additional studies are required to develop active packaging materials showing effective antioxidant and antimicrobial properties [5–7]. Currently, packaging materials fabricated from biocompatible and biodegradable polymers attracted more attention due to their safety and environmental appeal. Poly(vinyl alcohol) (PVA) is a hydrophilic synthetic polymer that provides good mechanical properties due to the presence of hydroxyl groups and the formation of hydrogen bonds [8]. Poly(ε-caprolactone) (PCL) is a hydrophobic synthetic polymer known for its slow biodegradation rate and high mechanical strength [9]. Both polymers are interesting to elaborate food packaging materials due their biocompatibility, biodegradability, good chemical and thermal stability and non-toxic nature [8, 9]. Electrospun nanofibers can be applied in active food packaging, due to their capacity for controlled release of encapsulated bioactive molecules. When compared with the traditional casting films, they are more sensitive to the changes of the surrounding environment due to the structural characteristics, which facilitate them to achieve functional activity in the food packaging application [10, 11]. Nanofibers are fibrous nanocarriers that can be synthesized from natural or synthetic polymers. They can be produced by electrospinning, a technology for obtaining continuous polymer fibers with a diameter ranging in the nanometer scale. The process employs high strength electric field to produce ultra-fine fibers from a polymeric solution incorporated with a drug accelerated towards a collector [12, 13]. These nanostructures present unique properties, such as a high surface area-to-volume ratio, high porosity, low density, small pore size stability, permeability, and morphology that resembles an extracellular matrix. They also have high mechanical strength, making them excellent platforms for drug delivery purposes. Nanofibers can deliver a significant amount of drug and provide effective interaction of desired compound at the site of action due to a larger surface area [13, 14]. PVA and PCL nanofibers have been described as suitable materials for development of active packaging by incorporating either antimicrobial [14, 15] or antioxidant substances [16, 17]. However, studies related to this topic are limited and nanofibers showing multiple biological activities are barely reported. In this work, PVA and PCL nanofibers loaded with LBA were manufactured for the first time and their antimicrobial activity, antioxidant activity and toxicology evaluation were achieved. In this regard, nanofibers incorporating LBA could be expected as useful active materials showing both antimicrobial and antioxidant properties. Therefore, the aim of this study was to obtain electrospun nanofibers with antibacterial and antioxidant activities through incorporation of LBA, and perform detailed toxicological evaluation and characterization of physical, thermal, and mechanical properti (...truncated)