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Kaloper S, Plohl O, Smole Možina S, Vesel A, Šimat V, Fras Zemljič L. Exploring chitosan-plant extract bilayer coatings: Advancements in active food packaging via polypropylene modification. Int J Biol Macromol 2024; 270:132308. [PMID: 38740163 DOI: 10.1016/j.ijbiomac.2024.132308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/11/2024] [Accepted: 05/10/2024] [Indexed: 05/16/2024]
Abstract
UV-ozone activated polypropylene (PP) food films were subjected to a novel bilayer coating process involving primary or quaternary chitosan (CH/QCH) as the first layer and natural extracts from juniper needles (Juniperus oxycedrus; JUN) or blackberry leaves (Rubus fruticosus; BBL) as the second layer. This innovative approach aims to redefine active packaging (AP) development. Through a detailed analysis by surface characterization and bioactivity assessments (i.e., antioxidant and antimicrobial functionalities), we evaluated different coating combinations. Furthermore, we investigated the stability and barrier characteristics inherent in these coatings. The confirmed deposition, coupled with a comprehensive characterization of their composition and morphology, underscored the efficacy of the coatings. Our investigation included wettability assessment via contact angle (CA) measurements, X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), which revealed substantial enhancements in surface concentrations of elements and functional groups of CH, QCH, JUN, and BBL. Scanning electron microscopy (SEM) unveiled the coatings' heterogeneity, while time-of-flight secondary ion mass spectrometry (ToF-SIMS) and CA profiling showed moderately compact bilayers on PP, providing active species on the hydrophilic surface, respectively. The coatings significantly reduced the oxygen permeability. Additionally, single-layer depositions of CH and QCH remained below the overall migration limit (OML). Remarkably, the coatings exhibited robust antioxidative properties due to plant extracts and exceptional antimicrobial activity against S. aureus, attributed to QCH. These findings underscore the pivotal role of film surface properties in governing bioactive characteristics and offer a promising pathway for enhancing food packaging functionality.
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Affiliation(s)
- Saša Kaloper
- University of Maribor, Faculty of Mechanical Engineering, Laboratory for Characterization and Processing of Polymers, Smetanova ulica 17, 2000 Maribor, Slovenia.
| | - Olivija Plohl
- University of Maribor, Faculty of Mechanical Engineering, Laboratory for Characterization and Processing of Polymers, Smetanova ulica 17, 2000 Maribor, Slovenia.
| | - Sonja Smole Možina
- University of Ljubljana, Biotechnical Faculty, Department of Food Science and Technology, Jamnikarjeva ulica 101, 1000 Ljubljana, Slovenia.
| | - Alenka Vesel
- Department of Surface Engineering and Optoelectronics, Jožef Stefan Institute, Teslova ulica 30, 1000 Ljubljana, Slovenia.
| | - Vida Šimat
- University Department of Marine Studies, University of Split, Ruđera Boškovića 37, 21000 Split, Croatia.
| | - Lidija Fras Zemljič
- University of Maribor, Faculty of Mechanical Engineering, Laboratory for Characterization and Processing of Polymers, Smetanova ulica 17, 2000 Maribor, Slovenia.
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Tone AM, Herranz Solana N, Khan MR, Borriello A, Torrieri E, Sánchez Reig C, Monedero Prieto FM. Study on the Properties of PLA- and PP-Based Films for Food Applications Incorporating Orange Peel Extract from Agricultural by-Products. Polymers (Basel) 2024; 16:1245. [PMID: 38732714 PMCID: PMC11085717 DOI: 10.3390/polym16091245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 05/13/2024] Open
Abstract
The aim of this work was to develop active packaging based on polypropylene (PP) and polylactic acid (PLA) matrices using a high value by-product extracted from orange peel as an active compound for food packaging applications. Different films with and without orange peel extract (OPE) based on PP and PLA were obtained via cast extrusion and characterized in terms of their mechanical, thermal, optical, and sealing properties. The films obtained were transparent, but when OPE was incorporated, the transmittance spectrum decreased, causing slight coloration. Mechanical properties were affected by the incorporation of OPE, as elongation at break and tensile strength increased in the cross-direction of the PP film, although the main differences found were related to the polymer itself. In addition, sealing strength also increased via the incorporation of OPE in the PP matrix. However, thermal properties were not affected by OPE in the PP matrix but slightly decreased stability in PLA. Regarding antimicrobial activity in in vitro studies, no inhibition of the growth of Listeria innocua, Saccharomyces cerevisiae, Aspergillus niger, or Escherichia coli was observed. Finally, antioxidant activity was observed in in vitro studies with 2,2-Diphenyl-1picrylhydrazyl (DPPH) radical. The results of this study showed that the obtention of materials with OPE incorporated into the PLA and PP matrix is feasible. The new materials obtained can be used for applications of oxidation-sensitive fresh products.
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Affiliation(s)
- Ana Maria Tone
- Packaging, Transport & Logistics Research Center (ITENE), Albert Einstein 1, 46980 Paterna, Valencia, Spain; (A.M.T.); (N.H.S.); (C.S.R.)
| | - Nuria Herranz Solana
- Packaging, Transport & Logistics Research Center (ITENE), Albert Einstein 1, 46980 Paterna, Valencia, Spain; (A.M.T.); (N.H.S.); (C.S.R.)
| | - Muhammad Rehan Khan
- Department of Agricultural Science, University of Naples Federico II, Via Università 100, 80055 Portici, Italy; (M.R.K.); (A.B.)
| | - Angela Borriello
- Department of Agricultural Science, University of Naples Federico II, Via Università 100, 80055 Portici, Italy; (M.R.K.); (A.B.)
| | - Elena Torrieri
- Department of Agricultural Science, University of Naples Federico II, Via Università 100, 80055 Portici, Italy; (M.R.K.); (A.B.)
| | - Carmen Sánchez Reig
- Packaging, Transport & Logistics Research Center (ITENE), Albert Einstein 1, 46980 Paterna, Valencia, Spain; (A.M.T.); (N.H.S.); (C.S.R.)
| | - F. María Monedero Prieto
- Packaging, Transport & Logistics Research Center (ITENE), Albert Einstein 1, 46980 Paterna, Valencia, Spain; (A.M.T.); (N.H.S.); (C.S.R.)
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Zhang X, Zhao J, Xie P, Wang S. Biomedical Applications of Electrets: Recent Advance and Future Perspectives. J Funct Biomater 2023; 14:320. [PMID: 37367284 DOI: 10.3390/jfb14060320] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 05/23/2023] [Accepted: 06/08/2023] [Indexed: 06/28/2023] Open
Abstract
Recently, electrical stimulation, as a non-pharmacological physical stimulus, has been widely exploited in biomedical and clinical applications due to its ability to significantly enhance cell proliferation and differentiation. As a kind of dielectric material with permanent polarization characteristics, electrets have demonstrated tremendous potential in this field owing to their merits of low cost, stable performance, and excellent biocompatibility. This review provides a comprehensive summary of the recent advances in electrets and their biomedical applications. We first provide a brief introduction to the development of electrets, as well as typical materials and fabrication methods. Subsequently, we systematically describe the recent advances of electrets in biomedical applications, including bone regeneration, wound healing, nerve regeneration, drug delivery, and wearable electronics. Finally, the present challenges and opportunities have also been discussed in this emerging field. This review is anticipated to provide state-of-the-art insights on the electrical stimulation-related applications of electrets.
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Affiliation(s)
- Xinyuan Zhang
- School of Health Science and Engineering, University of Shanghai for Science and Technology, No. 516 Jungong Road, Shanghai 200093, China
- Department of Gastroenterology, Changhai Hospital, Naval Medical University, No. 168 Changhai Road, Shanghai 200433, China
| | - Jiulong Zhao
- Department of Gastroenterology, Changhai Hospital, Naval Medical University, No. 168 Changhai Road, Shanghai 200433, China
| | - Pei Xie
- Department of Gastroenterology, Changhai Hospital, Naval Medical University, No. 168 Changhai Road, Shanghai 200433, China
| | - Shige Wang
- School of Materials and Chemistry, University of Shanghai for Science and Technology, No. 516 Jungong Road, Shanghai 200093, China
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Nagengast N, Bay C, Döpper F, Schmidt HW, Neuber C. Thermo-Mechanical Recyclability of Additively Manufactured Polypropylene and Polylactic Acid Parts and Polypropylene Support Structures. Polymers (Basel) 2023; 15:polym15102291. [PMID: 37242864 DOI: 10.3390/polym15102291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/07/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Polymers have a reputation for several advantageous characteristics like chemical resistance, weight reduction, and simple form-giving processes. The rise of additive manufacturing technologies such as Fused Filament Fabrication (FFF) has introduced an even more versatile production process that supported new product design and material concepts. This led to new investigations and innovations driven by the individualization of customized products. The other side of the coin contains an increasing resource and energy consumption satisfying the growing demand for polymer products. This turns into a magnitude of waste accumulation and increased resource consumption. Therefore, appropriate product and material design, taking into account end-of-life scenarios, is essential to limit or even close the loop of economically driven product systems. In this paper, a comparison of virgin and recycled biodegradable (polylactic acid (PLA)) and petroleum-based (polypropylene (PP) & support) filaments for extrusion-based Additive Manufacturing is presented. For the first time, the thermo-mechanical recycling setup contained a service-life simulation, shredding, and extrusion. Specimens and complex geometries with support materials were manufactured with both, virgin and recycled materials. An empirical assessment was executed through mechanical (ISO 527), rheological (ISO 1133), morphological, and dimensional testing. Furthermore, the surface properties of the PLA and PP printed parts were analyzed. In summary, PP parts and parts from its support structure showed, in consideration of all parameters, suitable recyclability with a marginal parameter variance in comparison to the virgin material. The PLA components showed an acceptable decline in the mechanical values but through thermo-mechanical degradation processes, rheological and dimensional properties of the filament dropped decently. This results in significantly identifiable artifacts of the product optics, based on an increase in surface roughness.
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Affiliation(s)
- Niko Nagengast
- Chair of Biomechanics, Faculty of Engineering, University of Bayreuth, Universitaetsstrasse 9, 95447 Bayreuth, Germany
| | - Christian Bay
- Research Center for Additive Innovations, University of Bayreuth, Universitaetsstrasse 30, 95447 Bayreuth, Germany
- Chair of Manufacturing and Remanufacturing Technology, Faculty of Engineering, University of Bayreuth, Universitaetsstrasse 9, 95447 Bayreuth, Germany
| | - Frank Döpper
- Research Center for Additive Innovations, University of Bayreuth, Universitaetsstrasse 30, 95447 Bayreuth, Germany
- Chair of Manufacturing and Remanufacturing Technology, Faculty of Engineering, University of Bayreuth, Universitaetsstrasse 9, 95447 Bayreuth, Germany
| | - Hans-Werner Schmidt
- Chair of Macromolecular Chemistry, Faculty of Natural Science, University of Bayreuth, Universitaetsstrasse 30, 95447 Bayreuth, Germany
- Bavarian Polymer Institute, University of Bayreuth, Universitaetsstrasse 30, 95447 Bayreuth, Germany
| | - Christian Neuber
- Chair of Macromolecular Chemistry, Faculty of Natural Science, University of Bayreuth, Universitaetsstrasse 30, 95447 Bayreuth, Germany
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Pilot-Scale Processing and Functional Properties of Antifungal EVOH-Based Films Containing Methyl Anthranilate Intended for Food Packaging Applications. Polymers (Basel) 2022; 14:polym14163405. [PMID: 36015660 PMCID: PMC9416094 DOI: 10.3390/polym14163405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/16/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial packaging has emerged as an efficient technology to improve the stability of food products. In this study, new formulations based on ethylene vinyl alcohol (EVOH) copolymer were developed by incorporating the volatile methyl anthranilate (MA) at different concentrations as antifungal compound to obtain active films for food packaging. To this end, a twin-screw extruder with a specifically designed screw configuration was employed to produce films at pilot scale. The quantification analyses of MA in the films showed a high retention capacity. Then, the morphological, optical, thermal, mechanical and water vapour barrier performance, as well as the antifungal activity in vitro of the active films, were evaluated. The presence of MA did not affect the transparency or the thermal stability of EVOH-based films, but decreased the glass transition temperature of the copolymer, indicating a plasticizing effect, which was confirmed by an increase in the elongation at break values of the films. Because of the additive-induced plasticization over EVOH, the water vapour permeability slightly increased at 33% and 75% relative humidity values. Finally, the evaluation of the antifungal activity in vitro of the active films containing methyl anthranilate showed a great effectiveness against P. expansum and B. cinerea, demonstrating the potential applicability of the developed films for active food packaging.
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Polyethylene Films Containing Plant Extracts in the Polymer Matrix as Antibacterial and Antiviral Materials. Int J Mol Sci 2021; 22:ijms222413438. [PMID: 34948232 PMCID: PMC8708998 DOI: 10.3390/ijms222413438] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/11/2021] [Accepted: 12/13/2021] [Indexed: 12/21/2022] Open
Abstract
Low density polyethylene (LDPE) films covered with active coatings containing mixtures of rosemary, raspberry, and pomegranate CO2 extracts were found to be active against selected bacterial strains that may extend the shelf life of food products. The coatings also offer antiviral activity, due to their influence on the activity of Φ6 bacteriophage, selected as a surrogate for SARS-CoV-2 particles. The mixture of these extracts could be incorporated into a polymer matrix to obtain a foil with antibacterial and antiviral properties. The initial goal of this work was to obtain active LDPE films containing a mixture of CO2 extracts of the aforementioned plants, incorporated into an LDPE matrix via an extrusion process. The second aim of this study was to demonstrate the antibacterial properties of the active films against Gram-positive and Gram-negative bacteria, and to determine the antiviral effect of the modified material on Φ6 bacteriophage. In addition, an analysis was made on the influence of the active mixture on the polymer physicochemical features, e.g., mechanical and thermal properties, as well as its color and transparency. The results of this research indicated that the LDPE film containing a mixture of raspberry, rosemary, and pomegranate CO2 extracts incorporated into an LDPE matrix inhibited the growth of Staphylococcus aureus. This film was also found to be active against Bacillus subtilis. This modified film did not inhibit the growth of Escherichia coli and Pseudomonas syringae cells; however, their number decreased significantly. The LDPE active film was also found to be active against Φ6 particles, meaning that the film had antiviral properties. The incorporation of the mixture of CO2 extracts into the polymer matrix affected its mechanical properties. It was observed that parameters describing mechanical properties decreased, although did not affect the transition of LDPE significantly. Additionally, the modified film exhibited barrier properties towards UV radiation. Modified PE/CO2 extracts films could be applied as a functional food packaging material with antibacterial and antiviral properties.
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