1. Mechanistic insights into biological activities of polyphenolic compounds from rosemary obtained by inverse molecular dockingSamo Lešnik, Urban Bren, 2022, izvirni znanstveni članek Opis: Rosemary (Rosmarinus officinalis L.) represents a medicinal plant known for its various
health-promoting properties. Its extracts and essential oils exhibit antioxidative, anti-inflammatory,
anticarcinogenic, and antimicrobial activities. The main compounds responsible for these effects are
the diterpenes carnosic acid, carnosol, and rosmanol, as well as the phenolic acid ester rosmarinic
acid. However, surprisingly little is known about the molecular mechanisms responsible for the
pharmacological activities of rosemary and its compounds. To discern these mechanisms, we performed a large-scale inverse molecular docking study to identify their potential protein targets. Listed
compounds were separately docked into predicted binding sites of all non-redundant holo proteins
from the Protein Data Bank and those with the top scores were further examined. We focused on
proteins directly related to human health, including human and mammalian proteins as well as
proteins from pathogenic bacteria, viruses, and parasites. The observed interactions of rosemary
compounds indeed confirm the beforementioned activities, whereas we also identified their potential
for anticoagulant and antiparasitic actions. The obtained results were carefully checked against the
existing experimental findings from the scientific literature as well as further validated using both
redocking procedures and retrospective metrics.
Ključne besede: rosemary, inverse molecular docking, carnosol, carnosic acid, rosmanol, rosmarinic acid
Objavljeno v DKUM: 10.04.2025; Ogledov: 0; Prenosov: 2
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2. Hydrothermal decomposition of virgin and waste polylactic acid with subcritical water under N[sub]2 and air atmospheresMaja Čolnik, Mihael Irgolič, Mojca Škerget, 2025, izvirni znanstveni članek Opis: This study addresses the inherent shortcomings of poly (lactic acid) (PLA), a biodegradable polymer widely used in industries such as packaging and biomedical applications. The principal challenge of PLA resides in its low crystallinity, which detrimentally affects its mechanical properties and thermal stability. Additionally, PLA is prone to water and hydrolysis, which compromises its chemical resistance and can lead to degradation over time. To overcome surmount these limitations, the study focuses on the development of hybrid films through the blending of PLA with poly (l-lactide-co-ethylene adipate) (pLEA) block copolymers. The objective is to augment the crystallinity, mechanical performance, and chemical resistance of the resulting materials. The study employs a range of analytical techniques, including Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Polarised Light Microscopy (PLM), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA), to thoroughly characterize the copolymers and blend films. By systematically selecting blending ratios and processing methodologies, the study demonstrates enhancements in the properties of the resultant hybrid films compared to neat PLA. Specifically, the structure of films significantly changed from amorphous to crystalline in a short duration - 5 min, of annealing., leading to better tensile strength, modulus and reduced wettability, which are crucial for applications requiring durability and resistance to environmental factors. Films made from 30 wt% of pLEA 97.5/2.5 with 70 % of PLA by fast cooling exhibited outstanding mechanical properties, with a tensile strength 20 MPa higher than that of neat PLA films. Additionally, the chemical resistance may be improved, as evidenced by a decrease in wettability by approximately 15° and a reduction in the polar component of the surface free energy by about 7 mN/m. Hydrophobic, water-repellent materials resist penetration by water and other polar solvents, reducing exposure to corrosive substances and enhancing chemical resistance through barrier protection. Overall, this research addresses the limitations of PLA through innovative copolymerization and blending strategies, offering valuable insights into optimizing the material's properties for various practical applications.
Ključne besede: biopolymers recycling, polylactic acid, subcritical water, lactic acid, carboxylic acids, gaseous products
Objavljeno v DKUM: 01.04.2025; Ogledov: 0; Prenosov: 1
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3. Effect of micro- and nano-lignin on the thermal, mechanical, and antioxidant properties of biobased PLA–lignin composite filmsSofia P. Makri, Eleftheria Xanthopoulou, Panagiotis A. Klonos, Alexios Grigoropoulos, Apostolos Kyritsis, Konstantinos Tsachouridis, Antonios Anastasiou, Ioanna Deligkiozi, Nikolaos P. Nikolaidis, Dimitrios Bikiaris, 2022, izvirni znanstveni članek Opis: Bio-based poly(lactic acid) (PLA) composite films were produced using unmodified soda
micro- or nano-lignin as a green filler at four different contents, between 0.5 wt% and 5 wt%. The PLA–
lignin composite polymers were synthesized by solvent casting to prepare a masterbatch, followed by
melt mixing. The composites were then converted into films, to evaluate the effect of lignin content
and size on their physicochemical and mechanical properties. Differential scanning calorimetry
(DSC), supported by polarized light microscopy (PLM), infrared spectroscopy (FTIR-ATR), X-ray
diffraction (XRD), and transmission electron microscopy (TEM) were employed to investigate the
PLA crystallization and the interactions with Lignin (L) and Nanolignin (NL). The presence of
both fillers (L and NL) had a negligible effect on the glass transition temperature (chain diffusion).
However, it resulted in suppression of the corresponding change in heat capacity. This was indicative
of a partial immobilization of the PLA chains on the lignin entities, due to interfacial interactions,
which was slightly stronger in the case of NL. Lignin was also found to facilitate crystallization, in
terms of nucleation; whereas, this was not clear in the crystalline fraction. The addition of L and
NL led to systematically larger crystallites compared with neat PLA, which, combined with the
higher melting temperature, provided indications of a denser crystal structure in the composites. The
mechanical, optical, antioxidant, and surface properties of the composite films were also investigated.
The tensile strength and Young’s modulus were improved by the addition of L and especially NL.
The UV-blocking and antioxidant properties of the composite films were also enhanced, especially
at higher filler contents. Importantly, the PLA–NL composite films constantly outperformed their
PLA–L counterparts, due to the finer dispersion of NL in the PLA matrix, as verified by the TEM
micrographs. These results suggest that bio-based and biodegradable PLA films filled with L, and
particularly NL, can be employed as competitive and green alternatives in the food packaging
industry.
Ključne besede: poly(lactic acid), PLA, lignin, nanolignin, composite films, nucleation, mechanical properties, antioxidant activity, food packaging
Objavljeno v DKUM: 26.03.2025; Ogledov: 0; Prenosov: 1
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4. Statistical modeling and optimization of the drawing process of bioderived polylactide/poly(dodecylene furanoate) wet-spun fibersDaniele Rigotti, Giulia Fredi, Davide Perin, Dimitrios Bikiaris, Alessandro Pegoretti, Andrea Dorigato, 2022, izvirni znanstveni članek Opis: Drawing is a well-established method to improve the mechanical properties of wet-spun
fibers, as it orients the polymer chains, increases the chain density, and homogenizes the microstructure. This work aims to investigate how drawing variables, such as the draw ratio, drawing speed,
and temperature affect the elastic modulus (E) and the strain at break (εB) of biobased wet-spun fibers
constituted by neat polylactic acid (PLA) and a PLA/poly(dodecamethylene 2,5-furandicarboxylate)
(PDoF) (80/20 wt/wt) blend. Drawing experiments were conducted with a design of experiment
(DOE) approach following a 24
full factorial design. The results of the quasi-static tensile tests on
the drawn fibers, analyzed by the analysis of variance (ANOVA) and modeled through the response
surface methodology (RSM), highlight that the presence of PDoF significantly lowers E, which instead
is maximized if the temperature and draw ratio are both low. On the other hand, εB is enhanced
when the drawing is performed at a high temperature. Finally, a genetic algorithm was implemented
to find the optimal combination of drawing parameters that maximize both E and εB. The resulting
Pareto curve highlights that the temperature influences the mechanical results only for neat PLA
fibers, as the stiffness increases by drawing at lower temperatures, while optimal Pareto points for
PLA/PDoF fibers are mainly determined by the draw ratio and the draw rate.
Ključne besede: fibers, poly(lactic acid), furanoate polyesters, drawing, response surface methodology, genetic algorithms
Objavljeno v DKUM: 24.03.2025; Ogledov: 0; Prenosov: 2
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5. Improving the Thermomechanical Properties of Poly(lactic acid) via Reduced Graphene Oxide and Bioderived Poly(decamethylene 2,5-furandicarboxylate)Giulia Fredi, Mahdi Karimi Jafari, Andrea Dorigato, Dimitrios Bikiaris, Alessandro Pegoretti, 2022, izvirni znanstveni članek Opis: Polylactide (PLA) is the most widely used biopolymer, but its poor ductility and scarce
gas barrier properties limit its applications in the packaging field. In this work, for the first time,
the properties of PLA solvent-cast films are improved by the addition of a second biopolymer, i.e.,
poly(decamethylene 2,5-furandicarboxylate) (PDeF), added in a weight fraction of 10 wt%, and a
carbon-based nanofiller, i.e., reduced graphene oxide (rGO), added in concentrations of 0.25–2 phr.
PLA and PDeF are immiscible, as evidenced by scanning electron microscopy (SEM) and Fouriertransform infrared (FTIR) spectroscopy, with PDeF spheroidal domains showing poor adhesion to
PLA. The addition of 0.25 phr of rGO, which preferentially segregates in the PDeF domains, makes
them smaller and considerably rougher and improves the interfacial interaction. Differential scanning
calorimetry (DSC) confirms the immiscibility of the two polymer phases and highlights that rGO
enhances the crystallinity of both polymer phases (especially of PDeF). Thermogravimetric analysis
(TGA) highlights the positive impact of rGO and PDeF on the thermal degradation resistance of PLA.
Quasi-static tensile tests evidence that adding 10 wt% of PDeF and a small fraction of rGO (0.25 phr)
to PLA considerably enhances the strain at break, which raises from 5.3% of neat PLA to 10.0%
by adding 10 wt% of PDeF, up to 75.8% by adding also 0.25 phr of rGO, thereby highlighting the
compatibilizing role of rGO on this blend. On the other hand, a further increase in rGO concentration
decreases the strain at break due to agglomeration but enhances the mechanical stiffness and strength
up to an rGO concentration of 1 phr. Overall, these results highlight the positive and synergistic
contribution of PDeF and rGO in enhancing the thermomechanical properties of PLA, and the
resulting nanocomposites are promising for packaging applications.
Ključne besede: nanocomposites, reduced graphene oxide, poly(decamethylene 2, 5-furandicarboxylate), furanoate polyesters, polylactic acid, compatibilization
Objavljeno v DKUM: 20.03.2025; Ogledov: 0; Prenosov: 1
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6. Functionalization of polycaprolactone 3D scaffolds with hyaluronic acid glycine-peptide conjugates and endothelial cell adhesionTamilselvan Mohan, Fazilet Gürer, Doris Bračič, Florian Lackner, Chandran Nagaraj, Uroš Maver, Lidija Gradišnik, Matjaž Finšgar, Rupert Kargl, Karin Stana-Kleinschek, 2025, izvirni znanstveni članek Opis: This study enhances the bioactivity of polycaprolactone (PCL) scaffolds for tissue engineering by functionalizing them with oxidized hyaluronic acid glycine-peptide conjugates to improve endothelial cell adhesion and growth. Hyaluronic acid was conjugated with a glycine-peptide to create a bioactive interface on PCL (static water contact angle, SCA(H2O): 98°). The scaffolds were fabricated using a melt extrusion 3D printing technique. The HA-glycine peptide conjugates were oxidized and immobilized on aminolyzed PCL via Schiff-base chemistry, introducing hydrophilicity (SCA(H2O): 21°), multiple functional groups, and a negative zeta potential (-12.04 mV at pH 7.4). A quartz crystal microbalance confirmed chemical conjugation and quantified the mass (8.5-10.3 mg m-2) of oxidized HA-glycine on PCL. The functionalized scaffolds showed enhanced swelling, improved mechanical properties (2-fold increase in strength, from 26 to 51 MPa), and maintained integrity during degradation. In-vitro experiments demonstrated improved endothelial cell adhesion, proliferation and viability, suggesting the potential for vascularized tissue constructs.
Ključne besede: 3D printing, polycaprolactone, hyaluronic acid
Objavljeno v DKUM: 19.03.2025; Ogledov: 0; Prenosov: 3
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7. Structural and chromatographic characterization of cation‑exchange membranes based on carboxymethyl/ nanofbrillated cellulose using lysozymeVanja Kokol, Tina Simčič, Urh Černigoj, 2025, izvirni znanstveni članek Opis: Bio-based membranes are becoming highly-desired low-cost, environmentally friendly, and readily available supports for the separation and purification of biomacromolecules. In this work, weak cation-exchange and highly (> 95%) microporous (> 80 μm) cellulose-based membranes were prepared from different weight ratios of carboxymethyl cellulose (CMC) as anionic polymer and cellulose nanofibrils (CNFs) as a stabilizing and structural filler, by the freeze-casting process and citric-acid (CA) mediated in situ cross-linking (esterification). It was ascertained that mono-esterified/grafted CA also contributes to the total carboxylic groups (1.7–2.6 mmol/g), while the CMC-induced CNF orientation affected the membrane’s morphology and lysozyme (Lys) binding capacity. A static binding capacity (SBC) between 370 and 1080 mg/g, and equilibrium within 3.3 h for 1 g/mL Lys was thus achieved with increasing the total solid and CMC content by forming more isotropic microporous structures. The selected membranes were then packed in a chromatographic housing, analyzed for pressure drop, and evaluated for dynamic binding capacity (DBC), depending on the process performance (flow rates, Lys concentration). A DBC in the 165–417 mg/g range was determined at a throughput of 0.5 mL/min, and elution yield of 78–99% with > 95% recovery. The Lys adsorption and transfer were reduced by the increasing flow rate and membrane density due to compressibility issues, resulting in smaller and irregularly distributed pores and the unavailability of carboxylic groups. Although the DBC was still comparable with the commercial CIM® monoliths, the convection-based transport of molecules inside the membrane and the membrane stiffness needs to be improved in further research.
Ključne besede: cation-exchange membrane, cellulose nanofibrils, carboxymethyl cellulose, citric acid, lysozyme, static and dynamic binding capacity
Objavljeno v DKUM: 17.03.2025; Ogledov: 0; Prenosov: 5
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8. Unlocking innovation: Novel films synthesised and structurally analysed from poly (l-lactide-co-ethylene adipate) block copolymers blended with poly(lactic acid)Athira John, Klementina Pušnik Črešnar, Johan Stanley, Sabina Vohl, Damjan Makuc, Dimitrios Bikiaris, Lidija Fras Zemljič, 2025, izvirni znanstveni članek Opis: This study addresses the inherent shortcomings of poly (lactic acid) (PLA), a biodegradable polymer widely used in industries such as packaging and biomedical applications. The principal challenge of PLA resides in its low crystallinity, which detrimentally affects its mechanical properties and thermal stability. Additionally, PLA is prone to water and hydrolysis, which compromises its chemical resistance and can lead to degradation over time. To overcome surmount these limitations, the study focuses on the development of hybrid films through the blending of PLA with poly (l-lactide-co-ethylene adipate) (pLEA) block copolymers. The objective is to augment the crystallinity, mechanical performance, and chemical resistance of the resulting materials. The study employs a range of analytical techniques, including Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Polarised Light Microscopy (PLM), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA), to thoroughly characterize the copolymers and blend films. By systematically selecting blending ratios and processing methodologies, the study demonstrates enhancements in the properties of the resultant hybrid films compared to neat PLA. Specifically, the structure of films significantly changed from amorphous to crystalline in a short duration - 5 min, of annealing., leading to better tensile strength, modulus and reduced wettability, which are crucial for applications requiring durability and resistance to environmental factors. Films made from 30 wt% of pLEA 97.5/2.5 with 70 % of PLA by fast cooling exhibited outstanding mechanical properties, with a tensile strength 20 MPa higher than that of neat PLA films. Additionally, the chemical resistance may be improved, as evidenced by a decrease in wettability by approximately 15° and a reduction in the polar component of the surface free energy by about 7 mN/m. Hydrophobic, water-repellent materials resist penetration by water and other polar solvents, reducing exposure to corrosive substances and enhancing chemical resistance through barrier protection. Overall, this research addresses the limitations of PLA through innovative copolymerization and blending strategies, offering valuable insights into optimizing the material's properties for various practical applications.
Ključne besede: Poly(lactic acid), Poly(l-lactide-co-ethylene adipate), copolymer, blend, crystallinity
Objavljeno v DKUM: 13.03.2025; Ogledov: 0; Prenosov: 7
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9. Study on impact of monomers towards high molecular weight bio-based poly(ethylene furanoate) via solid state polymerization techniqueJohan Stanley, Eleftheria Xanthopoulou, Margaritis Kostoglou, Lidija Fras Zemljič, Dimitra A. Lambropoulou, Dimitrios Bikiaris, 2024, izvirni znanstveni članek Opis: In recent years, bio-based poly(ethylene furanoate) has gained the attention of packaging industries owing to its remarkable properties as a promising alternative to fossil-based polymers. It is necessary to synthesize high-molecular-weight polymers using effective and straightforward techniques for their commercialization. In this present work, poly(ethylene 2,5-furan dicarboxylate) (PEF) was produced with a high molecular weight of 0.43 dL/g using 2,5-furan dicarboxylic acid (FDCA) or its derivative Dimethyl-2,5-Furan dicarboxylate (DMFD), followed by solid-state polymerization (SSP) conducted at different temperatures and reaction times. The intrinsic viscosity ([η]), carboxyl end-group concentration (–COOH), and thermal properties of the produced polyesters were evaluated using differential scanning calorimetry (DSC). The results indicated that the SSP process improved the melting temperature and crystallinity of both the PEF samples as the reaction times and temperatures increased, as corroborated by DSC and X-ray diffraction (XRD) analyses. Additionally, both intrinsic viscosity and number-average molecular weight saw an increase with longer SSP durations and higher temperatures, while the concentration of carboxyl end groups decreased, aligning with expectations. The overall results indicate that PEF (DMFD) samples exhibited a significant increase in crystallization and molecular weight, attributed to their lower degree of crystallinity and their monomer’s high purity.
Ključne besede: bio-based polymers, 2, 5-furan dicarboxylic acid, dimethyl 2, 5-furan dicarboxylate, poly(ethylene 2, 5-furan dicarboxylate), poly(ethylene furanoate), solid state polymerization, thermal properties
Objavljeno v DKUM: 10.03.2025; Ogledov: 0; Prenosov: 6
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10. Recent trends in the synthesis of monomers for furanoate polyesters and their nanocomposites’ fabrication as a sustainable packaging materialJohan Stanley, Lidija Fras Zemljič, Dimitra A. Lambropoulou, Dimitrios Bikiaris, 2024, izvirni znanstveni članek Opis: Furanoate polyesters are an extremely promising new class of materials for packaging applications, particularly furanoate-based nanocomposites, which have gained a high interest level in research and development in both academia and industries. The monomers utilised for the synthesis of furanoate-based polyesters were derived from lignocellulosic biomass, which is essential for both eco-friendliness and sustainability. Also, these polyesters have a lower carbon footprint compared to fossil-based plastics, contributing to greenhouse gas reduction. The furanoate-based nanocomposites exhibit enhanced performance characteristics, such as high thermal stability, excellent mechanical strength, superior barrier resistance, and good bacteriostatic rate, making them suitable for a wide range of industrial applications, especially for food-packaging applications. This paper reviews the recent trends in the synthesis routes of monomers, such as the various catalytic activities involved in the oxidation of 5(hydroxymethyl)furfural (HMF) into 2,5-furandicarboxylic acid (FDCA) and its ester, dimethyl furan-2,5-dicarboxylate (DMFD). In addition, this review explores the fabrication of different furanoate-based nanocomposites prepared by in situ polymerization, by melt mixing or solvent evaporation methods, and by using different types of nanoparticles to enhance the overall material properties of the resulting nanocomposites. Emphasis was given to presenting the effect of these nanoparticles on the furanoate polyester’s properties.
Ključne besede: 2, 5-furandicarboxylic acid, dimethyl furan-2, 5-dicarboxylat, furanoate polyesters, furanoate nanocomposites, thermal properties, mechanical properties, antibacterial properties, sustainable packaging
Objavljeno v DKUM: 10.03.2025; Ogledov: 0; Prenosov: 5
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