TY  - JOUR
AU  - Mitrović, Aleksandra D.
AU  - Milovanović, Jelena
AU  - Gurgul, Jacek
AU  - Žekić, Andrijana
AU  - Nikodinović-Runić, Jasmina
AU  - Maslak, Veselin
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6287
AB  - We present a novel approach for the enzymatic functionalization of graphene, utilizing horseradish peroxidase (HPO) and laccase (LC) from Trametes versicolor. This study demonstrates, for the first time, the covalent modification of non-homogeneous graphene with a low surface-to-volume ratio, both in solution and on solid support. Through thermogravimetry analysis, we estimate the degree of functionalization to be 11% with HPO and 4% with LC, attributed to the varying redox potentials of the enzymes. This work highlights the potential of enzymatic reactions for tailored functionalization of graphene under mild conditions.
PB  - Elsevier
T2  - Enzyme and Microbial Technology
T1  - Enzymatic functionalization of liquid phase exfoliated graphene using horseradish peroxidase and laccase
VL  - 170
SP  - 110293
DO  - 10.1016/j.enzmictec.2023.110293
ER  - 

@article{
author = "Mitrović, Aleksandra D. and Milovanović, Jelena and Gurgul, Jacek and Žekić, Andrijana and Nikodinović-Runić, Jasmina and Maslak, Veselin",
year = "2023",
abstract = "We present a novel approach for the enzymatic functionalization of graphene, utilizing horseradish peroxidase (HPO) and laccase (LC) from Trametes versicolor. This study demonstrates, for the first time, the covalent modification of non-homogeneous graphene with a low surface-to-volume ratio, both in solution and on solid support. Through thermogravimetry analysis, we estimate the degree of functionalization to be 11% with HPO and 4% with LC, attributed to the varying redox potentials of the enzymes. This work highlights the potential of enzymatic reactions for tailored functionalization of graphene under mild conditions.",
publisher = "Elsevier",
journal = "Enzyme and Microbial Technology",
title = "Enzymatic functionalization of liquid phase exfoliated graphene using horseradish peroxidase and laccase",
volume = "170",
pages = "110293",
doi = "10.1016/j.enzmictec.2023.110293"
}

Mitrović, A. D., Milovanović, J., Gurgul, J., Žekić, A., Nikodinović-Runić, J.,& Maslak, V.. (2023). Enzymatic functionalization of liquid phase exfoliated graphene using horseradish peroxidase and laccase. in Enzyme and Microbial Technology
Elsevier., 170, 110293.
https://doi.org/10.1016/j.enzmictec.2023.110293

Mitrović AD, Milovanović J, Gurgul J, Žekić A, Nikodinović-Runić J, Maslak V. Enzymatic functionalization of liquid phase exfoliated graphene using horseradish peroxidase and laccase. in Enzyme and Microbial Technology. 2023;170:110293.
doi:10.1016/j.enzmictec.2023.110293 .

Mitrović, Aleksandra D., Milovanović, Jelena, Gurgul, Jacek, Žekić, Andrijana, Nikodinović-Runić, Jasmina, Maslak, Veselin, "Enzymatic functionalization of liquid phase exfoliated graphene using horseradish peroxidase and laccase" in Enzyme and Microbial Technology, 170 (2023):110293,
https://doi.org/10.1016/j.enzmictec.2023.110293 . .

TY  - JOUR
AU  - Kop, Tatjana
AU  - Bjelaković, Mira S.
AU  - Živković, Ljiljana S.
AU  - Žekić, Andrijana
AU  - Milić, Dragana
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/5319
AB  - Despite many advantages, the practical application of fullerene C60 and curcumin (CUR) has been limited by their hydrophobic nature, deficient solubility in aqueous media and, therefore, poor bioavailability. In this study, aqueous nanoformulations containing C60 and CUR in the absence and presence of three solubility enhancers, β-cyclodextrin (CD), Tween 80 (T80) and polyvinylpyrrolidone (PVP), were prepared and subjected to the antioxidant activity assessment. The content of C60 and CUR, stability, size and morphology of nanoparticles were determined using UV–vis, DLS and SEM techniques. Contrary to better solubility of pure C60 than the corresponding C60-CUR system, the solubilization of CUR in hybrid suspensions was improved compared to corresponding pure CUR suspensions, with the exception of the C60-CUR-PVP formulation. The DLS results revealed nearly monodisperse nature of CUR-T80 nanoformulation, while other ones ranged from widely dispersed to polydispersed. Depending on the type of solubilizer, similarity was observed in the particle size distributions of T80- and PVP-coated nanoformulations as well as water and CD nanoformulations. The presence of T80 differently and significantly reduces the particle size in all three nanoformulations, while PVP slightly reduces CUR-based nanoparticles but increases the size of C60 nanoparticles. Zeta potential values, ranging from − 9 mV to − 34 mV, show variation in the starting stability of nanoparticles, from unstable or relatively stable three PVP formulations and C60-T80 to highly stable CUR-T80 and C60-water. Compared to water nanoformulations as a control, SEM images of dispersant-coated nanoparticles lost the visible morphology of active components, showing variation in their morphology depending on the type of dispersant and active component used. Nanoformulations containing CUR in PVP and T80 expressed a very good antioxidant potential in DPPH radical scavenging assay, much stronger than ascorbic acid. At the same time, a moderate to high antioxidant activity in β-carotene bleaching assay was reached in PVP and T80 nanoformulations containing C60, CUR, and their noncovalent hybrid, as well. Our studies have shown that T80 and PVP colloidal systems containing C60-CUR hybrid, but also their individual components, can be used as stable antioxidant nanoformulations with potential application in the field of food and pharmacology.
PB  - Elsevier
T2  - Colloids and Surfaces A: Physicochemical and Engineering Aspects
T1  - Stable colloidal dispersions of fullerene C60, curcumin and C60-curcumin in water as potential antioxidants
VL  - 648
DO  - 10.1016/j.colsurfa.2022.129379
ER  - 

@article{
author = "Kop, Tatjana and Bjelaković, Mira S. and Živković, Ljiljana S. and Žekić, Andrijana and Milić, Dragana",
year = "2022",
abstract = "Despite many advantages, the practical application of fullerene C60 and curcumin (CUR) has been limited by their hydrophobic nature, deficient solubility in aqueous media and, therefore, poor bioavailability. In this study, aqueous nanoformulations containing C60 and CUR in the absence and presence of three solubility enhancers, β-cyclodextrin (CD), Tween 80 (T80) and polyvinylpyrrolidone (PVP), were prepared and subjected to the antioxidant activity assessment. The content of C60 and CUR, stability, size and morphology of nanoparticles were determined using UV–vis, DLS and SEM techniques. Contrary to better solubility of pure C60 than the corresponding C60-CUR system, the solubilization of CUR in hybrid suspensions was improved compared to corresponding pure CUR suspensions, with the exception of the C60-CUR-PVP formulation. The DLS results revealed nearly monodisperse nature of CUR-T80 nanoformulation, while other ones ranged from widely dispersed to polydispersed. Depending on the type of solubilizer, similarity was observed in the particle size distributions of T80- and PVP-coated nanoformulations as well as water and CD nanoformulations. The presence of T80 differently and significantly reduces the particle size in all three nanoformulations, while PVP slightly reduces CUR-based nanoparticles but increases the size of C60 nanoparticles. Zeta potential values, ranging from − 9 mV to − 34 mV, show variation in the starting stability of nanoparticles, from unstable or relatively stable three PVP formulations and C60-T80 to highly stable CUR-T80 and C60-water. Compared to water nanoformulations as a control, SEM images of dispersant-coated nanoparticles lost the visible morphology of active components, showing variation in their morphology depending on the type of dispersant and active component used. Nanoformulations containing CUR in PVP and T80 expressed a very good antioxidant potential in DPPH radical scavenging assay, much stronger than ascorbic acid. At the same time, a moderate to high antioxidant activity in β-carotene bleaching assay was reached in PVP and T80 nanoformulations containing C60, CUR, and their noncovalent hybrid, as well. Our studies have shown that T80 and PVP colloidal systems containing C60-CUR hybrid, but also their individual components, can be used as stable antioxidant nanoformulations with potential application in the field of food and pharmacology.",
publisher = "Elsevier",
journal = "Colloids and Surfaces A: Physicochemical and Engineering Aspects",
title = "Stable colloidal dispersions of fullerene C60, curcumin and C60-curcumin in water as potential antioxidants",
volume = "648",
doi = "10.1016/j.colsurfa.2022.129379"
}

Kop, T., Bjelaković, M. S., Živković, L. S., Žekić, A.,& Milić, D.. (2022). Stable colloidal dispersions of fullerene C60, curcumin and C60-curcumin in water as potential antioxidants. in Colloids and Surfaces A: Physicochemical and Engineering Aspects
Elsevier., 648.
https://doi.org/10.1016/j.colsurfa.2022.129379

Kop T, Bjelaković MS, Živković LS, Žekić A, Milić D. Stable colloidal dispersions of fullerene C60, curcumin and C60-curcumin in water as potential antioxidants. in Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2022;648.
doi:10.1016/j.colsurfa.2022.129379 .

Kop, Tatjana, Bjelaković, Mira S., Živković, Ljiljana S., Žekić, Andrijana, Milić, Dragana, "Stable colloidal dispersions of fullerene C60, curcumin and C60-curcumin in water as potential antioxidants" in Colloids and Surfaces A: Physicochemical and Engineering Aspects, 648 (2022),
https://doi.org/10.1016/j.colsurfa.2022.129379 . .

TY  - JOUR
AU  - Kop, Tatjana
AU  - Jakovljević, Dragica M.
AU  - Živković, Ljiljana S.
AU  - Žekić, Andrijana
AU  - Beškoski, Vladimir
AU  - Milić, Dragana
AU  - Gojgić-Cvijović, Gordana D.
AU  - Bjelaković, Mira S.
PY  - 2020
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/3803
AB  - An efficient encapsulation of the fullerene into two hydrophobized and one native polysaccharide provided water soluble supramolecular hybrids. After covalent modification of polysaccharides by cholesterol, noncovalent hybrids were prepared by a three-step procedure, including mixing of individual aqueous solutions of hydrophobized, as well as native sugar with solution of the fullerene in pyridine, dialysis and lyophilization. Although the degree of the fullerene incorporation into hydrophobized substrates, cholesterol-levan and cholesterol-pullulan, was lower in comparison to the native polysaccharide levan, hydrophobization provided nanoparticles with improved properties. The particle size distribution, studied by dynamic light scattering and scanning electron microscopy revealed formation of moderately polydisperse aggregates, with the diameter contraction in comparison to the corresponding free polysaccharide, especially in the case of hydrophobized substrates. The morphological examination, done by scanning electron microscopy indicated the self-organization of the fullerene-native polysaccharide to round individual structures, while fullerene-hydrophobized polysaccharide hybrids tend to form networks. The antioxidant activity of the synthesized polysaccharide-C60 noncovalent hybrids versus starting polysaccharides was investigated by the DPPH radical scavenging and the β-carotene-linoleic acid bleaching methods. In all three complexes, the radical scavenging ability of the fullerene remained preserved, and a positive effect of levan hydrophobization was observed.
PB  - Elsevier
T2  - European Polymer Journal
T1  - Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity
VL  - 123
IS  - 109461
DO  - 10.1016/j.eurpolymj.2019.109461
ER  - 

@article{
author = "Kop, Tatjana and Jakovljević, Dragica M. and Živković, Ljiljana S. and Žekić, Andrijana and Beškoski, Vladimir and Milić, Dragana and Gojgić-Cvijović, Gordana D. and Bjelaković, Mira S.",
year = "2020",
abstract = "An efficient encapsulation of the fullerene into two hydrophobized and one native polysaccharide provided water soluble supramolecular hybrids. After covalent modification of polysaccharides by cholesterol, noncovalent hybrids were prepared by a three-step procedure, including mixing of individual aqueous solutions of hydrophobized, as well as native sugar with solution of the fullerene in pyridine, dialysis and lyophilization. Although the degree of the fullerene incorporation into hydrophobized substrates, cholesterol-levan and cholesterol-pullulan, was lower in comparison to the native polysaccharide levan, hydrophobization provided nanoparticles with improved properties. The particle size distribution, studied by dynamic light scattering and scanning electron microscopy revealed formation of moderately polydisperse aggregates, with the diameter contraction in comparison to the corresponding free polysaccharide, especially in the case of hydrophobized substrates. The morphological examination, done by scanning electron microscopy indicated the self-organization of the fullerene-native polysaccharide to round individual structures, while fullerene-hydrophobized polysaccharide hybrids tend to form networks. The antioxidant activity of the synthesized polysaccharide-C60 noncovalent hybrids versus starting polysaccharides was investigated by the DPPH radical scavenging and the β-carotene-linoleic acid bleaching methods. In all three complexes, the radical scavenging ability of the fullerene remained preserved, and a positive effect of levan hydrophobization was observed.",
publisher = "Elsevier",
journal = "European Polymer Journal",
title = "Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity",
volume = "123",
number = "109461",
doi = "10.1016/j.eurpolymj.2019.109461"
}

Kop, T., Jakovljević, D. M., Živković, L. S., Žekić, A., Beškoski, V., Milić, D., Gojgić-Cvijović, G. D.,& Bjelaković, M. S.. (2020). Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity. in European Polymer Journal
Elsevier., 123(109461).
https://doi.org/10.1016/j.eurpolymj.2019.109461

Kop T, Jakovljević DM, Živković LS, Žekić A, Beškoski V, Milić D, Gojgić-Cvijović GD, Bjelaković MS. Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity. in European Polymer Journal. 2020;123(109461).
doi:10.1016/j.eurpolymj.2019.109461 .

Kop, Tatjana, Jakovljević, Dragica M., Živković, Ljiljana S., Žekić, Andrijana, Beškoski, Vladimir, Milić, Dragana, Gojgić-Cvijović, Gordana D., Bjelaković, Mira S., "Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity" in European Polymer Journal, 123, no. 109461 (2020),
https://doi.org/10.1016/j.eurpolymj.2019.109461 . .

TY  - JOUR
AU  - Kop, Tatjana
AU  - Jakovljević, Dragica M.
AU  - Živković, Ljiljana S.
AU  - Žekić, Andrijana
AU  - Beškoski, Vladimir
AU  - Milić, Dragana
AU  - Gojgić-Cvijović, Gordana D.
AU  - Bjelaković, Mira S.
PY  - 2020
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/3830
AB  - An efficient encapsulation of the fullerene into two hydrophobized and one native polysaccharide provided water soluble supramolecular hybrids. After covalent modification of polysaccharides by cholesterol, noncovalent hybrids were prepared by a three-step procedure, including mixing of individual aqueous solutions of hydrophobized, as well as native sugar with solution of the fullerene in pyridine, dialysis and lyophilization. Although the degree of the fullerene incorporation into hydrophobized substrates, cholesterol-levan and cholesterol-pullulan, was lower in comparison to the native polysaccharide levan, hydrophobization provided nanoparticles with improved properties. The particle size distribution, studied by dynamic light scattering and scanning electron microscopy revealed formation of moderately polydisperse aggregates, with the diameter contraction in comparison to the corresponding free polysaccharide, especially in the case of hydrophobized substrates. The morphological examination, done by scanning electron microscopy indicated the self-organization of the fullerene-native polysaccharide to round individual structures, while fullerene-hydrophobized polysaccharide hybrids tend to form networks. The antioxidant activity of the synthesized polysaccharide-C60 noncovalent hybrids versus starting polysaccharides was investigated by the DPPH radical scavenging and the β-carotene-linoleic acid bleaching methods. In all three complexes, the radical scavenging ability of the fullerene remained preserved, and a positive effect of levan hydrophobization was observed.
PB  - Elsevier
T2  - European Polymer Journal
T1  - Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity
VL  - 123
SP  - 109461
DO  - 10.1016/j.eurpolymj.2019.109461
ER  - 

@article{
author = "Kop, Tatjana and Jakovljević, Dragica M. and Živković, Ljiljana S. and Žekić, Andrijana and Beškoski, Vladimir and Milić, Dragana and Gojgić-Cvijović, Gordana D. and Bjelaković, Mira S.",
year = "2020",
abstract = "An efficient encapsulation of the fullerene into two hydrophobized and one native polysaccharide provided water soluble supramolecular hybrids. After covalent modification of polysaccharides by cholesterol, noncovalent hybrids were prepared by a three-step procedure, including mixing of individual aqueous solutions of hydrophobized, as well as native sugar with solution of the fullerene in pyridine, dialysis and lyophilization. Although the degree of the fullerene incorporation into hydrophobized substrates, cholesterol-levan and cholesterol-pullulan, was lower in comparison to the native polysaccharide levan, hydrophobization provided nanoparticles with improved properties. The particle size distribution, studied by dynamic light scattering and scanning electron microscopy revealed formation of moderately polydisperse aggregates, with the diameter contraction in comparison to the corresponding free polysaccharide, especially in the case of hydrophobized substrates. The morphological examination, done by scanning electron microscopy indicated the self-organization of the fullerene-native polysaccharide to round individual structures, while fullerene-hydrophobized polysaccharide hybrids tend to form networks. The antioxidant activity of the synthesized polysaccharide-C60 noncovalent hybrids versus starting polysaccharides was investigated by the DPPH radical scavenging and the β-carotene-linoleic acid bleaching methods. In all three complexes, the radical scavenging ability of the fullerene remained preserved, and a positive effect of levan hydrophobization was observed.",
publisher = "Elsevier",
journal = "European Polymer Journal",
title = "Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity",
volume = "123",
pages = "109461",
doi = "10.1016/j.eurpolymj.2019.109461"
}

Kop, T., Jakovljević, D. M., Živković, L. S., Žekić, A., Beškoski, V., Milić, D., Gojgić-Cvijović, G. D.,& Bjelaković, M. S.. (2020). Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity. in European Polymer Journal
Elsevier., 123, 109461.
https://doi.org/10.1016/j.eurpolymj.2019.109461

Kop T, Jakovljević DM, Živković LS, Žekić A, Beškoski V, Milić D, Gojgić-Cvijović GD, Bjelaković MS. Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity. in European Polymer Journal. 2020;123:109461.
doi:10.1016/j.eurpolymj.2019.109461 .

Kop, Tatjana, Jakovljević, Dragica M., Živković, Ljiljana S., Žekić, Andrijana, Beškoski, Vladimir, Milić, Dragana, Gojgić-Cvijović, Gordana D., Bjelaković, Mira S., "Polysaccharide-fullerene supramolecular hybrids: Synthesis, characterization and antioxidant activity" in European Polymer Journal, 123 (2020):109461,
https://doi.org/10.1016/j.eurpolymj.2019.109461 . .