TY  - JOUR
AU  - Milojkov, Dušan V.
AU  - Silvestre, Oscar F.
AU  - Stanić, Vojislav
AU  - Janjić, Goran V.
AU  - Mutavdžić, Dragosav R.
AU  - Milanović, Marija
AU  - Nieder, Jana B.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8529
AB  - Fluorapatite doped with rare-earth elements has a wide-range of biomedical applications. Here, a new type of fluorapatite nanocrystals doped with praseodymium (FAP-Pr) with excitation-emission profiles in visible part of the spectrum is fabricated. Energy levels of Pr3+ activator ion contain metastable multiplet states that offer the possibility of efficient multicolor emission lines in FAP nanocrystals. Three types of FAP-Pr nanocrystals with 0.1%, 0.5% and 1% atomic percent of Pr3+ (along with the undoped FAP control sample) are studied. Their novel chemical production method is described, the FAP-Pr nanocrystals structure, biocompatibility and the suitability for cell imaging are analyzed. Physicochemical characterization confirms crystals down to nanometer size. In addition, quantum-chemical calculation predicts that Pr3+ ions are incorporated into the FAP crystal lattice at Ca2 (6 h) sites. In vitro viability results shows that FAP-Pr nanocrystals are nontoxic to live cells. Additionally, the cell uptake of the FAP-Pr nanocrystals is studied using fluorescence-based widefield and confocal microscopy. The nanocrystals show characteristic green emission at 545 nm (3P0→3H5 transition of Pr3+ ion) and orange emission at 600 nm (1D2→3H4), which we use to discriminate from cell autofluorescence background. Orthogonal projections across 3D confocal stacks show that the nanocrystals are able to enter the cells positioning themselves within the cytoplasm. Overall, the new FAP-Pr nanocrystals are biocompatible and of the tested types, the 0.5% Pr3+ doped nanocrystals show the highest promise as a tracking nanoparticle probe for bioimaging applications. © 2019
T2  - Journal of Luminescence
T1  - Fabrication and characterization of luminescent Pr3+ doped fluorapatite nanocrystals as bioimaging contrast agents
VL  - 217
SP  - 116757
DO  - 10.1016/j.jlumin.2019.116757
ER  - 

@article{
author = "Milojkov, Dušan V. and Silvestre, Oscar F. and Stanić, Vojislav and Janjić, Goran V. and Mutavdžić, Dragosav R. and Milanović, Marija and Nieder, Jana B.",
year = "2020",
abstract = "Fluorapatite doped with rare-earth elements has a wide-range of biomedical applications. Here, a new type of fluorapatite nanocrystals doped with praseodymium (FAP-Pr) with excitation-emission profiles in visible part of the spectrum is fabricated. Energy levels of Pr3+ activator ion contain metastable multiplet states that offer the possibility of efficient multicolor emission lines in FAP nanocrystals. Three types of FAP-Pr nanocrystals with 0.1%, 0.5% and 1% atomic percent of Pr3+ (along with the undoped FAP control sample) are studied. Their novel chemical production method is described, the FAP-Pr nanocrystals structure, biocompatibility and the suitability for cell imaging are analyzed. Physicochemical characterization confirms crystals down to nanometer size. In addition, quantum-chemical calculation predicts that Pr3+ ions are incorporated into the FAP crystal lattice at Ca2 (6 h) sites. In vitro viability results shows that FAP-Pr nanocrystals are nontoxic to live cells. Additionally, the cell uptake of the FAP-Pr nanocrystals is studied using fluorescence-based widefield and confocal microscopy. The nanocrystals show characteristic green emission at 545 nm (3P0→3H5 transition of Pr3+ ion) and orange emission at 600 nm (1D2→3H4), which we use to discriminate from cell autofluorescence background. Orthogonal projections across 3D confocal stacks show that the nanocrystals are able to enter the cells positioning themselves within the cytoplasm. Overall, the new FAP-Pr nanocrystals are biocompatible and of the tested types, the 0.5% Pr3+ doped nanocrystals show the highest promise as a tracking nanoparticle probe for bioimaging applications. © 2019",
journal = "Journal of Luminescence",
title = "Fabrication and characterization of luminescent Pr3+ doped fluorapatite nanocrystals as bioimaging contrast agents",
volume = "217",
pages = "116757",
doi = "10.1016/j.jlumin.2019.116757"
}

Milojkov, D. V., Silvestre, O. F., Stanić, V., Janjić, G. V., Mutavdžić, D. R., Milanović, M.,& Nieder, J. B.. (2020). Fabrication and characterization of luminescent Pr3+ doped fluorapatite nanocrystals as bioimaging contrast agents. in Journal of Luminescence, 217, 116757.
https://doi.org/10.1016/j.jlumin.2019.116757

Milojkov DV, Silvestre OF, Stanić V, Janjić GV, Mutavdžić DR, Milanović M, Nieder JB. Fabrication and characterization of luminescent Pr3+ doped fluorapatite nanocrystals as bioimaging contrast agents. in Journal of Luminescence. 2020;217:116757.
doi:10.1016/j.jlumin.2019.116757 .

Milojkov, Dušan V., Silvestre, Oscar F., Stanić, Vojislav, Janjić, Goran V., Mutavdžić, Dragosav R., Milanović, Marija, Nieder, Jana B., "Fabrication and characterization of luminescent Pr3+ doped fluorapatite nanocrystals as bioimaging contrast agents" in Journal of Luminescence, 217 (2020):116757,
https://doi.org/10.1016/j.jlumin.2019.116757 . .

TY  - JOUR
AU  - Leskovac, Andreja
AU  - Petrović, Sandra
AU  - Lazarević-Pašti, Tamara
AU  - Krstić, Milena P.
AU  - Vasić, Vesna M.
PY  - 2018
UR  - http://link.springer.com/10.1007/s00775-018-1560-x
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7765
AB  - In recent years, the search for effective anticancer compounds based on transition metal complexes has been the focus of medical investigations. The synergy between the ruthenium(II) and N-alkylphenothiazine counter-ions (chlorpromazine hydrochloride, thioridazine hydrochloride and trifluoperazine dihydrochloride, respectively) through the formation of three different complexes (1–3) was investigated. We explored whether the selected counter-ions and complexes might affect redox homeostasis and genome integrity of normal human blood cells, and induce an inhibition of Na+/K+-ATPase and AChE at pharmacologically relevant doses. Our results have shown that counter-ions and complexes did not affect the activity of Na+/K+-ATPase, while AChE activity was inhibited in a dose-dependent manner. All investigated compounds disturbed the viability and redox homeostasis of lymphocytes. Complexes 1 and 2 displayed potent cytotoxic and prooxidant action while complex 3 behaved as a weaker genotoxic inducer. Still, the tested complexes appeared to be less genotoxic and more cytostatic than the corresponding counter-ions. The effects of selected complexes were also tested in PC12 and U2OS cancer cells with special attention being given to the ability of phenothiazines to affect dopamine D2 receptors. Using the confocal laser scanning microscopy, we observed that all the complexes reduced cell viability. Although all investigated complexes have been bound to the dopamine receptor D2-eGFP, only complex 3 reduced its surface density and increased its lateral mobility in investigated cell lines. Albeit the role of alternative targets for complex 3 cannot be ruled out, its effects should be further examined as potential treatment strategy against cancer cells that overexpress D2.
T2  - JBIC Journal of Biological Inorganic Chemistry
T1  - Ruthenium(II)-N-alkyl phenothiazine complexes as potential anticancer agents
VL  - 23
IS  - 5
SP  - 689
EP  - 704
DO  - 10.1007/s00775-018-1560-x
ER  - 

@article{
author = "Leskovac, Andreja and Petrović, Sandra and Lazarević-Pašti, Tamara and Krstić, Milena P. and Vasić, Vesna M.",
year = "2018",
abstract = "In recent years, the search for effective anticancer compounds based on transition metal complexes has been the focus of medical investigations. The synergy between the ruthenium(II) and N-alkylphenothiazine counter-ions (chlorpromazine hydrochloride, thioridazine hydrochloride and trifluoperazine dihydrochloride, respectively) through the formation of three different complexes (1–3) was investigated. We explored whether the selected counter-ions and complexes might affect redox homeostasis and genome integrity of normal human blood cells, and induce an inhibition of Na+/K+-ATPase and AChE at pharmacologically relevant doses. Our results have shown that counter-ions and complexes did not affect the activity of Na+/K+-ATPase, while AChE activity was inhibited in a dose-dependent manner. All investigated compounds disturbed the viability and redox homeostasis of lymphocytes. Complexes 1 and 2 displayed potent cytotoxic and prooxidant action while complex 3 behaved as a weaker genotoxic inducer. Still, the tested complexes appeared to be less genotoxic and more cytostatic than the corresponding counter-ions. The effects of selected complexes were also tested in PC12 and U2OS cancer cells with special attention being given to the ability of phenothiazines to affect dopamine D2 receptors. Using the confocal laser scanning microscopy, we observed that all the complexes reduced cell viability. Although all investigated complexes have been bound to the dopamine receptor D2-eGFP, only complex 3 reduced its surface density and increased its lateral mobility in investigated cell lines. Albeit the role of alternative targets for complex 3 cannot be ruled out, its effects should be further examined as potential treatment strategy against cancer cells that overexpress D2.",
journal = "JBIC Journal of Biological Inorganic Chemistry",
title = "Ruthenium(II)-N-alkyl phenothiazine complexes as potential anticancer agents",
volume = "23",
number = "5",
pages = "689-704",
doi = "10.1007/s00775-018-1560-x"
}

Leskovac, A., Petrović, S., Lazarević-Pašti, T., Krstić, M. P.,& Vasić, V. M.. (2018). Ruthenium(II)-N-alkyl phenothiazine complexes as potential anticancer agents. in JBIC Journal of Biological Inorganic Chemistry, 23(5), 689-704.
https://doi.org/10.1007/s00775-018-1560-x

Leskovac A, Petrović S, Lazarević-Pašti T, Krstić MP, Vasić VM. Ruthenium(II)-N-alkyl phenothiazine complexes as potential anticancer agents. in JBIC Journal of Biological Inorganic Chemistry. 2018;23(5):689-704.
doi:10.1007/s00775-018-1560-x .

Leskovac, Andreja, Petrović, Sandra, Lazarević-Pašti, Tamara, Krstić, Milena P., Vasić, Vesna M., "Ruthenium(II)-N-alkyl phenothiazine complexes as potential anticancer agents" in JBIC Journal of Biological Inorganic Chemistry, 23, no. 5 (2018):689-704,
https://doi.org/10.1007/s00775-018-1560-x . .

TY  - JOUR
AU  - Laban, Bojana B.
AU  - Vodnik, Vesna
AU  - Dramićanin, Miroslav
AU  - Novaković, Mirjana M.
AU  - Bibić, Nataša M.
AU  - Sovilj, Sofija P.
AU  - Vasić, Vesna M.
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/155
AB  - The aim of the present work was to elucidate the binding mechanism and kinetics of anionic cyanine dye 3,3-disulfopropyl-5,5-dichlorothiacyanine sodium salt (TC) J-aggregation on the surface of silver nanoparticles (AgNPs, particle size similar to 6 nm). The hybrid J-aggregateAgNPs assembly was characterized by TEM analysis, UVvis spectrophotometry, and fluorescence measurements. In the elucidation of TC binding on the surface of AgNPs, they were considered as macromolecules with several binding sites and TC dye was considered as a ligand. Scatchard and Hill analysis revealed that TC binding was a random process rather than cooperative, with similar to 200 bonded TC molecules per AgNP and a binding constant K-a = 4.8 x 10(7) M. The TC-AgNP assembly exerted concentration-dependent fluorescence quenching properties. The linearity of the SternVolmer relation, accounting for both static and dynamic quenching, indicated that only one type of quenching occurred, suggesting that AgNPs quenched the fluorescence of TC with an extraordinarily high SternVolmer constant (KSV) in the range of 10(8) M-1. Additionally, the kinetics of J-aggregation of TC in the presence of AgNPs was studied using a stopped flow technique. Kinetic measurements were performed as a function of the TC and AgNP concentration, yielding sigmoidal kinetic curves. The concentration dependence of the parameters of the kinetic curves indicated that J-aggregate formation on the AgNP surface occurred via a two-step process; the first was adsorption of the initial dye layer, followed by the growth of consecutive layers.
T2  - Journal of Physical Chemistry. C
T1  - Mechanism and Kinetics of J-Aggregation of Thiacyanine Dye in the Presence of Silver Nanoparticles
VL  - 118
IS  - 40
SP  - 23393
EP  - 23401
DO  - 10.1021/jp507086g
ER  - 

@article{
author = "Laban, Bojana B. and Vodnik, Vesna and Dramićanin, Miroslav and Novaković, Mirjana M. and Bibić, Nataša M. and Sovilj, Sofija P. and Vasić, Vesna M.",
year = "2014",
abstract = "The aim of the present work was to elucidate the binding mechanism and kinetics of anionic cyanine dye 3,3-disulfopropyl-5,5-dichlorothiacyanine sodium salt (TC) J-aggregation on the surface of silver nanoparticles (AgNPs, particle size similar to 6 nm). The hybrid J-aggregateAgNPs assembly was characterized by TEM analysis, UVvis spectrophotometry, and fluorescence measurements. In the elucidation of TC binding on the surface of AgNPs, they were considered as macromolecules with several binding sites and TC dye was considered as a ligand. Scatchard and Hill analysis revealed that TC binding was a random process rather than cooperative, with similar to 200 bonded TC molecules per AgNP and a binding constant K-a = 4.8 x 10(7) M. The TC-AgNP assembly exerted concentration-dependent fluorescence quenching properties. The linearity of the SternVolmer relation, accounting for both static and dynamic quenching, indicated that only one type of quenching occurred, suggesting that AgNPs quenched the fluorescence of TC with an extraordinarily high SternVolmer constant (KSV) in the range of 10(8) M-1. Additionally, the kinetics of J-aggregation of TC in the presence of AgNPs was studied using a stopped flow technique. Kinetic measurements were performed as a function of the TC and AgNP concentration, yielding sigmoidal kinetic curves. The concentration dependence of the parameters of the kinetic curves indicated that J-aggregate formation on the AgNP surface occurred via a two-step process; the first was adsorption of the initial dye layer, followed by the growth of consecutive layers.",
journal = "Journal of Physical Chemistry. C",
title = "Mechanism and Kinetics of J-Aggregation of Thiacyanine Dye in the Presence of Silver Nanoparticles",
volume = "118",
number = "40",
pages = "23393-23401",
doi = "10.1021/jp507086g"
}

Laban, B. B., Vodnik, V., Dramićanin, M., Novaković, M. M., Bibić, N. M., Sovilj, S. P.,& Vasić, V. M.. (2014). Mechanism and Kinetics of J-Aggregation of Thiacyanine Dye in the Presence of Silver Nanoparticles. in Journal of Physical Chemistry. C, 118(40), 23393-23401.
https://doi.org/10.1021/jp507086g

Laban BB, Vodnik V, Dramićanin M, Novaković MM, Bibić NM, Sovilj SP, Vasić VM. Mechanism and Kinetics of J-Aggregation of Thiacyanine Dye in the Presence of Silver Nanoparticles. in Journal of Physical Chemistry. C. 2014;118(40):23393-23401.
doi:10.1021/jp507086g .

Laban, Bojana B., Vodnik, Vesna, Dramićanin, Miroslav, Novaković, Mirjana M., Bibić, Nataša M., Sovilj, Sofija P., Vasić, Vesna M., "Mechanism and Kinetics of J-Aggregation of Thiacyanine Dye in the Presence of Silver Nanoparticles" in Journal of Physical Chemistry. C, 118, no. 40 (2014):23393-23401,
https://doi.org/10.1021/jp507086g . .