TY  - JOUR
AU  - Osmokrović, Andrea
AU  - Jancić, Ivan
AU  - Vunduk, Jovana
AU  - Petrović, Predrag
AU  - Milenković, Marina
AU  - Obradović, Bojana
PY  - 2018
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/4785
AB  - New composites based on Ca-alginate hydrogels were produced that release activated charcoal (AC) particles with adsorbed povidone iodine (PVP-I) as a model antimicrobial substance in a physiological-like environment. Composite beads with different alginate (0.5-1.5% w/w) and AC (1-20% w/w) concentrations were analyzed by FE-SEM and characterized regarding textural parameters, swelling, and AC release kinetics. PVP-I was easily adsorbed onto AC particles within the optimized beads (0.5% w/w alginate, 20% w/w AC) as indicated by UV-vis spectroscopy, EDX and FT-IR analyses. The obtained beads have shown strong bactericidal effects against two standard bacterial strains (Staphylococcus aureus and Pseudomonas aeruginosa) and clinical multi-resistant wound isolates (MRSA, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis and Proteus mirabilis) and, at the same time, exhibited negligible PVP-I desorption in physiological saline solution. Thus, the obtained composites could provide utilization of potent antiseptics such as iodine, in wound dressings, without the concern of systemic absorption.
PB  - Elsevier Sci Ltd, Oxford
T2  - Carbohydrate Polymers
T1  - Achieving high antimicrobial activity: Composite alginate hydrogel beads releasing activated charcoal with an immobilized active agent
EP  - 288
SP  - 279
VL  - 196
DO  - 10.1016/j.carbpol.2018.05.045
ER  - 

@article{
author = "Osmokrović, Andrea and Jancić, Ivan and Vunduk, Jovana and Petrović, Predrag and Milenković, Marina and Obradović, Bojana",
year = "2018",
abstract = "New composites based on Ca-alginate hydrogels were produced that release activated charcoal (AC) particles with adsorbed povidone iodine (PVP-I) as a model antimicrobial substance in a physiological-like environment. Composite beads with different alginate (0.5-1.5% w/w) and AC (1-20% w/w) concentrations were analyzed by FE-SEM and characterized regarding textural parameters, swelling, and AC release kinetics. PVP-I was easily adsorbed onto AC particles within the optimized beads (0.5% w/w alginate, 20% w/w AC) as indicated by UV-vis spectroscopy, EDX and FT-IR analyses. The obtained beads have shown strong bactericidal effects against two standard bacterial strains (Staphylococcus aureus and Pseudomonas aeruginosa) and clinical multi-resistant wound isolates (MRSA, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis and Proteus mirabilis) and, at the same time, exhibited negligible PVP-I desorption in physiological saline solution. Thus, the obtained composites could provide utilization of potent antiseptics such as iodine, in wound dressings, without the concern of systemic absorption.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Carbohydrate Polymers",
title = "Achieving high antimicrobial activity: Composite alginate hydrogel beads releasing activated charcoal with an immobilized active agent",
pages = "288-279",
volume = "196",
doi = "10.1016/j.carbpol.2018.05.045"
}

Osmokrović, A., Jancić, I., Vunduk, J., Petrović, P., Milenković, M.,& Obradović, B.. (2018). Achieving high antimicrobial activity: Composite alginate hydrogel beads releasing activated charcoal with an immobilized active agent. in Carbohydrate Polymers
Elsevier Sci Ltd, Oxford., 196, 279-288.
https://doi.org/10.1016/j.carbpol.2018.05.045

Osmokrović A, Jancić I, Vunduk J, Petrović P, Milenković M, Obradović B. Achieving high antimicrobial activity: Composite alginate hydrogel beads releasing activated charcoal with an immobilized active agent. in Carbohydrate Polymers. 2018;196:279-288.
doi:10.1016/j.carbpol.2018.05.045 .

Osmokrović, Andrea, Jancić, Ivan, Vunduk, Jovana, Petrović, Predrag, Milenković, Marina, Obradović, Bojana, "Achieving high antimicrobial activity: Composite alginate hydrogel beads releasing activated charcoal with an immobilized active agent" in Carbohydrate Polymers, 196 (2018):279-288,
https://doi.org/10.1016/j.carbpol.2018.05.045 . .

TY  - JOUR
AU  - Manojlović, Verica
AU  - Rajić, Nevenka
AU  - Djonlagić, Jasna
AU  - Obradović, Bojana
AU  - Nedović, Viktor
AU  - Bugarski, Branko
PY  - 2008
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1836
AB  - The subject of this study was the development of flavour alginate formulations aimed for thermally processed foods. Ethyl vanilline was used as the model flavour compound. Electrostatic extrusion was applied for the encapsulation of ethyl vanilline in alginate gel microbeads. The obtained microbeads with approx. 10 % w/w of ethyl vanilline encapsulated in about 2 % w/w alginate were uniformly sized spheres of about 450 mu m. Chemical characterization by H-NMR spectroscopy revealed that the alginate used in this study had a high content ( 67 %) of guluronic residues and was rich in GG diad blocks (F-GG = 55%) and thus presented a high-quality immobilisation matrix. The thermal behaviour of alginate beads encapsulating ethyl vanilline was investigated by thermogravimetric (TG) and differential scanning calorimetry measurements (TG-DSC) under heating conditions which mimicked usual food processing to provide information about thermal decomposition of alginate matrix and kinetics of aroma release. Two well resolved weight losses were observed. The first one was in the 50-150 degrees C temperature range with the maximum at approx. 112 C, corresponding to the dehydration of the polymer network. The second loss in the 220-325 degrees C temperature range, with a maximum at similar to 247 degrees C corresponded to the release of vanilline. The obtained results indicate that up to 230 degrees C most of the vanilline remained intacta, while prolonged heating at elevated temperatures led to the entire loss of the aroma compound.
PB  - MDPI, BASEL
T2  - Sensors
T1  - Application of electrostatic extrusion - Flavour encapsulation and controlled release
EP  - 1496
IS  - 3
SP  - 1488
VL  - 8
DO  - 10.3390/s8031488
ER  - 

@article{
author = "Manojlović, Verica and Rajić, Nevenka and Djonlagić, Jasna and Obradović, Bojana and Nedović, Viktor and Bugarski, Branko",
year = "2008",
abstract = "The subject of this study was the development of flavour alginate formulations aimed for thermally processed foods. Ethyl vanilline was used as the model flavour compound. Electrostatic extrusion was applied for the encapsulation of ethyl vanilline in alginate gel microbeads. The obtained microbeads with approx. 10 % w/w of ethyl vanilline encapsulated in about 2 % w/w alginate were uniformly sized spheres of about 450 mu m. Chemical characterization by H-NMR spectroscopy revealed that the alginate used in this study had a high content ( 67 %) of guluronic residues and was rich in GG diad blocks (F-GG = 55%) and thus presented a high-quality immobilisation matrix. The thermal behaviour of alginate beads encapsulating ethyl vanilline was investigated by thermogravimetric (TG) and differential scanning calorimetry measurements (TG-DSC) under heating conditions which mimicked usual food processing to provide information about thermal decomposition of alginate matrix and kinetics of aroma release. Two well resolved weight losses were observed. The first one was in the 50-150 degrees C temperature range with the maximum at approx. 112 C, corresponding to the dehydration of the polymer network. The second loss in the 220-325 degrees C temperature range, with a maximum at similar to 247 degrees C corresponded to the release of vanilline. The obtained results indicate that up to 230 degrees C most of the vanilline remained intacta, while prolonged heating at elevated temperatures led to the entire loss of the aroma compound.",
publisher = "MDPI, BASEL",
journal = "Sensors",
title = "Application of electrostatic extrusion - Flavour encapsulation and controlled release",
pages = "1496-1488",
number = "3",
volume = "8",
doi = "10.3390/s8031488"
}

Manojlović, V., Rajić, N., Djonlagić, J., Obradović, B., Nedović, V.,& Bugarski, B.. (2008). Application of electrostatic extrusion - Flavour encapsulation and controlled release. in Sensors
MDPI, BASEL., 8(3), 1488-1496.
https://doi.org/10.3390/s8031488

Manojlović V, Rajić N, Djonlagić J, Obradović B, Nedović V, Bugarski B. Application of electrostatic extrusion - Flavour encapsulation and controlled release. in Sensors. 2008;8(3):1488-1496.
doi:10.3390/s8031488 .

Manojlović, Verica, Rajić, Nevenka, Djonlagić, Jasna, Obradović, Bojana, Nedović, Viktor, Bugarski, Branko, "Application of electrostatic extrusion - Flavour encapsulation and controlled release" in Sensors, 8, no. 3 (2008):1488-1496,
https://doi.org/10.3390/s8031488 . .

TY  - JOUR
AU  - Manojlović, Verica
AU  - Djonlagić, Jasna
AU  - Obradović, B.
AU  - Nedović, Viktor
AU  - Bugarski, Branko
PY  - 2006
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1302
AB  - The process of electrostatic extrusion as a method for cell immobilization was investigated that could be used for potential applications in medicine. An attempt was made to assess the effects of cell addition and polymer concentration on the overall entrapment procedure, ie, on each stage of immobilization: polymer-cell suspension rheological characteristics, electrostatic extrusion process, and the process of gelation. The findings should contribute to a better understanding of polymer-cell interactions, which could be crucial in possible medical treatments. Alginate-yeast was used as a model system for carrier-cells. The electrostatic extrusion was considered as a complex two-phase flow system and the effects of cell and alginate concentrations on the resulting microbead size and uniformity were assessed. Under investigated conditions, microbeads 50-600 mu m in diameter were produced and the increase in both alginate and cell concentrations resulted in larger microbeads with higher standard deviations in size. We attempted to rationalize the findings by rheological characterization of the cell-alginate suspensions. Rheological characterization revealed non-Newtonian, pseudoplastic behavior of cell-alginate suspensions with higher viscosities at higher alginate concentrations. However, the presence of cells even at high concentrations (5x10(8) and 1x10(9) cells/mL) did not significantly affect the rheological properties of Na-alginate solution. Lastly, we investigated the kinetics of alginate gelation with respect to the quantity of Ca2+ ions and cell presence. The gelation kinetics were examined under conditions of limited supply with Ca2+ ions, which can be essential for immobilization of highly sensitive mammalian cells that require minimal exposure to CaCl2 solution. The molar ratio of G units to Ca2+ ions of 3.8:1 provided complete crosslinking, while the increase in alginate concentration resulted in prolonged gelation times but higher strength of the resulting gel. The cell presence decreased the rate of network formation as well as the strength of the obtained Ca-alginate hydrogel.
PB  - Dove Medical Press Ltd, Albany
T2  - International Journal of Nanomedicine
T1  - Immobilization of cells by electrostatic droplet generation: a model system for potential application in medicine
EP  - 171
IS  - 2
SP  - 163
VL  - 1
DO  - 10.2147/nano.2006.1.2.163
ER  - 

@article{
author = "Manojlović, Verica and Djonlagić, Jasna and Obradović, B. and Nedović, Viktor and Bugarski, Branko",
year = "2006",
abstract = "The process of electrostatic extrusion as a method for cell immobilization was investigated that could be used for potential applications in medicine. An attempt was made to assess the effects of cell addition and polymer concentration on the overall entrapment procedure, ie, on each stage of immobilization: polymer-cell suspension rheological characteristics, electrostatic extrusion process, and the process of gelation. The findings should contribute to a better understanding of polymer-cell interactions, which could be crucial in possible medical treatments. Alginate-yeast was used as a model system for carrier-cells. The electrostatic extrusion was considered as a complex two-phase flow system and the effects of cell and alginate concentrations on the resulting microbead size and uniformity were assessed. Under investigated conditions, microbeads 50-600 mu m in diameter were produced and the increase in both alginate and cell concentrations resulted in larger microbeads with higher standard deviations in size. We attempted to rationalize the findings by rheological characterization of the cell-alginate suspensions. Rheological characterization revealed non-Newtonian, pseudoplastic behavior of cell-alginate suspensions with higher viscosities at higher alginate concentrations. However, the presence of cells even at high concentrations (5x10(8) and 1x10(9) cells/mL) did not significantly affect the rheological properties of Na-alginate solution. Lastly, we investigated the kinetics of alginate gelation with respect to the quantity of Ca2+ ions and cell presence. The gelation kinetics were examined under conditions of limited supply with Ca2+ ions, which can be essential for immobilization of highly sensitive mammalian cells that require minimal exposure to CaCl2 solution. The molar ratio of G units to Ca2+ ions of 3.8:1 provided complete crosslinking, while the increase in alginate concentration resulted in prolonged gelation times but higher strength of the resulting gel. The cell presence decreased the rate of network formation as well as the strength of the obtained Ca-alginate hydrogel.",
publisher = "Dove Medical Press Ltd, Albany",
journal = "International Journal of Nanomedicine",
title = "Immobilization of cells by electrostatic droplet generation: a model system for potential application in medicine",
pages = "171-163",
number = "2",
volume = "1",
doi = "10.2147/nano.2006.1.2.163"
}

Manojlović, V., Djonlagić, J., Obradović, B., Nedović, V.,& Bugarski, B.. (2006). Immobilization of cells by electrostatic droplet generation: a model system for potential application in medicine. in International Journal of Nanomedicine
Dove Medical Press Ltd, Albany., 1(2), 163-171.
https://doi.org/10.2147/nano.2006.1.2.163

Manojlović V, Djonlagić J, Obradović B, Nedović V, Bugarski B. Immobilization of cells by electrostatic droplet generation: a model system for potential application in medicine. in International Journal of Nanomedicine. 2006;1(2):163-171.
doi:10.2147/nano.2006.1.2.163 .

Manojlović, Verica, Djonlagić, Jasna, Obradović, B., Nedović, Viktor, Bugarski, Branko, "Immobilization of cells by electrostatic droplet generation: a model system for potential application in medicine" in International Journal of Nanomedicine, 1, no. 2 (2006):163-171,
https://doi.org/10.2147/nano.2006.1.2.163 . .

TY  - CONF
AU  - Manojlović, Verica
AU  - Djonlagić, Jasna
AU  - Obradović, B
AU  - Nedović, Viktor
AU  - Bugarski, Branko
PY  - 2006
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/1260
AB  - In this study, the process of electrostatic extrusion as a method for cell immobilization was investigated. We have assessed the effects of concentrations of yeast cells (as a model cell type) and Na alginate on the size of the resulting microbeads and attempted to rationalize the obtained findings by rheological characterization of the cell-alginate suspensions. Under the investigated conditions, microbeads, 50-600 mu m in diameter, were produced and the increase in both alginate and cell concentrations resulted in larger microbeads with their sizes having higher standard deviations. Rheological characterization revealed non-Newtonian, pseudoplastic behavior of cell-alginate suspensions with higher viscosities at higher alginate concentrations. However, the presence of cells even at high concentrations (5 x 10(8) and 1 x 10(9) cells mL(-1)) did not significantly affect the rheological properties of the Na alginate solution. Finally, we have investigated the kinetics of alginate gelation with respect to the quantity of Ca2+ ions and the presence of cells. The molar ratio of alpha-L-guluronic acid units to Ca2+ ions of 4:1 provided complete crosslinking. The presence of cells decreased the rate of network formation as well as the strength of the obtained Ca alginate hydrogel.
PB  - Wiley, Hoboken
C3  - Journal of Chemical Technology and Biotechnology
T1  - Investigations of cell immobilization in alginate: rheological and electrostatic extrusion studies
EP  - 510
IS  - 4
SP  - 505
VL  - 81
DO  - 10.1002/jctb.1465
ER  - 

@conference{
author = "Manojlović, Verica and Djonlagić, Jasna and Obradović, B and Nedović, Viktor and Bugarski, Branko",
year = "2006",
abstract = "In this study, the process of electrostatic extrusion as a method for cell immobilization was investigated. We have assessed the effects of concentrations of yeast cells (as a model cell type) and Na alginate on the size of the resulting microbeads and attempted to rationalize the obtained findings by rheological characterization of the cell-alginate suspensions. Under the investigated conditions, microbeads, 50-600 mu m in diameter, were produced and the increase in both alginate and cell concentrations resulted in larger microbeads with their sizes having higher standard deviations. Rheological characterization revealed non-Newtonian, pseudoplastic behavior of cell-alginate suspensions with higher viscosities at higher alginate concentrations. However, the presence of cells even at high concentrations (5 x 10(8) and 1 x 10(9) cells mL(-1)) did not significantly affect the rheological properties of the Na alginate solution. Finally, we have investigated the kinetics of alginate gelation with respect to the quantity of Ca2+ ions and the presence of cells. The molar ratio of alpha-L-guluronic acid units to Ca2+ ions of 4:1 provided complete crosslinking. The presence of cells decreased the rate of network formation as well as the strength of the obtained Ca alginate hydrogel.",
publisher = "Wiley, Hoboken",
journal = "Journal of Chemical Technology and Biotechnology",
title = "Investigations of cell immobilization in alginate: rheological and electrostatic extrusion studies",
pages = "510-505",
number = "4",
volume = "81",
doi = "10.1002/jctb.1465"
}

Manojlović, V., Djonlagić, J., Obradović, B., Nedović, V.,& Bugarski, B.. (2006). Investigations of cell immobilization in alginate: rheological and electrostatic extrusion studies. in Journal of Chemical Technology and Biotechnology
Wiley, Hoboken., 81(4), 505-510.
https://doi.org/10.1002/jctb.1465

Manojlović V, Djonlagić J, Obradović B, Nedović V, Bugarski B. Investigations of cell immobilization in alginate: rheological and electrostatic extrusion studies. in Journal of Chemical Technology and Biotechnology. 2006;81(4):505-510.
doi:10.1002/jctb.1465 .

Manojlović, Verica, Djonlagić, Jasna, Obradović, B, Nedović, Viktor, Bugarski, Branko, "Investigations of cell immobilization in alginate: rheological and electrostatic extrusion studies" in Journal of Chemical Technology and Biotechnology, 81, no. 4 (2006):505-510,
https://doi.org/10.1002/jctb.1465 . .

TY  - JOUR
AU  - Manojlović, Verica
AU  - Djonlagić, Jasna
AU  - Obradović, Bojana
AU  - Nedović, Viktor
AU  - Bugarski, Branko
PY  - 2005
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/887
AB  - In this study, an attempt was made to assess the effects of cell addition and final concentration on the process of electrostatic extrusion as a method for cell immobilization in alginate microbeads. The electrostatic extrusion process is a complex function of several operating parameters, the system geometry, and the properties of the polymer solution, which is being extruded. The addition of cells results in the formation of a two-phase system, adding to the complexity of the process by the associated phenomenon of two-phase flow. This study especially focused on analyzing the effects of cell presence on each stage of the immobilization process. Specifically, the effects of the cell and alginate concentrations on the resulting microbead size and uniformity were assessed. Under the investigated conditions, microbeads, 50-600 ěm in diameter, were produced and the increase in both alginate and cell concentrations resulted in larger microbeads with higher standard deviations in size. We attempted to rationalize the obtained findings by rheological characterization of the cell-alginate suspensions. H-NMR Spectroscopy of the alginate used in this study revealed a high content (67%) of guluronic residues and GG diad blocks (FGG = 55%). The mole fractions of the MM and GM diad sequences, Fmm and Fgm, were 21 and 12%, respectively. Rheological characterization revealed non-Newtonian, pseudoplastic behavior of the cell-alginate suspensions with an increase in viscosity as the alginate concentration was increased. However, the presence of cells even at high concentrations (5 ÷ 108 and 1 ÷ 109 cell/ml) did not significantly affect the rheological properties of Na alginate solution. Finally, the effects of the alginate and cell concentrations on the gelation kinetics and the dynamic-mechanical behavior of the obtained hydrogels were investigated. A molar ratio of G units to Ca2+ ions of 3.8 : 1 provided complete crosslinking, while an increase in the alginate concentration resulted in prolonged gelation times, but higher strength of the resulting gel. Cell presence decreased the rate of network formation, as well as the strength of the obtained Ca alginate hydrogel.
AB  - U ovom radu izvršeno je ispitivanje fenomena elektrostatičke ekstruzije. Proces elektrostatičke ekstruzije je vrlo složen, jer obuhvata pojedinačne uticaje različitih fenomenoloških parametara (jako spoljašnje električno polje, mikrohidrodinamičke pojave unutar kapilare, reološko ponašanje polimera), kao i međusobne uticaje ovih faktora. Prisustvo ćelija u sistemu čini ga još složenijim, što do sada fenomenološki nije razjašnjeno. Istraživanja su obuhvatila ispitivanje pojedinih značajnih fenomena koji se javljaju u ovoj metodi imobilizacije ćelija, polazeći od karakteristika samog nosača i suspenzije alginat/ćelije, preko parametara elektrostatičke ekstruzije, do kinetike geliranja alginata. Uz to, posebno je analiziran uticaj prisustva ćelija na sve faze ovog procesa. Detaljno je proučen uticaj promene koncentracije alginata i koncentracije ćelija u polaznoj suspenziji alginat/ćelije na veličinu i uniformnost proizvedenih mikročestica. Pri ispitivanim operativnim uslovima, proizvedene su mikročestice prečnika od 50-600 ěm i porast koncentracije bilo alginata, bilo ćelija uzrokuje nastajanje većih čestica neuniformnije raspodele veličina. U pokušaju da se objasne dobijeni rezultati i ispita reološko ponašanje suspenzije kao jedan od parametara koji utiču na dinamiku dvofaznog strujanja u toku ekstruzije, izvršeno je reološko karakterisanje suspenzija alginat/ćelije. Reološka ispitivanja su pokazala da prisustvo ćelija čak i pri visokim koncentracijama (5x108 i 1x10 ćelija/ml) ne utiče značajno na reološke osobine rastvora natrijum alginata. Na kraju, ispitan je uticaj koncentracije alginata i ćelija na kinetiku geliranja u uslovima ograničenog prisustva Ca jona, s obzirom da imobilizacija izuzetno osetljivih ćelija sisara može da zahteva minimalno izlaganje rastvoru CaCl2. Rezultati su pokazali da molski odnos guluronskih jedinica prema Ca2+ jonima od 3,8:1 omogućuje fizičko umrežavanje i da porast koncentracije alginata uzrokuje duže geliranje, ali i nastajanje jačeg gela. Prisustvo ćelija dovodi do sporijeg geliranja i prouzrokuje nastajanje slabijih hidrogelova što upućuje na zaključak da imobilisani mikroorganizmi uzrokuju nepravilnosti u strukturi mreže.
PB  - Savez hemijskih inženjera, Beograd
T2  - Chemical Industry and Chemical Engineering Quarterly / CICEQ
T1  - Effects of cell addition on immobilization by electrostatic droplet generation
T1  - Uticaj prisustva ćelija u procesu elektrostatičke ekstruzije alginata
EP  - 84
IS  - 2
SP  - 79
VL  - 11
DO  - 10.2298/CICEQ0502079M
ER  - 

@article{
author = "Manojlović, Verica and Djonlagić, Jasna and Obradović, Bojana and Nedović, Viktor and Bugarski, Branko",
year = "2005",
abstract = "In this study, an attempt was made to assess the effects of cell addition and final concentration on the process of electrostatic extrusion as a method for cell immobilization in alginate microbeads. The electrostatic extrusion process is a complex function of several operating parameters, the system geometry, and the properties of the polymer solution, which is being extruded. The addition of cells results in the formation of a two-phase system, adding to the complexity of the process by the associated phenomenon of two-phase flow. This study especially focused on analyzing the effects of cell presence on each stage of the immobilization process. Specifically, the effects of the cell and alginate concentrations on the resulting microbead size and uniformity were assessed. Under the investigated conditions, microbeads, 50-600 ěm in diameter, were produced and the increase in both alginate and cell concentrations resulted in larger microbeads with higher standard deviations in size. We attempted to rationalize the obtained findings by rheological characterization of the cell-alginate suspensions. H-NMR Spectroscopy of the alginate used in this study revealed a high content (67%) of guluronic residues and GG diad blocks (FGG = 55%). The mole fractions of the MM and GM diad sequences, Fmm and Fgm, were 21 and 12%, respectively. Rheological characterization revealed non-Newtonian, pseudoplastic behavior of the cell-alginate suspensions with an increase in viscosity as the alginate concentration was increased. However, the presence of cells even at high concentrations (5 ÷ 108 and 1 ÷ 109 cell/ml) did not significantly affect the rheological properties of Na alginate solution. Finally, the effects of the alginate and cell concentrations on the gelation kinetics and the dynamic-mechanical behavior of the obtained hydrogels were investigated. A molar ratio of G units to Ca2+ ions of 3.8 : 1 provided complete crosslinking, while an increase in the alginate concentration resulted in prolonged gelation times, but higher strength of the resulting gel. Cell presence decreased the rate of network formation, as well as the strength of the obtained Ca alginate hydrogel., U ovom radu izvršeno je ispitivanje fenomena elektrostatičke ekstruzije. Proces elektrostatičke ekstruzije je vrlo složen, jer obuhvata pojedinačne uticaje različitih fenomenoloških parametara (jako spoljašnje električno polje, mikrohidrodinamičke pojave unutar kapilare, reološko ponašanje polimera), kao i međusobne uticaje ovih faktora. Prisustvo ćelija u sistemu čini ga još složenijim, što do sada fenomenološki nije razjašnjeno. Istraživanja su obuhvatila ispitivanje pojedinih značajnih fenomena koji se javljaju u ovoj metodi imobilizacije ćelija, polazeći od karakteristika samog nosača i suspenzije alginat/ćelije, preko parametara elektrostatičke ekstruzije, do kinetike geliranja alginata. Uz to, posebno je analiziran uticaj prisustva ćelija na sve faze ovog procesa. Detaljno je proučen uticaj promene koncentracije alginata i koncentracije ćelija u polaznoj suspenziji alginat/ćelije na veličinu i uniformnost proizvedenih mikročestica. Pri ispitivanim operativnim uslovima, proizvedene su mikročestice prečnika od 50-600 ěm i porast koncentracije bilo alginata, bilo ćelija uzrokuje nastajanje većih čestica neuniformnije raspodele veličina. U pokušaju da se objasne dobijeni rezultati i ispita reološko ponašanje suspenzije kao jedan od parametara koji utiču na dinamiku dvofaznog strujanja u toku ekstruzije, izvršeno je reološko karakterisanje suspenzija alginat/ćelije. Reološka ispitivanja su pokazala da prisustvo ćelija čak i pri visokim koncentracijama (5x108 i 1x10 ćelija/ml) ne utiče značajno na reološke osobine rastvora natrijum alginata. Na kraju, ispitan je uticaj koncentracije alginata i ćelija na kinetiku geliranja u uslovima ograničenog prisustva Ca jona, s obzirom da imobilizacija izuzetno osetljivih ćelija sisara može da zahteva minimalno izlaganje rastvoru CaCl2. Rezultati su pokazali da molski odnos guluronskih jedinica prema Ca2+ jonima od 3,8:1 omogućuje fizičko umrežavanje i da porast koncentracije alginata uzrokuje duže geliranje, ali i nastajanje jačeg gela. Prisustvo ćelija dovodi do sporijeg geliranja i prouzrokuje nastajanje slabijih hidrogelova što upućuje na zaključak da imobilisani mikroorganizmi uzrokuju nepravilnosti u strukturi mreže.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Chemical Industry and Chemical Engineering Quarterly / CICEQ",
title = "Effects of cell addition on immobilization by electrostatic droplet generation, Uticaj prisustva ćelija u procesu elektrostatičke ekstruzije alginata",
pages = "84-79",
number = "2",
volume = "11",
doi = "10.2298/CICEQ0502079M"
}

Manojlović, V., Djonlagić, J., Obradović, B., Nedović, V.,& Bugarski, B.. (2005). Effects of cell addition on immobilization by electrostatic droplet generation. in Chemical Industry and Chemical Engineering Quarterly / CICEQ
Savez hemijskih inženjera, Beograd., 11(2), 79-84.
https://doi.org/10.2298/CICEQ0502079M

Manojlović V, Djonlagić J, Obradović B, Nedović V, Bugarski B. Effects of cell addition on immobilization by electrostatic droplet generation. in Chemical Industry and Chemical Engineering Quarterly / CICEQ. 2005;11(2):79-84.
doi:10.2298/CICEQ0502079M .

Manojlović, Verica, Djonlagić, Jasna, Obradović, Bojana, Nedović, Viktor, Bugarski, Branko, "Effects of cell addition on immobilization by electrostatic droplet generation" in Chemical Industry and Chemical Engineering Quarterly / CICEQ, 11, no. 2 (2005):79-84,
https://doi.org/10.2298/CICEQ0502079M . .

TY  - JOUR
AU  - Todosijević, Zoran
AU  - Obradović, Bojana M.
AU  - Nedović, Viktor
AU  - Bugarski, Branko
PY  - 2004
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/701
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Implementation of a combined differential-discrete cellular automata model for cell growth in gel beads
EP  - 43
IS  - 6a
SP  - 41
VL  - 58
UR  - https://hdl.handle.net/21.15107/rcub_agrospace_701
ER  - 

@article{
author = "Todosijević, Zoran and Obradović, Bojana M. and Nedović, Viktor and Bugarski, Branko",
year = "2004",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Implementation of a combined differential-discrete cellular automata model for cell growth in gel beads",
pages = "43-41",
number = "6a",
volume = "58",
url = "https://hdl.handle.net/21.15107/rcub_agrospace_701"
}

Todosijević, Z., Obradović, B. M., Nedović, V.,& Bugarski, B.. (2004). Implementation of a combined differential-discrete cellular automata model for cell growth in gel beads. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 58(6a), 41-43.
https://hdl.handle.net/21.15107/rcub_agrospace_701

Todosijević Z, Obradović BM, Nedović V, Bugarski B. Implementation of a combined differential-discrete cellular automata model for cell growth in gel beads. in Hemijska industrija. 2004;58(6a):41-43.
https://hdl.handle.net/21.15107/rcub_agrospace_701 .

Todosijević, Zoran, Obradović, Bojana M., Nedović, Viktor, Bugarski, Branko, "Implementation of a combined differential-discrete cellular automata model for cell growth in gel beads" in Hemijska industrija, 58, no. 6a (2004):41-43,
https://hdl.handle.net/21.15107/rcub_agrospace_701 .

TY  - JOUR
AU  - Bezbradica, Dejan
AU  - Matić, Goran
AU  - Obradović, Bojana M.
AU  - Nedović, Viktor
AU  - Leskošek-Čukalović, Ida
AU  - Bugarski, Branko
PY  - 2004
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/695
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Immobilization of brewing yeast in PVA/alginate micro beads using electrostatic droplet generation
EP  - 120
IS  - 6a
SP  - 118
VL  - 58
UR  - https://hdl.handle.net/21.15107/rcub_agrospace_695
ER  - 

@article{
author = "Bezbradica, Dejan and Matić, Goran and Obradović, Bojana M. and Nedović, Viktor and Leskošek-Čukalović, Ida and Bugarski, Branko",
year = "2004",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Immobilization of brewing yeast in PVA/alginate micro beads using electrostatic droplet generation",
pages = "120-118",
number = "6a",
volume = "58",
url = "https://hdl.handle.net/21.15107/rcub_agrospace_695"
}

Bezbradica, D., Matić, G., Obradović, B. M., Nedović, V., Leskošek-Čukalović, I.,& Bugarski, B.. (2004). Immobilization of brewing yeast in PVA/alginate micro beads using electrostatic droplet generation. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 58(6a), 118-120.
https://hdl.handle.net/21.15107/rcub_agrospace_695

Bezbradica D, Matić G, Obradović BM, Nedović V, Leskošek-Čukalović I, Bugarski B. Immobilization of brewing yeast in PVA/alginate micro beads using electrostatic droplet generation. in Hemijska industrija. 2004;58(6a):118-120.
https://hdl.handle.net/21.15107/rcub_agrospace_695 .

Bezbradica, Dejan, Matić, Goran, Obradović, Bojana M., Nedović, Viktor, Leskošek-Čukalović, Ida, Bugarski, Branko, "Immobilization of brewing yeast in PVA/alginate micro beads using electrostatic droplet generation" in Hemijska industrija, 58, no. 6a (2004):118-120,
https://hdl.handle.net/21.15107/rcub_agrospace_695 .

TY  - JOUR
AU  - Manojlović, Verica
AU  - Obradović, Bojana M.
AU  - Nedović, Viktor
AU  - Leskošek-Čukalović, Ida
AU  - Bugarski, Branko
PY  - 2004
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/687
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Electrostatic generation of alginate microbeads loaded with brewing yeast
EP  - 64
IS  - 6a
SP  - 62
VL  - 58
UR  - https://hdl.handle.net/21.15107/rcub_agrospace_687
ER  - 

@article{
author = "Manojlović, Verica and Obradović, Bojana M. and Nedović, Viktor and Leskošek-Čukalović, Ida and Bugarski, Branko",
year = "2004",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Electrostatic generation of alginate microbeads loaded with brewing yeast",
pages = "64-62",
number = "6a",
volume = "58",
url = "https://hdl.handle.net/21.15107/rcub_agrospace_687"
}

Manojlović, V., Obradović, B. M., Nedović, V., Leskošek-Čukalović, I.,& Bugarski, B.. (2004). Electrostatic generation of alginate microbeads loaded with brewing yeast. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 58(6a), 62-64.
https://hdl.handle.net/21.15107/rcub_agrospace_687

Manojlović V, Obradović BM, Nedović V, Leskošek-Čukalović I, Bugarski B. Electrostatic generation of alginate microbeads loaded with brewing yeast. in Hemijska industrija. 2004;58(6a):62-64.
https://hdl.handle.net/21.15107/rcub_agrospace_687 .

Manojlović, Verica, Obradović, Bojana M., Nedović, Viktor, Leskošek-Čukalović, Ida, Bugarski, Branko, "Electrostatic generation of alginate microbeads loaded with brewing yeast" in Hemijska industrija, 58, no. 6a (2004):62-64,
https://hdl.handle.net/21.15107/rcub_agrospace_687 .

TY  - JOUR
AU  - Boltić, Zorana
AU  - Petkovska, Menka
AU  - Obradović, Bojana M.
AU  - Nedović, Viktor
AU  - Bugarski, Branko
PY  - 2003
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/541
AB  - Results of this study have shown significantly prolonged release of selected antibiotic from liposome dispersion as compared to free antibiotic solution of the same initial concentration. Two models of non-steady one-dimensional diffusion were successfully applied to the experimental data and the antibiotic diffusion coefficients were estimated. In addition, the mass transfer resistance of the membrane was shown to be insignificant confirming the suitability of the applied experimental system. Since liposomes are known as systems with slower drug release, then, when it comes to their incorporation in the final form of a preparation for further experiments in vivo, the system of choice would be liposomes with an encapsulated antibiotic drug. The established experimental system could be extended to other liposome formulations with respect to the release rate of the active components.
AB  - Rezultati su pokazali značajan efekat produženog oslobađanja odabranog antibiotika iz lipidnih vezikula u membranskom sistemu sa cilindričnim modulom (namenski dizajniran u cilju mimike sistema primene topičnog preparata na koži) u poređenju sa rastvorom leka iste inicijalne koncentracije koji je podvrgnut istim eksperimentalnim uslovima. Dva modela nestacionarne, jednodimenzione difuzije primenjena su za predviđanje brzine oslobađanja leka iz lipidnih vezikula u cilindričnom membranskom modulu. Oba modela su pokazala dobro slaganje sa eksperimentalnim rezultatima i predskazala približno pedeset puta sporije otpuštanje iz lipidnih vezikula u poređenju sa čistim rastvorom leka. Osim toga, rezultati matematičkog modelovanja su pokazali da celulozno-acetatna membrana ima zanemarljiv uticaj na ukupnu brzinu oslobađanja leka. Ovakav rezultat potvrdio je pogodnost primenjenog eksperimentalnog sistema za ispitivanje kinetike otpuštanja odabranog antibiotika iz lipidnih vezikula.Kako se pokazalo da je otpuštanje leka iz disperzije lipidnih vezikula sporije u poređenju sa čistim rastvorom antibiotika, ovakav sistem nosača sa inkapsuliranim antibiotskim agensom ima prednost kada je u pitanju njegovo ugrađivanje u finalni oblik topičnog preparata za dalja ispitivanja in vivo. Odabrani eksperimentalni sistem se može primeniti i na druge formulacije na bazi lipidnih vezikula, za ispitivanje kinetike otpuštanja inkapsuliranih aktivnih supstanci. Na taj način bi se mogla uspostaviti relevantna metoda za in vitro karakterizaciju i poređenje različitih sistema nosača aktivnih komponenti.
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - In vitro evaluation of the controlled release of antibiotics from liposomes
T1  - In vitro ispitivanje kontrolisanog otpuštanja antibiotika iz liposoma
EP  - 595
IS  - 12
SP  - 589
VL  - 57
DO  - 10.2298/HEMIND0312589B
ER  - 

@article{
author = "Boltić, Zorana and Petkovska, Menka and Obradović, Bojana M. and Nedović, Viktor and Bugarski, Branko",
year = "2003",
abstract = "Results of this study have shown significantly prolonged release of selected antibiotic from liposome dispersion as compared to free antibiotic solution of the same initial concentration. Two models of non-steady one-dimensional diffusion were successfully applied to the experimental data and the antibiotic diffusion coefficients were estimated. In addition, the mass transfer resistance of the membrane was shown to be insignificant confirming the suitability of the applied experimental system. Since liposomes are known as systems with slower drug release, then, when it comes to their incorporation in the final form of a preparation for further experiments in vivo, the system of choice would be liposomes with an encapsulated antibiotic drug. The established experimental system could be extended to other liposome formulations with respect to the release rate of the active components., Rezultati su pokazali značajan efekat produženog oslobađanja odabranog antibiotika iz lipidnih vezikula u membranskom sistemu sa cilindričnim modulom (namenski dizajniran u cilju mimike sistema primene topičnog preparata na koži) u poređenju sa rastvorom leka iste inicijalne koncentracije koji je podvrgnut istim eksperimentalnim uslovima. Dva modela nestacionarne, jednodimenzione difuzije primenjena su za predviđanje brzine oslobađanja leka iz lipidnih vezikula u cilindričnom membranskom modulu. Oba modela su pokazala dobro slaganje sa eksperimentalnim rezultatima i predskazala približno pedeset puta sporije otpuštanje iz lipidnih vezikula u poređenju sa čistim rastvorom leka. Osim toga, rezultati matematičkog modelovanja su pokazali da celulozno-acetatna membrana ima zanemarljiv uticaj na ukupnu brzinu oslobađanja leka. Ovakav rezultat potvrdio je pogodnost primenjenog eksperimentalnog sistema za ispitivanje kinetike otpuštanja odabranog antibiotika iz lipidnih vezikula.Kako se pokazalo da je otpuštanje leka iz disperzije lipidnih vezikula sporije u poređenju sa čistim rastvorom antibiotika, ovakav sistem nosača sa inkapsuliranim antibiotskim agensom ima prednost kada je u pitanju njegovo ugrađivanje u finalni oblik topičnog preparata za dalja ispitivanja in vivo. Odabrani eksperimentalni sistem se može primeniti i na druge formulacije na bazi lipidnih vezikula, za ispitivanje kinetike otpuštanja inkapsuliranih aktivnih supstanci. Na taj način bi se mogla uspostaviti relevantna metoda za in vitro karakterizaciju i poređenje različitih sistema nosača aktivnih komponenti.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "In vitro evaluation of the controlled release of antibiotics from liposomes, In vitro ispitivanje kontrolisanog otpuštanja antibiotika iz liposoma",
pages = "595-589",
number = "12",
volume = "57",
doi = "10.2298/HEMIND0312589B"
}

Boltić, Z., Petkovska, M., Obradović, B. M., Nedović, V.,& Bugarski, B.. (2003). In vitro evaluation of the controlled release of antibiotics from liposomes. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 57(12), 589-595.
https://doi.org/10.2298/HEMIND0312589B

Boltić Z, Petkovska M, Obradović BM, Nedović V, Bugarski B. In vitro evaluation of the controlled release of antibiotics from liposomes. in Hemijska industrija. 2003;57(12):589-595.
doi:10.2298/HEMIND0312589B .

Boltić, Zorana, Petkovska, Menka, Obradović, Bojana M., Nedović, Viktor, Bugarski, Branko, "In vitro evaluation of the controlled release of antibiotics from liposomes" in Hemijska industrija, 57, no. 12 (2003):589-595,
https://doi.org/10.2298/HEMIND0312589B . .

TY  - JOUR
AU  - Nedović, Viktor
AU  - Obradović, B
AU  - Leskošek-Čukalović, Ida
AU  - Trifunović, O
AU  - Pesić, R
AU  - Bugarski, Branko
PY  - 2001
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/329
AB  - The substantial concern with the possible use of immobilized yeast cells for beer production is reduction of internal mass transfer resistance during continuous fermentation. One way to minimise this problem is to use small-diameter beads. The effects of bead diameters in the range 0.3-2.0 mm on yeast cell immobilization and growth over a short-term cultivation were investigated. Bead diameters in the range 0.5-0.6 mm were optimal and provided rapid cell growth and the highest final cell concentration (2.33 x 10(9) cells/ml of beads). Electrostatic droplet generation was investigated as a technique for production of alginate microbeads. The effects of applied potential, internal needle diameter and electrode position on bead diameter were assessed. The results have shown that this method can be used for controlled production of small-size microbeads loaded with yeast. Depending on applied conditions it was possible to produce the beads in the range 250 mum-2.0 mm in diameter.
PB  - Elsevier Sci Ltd, Oxford
T2  - Process Biochemistry
T1  - Electrostatic generation of alginate microbeads loaded with brewing yeast
EP  - 22
IS  - 1
SP  - 17
VL  - 37
DO  - 10.1016/S0032-9592(01)00172-8
ER  - 

@article{
author = "Nedović, Viktor and Obradović, B and Leskošek-Čukalović, Ida and Trifunović, O and Pesić, R and Bugarski, Branko",
year = "2001",
abstract = "The substantial concern with the possible use of immobilized yeast cells for beer production is reduction of internal mass transfer resistance during continuous fermentation. One way to minimise this problem is to use small-diameter beads. The effects of bead diameters in the range 0.3-2.0 mm on yeast cell immobilization and growth over a short-term cultivation were investigated. Bead diameters in the range 0.5-0.6 mm were optimal and provided rapid cell growth and the highest final cell concentration (2.33 x 10(9) cells/ml of beads). Electrostatic droplet generation was investigated as a technique for production of alginate microbeads. The effects of applied potential, internal needle diameter and electrode position on bead diameter were assessed. The results have shown that this method can be used for controlled production of small-size microbeads loaded with yeast. Depending on applied conditions it was possible to produce the beads in the range 250 mum-2.0 mm in diameter.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Process Biochemistry",
title = "Electrostatic generation of alginate microbeads loaded with brewing yeast",
pages = "22-17",
number = "1",
volume = "37",
doi = "10.1016/S0032-9592(01)00172-8"
}

Nedović, V., Obradović, B., Leskošek-Čukalović, I., Trifunović, O., Pesić, R.,& Bugarski, B.. (2001). Electrostatic generation of alginate microbeads loaded with brewing yeast. in Process Biochemistry
Elsevier Sci Ltd, Oxford., 37(1), 17-22.
https://doi.org/10.1016/S0032-9592(01)00172-8

Nedović V, Obradović B, Leskošek-Čukalović I, Trifunović O, Pesić R, Bugarski B. Electrostatic generation of alginate microbeads loaded with brewing yeast. in Process Biochemistry. 2001;37(1):17-22.
doi:10.1016/S0032-9592(01)00172-8 .

Nedović, Viktor, Obradović, B, Leskošek-Čukalović, Ida, Trifunović, O, Pesić, R, Bugarski, Branko, "Electrostatic generation of alginate microbeads loaded with brewing yeast" in Process Biochemistry, 37, no. 1 (2001):17-22,
https://doi.org/10.1016/S0032-9592(01)00172-8 . .