Preparation of zein nanoparticles and their application as functional colloids

Biljni proteini, odnosno belančevine izolovane iz različitog biljnog materijala, poseduju odličan potencijal za primenu u proizvodnji, ali i pakovanju hrane. Oni poseduju različite funkcionalne osobine, kao što su sposobnost emulgovanja, stabilizovanja pene, geliranja, formiranja omotača i filmova itd., što im omogućava primenu u prehrambenoj i farmaceutskoj industriji. Zein je biljni protein, koji se može naći u žitaricama, a osnovni izvor ovog proteina je kukuruz (Zea mays). Zein nije rastvoran u vodi, a za njegovo rastvaranje najčešće se koristi razblaženi etanol. Smanjenjem koncentracije etanola u rastvoru zeina, bilo da se to postiže dodatkom nerastvarača ili uklanjanjem etanola (isparavanjem), zein može formirati različite koloidne strukture, koje pokazuju veliki potencijal za primenu u prehrambenoj industriji. Osobine ovih struktura zavise od načina pripreme, ali se na njih može uticati i dodatkom drugih materija u toku procesa pripreme. Stoga, osnovni cilj istraživanja u okviru ove disertacije bio je da se ispita mogućnost i uslovi formiranja nanočestica zeina i kompozitnih nanočestica zein/prirodna smola, kao i mogućnost primene takvih nanočestica za inkapsulaciju lipofilne aktivne supstance, odnosno za formiranje filmova zeina. Nanočestice (NČ) zeina (Z) i kompozitne nanočestice zein/šelak (Z/Š) i zein/kalafonijuim (Z/K) pripremane su metodom (ko)precipitacije usled smanjenja rastvorljivosti, gde su se etanolni rastvori makromolekula mešali sa vodom kao nerastvaračem. Ispitani su uslovi pripreme nanočestica zeina na njihove koloidne osobine. Pripremljene nanočestice karakterisane su primenom različitih metoda (dinamičko rasipanje svetla, elektroforetska pokretljivost, SEM). Takođe, ispitane su interakcije gume arabike (GA) sa Z i Z/K nanočesticama, upotrebom različitih tehnika, kao što su dinamičko rasipanje svetla i izotermalna mikrokalorimetrija. Ispitana je mogućnost inkapsulacije lipofilne aktivne supstance u Z i Z/K nanočesticama, primenom metode koprecipitacije usled smanjenja rastvorljivosti, na isti način kao što su pripremane same nanočestice. Filmovi zeina pripremani su izlivanjem disperzija nanočestica zeina i sušenjem na povišenoj tempreturi. Pripremljeni su filmovi iz disperzija sa nanočesticama različitog prosečnog prečnika ZDNČ90 i ZDNČ180 bez plastifikatora, kao i uz dodatak plastifikatora ZDPGNČ90 i ZDPGNČ180. U svrhu poređenja osobina filmova, pripremani su i filmovi iz rastvora zeina bez plastifikatora, ZR, i sa dodatkom plastifikatora, ZRPG filmovi. Ispitan je uticaj veličine čestica zeina kao i uticaj plastifikatora na morfologiju, barijerna i optička svojstva filmova (rastvorljivost, propustljivost vodene pare, boju, itd.). Utvrđeno je da se metodom precipitacije u nerastvaraču mogu dobiti zeinske i kompozitne nanočestice zein/smola. Na veličinu nanočestica može se uticati koncentracijom etanolnog rastvora biopolimera. Takođe, pH vrednost disperzije nanočestica utiče na njihov zeta potencijal, površinsku gustinu naelektrisanja, veličinu i stabilnost. Dodatak GA, u disperziju NČ utiče na zeta potencijal i veličinu nanočestica, odnosno nastalih aglomerata nanočestica. Mikrokalorimetrijskim merenjima utvrđeno je da su interakcije Z i Z/K nanočestica sa GA egzotermne, te da su najinteinzivnije na pH = 4. Merenja su pokazala da do zasićenja površine kod Z/K NČ dolazi pri masenom odnosu GA/NČ od 0,7. Kod Z NČ promena entalpije postaje konstantna nakon masenog odnosa GA/NČ 1. Takođe, utvrđeno je da se moguće pripremiti kontinualne zeinske filmove iz disperzija nanočestica, sušenjem na vazduhu. U poređenju sa filmovima dobijenim iz rastvora zeina, filmovi dobijeni iz disperzija su bili hrapaviji i krtiji. Takođe, hrapavost površine ZDNČ180 filmova bila je veća nego kod ZDNČ90 filmova. Dodatkom propilen–glikola kao plastifikatora smanjuje se krtost i hrapavost ZDNČ filmova. Svi ispitivani filmovi su, u ispitivanim uslovima, apsorbovali manje od 8% vlage, dok je rastvorljivost i Zr i Zd filmova u vodi bila je ispod 5%. Propustljivost vodene pare se nije značajno razlikovala (p < 0,05) za ZR, ZD i ZDPG filmove, nezavisno od veličine čestica. Optička zamućenost ZD filmova bila je veća nego kod ZR filmova, dok je najmanja bila kod ZDPG filmova, s obzirom da je dodatak plastifikatora uticao na smanjenje optičke zamućenosti. Pokazano je da udeo bele u boji filmova raste po redosledu ZR < ZRPG < ZDPG < ZD. Takođe je utvrđeno da žuta boja preovlađuje kod svih ispitivanih filmova. Statistička analiza pokazala je da ne postoji značajna razlika u mehaničkim svojstvima između filmova izlivenih iz disperzija nanočestica i filmova izlivenih iz etanolnog rastvora zeina.Plant proteins, i.e. proteins isolated from various plant materials, have excellent potential for use in food production, but also in food packaging. They possess various functional properties, such as emulsifying, foam stabilizing, gelling, coating, and film-forming properties, which allow them to be used in the food and pharmaceutical industries. Zein is a plant protein, which can be found in cereals, and the main source of this protein is corn (Zea mays). Zein is not soluble in water, and dilute ethanol is most often used to dissolve it. By reducing the concentration of ethanol in the zein solution, whether this is achieved by adding non–solvents or removing ethanol (evaporation), zein can form various colloidal structures, which show great potential for use in the food industry. The properties of these structures depend on the method of preparation, but they can also be influenced by the addition of other substances during the preparation process. Therefore, the main goal of the research within this dissertation was to examine the possibility and conditions of formation of zein nanoparticles and zein/natural resin composite nanoparticles, as well as the possibility of using such nanoparticles for encapsulation of lipophilic active substance, as well as for zein film formation. Zein (Z) nanoparticles and zein/shellac (Z/Š) and zein/rosin (Z/K) composite nanoparticles were prepared by the antisolvent (co)precipitation method, where ethanolic solutions of macromolecules were mixed with water as a non-solvent. The influence of the zein nanoparticles' preparation parameters on their colloidal properties was examined. Prepared nanoparticles were characterized by the application of different methods (dynamic light scattering, electrophoretic mobility, scanning electron microscopy). Also, interactions of gum arabic (GA) with Z and Z/K nanoparticles were investigated, using various techniques, such as dynamic light scattering and isothermal microcalorimetry. The possibility of encapsulation of lipophilic active substance in Z and Z/K nanoparticles was investigated, using the method of antisolvent coprecipitation in the same way as the nanoparticles themselves were prepared. Zein films were prepared by casting dispersions of zein nanoparticles and air drying. Films were prepared from dispersions with nanoparticles of different average diameters ZDNČ90 and ZDNČ180 without plasticizers, as well as with the addition of plasticizers ZDPGNČ90 and ZDPGNČ180. In order to compare their properties, films were also prepared from a solution of zein without a plasticizer, ZR, and with the addition of a plasticizer, ZRPG films. The influence of zein particle size, as well as the influence of plasticizers on morphology, barrier properties, and optical properties of films (solubility, water vapor permeability, color, etc.), were examined. It has been found that zein and composite zein/resin nanoparticles can be obtained by the antisolvent precipitation method. Nanoparticle size can be affected by the concentration of ethanol biopolymer solution. Also, the pH value of the dispersion of nanoparticles affects their zeta potential, surface charge density, size, and stability. The addition of GA to the dispersion of NP affects the zeta potential and size of nanoparticles, i.e. the formed agglomerates of nanoparticles. Microcalorimetric measurements showed that the interactions of Z and Z/K nanoparticles with GA are exothermic and that they are most intense at pH = 4. Measurements showed that surface saturation of Z/K NP occurs at a GA/NP mass ratio of 0.7. For Z NP, the change in enthalpy becomes constant after the mass ratio GA / NC 1. Also, it was found that it is possible to prepare continuous zein films from nanoparticle dispersions, by air drying. Compared with films obtained from zein solution, films obtained from dispersions were rougher and more brittle. Also, the surface roughness of ZDNČ180 films was higher than that of ZDNČ90 films. The addition of propylene–glycol as a plasticizer reduces the brittleness and roughness of ZDNČ films. All tested films, absorbed less than 8% of moisture, under the tested conditions, while the solubility of both Zr and Zd films in water was below 5%. Water vapor permeability did not differ significantly (p <0.05) for ZR, ZD, and ZDPG films, regardless of the particle size. The opacity of ZD films was higher than that of ZR films, while the lowest was in ZDPG films, since the addition of plasticizers had the effect of reducing opacity. It was shown that the share of white in the color of films increases in the order ZR < ZRPG < ZDPG < ZD. It was also determined that yellow color predominates in all examined films. Statistical analysis showed that there was no significant difference in mechanical properties between films cast from nanoparticle dispersions and films cast from ethanol zein solution

Preparation of zein nanoparticles and their application as functional colloids

Biljni proteini, odnosno belančevine izolovane iz različitog biljnog materijala, poseduju odličan potencijal za primenu u proizvodnji, ali i pakovanju hrane. Oni poseduju različite funkcionalne osobine, kao što su sposobnost emulgovanja, stabilizovanja pene, geliranja, formiranja omotača i filmova itd., što im omogućava primenu u prehrambenoj i farmaceutskoj industriji. Zein je biljni protein, koji se može naći u žitaricama, a osnovni izvor ovog proteina je kukuruz (Zea mays). Zein nije rastvoran u vodi, a za njegovo rastvaranje najčešće se koristi razblaženi etanol. Smanjenjem koncentracije etanola u rastvoru zeina, bilo da se to postiže dodatkom nerastvarača ili uklanjanjem etanola (isparavanjem), zein može formirati različite koloidne strukture, koje pokazuju veliki potencijal za primenu u prehrambenoj industriji. Osobine ovih struktura zavise od načina pripreme, ali se na njih može uticati i dodatkom drugih materija u toku procesa pripreme. Stoga, osnovni cilj istraživanja u okviru ove disertacije bio je da se ispita mogućnost i uslovi formiranja nanočestica zeina i kompozitnih nanočestica zein/prirodna smola, kao i mogućnost primene takvih nanočestica za inkapsulaciju lipofilne aktivne supstance, odnosno za formiranje filmova zeina. Nanočestice (NČ) zeina (Z) i kompozitne nanočestice zein/šelak (Z/Š) i zein/kalafonijuim (Z/K) pripremane su metodom (ko)precipitacije usled smanjenja rastvorljivosti, gde su se etanolni rastvori makromolekula mešali sa vodom kao nerastvaračem. Ispitani su uslovi pripreme nanočestica zeina na njihove koloidne osobine. Pripremljene nanočestice karakterisane su primenom različitih metoda (dinamičko rasipanje svetla, elektroforetska pokretljivost, SEM). Takođe, ispitane su interakcije gume arabike (GA) sa Z i Z/K nanočesticama, upotrebom različitih tehnika, kao što su dinamičko rasipanje svetla i izotermalna mikrokalorimetrija. Ispitana je mogućnost inkapsulacije lipofilne aktivne supstance u Z i Z/K nanočesticama, primenom metode koprecipitacije usled smanjenja rastvorljivosti, na isti način kao što su pripremane same nanočestice. Filmovi zeina pripremani su izlivanjem disperzija nanočestica zeina i sušenjem na povišenoj tempreturi. Pripremljeni su filmovi iz disperzija sa nanočesticama različitog prosečnog prečnika ZDNČ90 i ZDNČ180 bez plastifikatora, kao i uz dodatak plastifikatora ZDPGNČ90 i ZDPGNČ180. U svrhu poređenja osobina filmova, pripremani su i filmovi iz rastvora zeina bez plastifikatora, ZR, i sa dodatkom plastifikatora, ZRPG filmovi. Ispitan je uticaj veličine čestica zeina kao i uticaj plastifikatora na morfologiju, barijerna i optička svojstva filmova (rastvorljivost, propustljivost vodene pare, boju, itd.). Utvrđeno je da se metodom precipitacije u nerastvaraču mogu dobiti zeinske i kompozitne nanočestice zein/smola. Na veličinu nanočestica može se uticati koncentracijom etanolnog rastvora biopolimera. Takođe, pH vrednost disperzije nanočestica utiče na njihov zeta potencijal, površinsku gustinu naelektrisanja, veličinu i stabilnost. Dodatak GA, u disperziju NČ utiče na zeta potencijal i veličinu nanočestica, odnosno nastalih aglomerata nanočestica. Mikrokalorimetrijskim merenjima utvrđeno je da su interakcije Z i Z/K nanočestica sa GA egzotermne, te da su najinteinzivnije na pH = 4. Merenja su pokazala da do zasićenja površine kod Z/K NČ dolazi pri masenom odnosu GA/NČ od 0,7. Kod Z NČ promena entalpije postaje konstantna nakon masenog odnosa GA/NČ 1. Takođe, utvrđeno je da se moguće pripremiti kontinualne zeinske filmove iz disperzija nanočestica, sušenjem na vazduhu. U poređenju sa filmovima dobijenim iz rastvora zeina, filmovi dobijeni iz disperzija su bili hrapaviji i krtiji. Takođe, hrapavost površine ZDNČ180 filmova bila je veća nego kod ZDNČ90 filmova. Dodatkom propilen–glikola kao plastifikatora smanjuje se krtost i hrapavost ZDNČ filmova. Svi ispitivani filmovi su, u ispitivanim uslovima, apsorbovali manje od 8% vlage, dok je rastvorljivost i Zr i Zd filmova u vodi bila je ispod 5%. Propustljivost vodene pare se nije značajno razlikovala (p < 0,05) za ZR, ZD i ZDPG filmove, nezavisno od veličine čestica. Optička zamućenost ZD filmova bila je veća nego kod ZR filmova, dok je najmanja bila kod ZDPG filmova, s obzirom da je dodatak plastifikatora uticao na smanjenje optičke zamućenosti. Pokazano je da udeo bele u boji filmova raste po redosledu ZR < ZRPG < ZDPG < ZD. Takođe je utvrđeno da žuta boja preovlađuje kod svih ispitivanih filmova. Statistička analiza pokazala je da ne postoji značajna razlika u mehaničkim svojstvima između filmova izlivenih iz disperzija nanočestica i filmova izlivenih iz etanolnog rastvora zeina.Plant proteins, i.e. proteins isolated from various plant materials, have excellent potential for use in food production, but also in food packaging. They possess various functional properties, such as emulsifying, foam stabilizing, gelling, coating, and film-forming properties, which allow them to be used in the food and pharmaceutical industries. Zein is a plant protein, which can be found in cereals, and the main source of this protein is corn (Zea mays). Zein is not soluble in water, and dilute ethanol is most often used to dissolve it. By reducing the concentration of ethanol in the zein solution, whether this is achieved by adding non–solvents or removing ethanol (evaporation), zein can form various colloidal structures, which show great potential for use in the food industry. The properties of these structures depend on the method of preparation, but they can also be influenced by the addition of other substances during the preparation process. Therefore, the main goal of the research within this dissertation was to examine the possibility and conditions of formation of zein nanoparticles and zein/natural resin composite nanoparticles, as well as the possibility of using such nanoparticles for encapsulation of lipophilic active substance, as well as for zein film formation. Zein (Z) nanoparticles and zein/shellac (Z/Š) and zein/rosin (Z/K) composite nanoparticles were prepared by the antisolvent (co)precipitation method, where ethanolic solutions of macromolecules were mixed with water as a non-solvent. The influence of the zein nanoparticles' preparation parameters on their colloidal properties was examined. Prepared nanoparticles were characterized by the application of different methods (dynamic light scattering, electrophoretic mobility, scanning electron microscopy). Also, interactions of gum arabic (GA) with Z and Z/K nanoparticles were investigated, using various techniques, such as dynamic light scattering and isothermal microcalorimetry. The possibility of encapsulation of lipophilic active substance in Z and Z/K nanoparticles was investigated, using the method of antisolvent coprecipitation in the same way as the nanoparticles themselves were prepared. Zein films were prepared by casting dispersions of zein nanoparticles and air drying. Films were prepared from dispersions with nanoparticles of different average diameters ZDNČ90 and ZDNČ180 without plasticizers, as well as with the addition of plasticizers ZDPGNČ90 and ZDPGNČ180. In order to compare their properties, films were also prepared from a solution of zein without a plasticizer, ZR, and with the addition of a plasticizer, ZRPG films. The influence of zein particle size, as well as the influence of plasticizers on morphology, barrier properties, and optical properties of films (solubility, water vapor permeability, color, etc.), were examined. It has been found that zein and composite zein/resin nanoparticles can be obtained by the antisolvent precipitation method. Nanoparticle size can be affected by the concentration of ethanol biopolymer solution. Also, the pH value of the dispersion of nanoparticles affects their zeta potential, surface charge density, size, and stability. The addition of GA to the dispersion of NP affects the zeta potential and size of nanoparticles, i.e. the formed agglomerates of nanoparticles. Microcalorimetric measurements showed that the interactions of Z and Z/K nanoparticles with GA are exothermic and that they are most intense at pH = 4. Measurements showed that surface saturation of Z/K NP occurs at a GA/NP mass ratio of 0.7. For Z NP, the change in enthalpy becomes constant after the mass ratio GA / NC 1. Also, it was found that it is possible to prepare continuous zein films from nanoparticle dispersions, by air drying. Compared with films obtained from zein solution, films obtained from dispersions were rougher and more brittle. Also, the surface roughness of ZDNČ180 films was higher than that of ZDNČ90 films. The addition of propylene–glycol as a plasticizer reduces the brittleness and roughness of ZDNČ films. All tested films, absorbed less than 8% of moisture, under the tested conditions, while the solubility of both Zr and Zd films in water was below 5%. Water vapor permeability did not differ significantly (p <0.05) for ZR, ZD, and ZDPG films, regardless of the particle size. The opacity of ZD films was higher than that of ZR films, while the lowest was in ZDPG films, since the addition of plasticizers had the effect of reducing opacity. It was shown that the share of white in the color of films increases in the order ZR < ZRPG < ZDPG < ZD. It was also determined that yellow color predominates in all examined films. Statistical analysis showed that there was no significant difference in mechanical properties between films cast from nanoparticle dispersions and films cast from ethanol zein solution

Physical (Morphometric) and Electrocardiographic Parameters in Balkan Donkey in Serbia

Balkan donkey is a native donkey breed that lives in Balkan peninsula and traditionally is reared in Serbia, Macedonia and Montenegro. Since the population has declined severely and only less than 200 males and females are actively breeding the breed status is endangered and it is included in AnGR preservation/conservation program in Serbia. The organized breeding and development of the breed description has started at the beginning of the 21 century and the breed is not fully described yet. This is the first time that that clinical procedures- ECG, have been evaluated in concern with frame and size of Balkan donkey. Our results show that there is a need to expand our investigation to fulfill gap in understanding Balkan donkey physiology and diagnostics. The evaluation of morphometric and electrocardiographic parameters in endangered Balkan donkey breed in Serbia was performed and individual data important for clinical evaluation and breeding were estimated in aim to provide initial morphometric and electrocardiographic data for the endangered Balkan donkey breed in Serbia and to assess the ECG procedure in relation to specific anatomy and body proportions of the breed

Redox interactions of epinephrine with iron at physiological pH

Epinephrine ((R)-4-(1-hydroxy-2-(methylamino)ethyl)-benzene-1,2-diol (Epi) is catecholamine that is released by the sympathetic nervous system and adrenal medulla. It is a physiologically important molecule that acts as a hormone, neurotransmitter, and medication with a broad range of effects 1-3 . Coordinate and redox interaction of Epi with iron affects the interactions with other molecules and its biological effects 4 . In this study, we reported details of redox interactions of Epi with Fe 2+ at pH 7.4, which correspond to the pH value of human plasma Epi and Fe 2+ form a complex that acts as a strong reducing agent. Cyclic voltammetry showed that the positions of E pa and E pc potentials were at approximately -480 and -1100 mV. This implies that Epi and Fe 2+ build a complex with unique redox properties. E1/2 was significantly lower compared to E0' for O 2 /O 2•- (-350 mV). It is important to point out this because superoxide radical anion is produced via spontaneous Fe 2+ reaction with O 2. In other words, Epi-Fe 2+ complex should be capable of reducing transition metals in (patho)physiologicaly relevant complexes that are not susceptible to reduction by O 2. Our results confirmed that Epi-Fe 2+ is capable of reducing the S-S group of glutathione disulfide. On the other hand, Epi acted in a catalyst-like fashion to promote Fe 2+ oxidation by molecular oxygen, and to a facilitated formation of the Epi–Fe 3+ complexes, at physiological pH. In addition, we examined the effects of epinepfrine and Epi/Fe3+ system on glioma cells. Epinephrine alone evokes changes in the membrane currents of glioma cells, but such effects were not observed for the complex with Fe 3+ . This implies that Epi-Fe 3+ might modulate neural activity of Epi in CNS

Značaj određivanja koštanih biomarkera u proceni rizika od fraktura i praćenju terapije kod pacijenata sa osteoporozom

Osteoporosis is characterised by reduced bone mineral density (BMD), increased bone fragility and risk of fractures. We investigated clinical significance of bone turnover biomarkers determination for the prediction of fracture risk and response to therapy. We performed three months follow-up study in 48 women with osteoporosis. During the follow-up period 32 patients were on antiresorptive and 16 patients received anabolic therapy. Serum alkaline phosphatase (ALP), osteocalcin, C-terminal telopeptide of collagen type I and vitamin D were measured before and 3 months after initiation of the therapy. Higher osteocalcin and ALP levels were significantly associated with increased risk of BMD loss. Following antiresorptive therapy levels of C-terminal telopeptide (P lt 0.001) and osteocalcin (P lt 0.001) significantly decreased. Anabolic therapy significantly increased osteocalcin (P lt 0.01). At the study entry 25.5% of the patients had optimal levels of 25(OH)D and 17% had severe vitamin D deficiency. Vitamin D supplementation during three months improved vitamin D status of the patients (P lt 0.001). In conclusion, our data indicate that osteocalcin and C-terminal telopeptide determination may be useful for BMD loss prediction and monitoring of osteoporosis therapy. This study confirmed importance of vitamin D testing in osteoporosis in order to detect the patients with deficiency and determine the need for supplementation.Osteoporoza se karakteriše smanjenom mineralnom gustinom kostiju, što povećava fragilnost kostiju i rizik za nastanak fraktura. U ovoj studiji pratili smo 48 pacijentkinja sa osteoporozom tokom tri meseca sa ciljem da utvrdimo značaj određivanja koštanih biomarkera u proceni rizika od fraktura i praćenju terapije osteoporoze. Tokom trajanja studije 32 pacijentkinje su bile na antiresorptivnoj, a 16 na anaboličkoj terapiji. Svim pacijentkinjama odredili smo aktivnost alkalne fosfataze (ALP) i koncentracije osteokalcina, C-terminalnog telopeptida kolagena tip I i vitamina D u serumu pre i tri meseca nakon uvođenja terapije. Sa povećanjem nivoa osteokalcina i ALP rastao je rizik za smanjenje mineralne gustine kostiju (BMD). Antiresorptivna terapija dovela je do značajnog smanjenja koncentracija C-terminalnog telopeptida (P lt 0,001) i osteokalcina (P lt 0,001). Tokom anaboličke terapije nivo osteokalcina je značajno porastao (P lt 0,01). Na početku studije 25,5% pacijentkinja je imalo optimalne koncentracije 25(OH)D u serumu, a tešku deficijenciju 17% žena. Nakon 3 meseca suplementacije većina je poboljšala status vitamina D (P lt 0,001). Naši rezultati ukazuju da određivanje osteokalcina i C-terminalnog telopeptida može biti korisno za predviđanje rizika za smanjenje BMD i praćenje efekata terapije osteoporoze. Takođe, potvrđena je važnost određivanja koncentracije 25(OH)D za procenu statusa vitamina D u osteoporozi, u cilju otkrivanja pacijenata sa insuficijencijom i utvrđivanja potrebe za suplementacijom

Study of vitamin E microencapsulation and controlled release from chitosan/sodium lauryl ether sulfate microcapsules

Potential benefit of microencapsulation is its ability to deliver and protect incorporated ingredients such as vitamin E. Microcapsule wall properties can be changed by adding of coss-linking agents that are usually considered toxic for application. The microcapsules were prepared by a spray-drying technique using coacervation method, by depositing the coacervate formed in the mixture of chitosan and sodium lauryl ether sulfate to the oil/water interface. All obtained microcapsules suspensions had slightly lower mean diameter compared to the starting emulsion (6.85 ± 0.213 μm), which shows their good stability during the drying process. The choice and absence of cross-linking agents had influence on kinetics of vitamin E release. Encapsulation efficiency of microcapsules without cross-linking agent was 73.17 ± 0.64 %. This study avoided the use of aldehydes as cross-linking agents and found that chitosan/SLES complex can be used as wall material for the microencapsulation of hydrophobic active molecules in cosmetic industry

Disodium hexaaquacobalt(II) bis[dihydrogen 1,2,4,5-benzenetetracarboxylate(2 –)] tetrahydrate

International audienc

Bis[μ-(hydrogen benzene-1,2-dicarboxylato)- O : O ']bis[bis(1,10-phenanthroline- N , N ')cobalt(II)] bis(hydrogen benzene-1,2-dicarboxylate) dihydrate

International audienc

SEROPREVALENCE OF NEOSPORA CANINUM IN DOGS

Neospora caninum is an apicomplexan parasitic protozoa that seriously impacts economic performance of diary and beef industries by causing abortion in cattle. Likewise, it is considered as a cause of severe neuromuscular disease in dogs around the world. Since canine neosporosis has not yet been properly investigated in Serbia,the aim of our work was to determine seroprevalence of N. caninum antibodies in a group of dogs from one region of Vojvodina (Serbia) and to evaluate the importance of the age as a possible risk factor for higher seropositivity to N.caninum in dogs. For this purpose, sera from 31 dog from territory of Krčedin and Vršac were examined using indirect fluorescent antibody test. All sera were screened at 1:50 dilution and positive samples were then titrated in two-fold dilution series to the respective endpoint (1:100). Our findings showed that 12,9% of tested dogs was positive to N. caninum antibodies, but no statistically important association between seroprevalence and the age of the dogs was discovered