TY  - JOUR
AU  - Magić, Marko
AU  - Čolović, Božana M.
AU  - Jokanović, Vukoman R.
AU  - Vasilijić, Saša
AU  - Marković, Milan
AU  - Vučević, Dragana
AU  - Rudolf, Rebeka
AU  - Čolić, Snježana
AU  - Čolić, Miodrag
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8425
AB  - Background/Aim. The deposition of hydroxyapatite (HAP) on the surface of titanium (Ti) alloys enhances bioactivity and osseointegration of the alloys which are widely used as implant materials in dentistry and orthopaedic surgery. However, the stability of HAP and subsequent biocompatibility of such alloys depends on the coating technique. The aim of this work was to test the cytotoxicity of a Ti alloy (Ti6Al4V), coated with HAP by a new plasma deposition method. Methods. The Ti6Al4V samples prepared as discs, 10 mm in diameter and 2 mm in thickness, were coated with HAP (one or both sides of the alloy) by an innovative atmospheric plasma jet method. The cytotoxicity of uncoated and HAP coated Ti6Al4V samples was evaluated by examining the morphological changes and viability of L929 fibroblasts in direct contact with the test materials. Adequate negative (polystyrene) and positive (nickel) control discs of the same size were used. The indirect cytotoxicity was determined by cultivating L929 cells with conditioning medium (CM), prepared as extract of the test samples incubated in the complete Roswell Park Memorial Institute (RPMI) 1640 medium for cell cultures. The cytotoxic effect was evaluated based on the degree of metabolic activity, necrosis, apoptosis and proliferation of L929 cells, using the appropriate assays. Results. Uncoated and one side HAP coated Ti6Al4V alloys were classified as non-cytotoxic according to the current ISO 10993-5 criteria, whereas two sides HAP coated Ti6Al4V alloy samples were slightlymoderate cytotoxic. The cytotoxicity manifested as the inhibition of metabolic activity and proliferation of L929 cells as well as the induction of their apoptosis and necrosis was significantly reduced by conditioning of HAP/Ti6Al4V alloys for 24 hours. The cytotoxic effect of HAP/Ti6Al4V CM only partly decreased in the presence of nifelate, a calcium (Ca) channel blocker, suggesting that Ca ions were not the only responsible cytotoxic agent. Conclusion. The original HAP coating procedure by atmospheric plasma spraying with high energy input enables the production of the stable adhesive coatings on Ti6Al4V alloys. Their cytotoxicity, which depends on the quantity of HAP coating layer, could be significantly reduced up to the non-cytotoxic level by prior conditioning of the alloys in culture medium. Such a procedure, which removes leachable toxic components, could be useful before implantation of HAP coated alloys in vivo. © 2019, Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.
T2  - Vojnosanitetski pregled
T1  - Cytotoxicity of a titanium alloy coated with hydroxyapatite by plasma jet deposition
VL  - 76
IS  - 5
SP  - 492
EP  - 501
DO  - 10.2298/VSP170809097M
ER  - 

@article{
author = "Magić, Marko and Čolović, Božana M. and Jokanović, Vukoman R. and Vasilijić, Saša and Marković, Milan and Vučević, Dragana and Rudolf, Rebeka and Čolić, Snježana and Čolić, Miodrag",
year = "2019",
abstract = "Background/Aim. The deposition of hydroxyapatite (HAP) on the surface of titanium (Ti) alloys enhances bioactivity and osseointegration of the alloys which are widely used as implant materials in dentistry and orthopaedic surgery. However, the stability of HAP and subsequent biocompatibility of such alloys depends on the coating technique. The aim of this work was to test the cytotoxicity of a Ti alloy (Ti6Al4V), coated with HAP by a new plasma deposition method. Methods. The Ti6Al4V samples prepared as discs, 10 mm in diameter and 2 mm in thickness, were coated with HAP (one or both sides of the alloy) by an innovative atmospheric plasma jet method. The cytotoxicity of uncoated and HAP coated Ti6Al4V samples was evaluated by examining the morphological changes and viability of L929 fibroblasts in direct contact with the test materials. Adequate negative (polystyrene) and positive (nickel) control discs of the same size were used. The indirect cytotoxicity was determined by cultivating L929 cells with conditioning medium (CM), prepared as extract of the test samples incubated in the complete Roswell Park Memorial Institute (RPMI) 1640 medium for cell cultures. The cytotoxic effect was evaluated based on the degree of metabolic activity, necrosis, apoptosis and proliferation of L929 cells, using the appropriate assays. Results. Uncoated and one side HAP coated Ti6Al4V alloys were classified as non-cytotoxic according to the current ISO 10993-5 criteria, whereas two sides HAP coated Ti6Al4V alloy samples were slightlymoderate cytotoxic. The cytotoxicity manifested as the inhibition of metabolic activity and proliferation of L929 cells as well as the induction of their apoptosis and necrosis was significantly reduced by conditioning of HAP/Ti6Al4V alloys for 24 hours. The cytotoxic effect of HAP/Ti6Al4V CM only partly decreased in the presence of nifelate, a calcium (Ca) channel blocker, suggesting that Ca ions were not the only responsible cytotoxic agent. Conclusion. The original HAP coating procedure by atmospheric plasma spraying with high energy input enables the production of the stable adhesive coatings on Ti6Al4V alloys. Their cytotoxicity, which depends on the quantity of HAP coating layer, could be significantly reduced up to the non-cytotoxic level by prior conditioning of the alloys in culture medium. Such a procedure, which removes leachable toxic components, could be useful before implantation of HAP coated alloys in vivo. © 2019, Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.",
journal = "Vojnosanitetski pregled",
title = "Cytotoxicity of a titanium alloy coated with hydroxyapatite by plasma jet deposition",
volume = "76",
number = "5",
pages = "492-501",
doi = "10.2298/VSP170809097M"
}

Magić, M., Čolović, B. M., Jokanović, V. R., Vasilijić, S., Marković, M., Vučević, D., Rudolf, R., Čolić, S.,& Čolić, M.. (2019). Cytotoxicity of a titanium alloy coated with hydroxyapatite by plasma jet deposition. in Vojnosanitetski pregled, 76(5), 492-501.
https://doi.org/10.2298/VSP170809097M

Magić M, Čolović BM, Jokanović VR, Vasilijić S, Marković M, Vučević D, Rudolf R, Čolić S, Čolić M. Cytotoxicity of a titanium alloy coated with hydroxyapatite by plasma jet deposition. in Vojnosanitetski pregled. 2019;76(5):492-501.
doi:10.2298/VSP170809097M .

Magić, Marko, Čolović, Božana M., Jokanović, Vukoman R., Vasilijić, Saša, Marković, Milan, Vučević, Dragana, Rudolf, Rebeka, Čolić, Snježana, Čolić, Miodrag, "Cytotoxicity of a titanium alloy coated with hydroxyapatite by plasma jet deposition" in Vojnosanitetski pregled, 76, no. 5 (2019):492-501,
https://doi.org/10.2298/VSP170809097M . .

TY  - JOUR
AU  - Jokanović, Vukoman R.
AU  - Vilotijević, Miroljub N.
AU  - Čolović, Božana M.
AU  - Jenko, Monika
AU  - Anzel, Ivan
AU  - Rudolf, Rebeka
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/334
AB  - Hydroxyapatite (HA) coatings were deposited on high purity titanium substrate by atmospheric plasma spraying (APS) with high electric energy input. Previously, the surface of the titanium was prepared by alkali etching with NaOH and subsequent diverse thermal treatments. The phase composition, structure and morphology of the nano-structured HA coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Auger electron spectroscopy (AES). The XRD pattern showed that the coatings deposited by APS consisted mainly of HA with crystallite sizes between 15.5 and 31 nm and small quantities of the amorphous HA phase. The SEM observation showed that the as-deposited coatings had very different morphology with typical features of micro-structural patterns, which are desirable for improving the biological performances of HA coatings. AES analysis of various spots of the titanium substrate-coating interface showed the presence of an oxide layer with implanted Ca ions owing to the high kinetic energy of the plasma jet. This layer caused a significant increase in the measured adhesive strength, showing values in the range of 51.8-62.5 MPa. The sintering mechanism was studied using several approaches that show that the dominant sintering mechanism was volume diffusion.
T2  - Plasma Chemistry and Plasma Processing
T1  - Enhanced Adhesion Properties, Structure and Sintering Mechanism of Hydroxyapatite Coatings Obtained by Plasma Jet Deposition
VL  - 35
IS  - 1
SP  - 1
EP  - 19
DO  - 10.1007/s11090-014-9599-0
ER  - 

@article{
author = "Jokanović, Vukoman R. and Vilotijević, Miroljub N. and Čolović, Božana M. and Jenko, Monika and Anzel, Ivan and Rudolf, Rebeka",
year = "2015",
abstract = "Hydroxyapatite (HA) coatings were deposited on high purity titanium substrate by atmospheric plasma spraying (APS) with high electric energy input. Previously, the surface of the titanium was prepared by alkali etching with NaOH and subsequent diverse thermal treatments. The phase composition, structure and morphology of the nano-structured HA coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Auger electron spectroscopy (AES). The XRD pattern showed that the coatings deposited by APS consisted mainly of HA with crystallite sizes between 15.5 and 31 nm and small quantities of the amorphous HA phase. The SEM observation showed that the as-deposited coatings had very different morphology with typical features of micro-structural patterns, which are desirable for improving the biological performances of HA coatings. AES analysis of various spots of the titanium substrate-coating interface showed the presence of an oxide layer with implanted Ca ions owing to the high kinetic energy of the plasma jet. This layer caused a significant increase in the measured adhesive strength, showing values in the range of 51.8-62.5 MPa. The sintering mechanism was studied using several approaches that show that the dominant sintering mechanism was volume diffusion.",
journal = "Plasma Chemistry and Plasma Processing",
title = "Enhanced Adhesion Properties, Structure and Sintering Mechanism of Hydroxyapatite Coatings Obtained by Plasma Jet Deposition",
volume = "35",
number = "1",
pages = "1-19",
doi = "10.1007/s11090-014-9599-0"
}

Jokanović, V. R., Vilotijević, M. N., Čolović, B. M., Jenko, M., Anzel, I.,& Rudolf, R.. (2015). Enhanced Adhesion Properties, Structure and Sintering Mechanism of Hydroxyapatite Coatings Obtained by Plasma Jet Deposition. in Plasma Chemistry and Plasma Processing, 35(1), 1-19.
https://doi.org/10.1007/s11090-014-9599-0

Jokanović VR, Vilotijević MN, Čolović BM, Jenko M, Anzel I, Rudolf R. Enhanced Adhesion Properties, Structure and Sintering Mechanism of Hydroxyapatite Coatings Obtained by Plasma Jet Deposition. in Plasma Chemistry and Plasma Processing. 2015;35(1):1-19.
doi:10.1007/s11090-014-9599-0 .

Jokanović, Vukoman R., Vilotijević, Miroljub N., Čolović, Božana M., Jenko, Monika, Anzel, Ivan, Rudolf, Rebeka, "Enhanced Adhesion Properties, Structure and Sintering Mechanism of Hydroxyapatite Coatings Obtained by Plasma Jet Deposition" in Plasma Chemistry and Plasma Processing, 35, no. 1 (2015):1-19,
https://doi.org/10.1007/s11090-014-9599-0 . .

TY  - JOUR
AU  - Rudolf, Rebeka
AU  - Stamenkovic, Dragoslav
AU  - Aleksić, Zoran
AU  - Jenko, Monika
AU  - Dordevic, Igor
AU  - Todorović, Aleksandar
AU  - Jokanović, Vukoman R.
AU  - Raic, Karlo T.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/427
AB  - Thin hydroxyapatite coatings were produced on Cp-Titanium Grade-2 samples, with new high-voltage pulse-power equipment PJ-100 (Plasma Jet, Serbia) in order to get a more stable implant structure appropriate for further clinical applications. A comparative analysis of differently prepared surfaces of the Cp-Titanium Grade-2 samples was done before the hydroxyapatite was applied. Microstructural observation of the modified hydroxyapatite/implant surface was done using scanning-electron-microscopy imaging and Auger electron spectroscopy, with the aim of detecting the morphology and the elements contained in the new surfaces of the samples. The results confirmed that the surface of Cp-Titanium Grade-2 modified with hydroxyapatite is very similar to the bone structure.
T2  - Materials and Technology = Materiali in Tehnologije
T1  - Hydroxyapatite Coatings on Cp-Titanium Grade-2 Surfaces Prepared with Plasma Spraying
VL  - 49
IS  - 1
SP  - 81
EP  - 86
UR  - https://hdl.handle.net/21.15107/rcub_vinar_427
ER  - 

@article{
author = "Rudolf, Rebeka and Stamenkovic, Dragoslav and Aleksić, Zoran and Jenko, Monika and Dordevic, Igor and Todorović, Aleksandar and Jokanović, Vukoman R. and Raic, Karlo T.",
year = "2015",
abstract = "Thin hydroxyapatite coatings were produced on Cp-Titanium Grade-2 samples, with new high-voltage pulse-power equipment PJ-100 (Plasma Jet, Serbia) in order to get a more stable implant structure appropriate for further clinical applications. A comparative analysis of differently prepared surfaces of the Cp-Titanium Grade-2 samples was done before the hydroxyapatite was applied. Microstructural observation of the modified hydroxyapatite/implant surface was done using scanning-electron-microscopy imaging and Auger electron spectroscopy, with the aim of detecting the morphology and the elements contained in the new surfaces of the samples. The results confirmed that the surface of Cp-Titanium Grade-2 modified with hydroxyapatite is very similar to the bone structure.",
journal = "Materials and Technology = Materiali in Tehnologije",
title = "Hydroxyapatite Coatings on Cp-Titanium Grade-2 Surfaces Prepared with Plasma Spraying",
volume = "49",
number = "1",
pages = "81-86",
url = "https://hdl.handle.net/21.15107/rcub_vinar_427"
}

Rudolf, R., Stamenkovic, D., Aleksić, Z., Jenko, M., Dordevic, I., Todorović, A., Jokanović, V. R.,& Raic, K. T.. (2015). Hydroxyapatite Coatings on Cp-Titanium Grade-2 Surfaces Prepared with Plasma Spraying. in Materials and Technology = Materiali in Tehnologije, 49(1), 81-86.
https://hdl.handle.net/21.15107/rcub_vinar_427

Rudolf R, Stamenkovic D, Aleksić Z, Jenko M, Dordevic I, Todorović A, Jokanović VR, Raic KT. Hydroxyapatite Coatings on Cp-Titanium Grade-2 Surfaces Prepared with Plasma Spraying. in Materials and Technology = Materiali in Tehnologije. 2015;49(1):81-86.
https://hdl.handle.net/21.15107/rcub_vinar_427 .

Rudolf, Rebeka, Stamenkovic, Dragoslav, Aleksić, Zoran, Jenko, Monika, Dordevic, Igor, Todorović, Aleksandar, Jokanović, Vukoman R., Raic, Karlo T., "Hydroxyapatite Coatings on Cp-Titanium Grade-2 Surfaces Prepared with Plasma Spraying" in Materials and Technology = Materiali in Tehnologije, 49, no. 1 (2015):81-86,
https://hdl.handle.net/21.15107/rcub_vinar_427 .

TY  - JOUR
AU  - Jokanović, Vukoman R.
AU  - Vilotijević, Miroljub N.
AU  - Jokanović, Bojan
AU  - Jenko, Monika
AU  - Anzel, Ivan
AU  - Stamenkovic, Dragoslav
AU  - Lazić, Vojkan
AU  - Rudolf, Rebeka
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5936
AB  - In this research, the structure changes along the depth gradient layers of titanium substrate, after etching with NaOH and subsequent thermal treatment at various temperatures between 300 and 800 degrees C, were investigated by XRD, FTIR and AES. Particularly, the changes of Ti substrate after etching with NaOH, subsequent ionic exchange of Na+ with Ca2+ ions and thermal treatment at 700 degrees C were analysed. Due to this approach, it was possible to get insight into the chemical changes and changes of Ti oxidation states and consequent phase analysis, along the depth of the titanium oxide coatings. In addition, Secondary Electron Imaging (SEI) showed very interesting nanotopology of all samples. Particularly interesting topology, consisting of very thin nano-designed walls between mutually interconnected pores, was observed for the sample in which Na+ were replaced with Ca2+ ions. This structure might be suitable for deposition of hydroxyapatite by biomimetic or plasma methods and as an appropriate scaffold for cell adhesion and proliferation. (C) 2014 Elsevier Ltd. All rights reserved.
T2  - Corrosion Science
T1  - Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment
VL  - 82
SP  - 180
EP  - 190
DO  - 10.1016/j.corsci.2014.01.014
ER  - 

@article{
author = "Jokanović, Vukoman R. and Vilotijević, Miroljub N. and Jokanović, Bojan and Jenko, Monika and Anzel, Ivan and Stamenkovic, Dragoslav and Lazić, Vojkan and Rudolf, Rebeka",
year = "2014",
abstract = "In this research, the structure changes along the depth gradient layers of titanium substrate, after etching with NaOH and subsequent thermal treatment at various temperatures between 300 and 800 degrees C, were investigated by XRD, FTIR and AES. Particularly, the changes of Ti substrate after etching with NaOH, subsequent ionic exchange of Na+ with Ca2+ ions and thermal treatment at 700 degrees C were analysed. Due to this approach, it was possible to get insight into the chemical changes and changes of Ti oxidation states and consequent phase analysis, along the depth of the titanium oxide coatings. In addition, Secondary Electron Imaging (SEI) showed very interesting nanotopology of all samples. Particularly interesting topology, consisting of very thin nano-designed walls between mutually interconnected pores, was observed for the sample in which Na+ were replaced with Ca2+ ions. This structure might be suitable for deposition of hydroxyapatite by biomimetic or plasma methods and as an appropriate scaffold for cell adhesion and proliferation. (C) 2014 Elsevier Ltd. All rights reserved.",
journal = "Corrosion Science",
title = "Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment",
volume = "82",
pages = "180-190",
doi = "10.1016/j.corsci.2014.01.014"
}

Jokanović, V. R., Vilotijević, M. N., Jokanović, B., Jenko, M., Anzel, I., Stamenkovic, D., Lazić, V.,& Rudolf, R.. (2014). Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment. in Corrosion Science, 82, 180-190.
https://doi.org/10.1016/j.corsci.2014.01.014

Jokanović VR, Vilotijević MN, Jokanović B, Jenko M, Anzel I, Stamenkovic D, Lazić V, Rudolf R. Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment. in Corrosion Science. 2014;82:180-190.
doi:10.1016/j.corsci.2014.01.014 .

Jokanović, Vukoman R., Vilotijević, Miroljub N., Jokanović, Bojan, Jenko, Monika, Anzel, Ivan, Stamenkovic, Dragoslav, Lazić, Vojkan, Rudolf, Rebeka, "Investigations of corrosion on the surface of titanium substrate caused by combined alkaline and heat treatment" in Corrosion Science, 82 (2014):180-190,
https://doi.org/10.1016/j.corsci.2014.01.014 . .