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  - Tomić, Sergej
AU  - Janjetović, Kristina D.
AU  - Mihajlovic, Dusan
AU  - Milenković, Marina
AU  - Kravić-Stevović, Tamara K.
AU  - Marković, Zoran M.
AU  - Todorović-Marković, Biljana
AU  - Špitalsky, Zdenko
AU  - Mičušik, Matej
AU  - Vucevic, Dragana
AU  - Colic, Miodrag
AU  - Trajković, Vladimir S.
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1782
AB  - Graphene quantum dots (GQD) are atom-thick nanodimensional carbon sheets with excellent physicochemical and biological properties; making them attractive for application in theranostics: However, their immunoregulatory properties are insufficiently investigated, especially in human primary immune cells. We found that non-toxic doses of GQD inhibit the production of proinflammatory and T helper (Th) 1 cytokines, and augment the production of anti-inflammatory and Th2 cytokines by human peripheral blood mononuclear cells. While unable to affect T cells directly, GQD impaired the differentiation and functions of monocyte-derived dendritic cells (DC), lowering their capacity to stimulate T cell proliferation, development of Thl and Th17 cells, and T-cell mediated cytotoxicity. Additionally, GQD-treated DC potentiated Th2 polarization, and induced suppressive CD4(+)CD25(high)Foxp3(+) regulatory T cells. After internalization in a dynamin-independent, cholesterol-dependent manner, GQD lowered the production of reactive oxygen species and nuclear translocation of NF-kappa B in DC. The activity of mammalian target of rapamycin (mTOR) was reduced by GQD, which correlated with the increase in transcription of autophagy genes and autophagic flux in DC. Genetic suppression of autophagy impaired the pro-tolerogenic effects of GQD on DC. Our results suggest that GQD-triggered autophagy promotes tolerogenic functions in monocyte-derived DC, which could be beneficial in inflammatory T-cell mediated pathologies, but also harmful in GQD-based anti-cancer therapy. (C) 2017 Elsevier Ltd. All rights reserved.
T2  - Biomaterials
T1  - Graphene quantum dots suppress proinflammatory T cell responses via autophagy-dependent induction of tolerogenic dendritic cells
VL  - 146
SP  - 13
EP  - 28
DO  - 10.1016/j.biomaterials.2017.08.040
ER  - 

@article{
author = "Tomić, Sergej and Janjetović, Kristina D. and Mihajlovic, Dusan and Milenković, Marina and Kravić-Stevović, Tamara K. and Marković, Zoran M. and Todorović-Marković, Biljana and Špitalsky, Zdenko and Mičušik, Matej and Vucevic, Dragana and Colic, Miodrag and Trajković, Vladimir S.",
year = "2017",
abstract = "Graphene quantum dots (GQD) are atom-thick nanodimensional carbon sheets with excellent physicochemical and biological properties; making them attractive for application in theranostics: However, their immunoregulatory properties are insufficiently investigated, especially in human primary immune cells. We found that non-toxic doses of GQD inhibit the production of proinflammatory and T helper (Th) 1 cytokines, and augment the production of anti-inflammatory and Th2 cytokines by human peripheral blood mononuclear cells. While unable to affect T cells directly, GQD impaired the differentiation and functions of monocyte-derived dendritic cells (DC), lowering their capacity to stimulate T cell proliferation, development of Thl and Th17 cells, and T-cell mediated cytotoxicity. Additionally, GQD-treated DC potentiated Th2 polarization, and induced suppressive CD4(+)CD25(high)Foxp3(+) regulatory T cells. After internalization in a dynamin-independent, cholesterol-dependent manner, GQD lowered the production of reactive oxygen species and nuclear translocation of NF-kappa B in DC. The activity of mammalian target of rapamycin (mTOR) was reduced by GQD, which correlated with the increase in transcription of autophagy genes and autophagic flux in DC. Genetic suppression of autophagy impaired the pro-tolerogenic effects of GQD on DC. Our results suggest that GQD-triggered autophagy promotes tolerogenic functions in monocyte-derived DC, which could be beneficial in inflammatory T-cell mediated pathologies, but also harmful in GQD-based anti-cancer therapy. (C) 2017 Elsevier Ltd. All rights reserved.",
journal = "Biomaterials",
title = "Graphene quantum dots suppress proinflammatory T cell responses via autophagy-dependent induction of tolerogenic dendritic cells",
volume = "146",
pages = "13-28",
doi = "10.1016/j.biomaterials.2017.08.040"
}

Tomić, S., Janjetović, K. D., Mihajlovic, D., Milenković, M., Kravić-Stevović, T. K., Marković, Z. M., Todorović-Marković, B., Špitalsky, Z., Mičušik, M., Vucevic, D., Colic, M.,& Trajković, V. S.. (2017). Graphene quantum dots suppress proinflammatory T cell responses via autophagy-dependent induction of tolerogenic dendritic cells. in Biomaterials, 146, 13-28.
https://doi.org/10.1016/j.biomaterials.2017.08.040

Tomić S, Janjetović KD, Mihajlovic D, Milenković M, Kravić-Stevović TK, Marković ZM, Todorović-Marković B, Špitalsky Z, Mičušik M, Vucevic D, Colic M, Trajković VS. Graphene quantum dots suppress proinflammatory T cell responses via autophagy-dependent induction of tolerogenic dendritic cells. in Biomaterials. 2017;146:13-28.
doi:10.1016/j.biomaterials.2017.08.040 .

Tomić, Sergej, Janjetović, Kristina D., Mihajlovic, Dusan, Milenković, Marina, Kravić-Stevović, Tamara K., Marković, Zoran M., Todorović-Marković, Biljana, Špitalsky, Zdenko, Mičušik, Matej, Vucevic, Dragana, Colic, Miodrag, Trajković, Vladimir S., "Graphene quantum dots suppress proinflammatory T cell responses via autophagy-dependent induction of tolerogenic dendritic cells" in Biomaterials, 146 (2017):13-28,
https://doi.org/10.1016/j.biomaterials.2017.08.040 . .