Search

Agarose hydrogels, combined with 45S5 Bioglass®, were elaborated to serve as copper delivery systems. Our aim was to study the antibacterial properties of these hydrogels. The results show that the amount of glass does not influence the stiffness properties, but it improves the hydrophilicity and the swelling profile of agarose hydrogel. Two bacterial strains, Bacillus sp. 4J6 and Pseudomonas aeruginosa sp. PAO1, were chosen. Their retention on the substrates was analyzed by confocal laser scanning microscopy. The mechanical characteristics and the release of copper have an effect on the bacterial adhesion and the biofilm formation. All the obtained results indicate that these hydrogels could be adapted to a potential application to the antibacterial coatings

The performance of the porous glass ceramic doped with 10 wt% Zinc and 2 wt% TiN (46S6-10Zn), in the restoration of critical diaphyseal bone defect, was evaluated by several physicochemical methods and histological studies. The critical defect in rabbits was created and then filled with 46S6-10Zn. At different periods after implementation, animals were sacrificed. Samples were harvested for exploration. The nuclear magnetic resonance (MAS-NMR) of 31 P and 29 Si illustrates the progressive degradation of 46S6-10Zn in favor to of the formation and the development of biological apatite. Therefore, after one month of implementation, MAS-NMR 29 Si proves the presence of Q 2 (25%), Q 3 (73%) and Q 4 (2%). However, after six months, the disappearance of all these species was revealed and characterized by the 46S6-10Zn dissolution. Besides, MAS-NMR 31 P demonstrates the presence of Q C 0 (4%), Q HA 0 (55%) and Q a 0 (41%) after one month. Nevertheless, six months later, we observe the presence of Q HA 0 (80%) and Q a 0 (20%). Histological study demonstrates an intimate contact of 46S6-10Zn surrounding bone after one month of implantation. However, after four months, mature bone matrix became calcified and the implanted 46S6-10Zn began to be degraded. Moreover, nine months later, 46S6-10Zn was nearly resorbed and replaced by a calcified tissue in the periphery and an osteoid tissue in the middle of bone defects.

International audience; Different bioactive glass systems have been prepared by sol-gel. However, the production of Na2O-containing bioactive glasses by sol-gel methods has proved to be difficult as the sodium nitrate used in the preparation could be lost from the glass structure during filtration and washing. The aim of this study was to prepare the quaternary system 46S6 of bioactive glass by modified sol-gel techniques with a decrease in the time of gelation. In addition, compare the behaviour of the prepared sol-gel bioactive glass system by its corresponding prepared by melting. The obtained glasses were characterized by using several physicochemical techniques; XRD, FTIR, TEM and SEM beside the effect of the glass particles on the viability of osteoblast like cells (Saos-2). Results show that nanopowders 40-60 nm of 46S6 glass system had been prepared by modified sol-gel (acid-base reaction) method at 600°C in just three days at 600°C. Cell viability by MTT assay confirmed the effectiveness of the prepared nanobioactive glass.

International audience; Chitosan scaffolds, combined with bioactive glass 46S6, were prepared to serve as gentamicin sulfate delivery in situ systems for bone biomaterials. This work presents a study about the effect of the ratio chitosan/bioactive glass (CH/BG) on the release of gentamicin sulfate and on the bioactivity during in vitro experiments. SEM observations allowed understanding the bond between the glass grains and the chitosan matrix. In vitro results showed that scaffolds form a hydroxyapatite (HA) Ca10(PO4)6(OH)2 after 15 days of immersion in a simulated body fluid (SBF).The interest of this study is to see that the increase of the content of bioactive glass in the chitosan matrix slows the release of gentamicin sulfate in the liquid medium. Starting concentration of gentamicin sulfate has an influence on the relaxation time of the scaffolds. Indeed, an increasing concentration delays the return to a new equilibrium. Contents of chitosan and bioactive glass do not affect the relaxation time. Synthesized scaffolds could be adapted to a clinical situation: severity and type of infection, weight and age of the patient.

Bioactive glasses belong to the ceramic family. They are good materials for implantation due to their excellent capacities to create an intimate bond with bones. Copper is known for its anti-inflammatory, antibacterial, and antifungal properties. Titanium is biocompatible and resistant to corrosion. These chemical elements can be introduced in bioactive glasses to provide a wide variety of uses and to enhance the physiological properties of implanted biomaterials. In this work, bioactive glasses doped with different contents of copper and titanium were synthesized by the melting method. The purpose is to study the effect of doping metal element on the thermal characteristics (T g, T c, and T f). The results revealed that the increase of the content of copper and titanium in the glass matrix decreases the melting temperature and induces an increase of the thermal stability. The excess entropies of pure and doped glasses were calculated. Obtained results highlighted the decrease of the excess entropy with the increase of metal elements contents.

Critical-sized bone defects have, in many cases, posed challenges to the current gold standard treatments. Bioactive glasses are reported to be able to stimulate more bone regeneration than other bioactive ceramics; however, the difficulty in producing porous scaffolds made of bioactive glasses has limited their extensive use in bone regeneration. On the other hand, calcium phosphate ceramics such as synthetic hydroxyapatite and tricalcium phosphate are widely used in the clinic, but they stimulate less bone regeneration. This paper gives an overview of the recent developments in the field of bioactive nanoparticles, with a focus on nanohydroxyapatite and bioactive glasses for bone repair and regeneration. First, a brief overview of the chemical structure and common methods used to produce synthetic nanohydroxyapatite and bioactive glasses has been presented. The main body of the paper covers the physical and biological properties of these biomaterials, as well as their composites with biodegradable polymers used in bone regeneration. A summary of existing challenges and some recommendations for future directions have been brought in the concluding section of this paper.

International audience; The purpose of this paper is to explore the effect of titanium and silver on the characteristic temperatures of 46S6 glass and the excess entropy. The results show that the adding of these metals in the chemical composition does not affect the amorphous character of glasses. The introduction of these elements greatly reduces the melting temperatures of glasses and involves similar variations on the crystallization and glass transition temperatures. These elements also increase the thermal stability of glasses. The excess entropy calculations show a decrease when the content of Ti or Ag increases. Contrary to crystals, synthesized glasses have entropy different to zero at T = 0 K.

Chitosan (CH) material reinforced by bioactive glass (46S6) was fabricated. 46S6 containing 17% wt% CH was studied in vitro and in vivo. Physicochemical techniques, such as Fourier transform infrared spectroscopy (FT-IR), coupled plasma optical emission spectrometry (ICP-OES) analysis were used. The behavior of 46S6CH17 was studied by measuring the in situ pH in a SBF solution. The 46S6CH17 was implanted in the rat femoral condyl. In vitro 46S6CH17 gave an FTIR - spectrum in which three absorption bands with the maxima at 565, 603 and 1039cm-1 after 3 days of soaking in physiological solution. They are assigned to stretching vibrations of PO4^3- group in phosphate crystalline. Moreover, the pH measurement was decreased in the SBF solution. The stability of the calcium phosphate precipitation depended on the pH value. In vivo, a rise in the Ca and phosphate P ions concentrations in the implanted microenvironment was determined., {"references":["R.A. Muzzarelli, F. Tanfani, M. Emanuelli, D. P. Pace, E. Chiumzzi,\n\"Sulfated n-(carboxymethyl) chitosans: novel blood anticoagulants,\"\nCarbohydr Res., Vol.126, NO.2, pp.225-31, Mar. 1984.","X.D. Liua, S. Tokurab, N. Nishia, N. Sakairi, \"A novel method for\nimmobilization of chitosan onto nonporous glass beads through a 1,3-\nthiazolidine linker\", J Polymer., Vol. 44, NO.4, pp. 1021-1026. Feb.\n2003.","M. Guiping, DongzhY. i, Kennedy J. F., Jun N., \"Synthesize and\ncharacterization of organic-soluble acylated chitosan\", Carbohyd\nPolym., VOL. 75, NO.3. PP. 390–394, Feb. 2009.","N. Annabi, J. W. Nichol, Zhong X , C. Ji, S. Koshy, A. Khademhosseini,\nF. Dehghani., \"Controlling the Porosity and Microarchitecture of\nHydrogels for Tissue Engineering\", Eng Part B Rev., VOL. 16, NO.4. PP.\n371–383, Aug. 2010.","G. Chen, T. Ushida, T. Tateishi., \"Development of biodegradable porous\nscaffolds for tissue engineering\". J. Mater Sci Eng C., Vol. 5, NO.2.\npp.77–83, Jun. 2002.","D. Eberli, F. L. Freitas, A. Atala, J. J. Yoo., \"Composite scaffolds for the\nengineering of hollow organs and tissues\". Methods, VOL. 47, NO.2.PP.\n109-15, Feb. 2009.","A. Bahetia, L. Kumarb, A.K.Bansal., J \"Excipients used in lyophilization\nof small molecules\". Excipients and Food Chem., VOL. 1, NO.1.PP. 41,\nJun. 2010.","WW. Thein-Han, J. Saikhun, C Pholpramoo, R. D. Misra, Y. Kitiyanant,\n\"chitosan–gelatin scaffolds for tissue engineering: physico-chemical\nproperties and biological response of buffalo embryonic stem cells and\ntransfectant of gfp–buffalo embryonic stem cells\", Acta Biomater, VOL.\n5, NO. 9, PP. 3453–3466, Nov. 2009.","M. Mami, A. Lucas-Girota, H. Oudadesse, R. Dorbez-Sridib, F.\nMezahia, E. Dietrich , \"Investigation of the surface reactivity of a sol–\ngel derived glass in the ternary system SiO2–CaO–P2O5\", App Sur Sci,\nVOL. 254, NO. 22, PP. 7386–7393, Sep. 2008.\n[10] S. Jebahi, H. Oudadesse, H. El Feki, T. Rebai, H. Keskes, P. Pellen, A.\nEl Feki, \"Antioxidative/oxidative effects of strontium-doped bioactive glass as bone graft. In vivo assays in ovariectomised rats,\" J Appl\nBiomed. VOL. 254, PP. 195–2097, Jan. 2012.\n[11] X. V. Bui, H. Oudadesse, Y. Le Gal, O. Merdrignac-Conanec, G.\nCathelineau. \"Bioactivity behaviour of biodegradable material\ncomprising bioactive glass,\" Korean J Chem Eng, VOL. 29, NO. 2, PP.\n215-220, Feb. 2012.\n[12] E. Dietrich, H. Oudadesse, M. Le Floch, B. Bureau, T. Gloriant . \"In\nvitro Chemical Reactivity of Doped Bioactive Glasses: an Original\nApproach by Solid-State NMR Spectroscopy,\" Adv Eng Mater ,VOL. 11,\n, NO. 8, PP. B98–B105, Aug. 2009.\n[13] S. Jebahi, H. Oudadesse, X.V. Bui, H. Keskes, T. Rebai, A. El Feki , H.\nEl Feki \"Repair of bone defect using bioglass-chitosan as a\npharmaceutical drug: An experimental study in an ovariectomised rat\nmodel\". Afr J Phar Pharm, vol. 6, no. 16, pp. 1276 - 1287, Apr. 2012.\n[14] S. Jebahi, R. Nsiri, M. Boujbiha, E. Bouroga, T. Rebai, H. Keskes, A. El\nFeki, H. Oudadesse, H. El Feki \"The impact of orthopedic device\nassociated with carbonated hydroxyapatite on the oxidative balance:\nexperimental study of bone healing rabbit model\". Eur J Orthop Surg\nTraumatol. Oct. 2012. (Epub ahead of print).\n[15] K. H. Karlsson, R. Backman, M. Hupa \"An equilibrium study of\nphosphate precipitation in bioactive glass,\". Key Eng Mater, vol. 220,\npp. 103–7. 2002.\n[16] V. Banchet, J. Michel, E. Jallot, L. Wortham, S. Bouthors, D. Laurent-\nMaquin \"Interfacial reactions of glasses for biomedical application by\nscanning transmission electron microscopy and microanalysis\", Acta\nBiomater, vol. 2, No 3. pp. 349–59. May. 2006.\n[17] X. Lu, Y. Leng. \"Theoretical analysis of calcium phosphate precipitation\nin simulated body fluid\", Biomaterials, vol. 2 6, No10. pp. 1097–108.\nApr.2005.\n[18] S. Jebahi, M. Saoudi, R. Badraoui, H. Oudadesse, Z. Ellouz, H. Keskese,\nA. El Feki, H. El Feki, \"Biologic Response to Carbonated\nHydroxyapatite Associated with Orthopedic Device: Experimental Study\nin a Rabbit Model,\" Kor J Path, vol. 4 6, No1. pp. 48-54. JAN. 2012.\n[19] H. Oudadesse, E. Dietrich , Y. L GAL, P .Pellen, B. Bureau, AA.\nMostapha, G .Cathelineau \"Apatite forming ability and\ncytocompatibility of pure and Zn-doped bioactive glasses,\" Biomed\nMater, vol. 6, no. 3, pp. 20, Jun. 2011.\n[20] E. Dietrich, H. Oudadesse, A. Lucas-Girot, M. Mami \"In vitro\nbioactivity of melt-derived glass 46S6 doped with magnesium\". J\nBiomed Mater Res A, vol. 88, no. 4, pp. 1087-96, Mar. 2009.\n[21] Neyman K. M., Rösch N. \"Bonding and vibrations of CO molecules\nadsorbed at transition metal impurity sites on the MgO (001) surface. A\ndensity functional model cluster study\", Chemical Physics, vol. 177, no.\n2, pp. 561–570, Nov. 1993.\n[22] J.R. Jones, P. Sepulveda, L.L. Hench. \"Dose dependent behavior of\nbioactive glass dissolution,\" J Biomed Mater Res , vol. 58, No 6 , pp.\n58:720, 2001.\n[23] M. Cerrutia, D. Greenspan, K. Powers. \"Effect of pH and ionic strength\non the reactivity of Bioglasss 45S5\". Biomaterials, vol. 26, no. 14, pp.\n1665-74, May. 2005.\n[24] M. Ashok, N. Meenakshi Sundaram, S. Narayana Kalkura.\n\"Crystallization of hydroxyapatite at physiological temperature\". Mater\nLett, vol. 57, no. 14, pp. 2066–2070, May. 2005.\n[25] Zhang Di, Mikko Hupa, Leena Hupa. \"In situ pH within particle beds of\nbioactive glasses\". Acta Biomaterialia, vol. 4, no. 5, pp. 1498-505, Sep.\n2008.\n[26] L. L. Hench, R. J. Splinter, W. C. Allen, T. K. Greenlee. \"Bonding\nmechanisms at the interface of ceramic prosthetic materials\". J Biomed\nMater Res Symp, vol. 5, no. 6, pp. 117–141, Nov. 1971.\n[27] M.G. Cerruti, D. Greenspan, K. Powers. \"An analytical model for the\ndissolution of different particle size samples of bioglass_ in TRIS\nbuffered solution\", Biomaterials, vol. 26, no. 24, pp. 4903-11, Aug.\n2005.\n[28] D.C. Greenspan, I.P. Zhong, G.P. La Torre. \"Effect of surface area to\nvolume ratio on in vitro surface reactions of bioactive glass particulates\".\nBioceramics, vol. 7, pp. 55–60, 1994."]}

Bioactive glass 46S6 and biodegradable therapeutic polymer (Chitosan: CH) have been elaborated to form 46S6-CH composite by freeze-drying process. The kinetics of chemical reactivity and bioactivity at the surface were investigated by using physicochemical techniques, particularly solid-state MAS-NMR. Immortalized cell line used to construct multicellular spheroids was employed as three-dimensional (3D) cell cultures for in vitro studies. Obtained results showed a novel structure of the composite; the chemical treatment (ultrasound, magnetic stirring, freeze drying process and lyophilization) led the bioactive glass particles to be loaded in the chitosan-based materials. 29Si and 31P MAS-NMR results showed the emergence of two new species, Q 3 (OH) and Q 4 , which are characteristic of the vitreous network dissolution in simulated body fluid (SBF). MAS-NMR also confirmed the formation of amorphous calcium phosphate (ACP) at the surface of the initial 46S6-CH. Three-dimensional (3D) cell cultures highlighted the effect of chitosan, where the cell viability reached up to 78% in 46S6-CH composite and up to 67% in 46S6. The association of (CH) and bioactive glass (BG) matrix promotes a highly significant bioactivity, demonstrating surface bone formation and satisfactory behavior in biological environment.

Bioactive glasses, doped with traces of copper (Cu) and zinc (Zn) were synthesized by fusion method. Cu and Zn present interesting functions for the biological metabolism through their antibacterial, anti-inflammatory and antifungal properties. Several physical methods were employed to characterize the bioactive glasses before and after immersion in a Simulated Body Fluid (SBF). The “in vitro” experiments showed that after soaking in SBF, the behavior of bioactive doped glasses are different compared to pure glass 46S6. Obtained results show that glass matrix undergoes some changes after 15 days of immersion. The non toxic character of doped glasses was confirmed after 24 hours of incubation. The kinetic of release of Cu and Zn was carried out. It highlights that Cu is more released than Zn. By SEM, the morphology of hydroxyapatite obtained with Zn-doped glass show a better crystallization compared to Cu-doped glass.

International audience; Bioactive glasses prepared in SiO2-CaO-Na2O and P2O5 system are used as biomaterials in orthopaedic and maxillofacial surgery. Zn presents high physiological interest. It enhances physiological effects of implanted biomaterials. In this work, the thermal characteristics (Tg, Tc and Tf) of pure bioactive glass elaborated with different amounts of CaO, Na2O in pure glass and with different amounts of introduced Zn in glass (ranging from 0.1 to 10 in wt%), were studied. The excess entropy was calculated for different compounds. Glasses were prepared by the melting process. The thermal behaviour of obtained bioactive glasses was determined using differential thermal analysis. Therefore, the glass transition (Tg), the crystallization (Tc) and the melting temperatures (Tf) were revealed. Moreover, according to Dietzel formula, the thermal stability (TS) of the studied bioactive glasses has been calculated. The first results concerning the impact of different oxides, revealed a decrease of the TS, Tg, Tc and Tf when the SiO2/CaO increases and revealed an increase of these thermal characteristics when the SiO2/Na2O and CaO/Na2O ratios increase. Introducing Zn into the bioactive glasses induces a decrease of Tf and an increase of TS. Contrary to crystals, prepared glasses have entropy different to zero at T = 0 K and vary versus Tf. The excess entropy of pure glasses and Zn-doped glasses were calculated. The significant variations were registered.