Study of bioactive glass ceramic for use as bone biomaterial in vivo: investigation by Nuclear Magnetic Resonance and Histology

International audienceThe 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 31P and 29Si 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 29Si proves the presence of Q2 (25%), Q3 (73%) and Q4 (2%). However, after six months, the disappearance of all these species was revealed and characterized by the 46S6-10Zn dissolution. Besides, MAS- NMR 31P demonstrates the presence of Qc° (4%), QHA° (55%) and Qa° (41%) after one month. Nevertheless, six months later, we observe the presence of QHA° (80%) and Qa° (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 defect

Risedronate adsorption on bioactive glass surface for applications as bone biomaterial

International audienceThe aim of the current work is to study the physicochemical interactions between bisphosphonates molecules, risedronate (RIS) and bioactive glass (46S6) after their association by adsorption phenomenon. To more understand the interaction processes of RIS with the 46S6 surface we have used complementary physicochemical techniques such as Infrared (FTIR), RAMAN and nuclear magnetic resonance (NMR) spectroscopy. The obtained results suggest that risedronate adsorption corresponds to an ion substitution reaction with silicon ions occurring at the bioactive glass surface. Thus, a pure bioactive glass was synthesized and fully characterized comparing the solids after adsorption (46S6-XRIS obtained after the interaction of 46S6 and X% risedronate). Therefore, based on the spectroscopic results FTIR, RMAN and MAS-NMR, it can be concluded that strong interactions have been established between RIS ions and 46S6 surface. In fact, FTIR and RAMAN spectroscopy illustrate the fixation of risedronate on the bioactive glass surface by the appearance of several bands characterizing risedrontre. The 31P MAS-NMR of the composite 46S6-XRIS show the presence of two species at a chemical shift of 15 and 19 ppm demonstrating thus the fixation of the RIS on 46S6 surface

The performance of a scaffold bioglass-chitosan in the treatment of bone defect

International audienceThe present research work is an in vivo study that aimed to evaluate the potential role of bioglass-chitosan (BG-CS) and bioglass-chitosan-20%ciprofloxacin (BG-CS-20Cip) in antioxidant profile and osteointegration. These scaffolds were implanted in the defect bone of femoral condyles in ovariectomized rats. The treatment with BG-CS-20Cip has shown a significantly higher stress proteins concentration in comparison with that implanted with BG-CS group. The thiol and vitamin C in BG-CS-20Cip group were significantly enhanced when compared with those in BG-CS group. The histological and physicochemical analyses highlight the BG-CS implications in the bone construction. This property was found to decrease with the presence of ciprofloxacin that caused the delay of this phenomenon. ICP-OES has revealed that the introduction of this antibiotic to the composite led to decrease bone mineralization by evaluating Ca/P ratio. The SEM results have confirmed a progressive degradation of BG-CS and BG-CS-20Cip. However, such bioresorbability and bioactivity of BG-CS was proven to be faster than those of BG-CS-20Cip. Therefore, the incorporation of ciprofloxacin in BG-CS was characterized by a delaying effect of composite dissolution and the formation of apatitic phase. The development of BG-CS as a therapeutic biomaterial protector against oxidative stress is likely to make an effective choice for the application in tissue engineering

Effect of spark plasma sintering process on the microstructure and mechanical properties of Nano crystalline hydroxyapatite ceramics prepared by hydrolysis in polyol medium

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Antioxidative/oxidative effects and retarding osteoconductivity of ciprofloxacin-loaded porous polyvinyl alcohol/bioactive glass hybrid

International audienceThis study investigated the effect of bioglass (melting)-polyvinyl alcohol (BG (M)-PVA) and bioglass (melting)-polyvinyl alcohol-20 %ciprofloxacin (BG(M)-PVA-20Cip) in improving antioxidant activity and regenerating bone capacity. These composites were implanted in femoral condyles of ovariectomized Wistar rats and compared to that of controls groups. After the different period of implantation (15, 30, 60 and 90 days), the treatment of ovariectomized rats with BG(M)-PVA-20Cip showed a significantly higher malondialdehyde concentration when compared to that of BG(M)-PVA group. The superoxide dismutase, glutathione peroxidase and catalase in BG(M)-PVA-20Cip group showed significantly lower activities when compared to those in BG(M)-PVA group. So, BG(M)-PVA is more tolerated by organism than BG(M)-PVA-20Cip. Moreover, the alkaline phosphatase and acid phosphatase activities showed an excellent osteoinductive property of BG (M)-PVA. This property decreased with the presence of ciprofloxacin which is confirmed by histopathological analysis. Several physicochemical techniques showed a rapid reduction in Si and Na in one hand and an accelerator rise in Ca and P ions concentrations in other hand in BG(M)-PVA than in the BG(M)-PVA-20Cip. Therefore, the incorporation of ciprofloxacin in BG(M)-PVA is characterized by a prooxidant effect in oxidant–antioxidant balance at the beginning of treatment and a retard effect of formation of apatitic phas

Accelerated bone ingrowth by local delivery of Zinc from bioactive glass: oxidative stress status, mechanical property, and microarchitectural characterization in an ovariectomized rat model.

International audienceBackground - Synthetic bone graft substitutes such as bioactive glass (BG) material are developed in order to achieve successful bone regeneration. Zn plays an important role in the proper bone growth, development, and maintenance of healthy bones. Aims - This study aims to evaluate in vivo the performance therapy of zinc-doped bioactive glass (BG-Zn) and its applications in biomedicine. Methods - Female Wistar rats were ovariectomized. BG and BG-Zn were implanted in the femoral condyles of Wistar rats and compared to that of control group. Grafted bone tissues were carefully removed to evaluate the oxidative stress status, histomorphometric profile, mechanical property, and mineral bone distribution by using inductively coupled plasma optical emission spectrometry. Results - A significant decrease of thiobarbituric acid-reactive substances was observed after BG-Zn implantation. Superoxide dismutase, catalase (CAT), and glutathione peroxidase (GPx) activities significantly increased in ovariectomized group implanted with Zinc-doped bioactive glass (OVX-BG-Zn) as compared to ovariectomized group implanted with bioactive glass (OVX-BG). An improved mechanical property was noticed in contact of OVX-BG-Zn (39±6 HV) when compared with that of OVX-BG group (26±9 HV). After 90 days of implantation, the histomorphometric analysis showed that trabecular thickness (Tb.Th) and trabecular number (Tb.N) were significantly increased with 28 and 24%, respectively, in treated rats of OVX-BG-Zn group as compared to those of OVX-BG groups. Trabecular separation (Tb.Sp) and trabecular bone pattern factor (TBPf) were significantly decreased in OVX-BG-Zn group with 29.5 and 54% when compared with those of OVX-BG rat groups. On the other hand, a rise in Ca and P ion concentrations in the implanted microenvironment was shown and lead to the formation/deposition of Ca-P phases. The ratio of pyridinoline [Pyr] to dihydroxylysinonorleucine [DHLNL] cross-links was normalized to the control level. Conclusion - Our findings suggested that BG-Zn might have promising potential applications for osteoporosis therapy

Antibacterial and in vivo reactivity of bioactive glass and poly(vinyl alcohol) composites prepared by melting and sol-gel techniques

International audienceBioactive glass particle is used in the repair of bone defects. This material undergoes a series of surface in vivo reactions, which leads to osteointegration. We evaluated the effect of the bioactive glass synthesis, sol-gel (BG(S)) versus melting (BG(M)), associated with polyvinyl-alcohol (PVA) on in vivo bioactivity with biochemical parameters, liver-kidney histological structure and antibacterial in vitro activity. These composites were testified in many bacteria and implanted in ovariectomized rat. The serum and organs (liver and kidney) of all groups, control and treated rats, were collected to investigate the side effects of our composites, BG(S)-PVA and BG(M)-PVA, in comparison with control and ovariectomized rats. Also, the implants, before and after implantation, were prepared for analysis using physicochemical techniques such as Fourier transform infrared spectroscopy and X-ray diffraction. Our results have shown the stability of natremia, kaliemia, calcemia and phosphoremia. The histological structures of liver and kidney in implanted rats are intact compared to control and ovariectomized rats. BG(S)-PVA is characterized by a higher antibacterial effect on negative and positive gram bacteria than BG(M)-PVA. The physicochemical results have confirmed a progressive degradation of BG(S)-PVA and BG(M)-PVA, while replacing the implant by an apatite layer. But this bioactivity of BG(S)-PVA is faster than BG(M)-PVA. We can therefore confirm, on the one hand, the biocompatibility of our two implants and, on the other hand, the beneficial effect of sol-gel synthesis technique versus melting, both on the antibacterial effect and on the rapid formation of layer hydroxyapatite, and consequently on osteogenesi