In vitro bioactivity of biphasic calcium phosphate silicate glassceramic in CaO-SiO2-P2O5 system

The main purpose of the paper is the evaluation of the influence of chemical composition of the gel of the synthesized 15CaO·0.5P2O5·6SiO2 glass-ceramic on the structure, crystallization behaviour and in vitro bioactivity in static conditions for different periods of time - 3, 9 and 30 days in 1.5SBF. The obtained glass-ceramic was synthesized via polystep sol-gel technique. The structure of the prepared and the one thermally treated at 1200°C for 2 h powder was studied by XRD, 29Si MAS NMR, FTIR and SEM

In Vitro Bioactivity of Silver-Containing Sol-Gel Glasses: FTIR Analysis

Introduction: The sol-gel glasses (BG) have been used for various biomedical applications, such as orthopedic, dental grafting and tissue engineering. The main purpose of the presented article is the preparation and evaluation of carbonate apatite formation on the BG in SiO2-CaO-P2O5-xAg2O system, where x=0,1,2 and 4wt.% Ag2O (BG/Ag), after soaking in a simulated body fluid (1.5 SBF) for 12 days in static conditions.Materials and Methods: BG/Ag were synthesized from tetraethyl orthosilicate (TEOS), calcium oxide (CaO), phosphoric acid (H3PO4) and silver nitrate (AgNO3) as sources. TEOS was stirred into the mixed solvent of C2H5OH and H2O with a very small amount of HCl in the volume ratio TEOS:C2H5OH:H2O:HCl=1:1:1:0.01. The mixture of calcium phosphate (CP) and appropriate amount of AgNO3 was added to SiO2 sol under stirring for 20h. The mixed sol obtained was gelated at 120oC for 12h and 600oC for 6h.Results: X-ray powder diffraction (XRD) of the synthesized samples showed that the presence of some crystalline phases is dependent on the gel composition. XRD proved the presence of CaCO3, wollastonite, HA and metallic Ag in accordance with gel compositions. Fourier transform infrared spectroscopy (FTIR) of the prepared BG showed the presence of basic absorption bands, corresponding to the different chemical bands and crystalline phases, in agreement with XRD results. FTIR of the examined samples, after soaking in 1.5 SBF solution for 12 days, confirmed that B-type carbonate apatite was formed preferentially on the soaked surface.Conclusions: BG in SiO2-CaO-P2O5-xAg2O system (x=0,1,2 and 4wt.% Ag2O) were synthesized via a polystep sol-gel method. After immersion of the studied BG in 1.5 SBF solutions for 12 days in static conditions, FTIR revealed the presence of some CO32- bands, i.e. after soaking carbonate apatite (CO3HA) may be formed on the surface of the prepared sol-gel glasses. On the basis of FTIR results, we can assume that B-type CO3HA preferentially formed on the soaked samples

Carbonate apatite formation on novel multiphase CaO-SiO2-P2O5-MgO glass-ceramics in TRIS-HCl buffer

The main purpose of the presented article is the preparation of novel glass-ceramics in CaO-SiO2-P2O5-MgO system and evaluation of carbonate apatite formation after soaking in TRIS-HCl buffer solution for 14 days. The investigated samples were prepared via sol-gel method and structure of the obtained samples was studied using XRD, FTIR, SEM, XPS and ICP-AES. XRD of the thermally treated samples showed that the presence of some crystalline phases is depended on the gel composition. FTIR revealed the existence of all characteristic bands for the observed crystalline phases. SEM monitored the presence of particles with different morphology. After soaking in TRIS-HCl solution, FTIR confirmed that carbonate apatite was formed on the soaked surface. The obtained data are in a good agreement with XPS analysis. The change of ions concentrations in TRIS-HCl buffer solution after immersion of the prepared glass-ceramics was recorded by ICP-AES measurements

In vitro bioactivity of glass-ceramic/fibroin composites

Bioactive composite materials were prepared by mixing 20 wt.% of silk fibroin (SF) and 80 wt.% of glassceramics from CaO-SiO2-P2O5-MgO system. In vitro bioactivity of the prepared composites was evaluated in 1.5 simulated body fluid (1.5 SBF) in static conditions. The obtained samples before and after in vitro tests were characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The changes in 1.5 SBF solutions after soaking the samples were evaluated by inductively coupled plasma atomic emission spectroscopy (ICP-AES). MG63 osteosarcoma cells were used for the biological experiments. The obtained experimental data proved that the synthesized composites exhibit excellent in vitro bioactivity

Collagen/silicocarnotite composites, cross-linked with chondroitin sulphate: in vitro bioactivity

In this work we present the experimental results on synthesis, structure evolution and in vitro bioactivity of collagen-silicocarnotite-chondroitin sulphate composites. The obtained samples were synthesised by mixing collagen (C) and silicocarnotite (S) powder with C:S ratio of 75:25 and 25:75 wt.% in the presence of chondroitin sulphate (ChS). Collagen was diluted in 5M CH3COOH before mixing. The obtained materials were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) before and after in vitro test in 1.5 simulated body fluid. XRD of synthesized samples showed that before immersion carbonate containing hydroxyapatite (CO3HA) were formed in situ in the composites. FTIR depicts the presence of HPO42– and the “red shift” of COO– and SO3– from ChS was also observed. This “red shift” could be attributed that the ChS prefers to chelate Ca2+ from partially dissolved S powder. SEM of the prepared samples show the presence of nanosized hydroxyapatite (HA) whiskers and flower-like HA assemblies. After in vitro test, XRD proved the presence of HA with well-defined crystallinity. According to the FTIR results B-type CO3HA can be observed. SEM of the precipitated layers show the presence of HA spheres. Inductively coupled plasma atomic emission spectroscopy results lead to a conclusion that after in vitro test of the prepared composites silicon containing carbonate substituted hydroxyapatite (Si-CO3HA) may be formed on the surface of the immersed samples

In vitro Bioactivity of Polycaprolactone/Bioglass Composites

A series of Polycaprolactone and Bioglass in the 85SiO 2-10CaO-5P2O 5 (mol. %) systems were synthesized at different quantity of the organic/inorganic co mponents. The 85S Bioglass was prepared via sol-gel method. It was added to the Polycaprolactone matrix at 20, 50 and 80 weight (wt.) %, respectively. In vitro bioactivity of the prepared composites was evaluated in 1.5 Simu lated Body Flu id (1.5 SBF). The obtained composite materials before and after static in vitro test were characterized by FTIR and SEM. The obtained experimental data proved that the synthesized co mposites exhibit good in vitro bioactivity. After immersion in 1.5SBF, SEM depicts the presence of nano-needle-like hydro xyapatite on the immersed 20PCL/80BG and 50PCL/50BG samples