scholarly journals A novel ceramic material with medical application

2008 ◽  
Vol 2 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Joanna Podporska ◽  
Marta Błażewicz ◽  
Barbara Trybalska ◽  
Łukasz Zych
Keyword(s):  
Body Fluid ◽  
Crystallization Process ◽  
Sol Gel ◽  
Medical Application ◽  
In Vitro Test ◽  
Glass Crystallization ◽  
Complex Shapes ◽  
Different Temperatures ◽  
Vitro Test

Until now the basic methods used in manufacturing of wollastonite have been chemical (melting together with glass crystallization process, chemical coprecipitation) and sol - gel methods. A new and promising way of wollastonite fabrication is controlled pyrolysis of polysiloxane precursors with inorganic fillers. Heat treatment of such mixtures leads to the formation of wollastonite-containing ceramics already at about 1000?C. This is a relatively inexpensive and efficient method which enables to obtain complex shapes of the samples. The aim of this work was to obtain sintered, wollastonite-containing bioceramics and determine its bioactive features. Samples were sintered at three different temperatures: 1000, 1100 and 1200?C. Then the bioactivity of the wollastonite-containing ceramics was investigated by the ?in vitro? test in simulated body fluid. On the basis of the achieved results, it can be assumed that the obtained material possesses bioactive features.

THE STUDY ON GRANTING BIOACTIVITY OF Ti ALLOY BY SURFACE TREATMENT

2010 ◽  
Vol 17 (02) ◽  
pp. 153-157 ◽  
Author(s):  
N. R. HA ◽  
Z. X. YANG ◽  
G. C. KIM ◽  
K. H. HWANG ◽  
D. S. SEO ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Body Fluid ◽  
Surface Effect ◽  
In Vitro Test ◽  
Ti Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Surface ◽  
Vitro Test

Titanium alloys are superior of biocompatibility, mechanical properties and chemical stability. The biocompatibility of Ti alloy is related to the surface effect between human tissue and implant. Therefore, the purpose of this study is to investigate the bioactivity of Ti alloy by alkali and acid chemical surface treatment; and the biocompatibility of Ti alloy was evaluated by in vitro test. Higher bone-bonding ability and bioactivity of the substrate were obtained by the formation of apatite layers on the Ti alloy in simulated body fluid. The microstructures of apatite layer were investigated by scanning electron microscope (SEM) and the formed phases were analyzed with X-ray diffraction (XRD).

scholarly journals In vitro bioactivity of Polyurethane/85S Bioglass composite scaffolds

2013 ◽  
Vol 11 (9) ◽  
pp. 1439-1446 ◽  
Author(s):  
Lachezar Radev ◽  
Darina Zheleva ◽  
Irena Michailova
Keyword(s):  
Sol Gel ◽  
Spherical Particles ◽  
Polymerization Reaction ◽  
In Vitro Test ◽  
In Vitro Bioactivity ◽  
Before And After ◽  
Vitro Test ◽  
Sbf Solution ◽  
Static Conditions

AbstractIn the present work Polyurethane (PU)/Bioglass (BG) composite materials were synthesized with different content of BG (10 and 20 mol.%) as filler. The 85S Bioglass was synthesized via polystep sol-gel method. The chemical composition of BG is 85SiO2-10CaO-5P2O5 (wt.%). The synthesis of PU was carried out by a two-step polyaddition reaction. The 85S BG was added in situ during the polymerization reaction. In vitro bioactivity of the prepared composites was examined in the presence of 1.5 SBF for 7 days in static conditions. The structure of synthesized PU/BG composites before and after in vitro test was determined by XRD, FTIR and SEM. XRD of the samples before in vitro test proved that the phase of γCa2P2O7 in the PU/20BG is visible. FTIR revealed the presence of urethane bond between OH-(from BG) and NCO groups (from PU). Based on FTIR results after in vitro test in 1.5 SBF solutions, A/B-carbonate containing hydroxyapatite (CO3HA) was formed. XRD proved that HA was formed on the surface of the samples, but Ca2P2O7 does not undergo any changes in the 1.5 SBF solution. SEM depicted the nano-HA agglomerated in spherical particles after immersion in 1.5 SBF for 7 days.

In Vitro Study of Microplasma Sprayed Hydroxyapatite Coatings in Simulated Body Fluid

2009 ◽  
Vol 79-82 ◽  
pp. 815-818 ◽  
Author(s):  
Qiu Ying Zhao ◽  
Ding Yong He ◽  
Xiao Yan Li ◽  
Jian Min Jiang
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Carbonate Apatite ◽  
In Vitro Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Hydroxyapatite Coatings ◽  
Vitro Test

Hydroxyapatite (HA) coatings were deposited onto Ti6Al4V substrate by microplasma spraying (MPS) in the current research. The morphology, phase compositions, and percentage of crystallinity of the coatings were characterized by means of scanning electron microscopy (SEM) and X-ray diffraction. An in vitro evaluation by soaking the coatings in simulated body fluid (SBF) for up to 14 days was conducted aiming at the evaluation of their bioactivity. Results from the present investigation suggest that microplasma sprayed HA coatings exhibited certain roughness, pores, and microcracks. Thermal decomposition existed in the coatings where HA, α-TCP，β-TCP, amorphous phases, and CaO-exclusive impurities were observed. The in vitro test indicated that HA coatings deposited by MPS possessed better bioactivity and stability. A layer of carbonate-apatite covered most of the coating surface, which did not exhibit significant spalling after incubation in SBF.

Evaluation of α-Tricalcium Phosphate Cement Obtained at Different Temperatures

2012 ◽  
Vol 727-728 ◽  
pp. 1187-1192 ◽  
Author(s):  
Rafaela Silveira Vieira ◽  
Wilbur Trajano Guerin Coelho ◽  
Mônica Beatriz Thürmer ◽  
Juliana Machado Fernandes ◽  
Luis Alberto Santos
Keyword(s):  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Setting Time ◽  
Calcium Pyrophosphate ◽  
In Vitro Test ◽  
Calcium Phosphate Cements ◽  
Similar Chemical ◽  
Different Temperatures ◽  
Vitro Test

The calcium phosphate cements (CPCs) based on α-tricalcium phosphate (α-TCP) are highly attractive for use in medicine and odontology, since they have similar chemical and phase composition of mineral phase of bones (calcium deficient hydroxyapatite (CDHA)). However, one of the biggest difficulties for use of this type of cement is its low mechanical strength due to the presence of undesirable phases, such as β-tricalcium phosphate. The route for obtaining α-TCP is at high temperature by solid state reaction, mixing calcium carbonate and calcium pyrophosphate. The aim of this work was to obtain calcium phosphate cements with improved strength, by studying the obtaining of α-TCP at temperatures of 1300, 1400 and 1500°C. The samples were analyzed by crystalline phases, pH, setting time, particle size, in vitro test (Simulated Body Fluid), porosity, density and compressive strength. The results show that the synthesis temperatures influence strongly the phases of powders obtained and the mechanical properties of cement, being unnecessary quenching for obtaining pure α-TCP.

scholarly journals Sol-gel bioactive glass-ceramics Part II: Glass-ceramics in the CaO-SiO2-P2O5-MgO system

2009 ◽  
Vol 7 (3) ◽  
pp. 322-327 ◽  
Author(s):  
Lachezar Radev ◽  
Vladimir Hristov ◽  
Irena Michailova ◽  
Bisserka Samuneva
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Static Condition ◽  
Ceramic Materials ◽  
Molar Ratio ◽  
In Vitro Test ◽  
X Ray Diffraction ◽  
Vitro Test ◽  
Good Agreement

AbstractCeramics, with basic composition based on the CaO-SiO2-P2O5-MgO system with different Ca+ Mg/P+Si molar ratio (R), were prepared via polystep sol-gel technique. The structure of the obtained ceramic materials has been studied by XRD, FTIR spectroscopy, and SEM. X-ray diffraction showed the presence of akermanite and HA for the sample with R = 1.68 and Mg substituted β-TCP and silicocarnotite for the sample with R = 2.16, after thermal treatment at 1200°C/2 h. The obtained results are in good agreement with FTIR. In vitro test for bioactivity in static condition proved that the carbonate containing hydroxyapatite (CO3HA) can be formed on the surface of the synthesized samples. CO3HA consisted of both A- and B-type CO 32− ions. SEM micrographs depicted different forms of HA particles, precipitated on the surface after soaking in 1.5 simulated body fluid (SBF).

scholarly journals In vitro bioactivity of 70 wt.% SiO2 — 30 wt.% CaO sol-gel glass, doped with 1, 3 and 5 wt.% NbF5

2012 ◽  
Vol 10 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Lachezar Radev ◽  
Katia Hristova ◽  
Valery Jordanov ◽  
Maria Fernandes ◽  
Isabel Salvado
Keyword(s):  
Sol Gel ◽  
Active Role ◽  
In Vitro Test ◽  
In Vitro Bioactivity ◽  
Soaking Time ◽  
Vitro Test ◽  
Sbf Solution ◽  
Gel Glasses ◽  
Static Conditions

AbstractThe 70SiO2-30CaO (wt.%) sol-gel glasses doped with 1, 3 and 5 NbF5 (wt.%) were prepared via polystep sol-gel route. The synthesized glasses were characterized by XRD, FTIR and SEM. Changes in 1.5 SBF solutions were measured by ICP-AES. XRD of the glasses stabilized at 700°C for 6 hours proved the presence of niocalite. FTIR was consistent with XRD data. The in vitro bioactivity study of all glasses prepared were carried out by soaking in 1.5 simulated body fluid (1.5 SBF) at 37°C for 6 and 12 days in static conditions. The FTIR reveals the formation of A-type and B-type carbonate containing hydroxyapatite (CO3HA) layer. Changes in 1.5 SBF solutions, after 6 days of soaking, show that the Ca concentration increased significantly, compared to the initial Ca content in the 1.5 SBF solution before in vitro test. After 12 days of immersion, the Ca concentration decreased, i.e., the formation of HA phase consumed Ca from 1.5 SBF solution. For all soaking times, the concentration of P is much lower than that the used 1.5 SBF. Based on these results we suggest that Ca and P play an active role in the future of the glasses. SEM depicts that the different morphology of hydroxyapatite can be formed as a function of soaking time.

scholarly journals Physicochemical and in vitro bioactivity studies of bioactive glasses in the SiO2-CaO-MgO-P2O5, SiO2-Na2O-CaO-P2O5 and SiO2-Na2O-CaO-MgO-P2O5 systems

2020 ◽  
Vol 10 (5) ◽  
pp. 492
Author(s):  
Smaiel Herradi ◽  
Sara Bouhazma ◽  
Sanae Chajri ◽  
Imane Adouar ◽  
Souad Rakib ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Sol Gel ◽  
Energy Dispersive ◽  
In Vitro Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vitro Test ◽  
Diffraction Patterns ◽  
The One

<p>Glasses in the quaternary and quinary system SiO<sub>2</sub>-CaO-MgO-P<sub>2</sub>O<sub>5 </sub>(SCMP), SiO<sub>2</sub>-Na<sub>2</sub>O-CaO-P<sub>2</sub>O<sub>5 </sub>(SNCP) and SiO<sub>2-</sub>Na<sub>2</sub>O-CaO-MgO-P<sub>2</sub>O<sub>5 </sub>(SNCMP), have been prepared by using the sol-gel technique. Investigations of structural and bioactive properties of these glasses have been undertaken by using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The <em>in vitro</em> bioactivity was assessed by determining the changes in surface morphology and composition after soaking in simulated body fluid (SBF) for up to 30 days at 37°C. X-ray diffraction patterns indicated the formation of hydroxycarbonated apatite layer (HCA) after only one hour for SNCMP glass and after four days for SCMP and SNCP glasses. Furthermore, observed bands of FTIR spectra confirmed the growth of HCA layer during in vitro test.</p><p>Moreover, the dissolution rate has been investigated using energy-dispersive X-ray spectroscopy. The observed EDS patterns confirmed the growth of HCA layer on all samples surfaces during <em>in vitro</em> analysis. On the one hand, we report the existence of Na<sub>2</sub>Ca<sub>2</sub>Si<sub>3</sub>O<sub>9 </sub>(that couple good mechanical strength with satisfactory biodegradability) as a single crystalline phase in the SNCP glass when calcined at 600°C. On the other hand, we have noticed that the coexistence of magnesium and sodium both enhanced the dissolution rate and hindered the crystallization in the SNCMP glass at 600°C.</p>

scholarly journals Influence of thermal treatment on the structure and in vitro bioactivity of sol-gel prepared CaO-SiO2-P2O5 glass-ceramics

2014 ◽  
Vol 8 (3) ◽  
pp. 155-166 ◽  
Author(s):  
Lachezar Radev
Keyword(s):  
Thermal Treatment ◽  
Calcium Silicate ◽  
Sol Gel ◽  
Glass Ceramics ◽  
In Vitro Test ◽  
In Vitro Bioactivity ◽  
X Ray ◽  
Vitro Test ◽  
Sbf Solution

Nowadays there is a substantial practical interest in the in vitro bioactivity of calcium silicate phosphate (CSP) glass-ceramics and carbonate apatite (CO3HA) formation on their surfaces after in vitro test in simulated body fluid (SBF). The main purpose of the presented article is the evaluation of the chemical composition of the gel with nominal composition 70.59 CaO:28.23 SiO2:1.18 P2O5 (mol.%) on the structure, crystallization behaviour and in vitro bioactivity in SBF solution for 14 and 28 days. The prepared glass-ceramics have been synthesized via a polystep sol-gel method. The structure of the obtaining samples was studied by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). After thermal treatment of the samples XRD confirmed the presence of ?-Ca2SiO4 and Ca15(PO4)2(SiO4)6, and indicated that at 1500?C Ca15(PO4)2(SiO4)6 becomes predominant phase. FTIR revealed the presence of all characteristics bands for calcium silicate phosphate (CSP) bonds. SEM monitors the presence of particles with different morphology. After in vitro test in SBF, FTIR depicted that B-type carbonate containing hydroxyapatite (CO3HA) is preferentially formed on the immersed glass-ceramics. SEMof the precipitated layers showed the presence of HA spheres. The changes in SBF solution after soaking the samples were recorded by inductively coupled plasma atomic emission spectroscopy (ICP-AES).

Haemostatic Platelet Plug Formation in the Isolated Rabbit Mesenteric Preparation - An Analysis of Red Blood Cell Participation

1980 ◽  
Vol 44 (01) ◽  
pp. 006-008 ◽  
Author(s):  
D Bergqvist ◽  
K-E Arfors
Keyword(s):  
Whole Blood ◽  
Platelet Rich Plasma ◽  
Adenosine Diphosphate ◽  
In Vitro Test ◽  
Pharmacological Agents ◽  
Vitro Test ◽  
Releasing Effect ◽  
Plug Formation

SummaryIn a model using an isolated rabbit mesenteric preparation microvessels were transected and the time until haemostatic plugs formed was registered. Perfusion of platelet rich plasma gave no haemostasis whereas whole blood did. Addition of chlorpromazine or adenosine to the whole blood significantly prolonged the time for haemostasis, and addition of ADP to the platelet rich plasma significantly shortened it. It is concluded that red cells are necessary for a normal haemostasis in this model, probably by a combination of a haemodynamic and ADP releasing effect.The fundamental role of platelets in haemostatic plug formation is unquestionable but there are still problems concerning the stimulus for this process to start. Three platelet aggregating substances have been discussed – thrombin, adenosine diphosphate (ADP) and collagen. Evidence speaking in favour of thrombin is, however, very minimal, and the discussion has to be focused on collagen and ADP. In an in vitro system using polyethylene tubings we have shown that "haemostasis" can be obtained without the presence of collagen but against these results can be argued that it is only another in vitro test for platelet aggregation (1).To be able to induce haemostasis in this model, however, the presence of red blood cells is necessary. To further study this problem we have developed a model where haemostatic plug formation can be studied in the isolated rabbit mesentery and we have briefly reported on this (2).Thus, it is possible to perfuse the vessels with whole blood as well as with platelet rich plasma (PRP) and different pharmacological agents of importance.

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