scholarly journals Collagen/silicocarnotite composites, cross-linked with chondroitin sulphate: In vitro bioactivity

2011 ◽  
Vol 5 (3) ◽  
pp. 161-170 ◽  
Author(s):  
Lachezar Radev ◽  
Vladimir Hristov ◽  
Irena Michailova ◽  
Maria Fernandes ◽  
Isabel Salvado
Keyword(s):  
Inductively Coupled Plasma ◽  
Chondroitin Sulphate ◽  
Atomic Emission ◽  
Red Shift ◽  
Structure Evolution ◽  
In Vitro Test ◽  
In Vitro Bioactivity ◽  
Before And After ◽  
Vitro Test

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 HPO4 2- 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.

scholarly journals Organic/Inorganic bioactive materials Part III: in vitro bioactivity of gelatin/silicocarnotite hybrids

2009 ◽  
Vol 7 (4) ◽  
pp. 721-730 ◽  
Author(s):  
Lachezar Radev ◽  
Maria Fernandes ◽  
Isabel Salvado ◽  
Daniela Kovacheva
Keyword(s):  
Calcium Phosphate ◽  
Hybrid Materials ◽  
Calcium Phosphates ◽  
Ceramic Powder ◽  
Structure Evolution ◽  
In Vitro Test ◽  
In Vitro Bioactivity ◽  
Bioactive Materials ◽  
Vitro Test

AbstractIn this work we present our experimental results on synthesis, structure evolution and in vitro bioactivity assessment of new gelatin/silicocarnotite hybrid materials. The hybrids were obtained by diluting gelatin (G) and silicocarnotite (S) ceramic powder with G:S ratios of 75:25 and 25:75 wt.% in hot (40°C) water. The hybrids were characterized using XRD, FTIR, SEM/EDS and XPS. FTIR depicts that the “red shift” of amide I and COO− could be attributed to the fact that the gelatin prefers to chelate Ca2+ from S. The growth of calcium phosphates on the surface of the hybrids synthesized and then immersed in 1.5 SBF for 3 days was studied by using of FTIR, XRD and SEM/EDS. According to FTIR results, after an immersion of 3 days, A and B-type CO3HA can be observed on the surface. XRD results indicate the presence of hydroxyapatite with well defined crystallinity. SEM/EDS of the precipitated layers show the presence of CO3HA and amorphous calcium phosphate on the surface of samples with different G/S content when immersed in 1.5 SBF. XPS of the G/S hybrid with 25:75 wt.% proved the presence of Ca-deficient hydroxyapatite after an in vitro test for 3 days.

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.

scholarly journals In vitro bioactivity of glass-ceramic/fibroin composites

2017 ◽  
Vol 11 (2) ◽  
pp. 136-146 ◽  
Author(s):  
Lachezar Radev ◽  
Irena Michailova ◽  
Silviya Stateva ◽  
Diana Zaimova ◽  
Hristo Georgiev ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Atomic Emission ◽  
Xrd Analysis ◽  
In Vitro Tests ◽  
In Vitro Bioactivity ◽  
X Ray ◽  
Before And After ◽  
Static Conditions

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.

scholarly journals FLUORIDE ABSORBED ON EXTRACTED TEETH AFTER IMMERSING IN FLUORIDE TABLET, FLUOCOL SOLUTION AND FLUORIDE DENTRIFICE (IN VITRO TEST)

2016 ◽  
Vol 3 (1) ◽  
pp. 42
Author(s):  
Diyah Fatmasari ◽  
Lanny Sunarjo
Keyword(s):  
Research Result ◽  
Fluoride Concentration ◽  
Group Iv ◽  
In Vitro Test ◽  
Significance Level ◽  
Group Iii ◽  
Group I ◽  
Before And After ◽  
Vitro Test

Background: The role of fluoride in preventing tooth decay both for children and adult has been acknowledged internationally. There are several types of fluoride modalities either topically or systemic way. In Indonesia the modalities used to apply are fluoride tablet, fluocol solution and fluoride containing toothpaste. The purpose of this research is to find the effectiveness of fluoride modalities.Method: The study design was quasy experimental with 40 extracted teeth (Premolar teeth). The teeth divided into four groups D group I soaked on tablet fluor, Group II ; soaked on fluocol solution, Group III soaked on fluoride tooth paste and group IV soaked on Mill J (Aquadest/ Control solution). Fluoride concentration before and after soaking was determined using Spectrophotometer UV-Vis. Fluoride absorption was determined by the reduction of fluoride concentration after soaking.Result: Research result shown that the highest fluoride absorption was on soaking in fluoride tablet, followed by soaking on fluocol and tooth paste (mean fluoride absorption was 0,32; 0,08 and 0,04 ppm). Anova test shown significance level was 0,000.Conclusion: there were a significance of fluoride absorption on soaking in tablet fluoride, fluocol solution and toothpaste. The mechanism of fluoride regimens shown different fluoride absorption.

scholarly journals In vitro Antimicrobial Effects of Virus Block, Which Contains Multiple Polyoxometalate Compounds, and Hygienic Effects of Virus Block-Supplemented Moist Hand Towels

Pharmacology ◽  
2019 ◽  
Vol 104 (1-2) ◽  
pp. 98-112 ◽  
Author(s):  
Katsuaki Dan ◽  
Naohiro Katoh ◽  
Takaaki Matsuoka ◽  
Katsuyuki Fujinami
Keyword(s):  
Inductively Coupled Plasma ◽  
Metal Ion ◽  
Bacterial Flora ◽  
Atomic Emission ◽  
Time Dependent ◽  
Antimicrobial Effects ◽  
Inductively Coupled ◽  
Before And After ◽  
Normal Bacterial Flora

Background: Historical evidence has verified the multifaceted antiviral efficacy of polyoxometalates (PMs). Methods: We carried out a study to investigate the antimicrobial effects of each of the 5 substances comprising virus block (VB): 3 PMs that have antibacterial and antiviral activity, an antibiotic agent, and an antibacterial agent. We also investigated the effectiveness of the addition of VB to moist hand towels in a study involving 120 volunteers. The time-dependent changes in metal ion concentrations in aqueous VB solution were analyzed using inductively coupled plasma atomic emission spectroscopy. Results: The metal elements in the aqueous VB solution remained stable for 12 weeks without undergoing time-dependent changes. Discussion: Further investigations were performed to study hand hygiene using moist hand towels in daily life settings. To this end, 120 volunteers provided 240 specimens that were used to investigate the presence of antibacterial compounds on the volunteers’ hands before and after hand towel use. An aliquot of each specimen was suspended in phosphate-buffered saline and plated on agar media, and the number of colonies formed was counted. Normal bacterial flora found on the hands of the volunteers was investigated before and after the use of 4 different moist hand towels. Conclusions: The effects of VB and PMs were superior to those of commercial moist hand towels, indicating that effective data were obtained that may be useful for the practical application of the tested items.

Preparation of the Nano-Hydroxyapatite/Chitosan/Konjac Glucomannan Composite as a Novel Degradable Drug Delivery System

2008 ◽  
Vol 569 ◽  
pp. 357-360
Author(s):  
Gang Zhou ◽  
Yu Bao Li ◽  
Soo Wohn Lee
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Konjac Glucomannan ◽  
In Vitro Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After ◽  
Vitro Test

Nano-hydroxyapatite (n-HA)/chitosan (CS)/konjac glucomannan (KGM) composite was prepared by integrating composition and molding. Then, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the physical, chemical and degradable properties of the composite before and after in simulated body fluid (SBF). Moreover, study in vitro test for drug delivery revealed that the amount of released pentoxifylline (1-[5-oxohexyl]-3,7-dimethylxanthine)(PTX) reached a plateau and equaled 80% of the drug loaded in an implant. The newly develop n-HA/CS/KGM composite may serve as a good degradable biomaterial for implantable drug delivery system (IDDS) in bone tissue engineering.

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 Organic/inorganic bioactive materials part IV: In vitro assessment of bioactivity of gelatin-calcium phosphate silicate/wollastonite hybrids

2010 ◽  
Vol 8 (2) ◽  
pp. 278-284 ◽  
Author(s):  
Lachezar Radev ◽  
Vladimir Hristov ◽  
Maria Fernandes ◽  
Isabel Salvado
Keyword(s):  
Calcium Phosphate ◽  
Hybrid Materials ◽  
Red Shift ◽  
In Vitro Test ◽  
Bioactive Materials ◽  
Phosphate Silicate ◽  
Vitro Test ◽  
In Vitro Assessment

AbstractBiohybrids consisting of gelatin (G) and calcium phosphate silicate/wollastonite (CPS/W) have not been prepared so far. In this work our results are focused on the possibility of obtaining G-CPS/W bioactive hybrids in vitro. XRD, FTIR, SEM/EDS techniques were employed to characterize the synthesized hybrid materials. FTIR shows that before immersion in 1.5 SBF the “red shift” of COO- band for pure G is observed. The presence of this bond could be attributed to the formation of COO-Ca2+ via non-biomimetic route. After immersion in 1.5 SBF, FTIR shows the presence of A- and B-type carbonate containing hydroxyapatite (A/B-CO3HA). ESD and FTIR show that small amount of calcite (CaCO3) are present after in vitro test in 1.5 SBF for 3 days. XRD reveals that CO3HA and small amounts of CaCO3 can be detected after in vitro test. SEM results obtained for immersed samples show that hydroxyapatite (HA) particles fully covered the surface of the hybrids by a layer composed of spherulites. At higher magnification, very small elongated crystallites could be observed.

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).

scholarly journals An S.E.M. evaluation of carbon-fiber post and core resin interface, before and after an in vitro test

2010 ◽  
Vol 3 (1) ◽  
Author(s):  
Adriana Ferreira Quintas ◽  
Maximiliano Piero Neisser ◽  
Marco Antonio Bottino
Keyword(s):  
Carbon Fiber ◽  
In Vitro Test ◽  
Fiber Post ◽  
Before And After ◽  
Vitro Test ◽  
Post And Core
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