scholarly journals Preparation, characterization and in vitro bioactivity of polyvinyl alcohol-hydroxyapatite biphasique membranes

2013 ◽  
Vol 6 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Zuzana Balgová ◽  
Martin Palou ◽  
Jaromír Wasserbauer ◽  
Gabriela Lutišanová ◽  
Jana Kozánkováb

Abstract Six membranes of polyvinyl alcohol (PVA) with various weight percent - 0 %, 10 %, 20 %, 30 %, 40 % and 50 % of hydroxyapatite (HA) were prepared. Fourier Transform Infrared (FTIR) spectroscopy was used to identify the different functional groups in membrane composites. The surface morphology was examined through scanning electron microscope. The in vitro bioactivity tests in Simulated Blood Fluid (SBF) have been performed up to 28 days, especially for membrane containing 50 wt. % HA. SEM was used to characterize surface microstructure of biocomposite membranes before and after immersion in SBF. It was observed the formation of clusters within membranes with increasing amount of HA particles due to hydrogen bond and also the agglomeration and crystal growth of HA particles during drying of membranes. The bioactivity was found increasing with time immersion of biocomposite materials in SBF solution.

2011 ◽  
Vol 493-494 ◽  
pp. 447-452
Author(s):  
George Theodorou ◽  
Ourania Menti Goudouri ◽  
Lambrini Papadopoulou ◽  
Nikolaos Kantiranis ◽  
Subramaniam Yugeswaran ◽  
...  

The clinical use of plasma-sprayed hydroxyapatite (HA) coatings on metal implants has been widely investigated as the HA coating can achieve the firm and direct biological fixation with the surrounding bone tissue. It is shown in previous studies that the mechanical properties of HA coatings are improved by the addition of ZrO2 particles during the deposition of the coating on the substrate. Subsequently, the cohesive and adhesive strengths of plasma-sprayed hydroxyapatite (HA) coatings were strengthened by the ZrO2 particles addition as a reinforcing agent in the HA coating (HA+ZrO2 composite coating). The aim of the present work is to investigate and evaluate the in vitro bioactivity assessment of HA and HA/ZrO2 coatings, on stainless steel substrate, soaked in c-SBF, in order to study and compare their biological responses. The coatings were produced using vapor plasma spraying (VPS). The characterization of the surface of the coatings before and after soaking in SBF solution was performed using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-ray Diffraction analysis (XRD). All samples were smoothed before insertion in the medium and the in vitro bioactivity of all coating samples was tested in conventional Simulated Body Fluid (c-SBF) solution for various immersion times.


2013 ◽  
Vol 11 (9) ◽  
pp. 1439-1446 ◽  
Author(s):  
Lachezar Radev ◽  
Darina Zheleva ◽  
Irena Michailova

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.


2013 ◽  
Vol 11 (9) ◽  
pp. 1403-1411 ◽  
Author(s):  
Zuzana Balgová ◽  
Martin Palou ◽  
Jaromír Wasserbauer ◽  
Jana Kozánková

AbstractAbstract A series of poly(vinyl alcohol) membranes reinforced with hydroxyapatite in various weight percent — 0%, 10%, 20%, 30%, 40% and 50% were prepared. Hydroxyapatite was prepared by a sol-gel procedure using diammonium hydrogen phosphate and calcium nitrate tetrahydrate as starting materials in an alkaline aqueous environment and then mixed with a solution of poly(vinyl alcohol), which was prepared by dissolving it in water at 85°C. The different mixtures were cast in a mould and evaporated for 7 days at a temperature of 30°C to obtain 1 mm thin membranes. FTIR spectroscopy was used to identify the different functional groups in the composites. The surface morphology was examined using a scanning electron microscope. In vitro bioactivity tests in Simulated Blood Fluid were performed for up to 28 days, especially for the membrane containing 50 wt.% HA. SEM was used to characterise the surface microstructure of biocomposite membranes before and after soaking in SBF. It was observed that the formation of clusters in membranes increases with increasing amount of HA. The clusters are formed due to agglomeration and crystal growth of HA particles during drying of the membranes. The in vitro bioactivity was found to increase with soaking time of biocomposite materials in simulated blood fluid. Graphical abstract


Mechanik ◽  
2017 ◽  
Vol 90 (1) ◽  
pp. 48-49
Author(s):  
Bartłomiej Wysocki ◽  
Agata Supeł ◽  
Tomasz Durejko ◽  
Wojciech Święszkowski

Laser Engineering Net Shaping (LENS), which is one of the 3DP techniques, allows for both, the fabrication and the modification of surface layer of the product previously prepared. In the current work, using LENS technique, highly developed bioactive layers, were prepared on the surface of the hip prosthesis. Both, fabricated layers and hip prosthesis, were fabricated from Ti-6Al-4V alloy. The tests were carried out using Simulated Body Fluid (SBF) solution, having all the necessary components on the inorganic human blood plasma. Scanning Electron Microscopy (SEM) showed the nucleation of calcium phosphates even after 2 days of immersion. Based on the results obtained in SEM and EDX tests, it can be claimed that Ti-6Al-4V layers manufactured using LENS technique exhibit high bioactivity in in-vitro, in the SBF solution.


2008 ◽  
Vol 47-50 ◽  
pp. 1351-1354 ◽  
Author(s):  
Yan Bao Li ◽  
Qing Lin ◽  
Jun Sheng Chen ◽  
Xiang Hui Lan ◽  
Chun Hua Lu ◽  
...  

The bioactivity of potassium titanate whiskers (PTW) was evaluated by soaking in simulated body fluids (SBF, Kokubo solution). At first, PTW was chemically treated by 1 M HCl and 1 M NaOH solutions at 60 oC for 48 h, respectively. Then PTW before and after treated were soaked in SBF solution and cultured at 37 oC for different times. The apatite deposit on PTW was examined by FTIR and SEM/EDX. The results showed that there was not apatite deposit on the raw PTW even after soaked for 14 days while apatite appeared on the treated PTW after soaked for only 7 days. This implies that treatment by HCl/NaOH solutions can improve the in vitro bioactivity of PTW. The possible mechanism is that more Ti–OH groups occur after treatment and induce Ca2+ and PO4 3- aggregate and accelerate to deposit of apatite. The bioactive PTW with good biocompatibility is a potential candidate as reinforcing agent to improve the mechanical properties of calcium phosphate ceramics or cements.


2018 ◽  
Vol 69 (6) ◽  
pp. 1416-1418
Author(s):  
Alexandru Szabo ◽  
Ilare Bordeasu ◽  
Ion Dragos Utu ◽  
Ion Mitelea

Hydroxyapatite (HA) is a very common material used for biomedical applications. Usually, in order to improve its poor mechanical properties is combined or coated with other high-strength materials.The present paper reports the manufacturing and the biocompatibility behaviour of two different biocomposite coatings consisting of alumina (Al2O3) and hydroxyapatite (HA) using the high velocity oxygen fuel (HVOF) spraying method which were deposited onto the surface of a commercially pure titanium substrate. The biological properties of the Al2O3-HA materials were evaluated by in vitro studies. The morphology of the coatings before and after their immersing in the simulated body fluid (SBF) solution was characterized by scanning electron microscopy (SEM). The results showed an important germination of the biologic hydroxyapatite crystallite on the surface of both coatings.


Author(s):  
Megha Mahabole ◽  
Manjushree Bahir ◽  
Rajendra Khairnar

Abstract: In this study, in-vitro bioactivity of manganese blended hydroxyapatite (Mn-HAp) pellets is carried out using simulated body fluid (SBF) solution. The incubated Mn-HAp samples are characterized by XRD, FTIR and SEM/EDAX. Dielectric and photoluminescence properties of Mn-HAp samples are studied as a function of incubation period in SBF. XRD profiles show that hexagonal apatite structure remains intact after partial replacement of calcium ions by manganese ions and even after incubation. The change in absorption due to phosphate group, depicted in FTIR spectra, for incubated samples confirms growth of apatite on Mn-HAp surface. SEM/ EDAX studies suggest that Mn-HAp surface promotes the growth of apatite without changing its structure due to apatite nucleation and growth on the surface of Mn-HAp. The value of dielectric constant of Mn-HAp increases after incubation. Increase in period of immersion in m-SBF leads to decrease in dielectric constant of manganese exchanged hydroxyapatite. The photoluminescence (PL) study reveals that the Mn-HAp can be used stable and efficient blue luminescent material.


2021 ◽  
Vol 3 ◽  
Author(s):  
Elena della Valle ◽  
Beomseo Koo ◽  
Paras R. Patel ◽  
Quentin Whitsitt ◽  
Erin K. Purcell ◽  
...  

Ultrasmall microelectrode arrays have the potential to improve the spatial resolution of microstimulation. Carbon fiber (CF) microelectrodes with cross-sections of less than 8 μm have been demonstrated to penetrate cortical tissue and evoke minimal scarring in chronic implant tests. In this study, we investigate the stability and performance of neural stimulation electrodes comprised of electrodeposited platinum-iridium (PtIr) on carbon fibers. We conducted pulse testing and characterized charge injection in vitro and recorded voltage transients in vitro and in vivo. Standard electrochemical measurements (impedance spectroscopy and cyclic voltammetry) and visual inspection (scanning electron microscopy) were used to assess changes due to pulsing. Similar to other studies, the application of pulses caused a decrease in impedance and a reduction in voltage transients, but analysis of the impedance data suggests that these changes are due to surface modification and not permanent changes to the electrode. Comparison of scanning electron microscope images before and after pulse testing confirmed electrode stability.


2006 ◽  
Vol 514-516 ◽  
pp. 985-989
Author(s):  
B.J.M. Leite Ferreira ◽  
M.G.G.M. Duarte ◽  
M. Helena Gil ◽  
Rui N. Correia ◽  
J. Román ◽  
...  

Two materials with potential application in bone tissue repair have been developed: 1) a non-biodegradable composite based in a new methacrylic-co-acrylic matrix; and 2) a biodegradable composite based in a chitosan (Ch) matrix. Both matrices were reinforced with glass-ceramic particles of composition (mol%) 70 SiO2 – 30 CaO. The in vitro bioactivity of composites was assessed by soaking in simulated body fluid (SBF) for periods of up to 7 days at 37º C. X-ray diffraction (XRD) and scanning electron microscopy coupled with X-ray energy dispersive spectroscopy (SEM-EDS) were used for deposit identification after different soaking periods. Calcium phosphate particulate deposits were detected after 3 days of immersion, followed by growth and maturation towards apatite.


2011 ◽  
Vol 492 ◽  
pp. 107-111 ◽  
Author(s):  
Yuan Fu Yi ◽  
Ning Wen ◽  
Xiao Ling Wang ◽  
Long Quan Shao ◽  
Chen Wang

The purpose of this study was to investigate the influence of in vitro low-temperature degradation (LTD) treatments on the structural stability and mechanical properties of two commercial Y-TZP ceramics candidate for dental application. TZ-3YS and TZ-3YS-E powder were chosen because of there minor differences of chemical composition. The two powders were compacted at 200MPa using cold isostatic pressure, and densely sintered at 1500°C and 1450°C for 2hr respectively. Two methods of in vitro LTD treatments were performed, the first is to autoclave specimens in steam at 134°C, 2bar, for 1 to 5hr; the second is to immerse specimens into 4% acetic acid at 80°C for 168 hr. XRD was used to identify the crystal phases, flexural strength were tested according to ISO 6872 standard, surface microstructure was evaluated by Atomic Force Microscopy (AFM). Results show that the relative content of monoclinic phase was increasing with the prolonged aging time, the TZ-3YS was more sensitive to LTD compared with TZ-3YS-E. LTD tests did not necessary reduce the flexural strength of Y-TZP ceramics, the nucleation and growth of monoclinic phase were detected by AFM, and the surface microstructure induced by LTD was not identical between the two Y-TZP ceramics. AFM was a sensitive method to evaluate the transformation of Y-TZP ceramics. To choose appropriate Y-TZP powder for dental application, it is mandatory to examine the microstructure before and after LTD.


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