scholarly journals Development of Composite Scaffolds Based on Cerium Doped-Hydroxyapatite and Natural Gums—Biological and Mechanical Properties

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2389 ◽  
Author(s):  
Marcus Vinicius Beserra dos Santos ◽  
Lorenna Bastos Nogueira Rocha ◽  
Ewerton Gomes Vieira ◽  
Ana Leite Oliveira ◽  
Anderson Oliveira Lobo ◽  
...  

Hydroxyapatite (HAp) is a ceramic material composing the inorganic portion of bones. Ionic substitutions enhance characteristics of HAp, for example, calcium ions (Ca2+) by cerium ions (Ce3+). The use of HAp is potentialized through biopolymers, cashew gum (CG), and gellan gum (GG), since CG/GG is structuring agents in the modeling of structured biocomposites, scaffolds. Ce-HApCG biocomposite was synthesized using a chemical precipitation method. The obtained material was frozen (–20 °C for 24 h), and then vacuum dried for 24 h. The Ce-HApCG was characterized by X-Ray diffractograms (XRD), X-ray photoemission spectra (XPS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS). XRD and FTIR showed that Ce-HApCG was successfully synthesized. XRD showed characteristic peaks at 2θ = 25.87 and 32.05, corresponding to the crystalline planes (0 0 2) and (2 1 1), respectively, while phosphate bands were present at 1050 cm−1 and 1098 cm−1, indicating the success of composite synthesis. FESEM showed pores and incorporated nanostructured granules of Ce-HApCG. The mechanical test identified that Ce-HApCG has a compressive strength similar to the cancellous bone’s strength and some allografts used in surgical procedures. In vitro tests (MTT assay and hemolysis) showed that scaffold was non-toxic and exhibited low hemolytic activity. Thus, the Ce-HApCG has potential for application in bone tissue engineering.

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 180
Author(s):  
Irina Atkinson ◽  
Ana Maria Seciu-Grama ◽  
Oana Catalina Mocioiu ◽  
Ana Maria Mocioiu ◽  
Luminita Predoana ◽  
...  

In recent years, the rising number of bone diseases which affect millions of people worldwide has led to an increased demand for materials with restoring and augmentation properties that can be used in therapies for bone pathologies. In this work, PMMA- MBG composite scaffolds containing ceria (0, 1, 3 mol%) were obtained by the phase separation method. The obtained composite scaffolds were characterized by X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. UV–Vis measurement and EDX analysis confirmed the presence of cerium ions in the composite scaffolds. Evaluation of the in-vitro biocompatibility using MTT assay showed that composite scaffold containing 1 mol% of ceria presented higher viability than control cells (100%) for concentrations ranging between 5 and 50% after 96 h of incubation.


2017 ◽  
pp. 106-115
Author(s):  
Isnaya Khamida Zulfah ◽  
Hari Sutrisno

Titanium dioksida (TiO2)merupakan semikonduktor yang memiliki fungsi sebagai fotokatalis, sel surya, anti bakteri, anti polutan, dan anti buram. Salah satu cara untuk meningkatkan aktifitas fungsional  TiO2dengan menggeser daerah aktifitas atau energi celah pita (Eg) dari sinar ultra violet (UV) ke daerah sinar tampak melalui penambahan zat pensensitif TiO2.Pada penelitian ini, perak klorida (AgCl) digunakan sebagai zat pensensitif TiO2. Tujuan penelitian ini untuk mengetahui pengaruh variasi perbandingan mol awal [Ti8O12(H2O)24]8.Cl8.HCl.7H2O dengan AgNO3 terhadap sifat-sifat fisik TiO2 tersensitifkan AgCl (TiO2@AgCl) yang disintesis dengan metode pengendapan basah dalam suasana asam. Variasi perbandingan awal yang digunakan yaitu perbandingan mol [Ti8O12(H2O)24]8.Cl8.HCl.7H2O :mol AgNO3sebesar 1:9, 1:10, 1:11, 1:12, dan 1:13yang dilarutkan dalam pelarut etanol (total pelarut 37.5 mL). Sampel padat TiO2@AgCl dihasilkan dengan metode pengendapan basah dalam kondisi asam melalui pengontrolan asam HNO3 pada pH~1. Sampel dihasilkan dari penguapan filtrat yang  bebas dari endapan AgCl, hingga volume yang didapat setengah dari volume awal. Sampel TiO2@AgCl dikarakterisasi dengan berbagai instrumen: Difraktometer Sinar-X (XRD),Scanning Electron Microscopy-Electron Dispersive X-Ray Analyzer (SEM-EDAX), dan Spektrofotometer UV-Vis Diffuse Reflectance. Hasil penelitian menunjukkan semua sampel TiO2@AgCl berisi 1 fasa nanopartikel (nanokristalit) TiO2 dan 3 fasa kristal yaitu rutil, anatas, dan AgCl.TiO2@AgCl memiliki bentuk morfologi berupa mikrosferik dengan ukuran berkisar 0.5-1 μm. Berdasarkan hasil analisisdengan spektrofotometer UV-Vis Diffuse Reflectance menunjukkan semua sampel TiO2@AgCl mengabsorbsi sinar ultra violet (UV) dengan Eg sebesar 2.87-3.89 eV, dan sinar tampak dengan Eg sebesar 1.60-2.40 eV. Titanium dioxide (TiO2) is a semiconductor that can be applied in the field of photocatalyst, solar cell, anti-bacterial, anti-pollutants, and anti-fogging. The functional activity of TiO2 can be increased by shifting the activity area from ultraviolet (UV) to visible through the addition of sensitizer. In this research, silver chloride (AgCl) was used as a sensitizer The objective of the research is to study the effect of the initial mole comparison of [Ti8O12(H2O)24]8.Cl8.HCl.7H2O and AgNO3on the physical properties of AgCl-sensitized TiO2(TiO2@AgCl). All TiO2@AgCl were synthesized using the wet chemical precipitation method under acidic conditions by the addition of a concentrated HNO3 with pH ~ 1. The initial comparison variation used was the mole ratio of [Ti8O12(H2O)24]8.Cl8.HCl.7H2O  : AgNO3 of 1: 9, 1:10, 1:11, 1:12, and 1:13. Each of these materials was dissolved in ethanol to 37.5 ml. All samples were produced from evaporation of filtrate free from AgCl precipitate, until the volume obtained half of the initial volume. The solid samples were characterized using X-Ray Diffractometer (XRD), Scanning Electron Microscopy-Electron Dispersive X-Ray Analyzer (SEM-EDAX), and UV-Vis spectrophotometer Diffuse Reflectance.The results showed that all samples of TiO2@AgCl consisted of 1 phase of TiO2-nanoparticles and 3 phases of rutile, anatase and AgCl crystals. The morphology of TiO2@AgCl is microspheric with a size ranging from 0.5-1 μm. Based on the results of the analysis with the UV-Vis spectrophotometer Diffuse Reflectance showed that all samples of TiO2@AgCl absorb ultraviolet (UV) rays with bandgap (Eg) ranging from 2.87 to 3.89 eV, and the visible light with Eg ranges from 1.60 to 2.40 eV.


2011 ◽  
Vol 356-360 ◽  
pp. 2583-2586
Author(s):  
Li Xue ◽  
Ying Zhi Cheng ◽  
Xiu Yu Sun

Using cadmium acetate and sodium sulfuret as Cd and S sources, CdS samples were synthesized by chemical precipitation method. The conditions of supersaturation and aging time had been investigated, which could influence the activity of CdS for photocatalytic degrading methyl orange. The products were characterized by X-ray powder diffraction and field emission scanning electron microscopy. The CdS samples synthesized under low supersaturation showed better photocatalytic activities. A phase transformation of hexagonal CdS to cubic CdS was observed when CdS precipitation aging and the presence of proper amount of hexagonal CdS should improve the photocatalytic performance of cubic CdS.


Author(s):  
A.O. Synytsia ◽  
◽  
A.P. Iatsenko ◽  
O. Ye. Sych ◽  
T.Ye. Babutina ◽  
...  

Magnetite powder (FeO·Fe2O3 or Fe3O4) is obtained by the chemical precipitation method, using FeCl3·6H2O and FeCl2·4H2O as a starting materials in the presence of hydrazine N2H4 at a temperature of 80 °C. X-ray diffraction analysis, infrared spectroscopy, and scanning electron microscopy are used for the study of the phase composition and morphology of the synthesized powder. Its specific surface area and magnetic properties such as, in particular, the specific saturation magnetization, coercive force and residual induction are investigated. It is established that the composition of the synthesized powder is represented by magnetite as the main phase with a small admixture of hematite. It is shown that the particles of the obtained magnetite have sizes of 33-84 nm and tend to the agglomeration. The prepared powder has superparamagnetic properties (specific magnetization — 35 A · m2/kg, coercive force — 0.24 kA/m, residual induction — 0.009 T) and is promising for the biocomposite creation.


Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.


2018 ◽  
Vol 69 (7) ◽  
pp. 1714-1717
Author(s):  
Roxana Ionela Vasluianu ◽  
Norina Consuela Forna ◽  
Elena Raluca Baciu ◽  
Mirela Zaltariov ◽  
Lavinia Vasiliu ◽  
...  

The anti-erosion effect of fluoride on the enamel surface was investigated by ATR-FTIR, SEM and EDX techniques. Four extracted teeth (two incisors and two premolars) were initially bleached with carabamide peroxide and etched with ortho-phosphoric acid then fluoride treatment was applied. Significant differences in enamel composition and morphology were observed providing the effect of fluoride application in remineralization of teeth. Infrared spectroscopy was employed to probe the changes in enamel structure. Scanning electron microscopy/energy dispersive X-ray spectroscopy analysis revealed higher content in F of teeth enamel. Morphology changes revealed a re-mineralization of enamel surface after the treatment with fluoride gel.


2014 ◽  
Vol 608 ◽  
pp. 224-229 ◽  
Author(s):  
Potjanaporn Chaengchawi ◽  
Karn Serivalsatit ◽  
Pornapa Sujaridworakun

A visible-light responsive CdS/ZnO nanocomposite photocatalyst was successfully synthesized by precipitation of CdS nanoparticles, using Cd (NO3)2 and Na2S as starting materials, on ZnO nanoparticles and then calcined at 400°C for 2 hours. The effects of the mole ratio of CdS and ZnO in the composites on their phase, morphology, and surface area were investigated by X-ray Diffraction (XRD), scanning electron microscope (SEM), Brunauer Emmett Teller method (BET), respectively. The photocatalytic degradation of methylene blue solution in the presence of composite products under visible-light irradiation was investigated. The results showed that the mole ratio of CdS and ZnO played a significant role on photocatalytic performance. The highest photocatalytic activity was obtained from the CdS/ZnO nanocomposite with mole ratio of 1:4, which is higher than that of pure CdS and pure ZnO.


2015 ◽  
Vol 638 ◽  
pp. 67-72
Author(s):  
Ana Maria Salantiu ◽  
Florin Popa ◽  
Petru Pascuta ◽  
Olga Soritau ◽  
Noemi Dirzu ◽  
...  

This work aims to investigate the influence of surface conditioning of porous Ti for enhancing its biological activity, as assessed by in vitro stem cell testing. Porous Ti samples with an average porosity of 32% were processed by Powder Metallurgy with dextrin as a space holder. The samples were subjected to H2O2 treatment to form an enhanced TiO2 film, followed by a heat treatment at 400°C and 600°C aiming to the crystallization of the as-formed amorphous titanium oxide. Samples characterization was performed by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-Ray Diffraction (XRD). The treated surfaces revealed to be made of both anatase and rutile TiO2, with groove–shaped structure and cracks on the surface of the TiO2 film. The intrinsic biocompatibility of the chemically modified porous Ti surfaces was assessed in vitro. In our cell culture tests, stem cells were found to attach and proliferate better on the chemically treated Ti surfaces compared to the control untreated Ti surfaces.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Kexin Fang ◽  
Lei Shi ◽  
Lishuang Cui ◽  
Chunwei Shi ◽  
Weiwei Si

A series of CoFe2O4/Bi12O17Cl2 (CFO/Bi12O17Cl2) nanocomposites have been prepared by chemical precipitation method. The result of X-ray diffraction showed that CFO/Bi12O17Cl2 composites had high crystallinity. It was found that CoFe2O4...


2011 ◽  
Vol 306-307 ◽  
pp. 410-415
Author(s):  
Li Sun ◽  
Fu Tian Liu ◽  
Qi Hui Jiang ◽  
Xiu Xiu Chen ◽  
Ping Yang

Core/shell type nanoparticles with an average diameter of 20nm were synthesized by chemical precipitation method. Firstly, Monodisperse Fe3O4 nanoparticles were synthesized by solvethermal method. FeSO4ž7H2O and NaBH4 were respectively dissolved in distilled water, then moderated Fe3O4 particles and surfactant(PVP) were ultrasonic dispersed into the FeSO4ž7H2O solution. The resulting solution was stirred 2 h at room temperature. Fe could be deposited on the surface of monodispersed Fe3O4 nanoparticles to form core-shell particles. The particles were characterized by using various experimental techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), AGM and DTA. The results suggest that the saturation magnetization of the nanocomposites is 100 emu/g. The composition of the samples show monodisperse and the sides of the core/shell nanoparticles are 20-30nm. It is noted that the formation of Fe3O4/Fe nanocomposites magnetite nanoparticles possess superparamagnetic property.


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