Biocompatible luminescent nanoparticles on the basis of calcium phosphate

2011 ◽  
Vol 1355 ◽  
Author(s):  
Sofia Dembski ◽  
Moritz Milde ◽  
Emeline Dassonneville ◽  
Carsten Gellermann ◽  
Torsten Klockenbring ◽  
...  

ABSTRACTLuminescent lanthanide doped SiO2/Hydroxylapatite (HAp) core/shell nanoparticles (NPs) were synthesized by sol-gel technology. The resulting NPs exhibited an amorphous SiO2 core and a crystalline luminescent shell. The formation of the HAp layer was possible at pH 8.5. The characterization of the resulting NPs was done by transmission electron microscopy, X-ray diffraction analysis, inductively-coupled plasma combined with optical emission spectrometry, and photoluminescence spectroscopy. Additionally, the newly developed SiO2/HAp:Ln3+ core/shell NPs were tested for their biocompatibility, e. g. by an in vitro cell culture based assay.

2012 ◽  
Vol 531 ◽  
pp. 211-214 ◽  
Author(s):  
Jun Jie Jing ◽  
Ji Min Xie ◽  
Hui Ru Qin ◽  
Wen Hua Li ◽  
Ming Mei Zhang

Nickel(Ni)-silver(Ag) core-shell nanoparticles with different shell thickness were synthesized with Ni nanoparticles by liquid phase reduction technique form water solution. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and inductively coupled plasma spectroscopy (ICP). The results showed that the Ni nanoparticles are in sphere shape and the average diameter is 104nm , the nickel(Ni)-silver(Ag) core-shell nanoparticles has good crystallinity and the thinkness of Ag nanoshells could be effectively controlled by changing the concentration of silver nitrate. The product can be used for nickel-based conductive paste preparation because of the surface character of Ag and the magnetic property of Ni


2009 ◽  
Vol 1164 ◽  
Author(s):  
Teng-Kuan Tseng ◽  
Jihun Choi ◽  
Paul H. Holloway

AbstractScintillating nanoparticles with a SiO2 core and a Gd2O3 shell doped with Eu3+ were synthesized with a sol-gel process. Based on transmission electron microscopy (TEM) data, a ∼13 nm Gd2O3 shell was successfully coated onto ∼220 nm mono-dispersed SiO2 nanocores. Eu3+ ions at concentrations of nominally 5 at% exhibited photoluminescent (PL) emission from the SiO2/Gd2O3 nanoparticles after being calcined at 800 0C for 2 h. The SiO2 remained amorphous after calcining, while the Gd2O3 crystallized to a cubic structure. The PL emission was from the 5D0-7F2 transitions of Eu3+ at 609 and 622 nm. Photoluminescence excitation (PLE) data showed that emission from Eu3+ could result from direct excitation, but was dominated by the oxygen to europium charge-transfer band (CTB) between 250 and 280 nm for Eu3+ doped in Gd2O3. The quantum yield (QY) from thin films drop cast from a mixture of 20 mg of calcined nanoparticles in 500 μL of polymethylmethacrylate (PMMA) and excited in the CTB was 20% for SiO2/Gd2O3:Eu3+ core/shell scintillation nanoparticles. Finally, the above core/shell nanoparticles were passivated with a shell of SiO2 to create e.g. SiO2/Gd2O3:Eu3+/SiO2 nanoparticles. The QYs for this nanostructure were lower than unpassivated nanoparticles which was attributed to a weak CTB for the amorphous SiO2 shell and a higher density of interface quenching sites.


Author(s):  
S. Adibnia ◽  
Ali Nemati ◽  
Mohammad Hosseien Fathi ◽  
S. Baghshahi

The main purpose of this study is to prepare and characterize hydroxyapatite (HA)–10%wt bioglass (BG) composite nanopowders and its bioactivity. Composites of hydroxyapatite with synthesized bioglass are prepared at various temperatures. Suitable calcination temperature is chosen by evaluating of the phase composition. X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM) techniques are utilized to characterize the prepared nanopowders. The bioactivity of the prepared composite samples is evaluated in an in vitro study by immersion of samples in simulated body fluid (SBF) for predicted time. Fourier transformed infrared (FTIR) spectroscopy and inductively coupled plasma (ICP) are used for evaluation of apatite formation and the bioactivity properties. Results show that HA-BG composite nanopowders are successfully prepared without any decomposition of hydroxyapatite. The suitable temperature for calcination is 600°C and the particle size of hydroxyapatite is about 40-70 nm. The apatite phase forms after 14 days immersing of the samples in SBF. It could be concluded that this process can be used to synthesize HA-BG composite nanopowders with improved bioactivity which is much needed for hard tissue repair and biomedical applications.


Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 283
Author(s):  
Ta Anh Tuan ◽  
Elena V. Guseva ◽  
Nguyen Anh Tien ◽  
Ho Tan Dat ◽  
Bui Xuan Vuong

The paper focuses on the acid-free hydrothermal process for the synthesis of bioactive glass. The new method avoids the use of harmful acid catalysts, which are usually used in the sol-gel process. On the other hand, the processing time was reduced compared with the sol-gel method. A well-known ternary bioactive glass 58SiO2-33CaO-9P2O5 (wt%), which has been widely synthesized through the sol-gel method, was selected to apply to this new process. Thermal behavior, textural property, phase composition, morphology, and ionic exchange were investigated by thermal analysis, N2 adsorption/desorption, XRD, FTIR, SEM, and inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. The bioactivity and biocompatibility of synthetic bioactive glass were evaluated by in vitro experiments with a simulated body fluid (SBF) solution and cell culture medium. The obtained results confirmed that the acid-free hydrothermal process is one of the ideal methods for preparing ternary bioactive glass.


Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1256
Author(s):  
Maja Welna ◽  
Anna Szymczycha-Madeja ◽  
Pawel Pohl

Commercially bottled birch saps (BSs) were analyzed for several nutrient (Ca, Cu, Fe, Mg, and Zn) and toxic (As, Cd, Ni, and Pb) elements using inductively coupled plasma optical emission spectrometry (ICP OES). The method was validated under the conditions of several sample preparation procedures, including a traditional digestion as well as alternative non-digestion schemes. It was found that the direct analysis of untreated BSs gives the best results, i.e., limits of detection at 0.02–5.8 ng mL−1, precision better than 5%, accuracy from 98.0% to 104.5% and determination of 12 elements in a short time (~1 min per sample). The multi-element analysis of nine commercially available bottled BSs showed that they contained mainly Mg and Ca, small quantities of Mn, Zn, Cu, and Fe, but are free from toxic elements such as As, Cd, Ni, and Pb. Additionally, the nutritional value of BSs was examined using in vitro gastro-intestinal digestion (GID) to determine the bioaccessible fraction of elements. Accordingly, bioaccessibility of nutritious ones (Ca, Cu, Fe, Mg, Zn) was <40%. Drinking daily 1 L of BSs covered <2.5% of recommended dietary intakes (RDIs) of the aforementioned elements. Only the bioaccessibility of Mn highly contributes to its RDI.


2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
J. Varshosaz ◽  
H. Sadeghi-aliabadi ◽  
S. Ghasemi ◽  
B. Behdadfar

Amphiphilic copolymer of folate-conjugated dextran/retinoic acid (FA/DEX-RA) was self-assembled into micelles by direct dissolution method. Magnetic iron oxide nanoparticles (MNPs) coated with oleic acid (OA) were prepared by hydrothermal method and encapsulated within the micelles. Doxorubicin HCl was loaded in the magnetic micelles. The characteristics of the magnetic micelles were determined by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). The crystalline state of OA-coated MNPs and their heat capacity were analyzed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) methods, respectively. The iron content of magnetic micelles was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Bovine serum albumin (BSA) was used to test the protein binding of magnetic micelles. The cytotoxicity of doxorubicin loaded magnetic micelles was studied on MCF-7 and MDA-MB-468 cells using MTT assay and their quantitative cellular uptake by fluorimetry method. TEM results showed the MNPs in the hydrophobic core of the micelles. TGA results confirmed the presence of OA and FA/DEX-RA copolymer on the surface of MNPs and micelles, respectively. The magnetic micelles showed no significant protein bonding and reduced the IC50of the drug to about 10 times lower than the free drug.


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