scholarly journals Comparison of the Effect of the Amino Acids on Spontaneous Formation and Transformation of Calcium Phosphates

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 792
Author(s):  
Ina Erceg ◽  
Nadica Maltar-Strmečki ◽  
Darija Domazet Jurašin ◽  
Vida Strasser ◽  
Marija Ćurlin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Calcium Phosphate ◽  
Calcium Phosphates ◽  
Functional Materials ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Transmission Electron ◽  
Electron Paramagnetic Spectroscopy

Understanding the effect that specific amino acids (AA) exert on calcium phosphate (CaPs) formation is proposed as a way of providing deeper insight into CaPs’ biomineralization and enabling the design of tailored-made additives for the synthesis of functional materials. Despite a number of investigations, the role of specific AA is still unclear, mostly because markedly different experimental conditions have been employed in different studies. The aim of this paper was to compare the influence of different classes of amino acids, charged (aspartic acid, Asp and lysine, Lys), polar (asparagine, Asn and serine, Ser) and non-polar (phenylalanine, Phe) on CaPs formation and transformation in conditions similar to physiological conditions. The precipitation process was followed potentiometrically, while Fourier transform infrared spectroscopy, powder X-ray diffraction, electron paramagnetic spectroscopy (EPR), scanning and transmission electron microscopy were used for the characterization of precipitates. Except for Phe, all investigated AAs inhibited amorphous calcium phosphate (ACP) transformation, with Ser being the most efficient inhibitor. In all systems, ACP transformed in calcium-deficient hydroxyapatite (CaDHA). However, the size of crystalline domains was affected, as well as CaDHA morphology. In EPR spectra, the contribution of different radical species with different proportions in diverse surroundings, depending on the type of AA present, was observed. The obtained results are of interest for the preparation of functionalized CaPs’, as well as for the understanding of their formation in vivo.

scholarly journals Biphasic Calcium Phosphate Biomaterials: Stem Cell-Derived Osteoinduction or In Vivo Osteoconduction? Novel Insights in Maxillary Sinus Augmentation by Advanced Imaging

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2159
Author(s):  
Giovanna Iezzi ◽  
Antonio Scarano ◽  
Luca Valbonetti ◽  
Serena Mazzoni ◽  
Michele Furlani ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Maxillary Sinus ◽  
Biphasic Calcium Phosphate ◽  
Calcium Phosphates ◽  
Three Dimensional ◽  
Sinus Augmentation ◽  
Native Bone ◽  
Maxillary Sinus Augmentation ◽  
Posterior Maxilla

Maxillary sinus augmentation is often necessary prior to implantology procedure, in particular in cases of atrophic posterior maxilla. In this context, bone substitute biomaterials made of biphasic calcium phosphates, produced by three-dimensional additive manufacturing were shown to be highly biocompatible with an efficient osteoconductivity, especially when combined with cell-based tissue engineering. Thus, in the present research, osteoinduction and osteoconduction properties of biphasic calcium-phosphate constructs made by direct rapid prototyping and engineered with ovine-derived amniotic epithelial cells or amniotic fluid cells were evaluated. More in details, this preclinical study was performed using adult sheep targeted to receive scaffold alone (CTR), oAFSMC, or oAEC engineered constructs. The grafted sinuses were explanted at 90 days and a cross-linked experimental approach based on Synchrotron Radiation microCT and histology analysis was performed on the complete set of samples. The study, performed taking into account the distance from native surrounding bone, demonstrated that no significant differences occurred in bone regeneration between oAEC-, oAFMSC-cultured, and Ctr samples and that there was a predominant action of the osteoconduction versus the stem cells osteo-induction. Indeed, it was proven that the newly formed bone amount and distribution decreased from the side of contact scaffold/native bone toward the bulk of the scaffold itself, with almost constant values of morphometric descriptors in volumes more than 1 mm from the border.

A Comparative Study of Bioceramics In Vitro and In Vivo

2005 ◽  
Vol 284-286 ◽  
pp. 11-14 ◽  
Author(s):  
Yang Leng ◽  
Ren Long Xin ◽  
Ji Yong Chen
Keyword(s):  
Calcium Phosphates ◽  
Glass Ceramics ◽  
Octacalcium Phosphate ◽  
Rabbit Muscle ◽  
In Vivo Experiments ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Dental Applications

Bioactive calcium phosphate (Ca-P) formation in bioceramics surfaces in simulated body fluid (SBF) and in rabbit muscle sites was investigated. The examined bioceamics included most commonly used bioglass®, A-W glass-ceramics and calcium phosphates in orthopedic and dental applications. The Ca-P cyrstal structures were examined with single crystal diffraction patterns in transmission electron microscopy, which reduced possibility of misidentifying Ca-P phases. The experimental results show that capability of Ca-P formation considerably varied among bioceramics, particularly in vivo. Octacalcium phosphate (OCP) was revealed on the all types of bioceramics in vitro and in vivo experiments. This work leads us to rethink how to evaluate bioactivity of bioceramics and other orthopedic materials which exhibit capability of osteoconduction by forming direct bonding with bone.

scholarly journals Effect of Tetramethylammonium Hydroxide on Nucleation, Surface Modification and Growth of Magnetic Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Ângela L. Andrade ◽  
José D. Fabris ◽  
José D. Ardisson ◽  
Manuel A. Valente ◽  
José M. F. Ferreira
Keyword(s):  
Zeta Potential ◽  
Magnetite Nanoparticles ◽  
Heat Dissipation ◽  
Tetramethylammonium Hydroxide ◽  
Precipitation Method ◽  
Attenuated Total Reflectance ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Transmission Electron ◽  
Magnetite Particles

Nanoparticles of magnetite (Fe3O4) were obtained by reacting ferric chloride with sodium sulphite, through the reduction-precipitation method. The effects of adding tetramethylammonium hydroxide (TMAOH) during or after the precipitation of the iron oxide were studied in an attempt to obtain well-dispersed magnetite nanoparticles. Accordingly, the following experimental conditions were tested: (i) precipitation in absence of TMAOH (sample Mt), (ii) the same as (i) after peptizing with TMAOH (Mt1), (iii) TMAOH added to the reaction mixture during the precipitation of magnetite (Mt2). Analyses with transmission electron microscopy (TEM), X-ray diffraction, Mössbauer spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), zeta potential, and magnetization measurements up to 2.5 T revealed that magnetite was normally formed also in the medium containing TMAOH. The degree of particles agglomeration was monitored with laser diffraction and technique and inspection of TEM images. The relative contributions of Néel and Brownian relaxations on the magnetic heat dissipation were studied by investigating the ability of suspensions of these magnetite nanoparticles to release heat in aqueous and in hydrogel media. Based on ATR-FTIR and zeta potential data, it is suggested that the surfaces of the synthesized magnetite particles treated with TMAOH become coated with (CH3)4N+cations.

scholarly journals Biomass-Derived Activated Carbon as a Catalyst for the Effective Degradation of Rhodamine B dye

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 926
Author(s):  
Shamim Ahmed Hira ◽  
Mohammad Yusuf ◽  
Dicky Annas ◽  
Hu Shi Hui ◽  
Kang Hyun Park
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
High Specific Surface Area ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Transmission Electron

Activated carbon (AC) was fabricated from carrot waste using ZnCl2 as the activating agent and calcined at 700 °C for 2 h in a tube furnace. The as-synthesized AC was characterized using Fourier-transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis; the results revealed that it exhibited a high specific surface area and high porosity. Moreover, this material displayed superior catalytic activity for the degradation of toxic Rhodamine B (RhB) dye. Rate constant for the degradation of RhB was ascertained at different experimental conditions. Lastly, we used the Arrhenius equation and determined that the activation energy for the decomposition of RhB using AC was approximately 35.9 kJ mol−1, which was very low. Hopefully it will create a great platform for the degradation of other toxic dye in near future.

Effect of free fatty acids on blood amino acid levels in human

1986 ◽  
Vol 250 (6) ◽  
pp. E686-E694 ◽  
Author(s):  
E. Ferrannini ◽  
E. J. Barrett ◽  
S. Bevilacqua ◽  
R. Jacob ◽  
M. Walesky ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Insulin ◽  
Plasma Free Fatty Acid ◽  
Blood Levels ◽  
Experimental Conditions ◽  
Lipid Infusion ◽  
Amino Acid Levels ◽  
Branched Chain

Raised plasma free fatty acid (FFA) levels effectively impede glucose uptake in vivo, thereby conserving plasma glucose and sparing glycogen. To test whether FFA have any effect on blood amino acid levels, we infused Intralipid plus heparin or saline into healthy volunteers under four different experimental conditions: A) overnight fast; B) euglycemic hyperinsulinemia (approximately 100 microU/ml); C) hyperglycemic (approximately 200 mg/100 ml) hyperinsulinemia (approximately 50 microU/ml); and D) hyperglycemic (approximately 300 mg/100 ml) normoinsulinemia (approximately 20 microU/ml). In the fasting state (A), lipid infusion was associated with lower blood levels of most amino acids, both branched chain and glucogenic. This effect, however, could not be ascribed to lipid infusion alone, because plasma insulin levels were also stimulated. The clamp studies (B, C, and D) allowed to assess the influence of lipid on blood amino acid levels at similar plasma insulin and glucose levels. It was thus observed that lipid infusion has a significant hypoaminoacidemic effect of its own under both euglycemic (B) and hyperglycemic (C) conditions; this effect involved many glucogenic amino acids (alanine, glycine, phenylalanine, serine, threonine, and cystine) but none of the branched-chain amino acids (leucine, isoleucine, and valine). In marked contrast, normoinsulinemic hyperglycemia (D), with or without lipid infusion, caused no change in the blood level of any measured amino acid. We conclude that lipid infusion has a hypoaminoacidemic action. We also suggest that this action is permitted by insulin and may involve specific metabolic interactions (e.g., reduced availability of glucose-derived pyruvate or glycerophosphate) as well as enhanced uptake by the liver.

Bioinspired synthesis of self-assembled calcium phosphate nanocomposites using block copolymer-peptide conjugates

2008 ◽  
Vol 23 (12) ◽  
pp. 3196-3212 ◽  
Author(s):  
Yusuf Yusufoglu ◽  
Yanyan Hu ◽  
Mathumai Kanapathipillai ◽  
Matthew Kramer ◽  
Yunus E. Kalay ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Phosphate ◽  
Small Angle ◽  
Polymer Chains ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Assembling ◽  
Transmission Electron ◽  
Angle Scattering ◽  
Inorganic Content

Thermoreversibly gelling block copolymers conjugated to hydroxyapatite-nucleating peptides were used to template the growth of inorganic calcium phosphate in aqueous solutions. Nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), transmission electron microscopy, x-ray diffraction, and small-angle scattering were used to characterize these samples and confirm that the peptides promoted the growth of hydroxyapatite as the inorganic phase. Three different polymer templates were used with varying charges on the polymer chains (nonionic, anionic, and zwitterionic), to investigate the role of charge on mineralization. All of the polymer-inorganic solutions exhibited thermoreversible gelation above room temperature. Nanocomposite formation was confirmed by solid-state NMR, and several methods identified the inorganic component as hydroxyapatite. Small angle x-ray scattering and electron microscopy showed thin, elongated crystallites. Thermogravimetric analysis showed an inorganic content of 30–45 wt% (based on the mass of the dried gel at ∼200 °C) in the various samples. Our work offers routes for bioinspired bottom-up approaches for the development of novel, self-assembling, injectable nanocomposite biomaterials for potential orthopedic applications.

scholarly journals Calcium Phosphate Ceramics Can Prevent Bisphosphonate-Related Osteonecrosis of the Jaw

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1955
Author(s):  
Siri Paulo ◽  
Mafalda Laranjo ◽  
Anabela Paula ◽  
Ana Margarida Abrantes ◽  
João Martins ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
Calcium Phosphate ◽  
Tooth Extraction ◽  
Soft Tissues ◽  
Calcium Phosphates ◽  
Test Group ◽  
Osteonecrosis Of The Jaw ◽  
In Vivo Model ◽  
Calcium Phosphate Ceramics

Bisphosphonate-associated osteonecrosis of the jaw (BRONJ), a post-surgical non-healing wound condition, is one of the most common side effects in patients treated with nitrogen-containing bisphosphonates. Its physiopathology has been related with suppression of bone turnover, of soft tissue healing and infection. Biphasic calcium phosphates (BCP) are used as a drug delivery vehicle and as a bone substitute in surgical wounds. Due to their capacity to adsorb zoledronate, it was hypothesized these compounds might have a protective effect on the soft tissues in BRONJ wounds. To address this hypothesis, a reproducible in vivo model of BRONJ in Wistar rats was used. This model directly relates chronic bisphosphonate administration with the development of osteonecrosis of the jaw after tooth extraction. BCP granules were placed in the alveolus immediately after tooth extraction in the test group. The animals were evaluated through nuclear medicine, radiology, macroscopic observation, and histologic analysis. Encouragingly, calcium phosphate ceramics were able to limit zoledronate toxicity in vivo and to favor healing, which was evidenced by medical imaging (nuclear medicine and radiology), macroscopically, and through histology. The studied therapeutic option presented itself as a potential solution to prevent the development of maxillary osteonecrosis.

scholarly journals The mineralization, drug release and in vivo bone defect repair properties of calcium phosphates/PLA modified tantalum scaffolds

RSC Advances ◽  
2020 ◽  
Vol 10 (13) ◽  
pp. 7708-7717 ◽  
Author(s):  
Rong Zhou ◽  
Hai-Jian Ni ◽  
Jin-Hui Peng ◽  
Ning Liu ◽  
Shu Chen ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Drug Release ◽  
Bone Defect ◽  
High Performance ◽  
Calcium Phosphates ◽  
Sustained Drug Release ◽  
Bone Defect Repair ◽  
Defect Repair

Calcium phosphate modified tantalum scaffolds displayed high performance on mineralization, sustained drug release and in vivo bone defect repair.

Controllable one-step synthesis of ZnO nanostructures using molybdophosphoric acid

2014 ◽  
Vol 68 (4) ◽  
Author(s):  
Hamed Rashidi ◽  
Ali Ahmadpour ◽  
Fatemeh Bamoharram ◽  
Seyed Zebarjad ◽  
Majid Heravi ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
High Performance ◽  
Hydrothermal Reaction ◽  
Hexagonal Phase ◽  
Zno Nanostructures ◽  
Molybdophosphoric Acid ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Transmission Electron ◽  
One Step

AbstractZnO nanostructures were synthesised in a hydrothermal reaction of zinc acetate in the presence of molybdophosphoric acid (H3[PMo12O40]) as well as its vanadium-substituted acid (H4[PMo11VO40]) at various times, temperatures, and concentrations. The ZnO nanostructures were characterised by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The results demonstrated that the synthesised products are crystalline with a zincite hexagonal phase. Various ZnO nanostructures, such as nanoparticles, microrods, and nanosheets, were produced by changing the experimental conditions. The photocatalytic degradation of methyl orange was also investigated using the ZnO nanoparticles thus prepared. These particles exhibited high performance in the photocatalytic degradation of MO and almost 100 % decolourisation occurred within only 20 min.

Facile aqueous synthesis of functionalized CdTe nanoparticles and their application as fluorescence probes for determination of adenine and guanine

2012 ◽  
Vol 90 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Li Li ◽  
Yaxiang Lu ◽  
Yaping Ding ◽  
Fenfen Zhang ◽  
Yaping Wang
Keyword(s):  
Dynamic Range ◽  
Fluorescence Emission ◽  
Fluorescence Probes ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Aqueous Synthesis ◽  
Cdte Nanoparticles ◽  
Transmission Electron ◽  
Quantitative Analysis Method

Thioglycolic acid (TGA)-capped CdTe nanoparticles (NPs) were synthesized in aqueous medium, and their application as fluorescence probes in the detection of adenine and guanine was studied. The TGA-capped CdTe NPs were characterized by transmission electron microscopy, X–ray diffraction spectrometry, spectrofluorometry, Fourier transform infrared, and ultraviolet-visible spectrometry. Based on the significant enhancement of fluorescence emission of these CdTe fluorescence probes in the presence of adenine or guanine, a quantitative analysis method for these purines was proposed. Experimental conditions that govern the extent of fluorescence enhancement were optimized. Under the optimal conditions, the relative fluorescence intensity versus adenine or guanine concentrations gave a linear response, permitting the dynamic range of 7.0 × 10−7–1.0 × 10−4 mol/L and 6.0 × 10−7–9.0 × 10−5 mol/L for adenine and guanine, respectively. The method has also been applied successfully to the detection of adenine and guanine in synthetic samples with satisfactory results.

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