Investigation into the role of NaOH and calcium ions in the synthesis of calcium phosphate nanoshells
01 Mar 2012-Brazilian Journal of Chemical Engineering (Brazilian Society of Chemical Engineering)-Vol. 29, Iss: 1, pp 147-158
TL;DR: In this paper, negatively charged liposomes (1,2-dioleoyl-sn-glycero-3-phosphate sodium salt) were used as a template by base titration synthesis at various concentrations of NaOH and calcium ions.
Abstract: Calcium phosphate (CaP) nanoshells were prepared using negatively charged liposomes (1,2-dioleoyl-sn-glycero-3-phosphate sodium salt (DOPA)) as a template by base titration synthesis at various concentrations of NaOH and calcium ions. The elemental composition, morphology, particle size, particle size distribution and zeta potential of the products were determined via various characterisation techniques, such as energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), dynamic light scattering (DLS), laser Doppler velocimetry (LDV) and Fourier transform infrared spectroscopy (FTIR). The best results showed that stable spherical CaP nanoshells with a mean particle size of 197.5 ± 5.8 nm and a zeta potential of -34.5 ± 0.6 mV were successfully formed when 0.100 M sodium hydroxide (NaOH) and 0.100 M calcium ions were used. Moreover, an optimal pH of 10.52 and a final Ca/P molar ratio of 0.97 were achieved under these conditions.
Citations
More filters
TL;DR: This chapter describes current state-of-the-art and recent developments on the subject of nanodimensional CaPO4, starting from synthesis and characterization to biomedical and clinical applications.
Abstract: Nano-scaled particles and crystals play very important roles in biological systems. For example, calcium orthophosphates (CaPO4) with nano-size dimensions represent the basic inorganic building blocks of bones and teeth of mammals. According to recent discoveries in biomineralization, zillions of nanodimensional crystals of biological apatites are nucleated in body fluids, and afterward, they are self-assembled into these complex structures. In addition, both a greater viability and a better proliferation of various types of cells have been detected on smaller crystals of CaPO4. All these effects are due to the higher surface-to-volume ratio, increased reactivity, and biomimetic morphologies of the nano-scaled particles. Thus, the nano-sized and nanocrystalline forms of CaPO4 have a great potential to revolutionize the hard tissue engineering field, starting from bone repair and augmentation to controlled drug delivery systems. Therefore, preparation and application of nanodimensional CaPO4 are the important topics in modern material science, and such formulations have been already tested clinically for various purposes. Currently, more efforts are focused on the possibility of combining nano-scaled CaPO4 with cells, drugs, and other biologically active substances for multipurpose applications. This chapter describes current state-of-the-art and recent developments on the subject, starting from synthesis and characterization to biomedical and clinical applications.
55 citations
01 Jan 2018
TL;DR: In this chapter, a further understanding of the chemical, physical, and biological properties of CPC, along with the clinical applications, is addressed to provide a deeper insight into the regulation mechanism between the material properties and the clinical uses.
Abstract: Calcium phosphate cement (CPC) has opened up a new era in the construction of bone-related defects in biomedical fields. Such unique properties as the easy shaping, injectability in practical use, excellent biocompatibility, and biodegradability of CPC make it a perfect substitution material and maintain the research focus during the years. In this chapter, the brief history, classification, setting mechanism, and kinetics of CPC are introduced. A further understanding of the chemical, physical, and biological properties of CPC, along with the clinical applications, is also addressed to provide a deeper insight into the regulation mechanism between the material properties and the clinical uses.
29 citations
TL;DR: Results suggested that functionally graded bilayered membranes hold potential for GBR applications in regenerative dentistry.
Abstract: Barrier membranes are used in periodontal tissue engineering for successful neo-bone tissue formation and prevention of bacterial colonization. We aimed to prepare and characterize novel 7% boron-modified bioactive glass (7B-BG) containing bilayered membrane for this end. We hypothesized that presence of 7B-BG could promote structural and biological properties of guided bone regeneration (GBR) membrane. Cellulose acetate (CA) layer was prepared by solvent casting, and functionally graded layer of CA/gelatin/BG nanoparticles was prepared by electrospinning. 0B-BG, and 7B-BG were synthesized by quick alkali-mediated sol-gel method and were characterized by scanning electron microscopy (SEM) and Fourier-transform Raman spectroscopy. Membranes were cross-linked with glutaraldehyde to preserve their stability. SEM analysis showed the asymmetric nature of membranes consisting of a smooth membrane layer and a rough surface composed of 0B-BG and 7B-BG containing nanofibres. 7B-BG addition increased surface wettability (from 110.5° ± 0.8 to 73.46° ± 7.6) and biodegradability of the membranes. Additionally, a significant increase in Ca-P layer formation was observed in 7B-BG containing group after 1-week incubation in stimulated body fluid. 7B-BG incorporation resulted in a decrease in tensile strength and Young's modulus values. Human dental pulp stem cells showed better attachment, spreading, and proliferation on 7B-BG containing bilayered membranes. Osteogenic differentiation analysis revealed higher alkaline phosphatase (ALP) enzyme activity of cells (~1.5-fold), higher intracellular calcium deposition (approximately twofold), and higher calcium deposition revealed by Alizarin red staining on 7B-BG containing bilayered membranes. Overall, results suggested that functionally graded bilayered membranes hold potential for GBR applications in regenerative dentistry.
23 citations
TL;DR: In this paper, different metal ions (i.e., Ag, Cu, Zn, and Mg) were doped into nano-hydroxyapatite (HAp) to improve the antibacterial activity.
Abstract: Earth-abundant mineral limestone obtained from North Sumatera, Indonesia, has been utilized to synthesize nano-hydroxyapatite (HAp). Although HAp is biocompatible to the human bone, its antibacterial activity is still very low. Herein, different metal ions (i.e., Ag, Cu, Zn, and Mg) were doped into HAp to improve the antibacterial activity. The as-synthesized HAp was characterized by X-ray ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), energy disperse spectroscopy (EDS), Fourier transmission infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET). The antibacterial test showed that the performance of HAp to inactivate bacterial growth was significantly improved after incorporating the metal ion dopants into HAp. Ag-HAp exhibited the highest activity toward E. coli and S. aureus with an antibacterial rate of 99.9 ± 0.1%, followed by Zn-HAp, Cu-HAp, and Mg-HAp.
13 citations
TL;DR: In this article, binary (ZnO)x(TiO2)1−x NPs were effectively blended by using thermal treatment technique, where Zinc nitrate and titanium(IV) propoxide with polyvinylpyrrolidone, PVP, were utilized to set up the samples.
Abstract: Numerous studies have explored the behaviors of ZnO–TiO2 nanoparticles resulting through various routes of fabrication. To date, the utilization of thermal treatment method to convey ZnO–TiO2 nanoparticles has never been considered. In the present study, binary (ZnO)x(TiO2)1−x NPs were effectively blended by using thermal treatment technique. Zinc nitrate and titanium(IV) propoxide with polyvinylpyrrolidone, PVP, were utilized to set up the samples. Energy-dispersive X-ray (EDX) spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction (XRD) spectroscopy, ultraviolet–visible (UV–Vis) spectrophotometer transmission electron microscopy (TEM) and photoluminescence spectroscopy were utilized to examine the impact of changing the molar proportion to the structure and optical features of (ZnO)x(TiO2)1−x NPs. The XRD spectra revealed that after calcination, the amorphous sample had transformed into crystalline nanoparticles. The prepared (ZnO)x(TiO2)1−x NPs average diameter was around 25.922–28.531 nm according to TEM analysis. The analyzation of UV–Vis spectroscopy determined the optical measurements parameters including the energy gap and Urbach energy of binary (ZnO)x(TiO2)1−x NPs. The optical energy gap varied in the range of 3.2496–3.2863 eV as the molar ratio increases from x = 0.24 to x = 0.72. The enhancement within the nanoparticles optical properties suggests a good potential for photocatalysis application.
9 citations
References
More filters
TL;DR: The density and microhardness of the BCP ceramics neglectly depended on the composition, however, the compressive strength did: the lower the HA/β-TCP ratio, the higher the strength in the dense materials.
Abstract: A modified processing route for fabricating dense and porous biphasic calcium phosphate (BCP) ceramics of desired and reproducible phase composition (hydroxyapatite (HA)/beta-tricalcium phosphate (beta-TCP) ratio) has been developed. The principal idea of the route was combining a precipitation and a solid phase methods. First, a nonstoichiometric (slightly carbonated calcium-deficient) HA (CdHA) precipitate was synthesized by mixing a calcium carbonate (CaCO(3)) water suspension with an orthophosphoric acid (H(3)PO(4)) solution in abundance (related to the amount resulting in a stoichiometric HA) under definite conditions, and a powder of the precipitate was prepared and calcinated in air (860 degrees C, 1.5 h). In the second stage, a BCP ceramics of the composition determined by the calcium-deficiency in a calcinated powder (the acid abundance in a mixture) was processed by sintering powder compacts with or without a porosizer under appropriate conditions (1,200 degrees C, 2h). A calibrating dependence of the HA/beta-TCP ratio in the ceramics on the acid abundance has been plotted which enabled a controlled preparation of BCP ceramics. A correlation based on unresolved bands in nu(4)-PO (4) (3-) domain in IR-spectra of nanostructured BCP materials was found. Using the correlation, the process of CdHA --> beta-TCP transformation could be easily monitored. The density and microhardness of the BCP ceramics neglectly depended on the composition, however, the compressive strength did: the lower the HA/beta-TCP ratio, the higher the strength in the dense materials.
48 citations
"Investigation into the role of NaOH..." refers background in this paper
...In addition, the high wt % of C and O in all the samples originated from the long carbon chains of the DOPA liposome template or were attributable to carbonate ions (CO32-) in the samples....
[...]
...The main functional groups observed in the CaP nanoshells were PO43-, HPO42-, CO32-, C=O, C–...
[...]
...Additionally, the presence of peaks in the region of 1450 cm-1 and near 878 cm-1 in the FTIR spectrum are attributed to carbonate groups (CO32-) (Sugawara et al., 2006; Zyman et al., 2008)....
[...]
...Based on the results of LeGeros (1991), HA contains CO32and is well known to show better bioactivity than stoichiometric HA because of its parallel to the composition of biological apatite in natural bone....
[...]
...The presence of carbonate is due to the substitution of PO43- by CO32ions (Sonoda et al., 2002; Kumta et al., 2005)....
[...]
TL;DR: In this paper, the effect of powder shape on injectability was studied using spherical tetracalcium phosphate (s-TTCP) prepared with plasma melting method, and the authors concluded that spherical powder is very useful to improve the injectability of apatite cement.
Abstract: Although injectability through syringe is one of the key advantages of apatite cement (AC), injectability of current AC is not satisfactory for its clini cal use. In this investigation, therefore, effects of powder shape on injectability were studied using spherical tetrac alcium phosphate (s-TTCP) prepared with plasma melting method. Bulk density of AC using s-TTCP (s-AC) s howed larger value than AC using irregular TTCP (i-TTCP) (i-AC). Also we found be tter injectability when we used s-TTCP. However, diametral tensile strength of set s-AC was significantly lower than i-AC. X-ray powder diffraction analysis revealed limited transformation to apat ite in the case of set s-AC. To avoid the drawback due to plasma melting method, s-TTCP was again heated to 1500 degree for four hours and quenched to room temperature (q-TTCP). AC using q-TTCP (q-AC) tr ansfo med to apatitic mineral and showed the similar DTS value with i-AC. We concluded, t herefore, spherical powder is very useful to improve the injectability of AC. Also, we found re-hea t treatment of TTCP is useful if s-TTCP is prepared using plasma melting method. Introduction Since apatite cement (AC) shows setting ability, it can be inj cted through a syringe. This behaviour is very useful for the bloodless operation. However, injectabili ty of current AC is, unfortunately, not satisfactory for its clinical use. To improve inj ctability of AC, lower powder to liquid mixing ratio and/or gelling agent is used. However, lower powder to liquid mix ing ratio results in the lower mechanical strength and use of gelling agent sometim es reduces the tissue response to AC. On the other hand, shape of the powder is expected to have effects on inje ctab lity. Powders with spherical shape may contribute good injectability. Spheroidization of P ortland cement particles increased the handling property. Many methods are used to prepare spherical powders. Among them, spheroidization method using the surface tension is known to be a good method t o prepare ideal spherical powder. The objective of this study was to evaluate the usefulness of AC usi ng spherical tetracalcium phosphate (TTCP). Methods Spherical TTCP (s-TTCP) was prepared by plasma melting method using commercially available irregular TTCP (i-TTCP) powder (Fig. 1). Some of the s-TTCP was re-heated at 1500°C for 4 hours and quenched to room temperature (q-TTCP). AC was prepared by mixing Fig 1. SEM photographs. Left: Commercially obtained irregular TTCP; Right: Spherical TTCP (s-TTCP) s-TTCP i-TTCP Key Engineering Materials Online: 2003-05-15 ISSN: 1662-9795, Vols. 240-242, pp 369-372 doi:10.4028/www.scientific.net/KEM.240-242.369 © 2003 Trans Tech Publications Ltd, Switzerland All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications Ltd, www.scientific.net. (Semanticscholar.org-13/03/20,21:20:41) equimolar amount of TTCP and dicalcium phosphate anhydrous. AC made using i -TTCP s-TTCP and q-TTCP are called i-AC, s-AC and q-AC, respectively. Bulk density of TTCP and AC powder was calculated based on volume and it s weight measurement. After the powder was mixed with distilled water wi h powder to liquid mixing ratio (P/L ratio) of 3.5, consistency was measured. In brief, 0.1g cement paste w s held between two glass and loaded 150N. Cement spread area was measured as an index of the consi st ncy. Also, the pastes mixed with various powders to liquid ratios were injected through 16G syringe with at a rate of 0.9cc/min and the load was measured using a universal testing machine. Diametr al tensile strength (DTS) was measured as an index of the mechanical strength of set mass. Spe cimens kept in an incubator at 37 degrees and 100% relative humidity for 24 hours were used for DTS meas urements. Also, powder x-ray diffraction patterns were obtained for compositional analysis. Results Bulk density for TTCP and AC is summarized in Table 1. Bulk densities of s-TTCP and s-AC are higher than i-TTCP and i-AC, respectively. Figure 2 shows the cement-spread area as an index of the handling properties of cement as a function of powder to liquid mixing ratio, P/ L ratio. Cement spread area decreased with increase in the P/L ratio regardless of the ty pe of AC. s-AC showed significantly higher cement spread area than i-AC when compared with the same P/L ra tio. Figure 3 shows the load required to inject i-AC and s-AC through 16G syringe at a rate of 0.9cc/min. Figure 4 shows the powder x-ray diffraction patterns of i-TTCP, s-TTCP and q-TTCP. We found small amount of heat decomposition product of TTCP in the case of s-TTCP as well as q-T TCP. Figure 5 shows the powder x-ray diffraction patterns of i-AC, s-AC and q-AC after kept i n an incubator for 24 hours. When ACs were kept in an incubator at 37 degrees and 100% relative humidity, i-AC and q-AC became apatite after 24 hours. However, only a limited amount of apatite is found in the case of s-AC. The amount of Table 1. Bulk Density of TTCP and AC Bulk density (g/cc) Powder irregular spherical TTCP 0.96 ± 0.05 1.52 ± 0.06 AC 0.61 ± 0.02 1.13 ± 0.04
42 citations
"Investigation into the role of NaOH..." refers background in this paper
...The small sizes and spherical shapes of nanoshells make them ideal for injection into the body (Ishikawa, 2003; Dorozhkin, 2008; Sounderya and Zhang, 2008)....
[...]
TL;DR: In this paper, the behavior of amorphous calcium phosphate with an atomic Ca/P ratio of 1.33 in a wet atmosphere at 40, 60, and 80°C was investigated.
31 citations
"Investigation into the role of NaOH..." refers background in this paper
...…final molar ratio of Ca/P of sample C-DOPA-4 (0.97) most closely approaches the expected Ca/P molar ratio for the CaP nanoshells (1.00) suggested by Schmidt et al. (2008), which corresponded to either crystalline brushite or amorphous CaPs (ACP) (Markovic et al., 1993; Rodrigues and Lebugle, 1999)....
[...]
...The final molar ratio of Ca/P of sample C-DOPA-4 (0.97) most closely approaches the expected Ca/P molar ratio for the CaP nanoshells (1.00) suggested by Schmidt et al. (2008), which corresponded to either crystalline brushite or amorphous CaPs (ACP) (Markovic et al., 1993; Rodrigues and Lebugle, 1999)....
[...]
...(2008), which corresponded to either crystalline brushite or amorphous CaPs (ACP) (Markovic et al., 1993; Rodrigues and Lebugle, 1999)....
[...]
24 citations
"Investigation into the role of NaOH..." refers background in this paper
...The final molar ratio of Ca/P of sample C-DOPA-4 (0.97) most closely approaches the expected Ca/P molar ratio for the CaP nanoshells (1.00) suggested by Schmidt et al. (2008), which corresponded to either crystalline brushite or amorphous CaPs (ACP) (Markovic et al., 1993; Rodrigues and Lebugle, 1999)....
[...]
...(2008), which corresponded to either crystalline brushite or amorphous CaPs (ACP) (Markovic et al., 1993; Rodrigues and Lebugle, 1999)....
[...]
...…final molar ratio of Ca/P of sample C-DOPA-4 (0.97) most closely approaches the expected Ca/P molar ratio for the CaP nanoshells (1.00) suggested by Schmidt et al. (2008), which corresponded to either crystalline brushite or amorphous CaPs (ACP) (Markovic et al., 1993; Rodrigues and Lebugle, 1999)....
[...]
TL;DR: In this paper, CdSe hollow and solid nanospheres have been prepared using liposomes as templates and the products were characterized through transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Vis absorption spectra.
24 citations
"Investigation into the role of NaOH..." refers background in this paper
...In this case, calcium ions were not only adsorbed on the outer surface of the liposome template, but also encapsulated inside the template (Chu and Liu, 2006)....
[...]
...According to Chu and Liu (2006), the structures of cadmium selenide (CdSe) nanospheres synthesised using liposome templates were affected by the concentration of the reaction precursors....
[...]