Basam Ben-Arfa
University of Aveiro, Engenharia de Materiais e Cerâmica (demac), Graduate Student
- Material Science and Engineering, Nano material, Biomaterialedit
We show the influence of two functional ions (Cu2+ and La3+), incorporated into a quaternary (Si, Ca, Na, P) sol‐gel derived bioactive glass system, on its particle size, cytotoxicity, and bioactivity. By doping the parent glass with the... more
We show the influence of two functional ions (Cu2+ and La3+), incorporated into a quaternary (Si, Ca, Na, P) sol‐gel derived bioactive glass system, on its particle size, cytotoxicity, and bioactivity. By doping the parent glass with the two ions in singular or combined forms, 15 doped glasses were prepared by a rapid sol‐gel technique. The influence of the combined doping on the particle size and cell viability was successfully evaluated by the aid of signal‐to‐noise‐ratio (S/N), using Taguchi analysis. This allowed us to analyze the complex interplay of effects between these ions, and the marked differences in biocompatibility between the three cell types studied. Cu addition had a significant effect on reducing the glass particle size, while both increased density. Cell viability was significantly improved for some doping combinations, demonstrating that while combined Cu–La doping was beneficial for biocompatibility with lymphoblasts, individual high‐Cu or low‐La doping was better with fibroblasts, and either high‐Cu or low‐La doping, or certain combined Cu–La combinations, were the optimum for osteoblasts. However, the bioactivity of doped samples was generally similar to that of the parent glass, although both La, and particularly Cu, did appear to aid dissolution of ions when immersed in SBF, act as glass modifiers, and encourage HAp crystallization. The results reveal that potential synergistic benefits can be obtained by combining the effects on the mean particle size, density, cytotoxicity, and bioactivity of the glasses. The greatly improved biocompatibility of some of the doped glasses makes them promising candidates for biomedical applications.
Research Interests: Biomaterials, Sol-Gel Technology, Cytotoxicity, Biocompatibility, Copper, and 12 moreSol Gel Process, Taguchi Methods, Lanthanum, Cytotoxicity assay, Optimization method using Taguchi Method, Biomaterials and tissue engineering scaffolds, Taguchi, Bioactive Glass, Preparation of nano-bioglass for medical applications, Sol-gel Synthesis, Bioactivity, and Bioglass
To highlight the effect of salt precursors on the final properties, bioactivity and biocompatibility, five quaternary (Si–Ca–P–Na) glass compositions were successfully prepared through two distinct rapid sol–gel routes; one using acetate... more
To highlight the effect of salt precursors on the final properties, bioactivity and biocompatibility, five quaternary (Si–Ca–P–Na) glass compositions were successfully prepared through two distinct rapid sol–gel routes; one using acetate salt precursors (A) catalysed by nitric acid, and the other using nitrate salts (N) and citric acid as a catalyst. The sols dried rapidly, and stabilised at 550 & 800 °C to be characterised by X–ray diffraction (XRD), Magic angle spinning–Nuclear magnetic resonance (29Si MAS–NMR) and Fourier transform infra–red spectroscopy (FTIR). Upon immersion in simulated body fluid (SBF), hydroxyapatite (HAp) formation was initially enhanced by increasing Ca–content up to 40 mol%, but the formation of calcite was favoured with further increments of Ca to 45 and 48 mol%. The A–glasses exhibited lower density and lower network connectivity compared with N–glasses. The chemical surface modifications after 4 h in SBF were more evident for N–glasses in comparison to A–glasses. The biocompatibility is favoured for the samples treated at 800 °C and for the samples of the higher silica contents.
Research Interests: Biomaterials, Hydroxyapatite, Sol-Gel Technology, Tissue Engineering: Hard Tissue Engineering (Bone Substitutes and Implants),Bioceramics such as Calcium Phosphate Especially Hydroxyapatite and Beta Tricalcium Phosphate, Porous Bioceramics for Bone Implants, Biocompatibility, and 12 moreSol-gel chemistry, Scaffolds, Bone Scaffolds, Glasses, Sol-Gel, Biomaterials and tissue engineering scaffolds, Preparation of nano-bioglass for medical applications, Sol-gel Synthesis, Sol gel, Biocompatible Materials, Glasses Fabrication, and Bioglass
Magnetic particles were successfully synthesised by a new and simple one-step auto-ignition method, with octylamine as organic fuel and iron nitrate nonahydrate as an oxidant, both in an aqueous solution. After synthesis and stabilising... more
Magnetic particles were successfully synthesised by a new and simple one-step auto-ignition method, with octylamine as organic fuel and iron nitrate nonahydrate as an oxidant, both in an aqueous solution. After synthesis and stabilising at 550 °C in reduced atmosphere, the samples consisted of mostly well crystalline magnetite (Fe3O4), with a small amount of hematite present, in the form of micron–scale agglomerations of nanoparticles. A noticeable reduction of crystallite size of magnetite (42–28 nm) and an increase in the hematite crystallite sizes were observed with increasing octylamine addition, although the actual observed nanoparticle size increased slightly from ∼30 up to 50 nm. The magnetic properties were assessed at room temperature, and all were found to be strongly ferrimagnetic with very narrow hysteresis loops. The saturation magnetisation at 4 T was 77.2–91.6 A m2 kg−1, and coercivity was only 10.03–11.30 kA m−1 (126–142 Oe). These results are also compared to the few previous studies on using octylamine to produce magnetite nanoparticles, which were all purely organic hydrothermal processes, and produced materials with lower magnetisation values and comparable coercivity in similarly sized particles.
Research Interests: Magnetic Materials, Magnetic nanoparticles, Magnetic Nano Ferrites, Magnetite, Nanosynthesis, and 9 moreMagnetic Properties of Soft Ferrites, Magnetism and Magnetic Materials, Self-propogating low temperature combustion method, Spinel Ferrite, Aqueous Solution, Auto ignition, Maghemite Nanoparticles, Magnetite Nanoparticles, and octylamine
Sol-gel glasses in quaternary silica-sodium-calcium-phosphorous systems have been synthesised using a rotary evaporator for rapid drying without ageing. This novel fast drying method drastically decreases the total drying and ageing time... more
Sol-gel glasses in quaternary silica-sodium-calcium-phosphorous systems have been synthesised using a rotary evaporator for rapid drying without ageing. This novel fast drying method drastically decreases the total drying and ageing time from several weeks to only 1 hour, thus overcoming a serious drawback in sol-gel preparation procedures for bioglasses. This work investigates the bioactivity behaviour of two glasses synthesised by this fast method, with Ca:P ratios of 1.5, and 1.67. X-ray diffraction (XRD), Inductive coupled plasma (ICP), Fourier-transform infrared (FTIR) and Raman spectroscopy were used to confirm the bioactivity of the synthesised powders. MAS-NMR was also used to assess the degree of silica polymerisation. The composition with a higher Ca:P = 1.67 ratio showed better bioactivity in comparison to the one with Ca:P = 1.5, which exhibited little bio-response with up to 4 weeks of immersion in SBF (simulated body fluid). It was also found that an orbital agitation rate of 120 rpm favours the interfacial bio-mineralisation reactions, promoting the formation of a crystalline hydroxyapatite (HAp) layer at the surface of the (Ca:P = 1.67) composition after 2 weeks immersion in SBF. This article is protected by copyright. All rights reserved.
Research Interests: Engineering, Hydroxyapatite, Sol-Gel Technology, Glass & Glass-Ceramics, Biological Sciences, and 17 moreSol-gel chemistry, Sol Gel Process, Glasses, Calcium Phosphates, Bioceramics, Calcium Phosphate, Glass & Ceramics Technology, Bioactive Glass, Ageing effects on Glass Transition, Sol gel, Bioactivity, Bioactive Glasses, Sol Gel Method, SOL GEL SYNTHESIS, Bioactive Glass-ceramic, Glass and Glass Ceramic, and Bioglass
We have developed an innovative, rapid sol-gel method of producing hydroxyapatite nanopowders that avoids the conventional lengthy ageing and drying processes (over a week), being 200 times quicker in comparison to conventional aqueous... more
We have developed an innovative, rapid sol-gel method of producing hydroxyapatite nanopowders that avoids the conventional lengthy ageing and drying processes (over a week), being 200 times quicker in comparison to conventional aqueous sol-gel preparation, and 50 times quicker than ethanol based sol-gel synthesis. Two different sets of experimental conditions, in terms of pH value (5.5 and 7.5), synthesis temperature (45 and 90°C), drying temperature (60 and 80°C) and calcination temperature (400 and 700°C) were explored. The products were characterised by X-ray diffraction (XRD) Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and specific surface area (SSA) measurements. Pure hydroxyapatite (Ca10(PO4)6(OH)2, HAp) was obtained for the powders synthesised at pH7.5 and calcined at 400°C, while biphasic mixtures of HAp/β-tricalcium phosphate (β-Ca3(PO4)2, TCP) were produced at pH5.5 and (pH7.5 at elevated temperature). The novel rapid drying was up to...
Research Interests: Biomedical Engineering, Biomaterials, Hydroxyapatite, Scanning Electron Microscopy, Sol-Gel Technology, and 16 moreSol-gel chemistry, Sol Gel Process, Bioceramics, Desiccation, Bioceramic, X ray diffraction, Fourier transform infrared spectroscopy, Time Factors, Hydroxylapatite, Powders, Materials Testing, Calcium-phosphate Apatites, Durapatite, Sol gel, Sol Gel Method, and SOL GEL SYNTHESIS
The Taguchi experimental design method is an elegant and efficient way of deriving optimum conditions for processes from the minimum number of experiments. We correlated various relevant synthesis parameters in the precipitation synthesis... more
The Taguchi experimental design method is an elegant and efficient way of deriving optimum conditions for processes from the minimum number of experiments. We correlated various relevant synthesis parameters in the precipitation synthesis of single-phase pure hydroxyapatite (Ca10(PO4)6(OH)2, HAp) nanoparticles, via a rapid wet precipitation method, without any aging time. Taguchi planning was used for a systematic study of the combined effects of five different parameters: pH, synthesis temperature, synthesis time, drying temperature and calcination temperature. Using T\aguchi methods, we were able to evaluate the effects of four variations (levels) in each of these five parameters, with just 16 experiments (an L16 (1024) orthogonal array). We assessed the impact of these parameters on four distinct properties, namely crystallite size, surface area, Ca/P atomic ratio and mol% of HAp. Calcination temperature exerted the greatest impact on hydroxyapatite morphology, corresponding to crystallite size and specific surface area, for which the role of other processing parameters was not significant. On the contrary, the Ca:P ratio was affected mainly by pH. These findings were confirmed by microstructural, structural and spectroscopic characterisation. FTIR spectra, revealing the conditions to retain a pure or prevailing hydroxyapatite phase, and also to indicate favourable conditions for A-type substitutions of carbonate for hydroxide groups, or B-type substitution for phosphate groups.
Research Interests: Materials Engineering, Mechanical Engineering, Hydroxyapatite, Sol-Gel Technology, Sol-gel chemistry, and 21 moreSol Gel Process, Taguchi Methods, Optimization method using Taguchi Method, Materials Design, Apatite, Taguchi method, Taguchi, Wet Precipitation of Hydroxyapatite, Taguchi Methode, Apatites, Hydroxyapatites, Taguchi Method with Robust Design and Optimization, Taguchi and Its Anova Test, Calcium-phosphate Apatites, Taguchi Approach, Sol gel, Bio Meterial (Hydroxyapatite, Sol Gel Method, SOL GEL SYNTHESIS, Nanocrystalline Apatite, and Biomaterials Using Hydroxyapatite
The effects of three functional ions (yttrium Y 3+ , fluorine F − , titanium Ti 4+) on the glass forming ability, sintering, crystallization, and thermo-physical properties of glasses and glass-ceramics were studied in a diopside–calcium... more
The effects of three functional ions (yttrium Y 3+ , fluorine F − , titanium Ti 4+) on the glass forming ability, sintering, crystallization, and thermo-physical properties of glasses and glass-ceramics were studied in a diopside–calcium pyrophosphate (90% CaMgSi 2 O 6 –10% Ca 2 P 2 O 7) system. Three different percentages (1, 3 and 5 wt%) for each additive were tested. The structural features of glasses were assessed through FT-IR (Fourier Transform infra-red spectroscopy) and 29 Si and 31 P NMR (nuclear magnetic resonance), showing that the silicate network in all the investigated glasses is predominantly coordinated in Q 2 (Si) units, while phosphorus tends to remain in the orthophosphate (Q 0) environment. All glasses exhibited fast rates of biomineralization, making them promising candidates for biomedical applications. The sintering and crystallization behaviours of the glass powders were studied by differential thermal analysis (DTA), while the coefficient of thermal expansion (CTE) was determined by dilatometry. Glass transition temperature (T g) values of all doped glasses were lower than the parent glass, while CTE values decreased with initial addition (1 wt%), of dopants before exhibiting an increase with further addition. In Y-doped glasses, a gradual increase was seen in the values of maximum crys-tallization peak temperature, T p , up to 3 wt%, while an opposite trend was observed in Ti-doped glasses, showing an enhancement of the stability of the Y-doped glasses against devitrification. F-doped glasses exhibited a similar trend. Crystalline phase evolution was analysed by X-ray diffraction (XRD), and amorphous glass were obtained by sintering powder compacts from all the glasses at 800 °C for 1 h.
Research Interests:
The influence of two divalent cations, Cu2+ and Mn2+ , on the structure, sintering, and crystallization of glasses and glass-ceramics in the diopside–calcium pyrophosphate system (90 wt.% diopside (CaMgSi2O6), 10 wt.% calcium... more
The influence of two divalent cations, Cu2+ and Mn2+ , on the structure, sintering, and crystallization of glasses and glass-ceramics in the diopside–calcium pyrophosphate system (90 wt.% diopside (CaMgSi2O6), 10 wt.% calcium pyrophos-phate (Ca2P2O7)) was investigated. Glasses with 1, 3, and 5 wt% MnO or CuO additives were prepared by melt-quenching and characterized by XRD, 29 Si and 31 P NMR, DTA, and FTIR This revealed that the silicate network is predominantly coordinated in Q2 (Si) units for all glasses, while phosphorus tends to inhabit an orthophosphate (Q0) environment. All glasses had a high rate of bioactivity after immersion in simulated body fluid. A slight depolymerization was observed in the doped glasses leading to lower Tg values in comparison with the parent glass. All glass-ceramics exhibited the formation of diopside as the primary crystalline phase after sintering at 850 °C/1 h. In comparison with the parent glass, the doped glasses featured significantly larger processing windows (ΔT = Tc –Tg), ensuring good sinterability. Further, with increasing doping levels, the glasses exhibited a gradual decrease in T p and ΔT, suggesting an increased tendency toward devitrification. All Cu-and Mn-containing glasses exhibited the formation of hydroxyapatite, making them good candidates for biomedical applications and tissue engineering.
Research Interests:
A quaternary bioactive sol-gel glass of high silica content was heat treated at different temperatures, and then wet ball milled under different balls-to-powder ratios. A total of sixteen experiments were performed to study in detail the... more
A quaternary bioactive sol-gel glass of high silica content was heat treated at different temperatures, and then wet ball milled under different balls-to-powder ratios. A total of sixteen experiments were performed to study in detail the effects of both experimental variables on the structure, morphology, particle size distributions and nitrogen adsorption isotherms. The balls–to–powder ratio exerts a tremendous influence on the final particle size distribution of the powders, while its effects on the pore volume and morphology are minimal. These structural features are mostly governed by the changes in calcination temperature. Therefore, understanding the specific roles of each experimental parameter is of paramount importance towards achieving optimum powders with the desired properties. This work sheds light on the importance of using a suitable combination of these two parameters for tuning the morphology and the granulometry of the sol-gel derived bioactive glass powders.