ABSTRACT
The effect of LiCl additions on the in vitro bioactivity, hemolysis, cytotoxicity, compressive strength and setting time of calcium aluminate cements was studied. Calcium aluminate clinker (AC) was obtained via solid state reaction from reagent grade chemicals of CaCO3 and Al2O3. Calcium aluminate cements (CAC) were prepared by mixing the clinker with water or aqueous LiCl solutions (0.01, 0.0125 or 0.015M (M)) using a w/c ratio of 0.4. After 21days of immersion in a simulated body fluid (SBF) at physiological conditions of temperature and pH, a Ca-P rich layer, identified as hydroxyapatite (HA), was formed on the cement without LiCl and on the cement prepared with 0.01M of LiCl solution. This indicates the high bioactivity of these cements. The cements setting times were significantly reduced using LiCl. The measured hemolysis percentages, all of them lower than 5%, indicated that the cements were not hemolytic. The compressive strength of the cements was not negatively affected by the LiCl additions. The obtained cement when a solution of LiCl 0.010M was added, presented high compressive strength, appropriated bioactivity, no cytotoxicity and low setting time, making this material a potentially bone cement.
Subject(s)
Aluminum Compounds/pharmacology , Bone Cements/pharmacology , Bone Regeneration/drug effects , Bone Remodeling/drug effects , Calcium Compounds/pharmacology , Lithium Chloride/pharmacology , Animals , Body Fluids/chemistry , Cell Count , Cell Line , Cell Survival/drug effects , Compressive Strength , Hemolysis/drug effects , Humans , Mice , Solutions , Spectrometry, X-Ray Emission , Stress, Mechanical , Temperature , Time Factors , X-Ray DiffractionABSTRACT
Hyperthermia is one of the most recents therapies for cancer treatment using particles with nanometric size and appropriate magnetic properties for destroying cancer cells. Magnetic nanoparticles (MNP's) of Fe-Ga and synthesized using a polycondensation reaction by sol-gel method were obtained. MNP's of Fe(1.4)Ga(1.6)O(4) that possess an inverse spinel structure were identified by X-Ray Diffraction, Transmission Electron Microscopy, Scanning Electron Microscopy and Energy Dispersive Spectroscopy. The results showed that the MNP's are composed only by Fe, Ga and O and their size is between 15 and 20 nm. The magnetic properties measured by Vibration Sample Magnetometry demonstrated a saturation magnetization value of 37.5 emu/g. To induce the MNP's bioactivity, a biomimetic method was used which consisted in the immersion of MNP's in a Simulated Body Fluid (SBF) for different periods of time (7, 14 and 21 d) along with a wollastonite disk. The formation of a bioactive layer, which closely resembles that formed on the existing bioactive systems and with a Ca/P atomic ratio within a range of 1.37-1.73 was observed on the MNP's. Cytotoxicity of MNP's was evaluated by in vitro hemolysis testing using human red blood cells at concentrations between 0.25 and 6.0 mg/mL. It was found that the MNP's were not cytotoxic at none of the concentrations used. The results indicate that Fe-Ga MNP's are potential materials for cancer treatment of both hard and soft tissue by hyperthermia and drug carriers, among other applications.
Subject(s)
Ferric Compounds/chemistry , Ferric Compounds/chemical synthesis , Gallium/chemistry , Hyperthermia, Induced , Magnetite Nanoparticles , Biocompatible Materials/adverse effects , Biocompatible Materials/chemical synthesis , Biocompatible Materials/chemistry , Erythrocytes/drug effects , Ferric Compounds/adverse effects , Humans , Hyperthermia, Induced/instrumentation , Hyperthermia, Induced/methods , Magnetite Nanoparticles/adverse effects , Magnetite Nanoparticles/chemistry , Materials Testing , Microscopy, Electron, Scanning , Nanotechnology/methods , X-Ray DiffractionABSTRACT
In this work, Zn(1-x)CaxFe(2)O(4) nanoparticles (x = 0, 0.5 and 1) have been synthesized by sol-gel method followed by heat treatment at a temperature within the range of 300-700 °C. The samples with appropriate saturation magnetization (Ms), low coercivity and remanence were Zn(0)Ca(1)Fe(2)O(4) treated at 300 °C (Ms ~ 25 emu/g), Zn(0)Ca(1)Fe(2)O(4) treated at 400 °C (Ms ~ 40 emu/g) and Zn(0.50)Ca(0.50)Fe(2)O(4) treated at 400 °C (Ms ~ 31 emu/g). These samples were analyzed by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and transmission electron microscopy. The heating ability of selected nanoparticles was evaluated under a magnetic field using a solid state induction heating equipment. The obtained nanoferrites showed a particle size within the range of 13-14 nm. The Zn(0)Ca(1)Fe(2)O(4) treated at 400 °C was able to heat the nanoferrite particles/water suspension (10 mg/2 ml) at a temperature of 44 °C under the selected magnetic field (10.2 kA/m and frequency 362 kHz). Additionally, in vitro bioactivity assessment was performed by immersing samples in a simulated body fluid for different periods of time at physiological conditions of pH and temperature. The samples showed an appropriate bioactivity. These nanoferrites are highly potential materials for hyperthermia treatment.
Subject(s)
Calcium/chemistry , Ferric Compounds/chemical synthesis , Nanoparticles , Zinc/chemistry , Ferric Compounds/chemistry , Magnetics , Microscopy, Electron, Scanning , Nanoparticles/chemistry , Particle Size , Spectrometry, X-Ray Emission , Temperature , X-Ray DiffractionABSTRACT
Magnetic materials, which have the potential for application in heating therapy by hyperthermia, were prepared. This alternative treatment is used to eliminate cancer cells. Magnetite, magnesium-calcium ferrites and manganese-calcium ferrites were synthesized by sol-gel method followed by heat treatment at different temperatures for 30 min in air. Materials with superparamagnetic behavior and nanometric sizes were obtained in all the cases. Thus, these nanopowders may be suitable for their use in human tissue. The average sizes were 14 nm for magnetite, 10 nm for both Mg(0.4)Ca(0.6)Fe(2)O(4) and Mg(0.6)Ca(0.4)Fe(2)O(4) and 11 nm for Mn(0.2)Ca(0.8)Fe(2)O(4). Taking into account that the Mg(0.4)Ca(0.6)Fe(2)O(4) and Mg(0.6)Ca(0.4)Fe(2)O(4) treated at 350 °C showed the lower coercivity values, these nanoparticles were selected for heating tests and cell viability. Heating curves of Mg(0.4)Ca(0.6)Fe(2)O(4) subjected to a magnetic field of 195 kHz and 10 kA/m exhibited a temperature increase up to 45 °C in 15 min. A high human osteosarcoma cell viability of 90-99.5% was displayed. The human osteosarcoma cell with magnesium-calcium ferrites exposed to a magnetic field revealed a death cell higher than 80% in all the cases.
Subject(s)
Ferric Compounds/chemistry , Ferrosoferric Oxide/chemistry , Hyperthermia, Induced/instrumentation , Magnetic Phenomena , Nanoparticles/chemistry , Calcium/chemistry , Cell Survival , Cells, Cultured , Humans , Magnesium Compounds/chemistry , Magnetics/instrumentation , Magnetics/methods , Manganese Compounds/chemistry , Materials Testing , Nanoparticles/therapeutic useABSTRACT
The aim of this study was to determine the biocompatibility and potential toxicity of apatite-coated magnetite nanoparticles. The in vitro biocompatibility with human red blood cells was evaluated, not hemolytic effects were found at concentrations lower than 3 mg/ml. For the in vivo study, Balb/c mice were used. The animals were injected intravenously or intraperitoneally, the doses ranged from 100 to 2,500 mg/Kg. All the injected animals showed normal kidney and liver function. No significant changes were found in the body weight, the organs weight and the iron levels in liver due to the administration. In conclusion, apatite-coated magnetite nanoparticles did not induce any abnormal clinical signs in the laboratory animals. The results demonstrated that apatite-coated magnetite nanoparticles of 8 ± 2 nm in size did not have hemolytic effect in human erythrocytes and did not cause apparent toxicity in Balb/c mice under the experimental conditions of this study.
