Ultrasound studies on magnetic fluids based on maghemite nanoparticles

Abstract

In the last decades, the study of magnetic fluids with different biomedical applications such as targeted delivery of a chemotherapeutic solution to the tumor site has been of high interest. For this purpose, ultrasonic and antimicrobial studies were used to characterize the aqueous solutions based on maghemite nanoparticles. The maghemite (γ‐Fe2O3) and dextran‐coated maghemite nanoparticles (DMNp) were synthesized by coprecipitation method. The spherical shape of the nanoparticles and uniform size with an average diameter around 9.5 ± 0.5 nm for γ‐Fe2O3 were observed in transmission electron microscopy micrographs. Dynamic light scattering was used to determine the hydrodynamic size of γ‐Fe2O3 nanoparticles and DMNp in suspensions. The hydrodynamic diameter obtained of γ‐Fe2O3 and DMNp was 17 and 21 nm, respectively. Moreover, a noninvasive method based on ultrasounds was used to characterize the aqueous solutions. The preliminary results showed the attainable accuracy in determining acoustic wave velocity and attenuation in various solutions. These data could be correlated with particle density and size. More than that, velocity and attenuation can be used as characteristic parameters of a given solution. A finite element model of the dispersed particles, correlated with measured velocity, allowed to solve for the elastic properties of the particles. POLYM. ENG. SCI., 57:485–490, 2017. © 2017 Society of Plastics Engineers

Textural, Structural and Biological Evaluation of Hydroxyapatite Doped with Zinc at Low Concentrations

“…The vibrational bands found in the spectral regions 870–880 cm −1 and 1036–1050 cm −1 correspond to carbonate and phosphate groups, although it is difficult to separate them. At around 873 cm −1 , a vibrational band characteristic to the phosphate group can be found [ 2 ], which overlaps with the 875 cm −1 band characteristic to the carbonate group [ 28 ]. The same behavior occurs at around 1420 cm −1 .…”

“…In the last decades, researchers worldwide have focused their attention on the development of new and improved biomaterials for different biomedical applications [ 1 , 2 , 3 , 4 ]. One of the main concerns in the medical field is finding new ways to treat bone diseases such as osteoporosis.…”

“…Due to the fact that in most cases the installation of osteoporosis does not exhibit any symptoms, one of the first indication of this disease being a fractured bone, physicians from all around the world are trying to create synthetic materials that can not only mimic the human hard tissue, but also improve the quality of the host tissue. Considering that hydroxyapatite (HAp), having the chemical formula Ca 10 (PO 4 ) 6 (OH) 2 , is the main inorganic constituent of human bones, synthetic HAp is already used in bone graft surgeries [ 1 , 2 , 3 , 4 ]. Hydroxyapatite is a biomaterial used on a large scale due to its outstanding biocompatible and bioactive properties [ 5 ].…”

Preparation and Characterization of Dextran Coated Iron Oxide Nanoparticles Thin Layers

“…In general, to prevent the agglomeration of nanoparticles and to improve their colloidal stability and biological properties, they are incorporated into polymers (chitosan, dextran, poly(vinyl alcohol)—PVA, gelatin, polyvinylpyrrolidone (PVP), etc.) [ 6 , 13 , 14 , 15 , 16 ]. Dextran, (H(C 6 H 10 O 5 )xOH), is one of the most widely used natural polysaccharides used as a coating for SPION [ 1 ].…”

Structural and Antimicrobial Evaluation of Silver Doped Hydroxyapatite-Polydimethylsiloxane Thin Layers

“…Also, a frequent cause of infection acquired in hospitals is contamination with fungi, especially with Candida albicans (C. albicans) [8][9][10]. This lifethreatening fungus is considered in United States to be the fourth most frequently encountered cause of systemic infections acquired from hospitals [8][9][10][11]. It is responsible for deep tissue and mucosal infections being associated with biofilm growth [12].…”