8 November 2010 in Journal of Biomedical Materials Research Part B: Applied Biomaterials
The first part of this review looks at the fundamental properties of hydroxyapatite (HAP), the basic mineral constituent of mammalian hard tissues, including the physicochemical features that govern its formation by precipitation. A special emphasis is placed on the analysis of qualities of different methods of synthesis and of the phase transformations intrinsic to the formation of HAP following precipitation from aqueous solutions. This serves as an introduction to the second part and the main subject of this review, which relates to the discourse regarding the prospects of fabrication of ultrafine, nanosized particles based on calcium phosphate carriers with various therapeutic and/or diagnostic agents coated on and/or encapsulated within the particles. It is said that the particles could be either surface‐functionalized with amphiphiles, peptides, proteins, or nucleic acids or injected with therapeutic agents, magnetic ions, or fluorescent molecules. Depending on the additive, they could be subsequently used for a variety of applications, including the controlled delivery and release of therapeutic agents (extracellularly or intracellularly), magnetic resonance imaging and hyperthermia therapy, cell separation, blood detoxification, peptide or oligonucleotide chromatography and ultrasensitive detection of biomolecules, andin vivoandin vitrogene transfection. Calcium phosphate nanoparticles as carriers of therapeutic agents that would enable a controlled drug release to treat a given bone infection and at the same be resorbed in the body so as to regenerate hard tissue lost to disease are emphasized hereby as one of the potentially attractive smart materials for the modern medicine. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
1 May 2009 in Journal of Power Sources
Olivine structure LiFePO4 attracted much attention as a promising cathode material for lithium-ion batteries. The overwhelming advantage of iron-based compounds is that, in addition to being inexpensive and naturally abundant, they are less toxic than Co, Ni, and Mn. Its commercial use has already started and there are several companies that base their business on lithium phosphate technology. Still, there is a need for a manufacturing process that produces electrochemically active LiFePO4 at a low cost. Therefore the interest in developing new approaches to the synthesis of LiFePO4 did not fade. Here is presented a review of the synthesis procedures used for the production of LiFePO4 powders along with the highlights of doped and coated derivatives. Apart from already established conventional routes of preparation, numerous alternative procedures are mentioned
1 February 2013 in Colloids and Surfaces B: Biointerfaces
17 June 2008 in Crystal Growth & Design
17 September 2010 in Nanotoxicology
We investigated the genotoxic responses to two types of TiO2 nanoparticles (<25 nm anatase: TiO(2)-An, and <100 nm rutile: TiO2-Ru) in human hepatoma HepG2 cells. Under the applied exposure conditions the particles were agglomerated or aggregated with the size of agglomerates and aggregates in the micrometer range, and were not cytotoxic. TiO2-An, but not TiO2-Ru, caused a persistent increase in DNA strand breaks (comet assay) and oxidized purines (Fpg-comet). TiO2-An was a stronger inducer of intracellular reactive oxygen species (ROS) than TiO2-Ru. Both types of TiO2 nanoparticles transiently upregulated mRNA expression of p53 and its downstream regulated DNA damage responsive genes (mdm2, gadd45α, p21), providing additional evidence that TiO2 nanoparticles are genotoxic. The observed differences in responses of HepG2 cells to exposure to anatase and rutile TiO2 nanoparticles support the evidence that the toxic potential of TiO2 nanoparticles varies not only with particle size but also with crystalline structure.
4 June 1999 in Biomaterials