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ABSTRACT: Albumin/drug loaded magnetic nanocomposite spheres were fabricated using an oil-in-oil emulsion/solvent evaporation method, and tested on a mouse model (experimental squamous cell carcinoma) to determine the efficacy of the drug delivery system (DDS) on skin cancer. This novel DDS consists of human serum albumin, poly(lactic-co-glycolic acid) (PLGA), 5-fluorouracil (5-Fu), magnetic nanoparticles (10nm) and fluorescent labeling molecule (diphenylhexatriene). One of the major purposes of using albumin is that it likely provides internal binding to and retention by the inflammatory tissues to reduce the amount of magnetic nanoparticles needed in the drug loaded microspheres (750-1100nm). This study is aimed at reducing many negative side effects of conventionally used chemotherapy drugs by localizing the chemotherapy drug, controlling the release of the therapeutic agent and encouraging uptake of the DDS into cancerous cells. A group of mice treated with (1) the magnetic targeted DDS were compared to the other three groups, including (2) DDS without a magnet, (3) 5-Fu local injection, and (4) untreated groups. The fluorescent tracer was ubiquitously identified inside the tumor tissue, and the DDS/tumor tissue boundary presented a leaky interface. The test results clearly showed that the magnetic targeted DDS exhibited significantly superior therapeutic effects in treating the skin cancer, with the increased efficacy to halt the tumor growth.
Journal of biotechnology 02/2013; · 2.88 Impact Factor
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ABSTRACT: The efficacy of chemotherapy can be significantly improved if the therapeutic agent remains localized at the afflicted area and released at controlled rates. Such a targeted drug delivery can be achieved using magnetic nanocomposite (MNC), which incorporates drug and magnetic nanoparticles in biodegradable polymer microspheres. Reported here are results from an in vitro study on drug release rate and cytotoxicity of other release products from MNC. The model system contains an anti-cancer chemotherapy agent 5-flurouracil (5-FU) and (Co(0.5)Zn(0.5))Fe(2)O(4) in poly(lactic-co-glycolic acid) (PLGA) matrix produced by an oil/oil emulsion technique. Cell proliferation data indicate a sustained release of 5-FU for mouse macrophage cell eradication, whereas other microsphere components of magnetic nanoparticles and PLGA have little cytotoxic effects.
Journal of Biomaterials Applications 11/2011; · 2.08 Impact Factor
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ABSTRACT: A microfluidic device was fabricated via UV lithography technique to separate non-magnetic fluoresbrite carboxy microspheres (approximately 4.5 microm) in the pH 7 ferrofluids made of magnetite nanoparticles (approximately 10 nm). A mixture of microspheres and ferrofluid was injected to a lithographically developed Y shape microfluidic device, and then by applying the external magnet fields (0.45 T), the microspheres were clearly separated into different channels because of the magnetic force acting on those non-magnetic particles. During this study, various pumping speeds and particle concentrations associated with the various distances between the magnet and the microfluidic device were investigated for an efficient separation. This study may be useful for the separation of biological particles, which are very sensitive to pH value of the solutions.
Journal of Nanoscience and Nanotechnology 10/2010; 10(10):6383-7. · 1.56 Impact Factor
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ABSTRACT: In the tetragonal crystalline structure of MnxFe1−xSe0.85, the magnetic state contains low- and high-spin Fe2+, with high-spin numbers equal to that of the combined Mn substitute and Se deficiency atoms. The state is pinned by "spin-hopping" around substitution centers via high-spin↔low-spin conversions. During the structural distortion from tetragonal to orthorhombic, from 90 K to 70 K, the rate of spin conversions increases and the iterant character of the magnetic state is enhanced. In the orthorhombic structure, the spin dynamics evolve into an incommensurate spin-density wave (ISDW). Excitations of the ISDW decrease with temperature and level out across the superconducting phase. The ISDW appears to have more than one oscillation mode and contributions from high-order harmonics.
EPL (Europhysics Letters) 04/2010; 89(6):67009. · 2.17 Impact Factor
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http://dx.doi.org/10.1209/0295-5075/89/67009.
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ABSTRACT: Nanotechnology can improve many physical, chemical, physicochemical, and biological properties of materials, which can be very useful for many industries, including biomedical, aerospace, textile, cosmetic, manufacturing, oil, agricultural, defense, and electronic. However, nanotechnology products (or nanomaterials) also can be hazardous materials because of the way they are manipulated on an atomic scale. Since nanomaterials, such as nanotubes, nanoparticles, nanowires, nanofibers, nanocomposites, and nanofilms, are all new materials produced with entirely new manufacturing techniques, there are no specific rules and regulations for many of them. In the present nanoethics study, we will provide a detailed report of the ethical, social, philosophical, environmental, safety, and other legal issues of nanotechnology and its products, which can be very useful for the training and protection of students, as well as scientists, engineers, policymakers, and regulators working in the field.
