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Polymeric and Ceramic Nanoparticles in Biomedical Applications  [PDF]
Aura-Ileana Moreno-Vega,Teresa Gómez-Quintero,Rosa-Elvira Nu?ez-Anita,Laura-Susana Acosta-Torres,Víctor Casta?o
Journal of Nanotechnology , 2012, DOI: 10.1155/2012/936041
Abstract: Materials in the nanometer size range may possess unique and beneficial properties, which are very useful for different medical applications including stomatology, pharmacy, and implantology tissue engineering. The application of nanotechnology to medicine, known as nanomedicine, concerns the use of precisely engineered materials at this length scale to develop novel therapeutic and diagnostic modalities. Nanomaterials have unique physicochemical properties, such as small size, large surface area to mass ratio, and high reactivity, which are different from bulk materials of the same composition. Polymeric and ceramic nanoparticles have been extensively studied as particulate carriers in the pharmaceutical and medical fields, because they show promise as drug delivery systems as a result of their controlled- and sustained-release properties, subcellular size, and biocompatibility with tissue and cells. These properties can be used to overcome some of the limitations found in traditional therapeutic and diagnostic agents. Nanotechnology is showing promising developments in many areas and may benefit our health and welfare. However, a wide range of ethical issues has been raised by this innovative science. Many authorities believe that these advancements could lead to irreversible disasters if not limited by ethical guidelines. 1. Introduction Recently, nanoparticles have been widely used in biomedical applications due to their specific physical and chemical properties which alter the normal biological activity, as compared to bulk materials [1]. The rise in the use of nanoparticles in this field therefore raises concern over the impact on human health such particles may have. This then requires the establishment of new regulations or adaptation of previous ones, based on a new definition of what needs to be regulated [2]. Such a science-based definition must be developed by several national and international standardization bodies, as well as organizations and authorities in order to have a definition that is broadly applicable to regulatory legislations. 2. Nanoparticles Assessments 2.1. A Working Definition of Nanoparticles Based on this, European and other International Committees have defined a nanoparticle as a discrete entity which has three dimensions in the order of 100?nm or less. Nevertheless it is important to remember that the nanoscale (1–100?nm) used to describe nanoparticles should not be considered as strictly due to the variations that may exist during the nanoparticle measurement as well as the appearance of nanoscale properties in
The Edge Electric Field of a Pyroelectric and its Applications  [PDF]
V. Sandomirsky,Y. Schlesinger,R. Levin
Physics , 2006, DOI: 10.1063/1.2399306
Abstract: Following a change of temperature of a pyroelectric (PE), a depolarizing electric field appears both inside the PE, as well as outside its edges, the edge depolarizing electric field (EDEF). The EDEF extends outwards up to a distance of the order of magnitude of the PE width. The mapping and the strength of the EDEF have been calculated and analyzed for the case of a semi-infinite pyroelectric plate. This strong EDEF (104-105 V/cm), when penetrating into the surrounding medium, creates a variety of physical effects: inducing electrical current in a semiconductor and affecting its resistance, accelerating charged and neutral particles in vacuum or in a gas, generating electromagnetic waves, modifying optical characteristics by electrooptical and photoelasic effects, generating piezoelectric deformation and more. We show that these EDEF induced effects could serve as a basis for the development of various applications and devices.
Functionalized Gold Nanoparticles and Their Biomedical Applications  [PDF]
Pooja M. Tiwari,Komal Vig,Vida A. Dennis,Shree R. Singh
Nanomaterials , 2011, DOI: 10.3390/nano1010031
Abstract: Metal nanoparticles are being extensively used in various biomedical applications due to their small size to volume ratio and extensive thermal stability. Gold nanoparticles (GNPs) are an obvious choice due to their amenability of synthesis and functionalization, less toxicity and ease of detection. The present review focuses on various methods of functionalization of GNPs and their applications in biomedical research. Functionalization facilitates targeted delivery of these nanoparticles to various cell types, bioimaging, gene delivery, drug delivery and other therapeutic and diagnostic applications. This review is an amalgamation of recent advances in the field of functionalization of gold nanoparticles and their potential applications in the field of medicine and biology.
Tagetes erecta mediated phytosynthesis of silver nanoparticles: an eco-friendly approach
Nusantara Bioscience , 2012,
Abstract: Dhuldhaj UP, Deshmukh SD, Gade AK, Yashpal M, Rai MK. 2012. Tagetes erecta mediated phytosynthesis of silver nanoparticles:an eco-friendly approach. Nusantara Bioscience 4: 109-112. Nanotechnology is a multidisciplinary field having applications in the various fields like medicine, pharmacy, engineering and biotechnology. An important step in nanotechnology is to develop simple and eco-friendly method for the nanomaterial synthesis. Here we describe simple and eco-friendly method for synthesis of silver nanoparticles by extract of Tagetes erecta plant leaves. The phytosynthesis (synthesis by plant) of silver nanoparticles was detected by color change from light-green to dark-brown. Synthesis of silver nanoparticles was confirmed by UV-Vis spectrophotometry, further characterization includes nanoparticle tracking analysis system (NTA) (LM20) and transmission electron microscopy (TEM). TEM analysis confirms the synthesis of the polydispersed spherical silver nanoparticles of 20-50 n
Finite field dependent BRST transformations and its applications to gauge field theories  [PDF]
Sudhaker Upadhyay
Physics , 2013,
Abstract: The Becchi-Rouet-Stora and Tyutin (BRST) transformation plays a crucial role in the quantization of gauge theories. The BRST transformation is also very important tool in characterizing the various renormalizable field theoretic models. The generalization of the usual BRST transformation, by making the infinitesimal global parameter finite and field dependent, is commonly known as the finite field dependent BRST (FFBRST) transformation. In this thesis, we have extended the FFBRST transformation in an auxiliary field formulation and have developed both on-shell and off-shell FF-anti-BRST transformations. The different aspects of such transformation are studied in Batalin-Vilkovisky (BV) formulation. FFBRST transformation has further been used to study the celebrated Gribov problem and to analyze the constrained dynamics in gauge theories. A new finite field dependent symmetry (combination of FFBRST and FF-anti-BRST) transformation has been invented. The FFBRST transformation is shown useful in connection of first-class constrained theory to that of second-class also. Further, we have applied the Batalin-Fradkin-Vilkovisky (BFV) technique to quantize a field theoretic model in the Hamiltonian framework. The Hodge de Rham theorem for differential geometry has also been studied in such context.
Polylactide-co-glycolide nanoparticles for controlled delivery of anticancer agents  [cached]
Dinarv,R,Sepehri N,Manoochehri S
International Journal of Nanomedicine , 2011,
Abstract: R Dinarvand1,2, N Sepehri1, S Manoochehri1, H Rouhani1, F Atyabi1,21Department of Pharmaceutics, Faculty of Pharmacy, 2Nanotechnology Research Centre, Tehran University of Medical Sciences, Tehran, IranAbstract: The effectiveness of anticancer agents may be hindered by low solubility in water, poor permeability, and high efflux from cells. Nanomaterials have been used to enable drug delivery with lower toxicity to healthy cells and enhanced drug delivery to tumor cells. Different nanoparticles have been developed using different polymers with or without surface modification to target tumor cells both passively and/or actively. Polylactide-co-glycolide (PLGA), a biodegradable polyester approved for human use, has been used extensively. Here we report on recent developments concerning PLGA nanoparticles prepared for cancer treatment. We review the methods used for the preparation and characterization of PLGA nanoparticles and their applications in the delivery of a number of active agents. Increasing experience in the field of preparation, characterization, and in vivo application of PLGA nanoparticles has provided the necessary momentum for promising future use of these agents in cancer treatment, with higher efficacy and fewer side effects.Keywords: nanotechnology, polymeric nanocarriers, targeting, anticancer agents, surface modification
Structure and Magnetic Properties of Aerosol Nanoparticles of Fe and Its Alloys  [PDF]
Yu. I. Petrov,E. A. Shafranovsky
International Journal of Inorganic Chemistry , 2012, DOI: 10.1155/2012/610305
Abstract: Structure and magnetic properties of aerosol nanoparticles of Fe and its alloys (FeMn, FeNi, FeNiMn, FePt, FeCr, FeCo, and FeCu) have been reviewed. It has been shown that, compared to a bulk material, the particles have a number of specific features being of much fundamental and applied interest. The effect of both a quenched high-temperature Fe modification and its oxides on the structure and magnetism of nanoparticles has been considered in detail. Particular attention has been paid to the recently observed fine structure in the hyperfine field distribution at iron nuclei in M?ssbauer spectra for pure iron and its alloys both as a bulk and aerosol nanoparticles. This phenomenon makes it possible to reveal very weak magnetic interactions in the system under study. The plausible origin of these magnetic interactions has been also discussed. 1. Introduction Nowadays investigation of the properties of Fe-based nanoparticles is of much interest from fundamental and applied standpoints [1–3]. These particles have high coercivity, and, according to estimates, they are single domain. Short chains of Fe particles and elongated Fe3O4 particles have long been used for magnetic recording. This is due to their high magnetic anisotropy, large magnetic moment per volume unit, and rectangular hysteresis loop. A rapidly developing nanotechnology [4] offers new applications of magnetic particles. This is, first, development of ultrahigh-density magnetic storage devices based on the giant magnetoresistance effect. Nanoparticles of metastable ball-milled Cu-rich FeCu alloys approach for this purpose. They show a giant magnetoresistance effect, which can be also used to develop sensors [5–8]. Second, magnetic nanoparticles can be used for drug delivery. Magnetic fine particles can act as a contrast agent for magnetic resonance imaging and can be used for cell separation and various cancer treatments. The latter may be performed, for example, by directing Fe3O4 particles to tumour sites, using a liquid suspension comprising ultrafine particles surrounded by chains of a blood-plasma substitute. Then one can induce hyperthermia in the targeted cells by a localized heating of magnetite with an RF generator. Magnetic fine particles have also been used to orient biological assemblies and to isolate red blood cells. A number of reviews on magnetic nanoparticles for applying in technology and biomedicine is growing rapidly day by day. The properties of ferromagnetic and antiferromagnetic nanoparticles applied in magnetic fluids for sealing, damping, sensing, and bearing
Sustained Release of Prindopril Erbumine from Its Chitosan-Coated Magnetic Nanoparticles for Biomedical Applications  [PDF]
Dena Dorniani,Mohd Zobir Bin Hussein,Aminu Umar Kura,Sharida Fakurazi,Abdul Halim Shaari,Zalinah Ahmad
International Journal of Molecular Sciences , 2013, DOI: 10.3390/ijms141223639
Abstract: The preparation of magnetic nanoparticles coated with chitosan-prindopril erbumine was accomplished and confirmed by X-ray diffraction, TEM, magnetic measurements, thermal analysis and infrared spectroscopic studies. X-ray diffraction and TEM results demonstrated that the magnetic nanoparticles were pure iron oxide phase, having a spherical shape with a mean diameter of 6 nm, compared to 15 nm after coating with chitosan-prindopril erbumine (FCPE). Fourier transform infrared spectroscopy study shows that the coating of iron oxide nanoparticles takes place due to the presence of some bands that were emerging after the coating process, which belong to the prindopril erbumine (PE). The thermal stability of the PE in an FCPE nanocomposite was remarkably enhanced. The release study showed that around 89% of PE could be released within about 93 hours by a phosphate buffer solution at pH 7.4, which was found to be of sustained manner governed by first order kinetic. Compared to the control (untreated), cell viability study in 3T3 cells at 72 h post exposure to both the nanoparticles and the pure drug was found to be sustained above 80% using different doses.
Biosynthesis of Silver Chloride Nanoparticles Using Bacillus subtilis MTCC 3053 and Assessment of Its Antifungal Activity  [PDF]
Kanniah Paulkumar,Shanmugam Rajeshkumar,Gnanadhas Gnanajobitha,Mahendran Vanaja,Chelladurai Malarkodi,Gurusamy Annadurai
ISRN Nanomaterials , 2013, DOI: 10.1155/2013/317963
Abstract: The present investigation reported the synthesis of silver chloride nanoparticles using Bacillus subtilis. The adsorption of colloidal silver chloride nanoparticles showed an intense peak at the wavelength of 400?nm after 20?hrs of biomass incubation. The size of the silver nanoparticles ranges from 20 to 60?nm which was obtained from transmission electron microscope (TEM). The X-ray diffraction (XRD) pattern confirmed the crystalline nature of the nanoparticles. The bright circular spots of selected diffraction area (SAED) pattern also confirmed the good crystalline nature of the silver chloride nanoparticles with high magnification of TEM images. The presence of nitrate reductase enzyme in the cellular membrane of B. subtilis was confirmed by sodium dodecyl (SDS) polyacrylamide gel electrophoresis and it was found that the molecular weight is 37?kDa. The possible functional groups of the reductase enzyme in B. subtilis were identified by Fourier transform infrared spectroscopy (FTIR). Finally, antifungal activity of silver chloride nanoparticle was examined against Candida albicans, Aspergillus niger, and Aspergillus flavus. We conclude that the synthesis of silver chloride nanoparticles using microorganisms is more economical and simple. The antifungal property of silver chloride nanoparticles will play a beneficial role in biomedical nanotechnology. 1. Introduction After a glorious invention of microorganisms by “Louis Pasteur,” it could spread all over the field of life sciences and delivered its beneficial applications to improve human health. From 19th century onwards, the microorganisms have been utilized for making dairy products, beverages (alcoholic), enzymes, proteins production, and so forth [1]. In modern microbiology, the interaction between metals and microbes brings a great attention to exclude the heavy metals from the environment [1, 2]. The presence of active biomolecules like enzymes in the cell wall membrane of microorganisms plays an adverse effect in degradation of toxic metals by the way of bioremediation process [1, 3]. Nowadays, the biosynthesis of nanomaterials like inorganic nanoparticles and semiconductor nanoparticles using microorganisms such as bacteria [4, 5] and fungi [6, 7] is a popularly known field and attracts more interest day-by-day due to its ecofriendly nature. Traditionally, nanoparticles have been synthesized through physical [8–10] and chemical methods [11–13]. However, these methods are not environmentally benign. Some of the chemicals such as thiophenol [14] and thiourea [15] have been used in the
Polymerase Chain Reaction: Types and its Applications in the Field of Biology
R. Manojkumar,Mrudula Varanat
International Journal of Tropical Medicine , 2012,
Abstract: For disease control and eradication and in countries trying to establish a disease free status, effective diagnostic is a paramount. Many diagnostics find its application throughout different levels of laboratory research processes. Polymerase Chain Reaction (PCR) is one of the most important molecular diagnostic tools which allow the detection of nucleic acid targets. Because of its excellent sensitivity, specificity and speed, PCR has rapidly become the widely used molecular biological techniques in scientific, medical and research fields. There are different types of PCRs which are used specifically for certain specific purposes. The types of PCR and their applications are discussed in this review article.
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