IN THE PRESENT STUDY, THE EFFECTS OF VARIOUS EXPERIMENTAL FACTORS ON THE SIZE OF OBTAINED FE3O4 NANOPARTICLES WERE INVESTIGATED BY RESPONSE SURFACE METHOD (RSM).SUPER-PARAMAGNETIC IRON OXIDE (FE3O4) NANOPARTICLES HAVE GAINED MUCH ATTENTION DUE TO THEIR DISTINCTIVE PROPERTIES AND POTENTIAL BENEFITS IN BIOMEDICAL APPLICATION [1]. ONE OF THE PROMINENT SYNTHETIC ROUTS TOWARDS FE3O4 NANOPARTICLES IS CO-PRECIPITATION [2, 3].SYNTHETIC PROCEDURES NEED TO BE OPTIMIZED IN ORDER TO ACHIEVE THE BEST RESULTS. A MAJOR BOTTLENECK OF COMMON OPTIMIZATION PROTOCOLS IS THE VARIATION OF JUST ONE FACTOR AT EACH TRIAL WHILE MODERN OPTIMIZATION PROTOCOLS (EXPERIMENTAL DESIGN) TAKE INTO ACCOUNT A COMBINATION OF FACTOR LEVELS SIMULTANEOUSLY SATISFYING THE REQUIREMENTS CONSIDERED FOR EACH OF THE RESPONSES AND FACTORS. RSM IS A MODERN OPTIMIZATION PROTOCOL PROVIDING A QUANTIFICATION OF THE RELATIONSHIPS BETWEEN ONE OR MORE MEASURED RESPONSES AND THE VITAL INPUT FACTORS [4]. THIS TECHNIQUE INCLUDES A CATEGORY OF STATISTICAL METHODS FOR MODEL BUILDING AND EXPLOITATION.

Introduction: The synthesis of uniformly sized magnetic NANOPARTICLEs has been intensively pursued because of their broad applications, including magnetic storage media, ferrofluids, magnetic resonance imaging, and magnetically guided drug delivery.In this paper we have developed a novel water dispersible chitosan coated iron oxide magnetic NANOPARTICLE formulation that can be loaded easily with phenythoin sodium.Material and Methods: Synthesis of MAGNETITE NANOPARTICLEs was done through co-precipitation of Fe (II) and Fe (III) salts in the presence of NH4OH. The MAGNETITE NANOPARTICLEs were reacted with NH3 + groups of chitosan in acidic solution. During this process the chitosan absorbed on the surface of NANOPARTICLEs by electrostatic forces. Phenythoin sodium was dissolved into the mixture of methanol/water and added to nanaoparticle/chitosan dispersed solution, the solution was stirred for 24h at room temperature to ensure the particles were coated evenly. Transmission electron microscopy (TEM) was employed to study particle size and of the MAGNETITE/chitosan NANOPARTICLEs. The amount of drug loaded was examined by HPLC. The release behaviors of phenythoin sodium from this proposed controlled release system in PBS solution at 37ºC were also studied by HPLC method.Result and discussion: The results from HPLC show that more than 92% of added drug was entrapped in the formulation. The result also indicated that more than 50% of phenythoin sodium was loaded and the release profile was improved.

IN THIS STUDY, COBALT FERRITE MAGNETIC NANOPARTICLES WERE SYNTHESIZED FROM COBALT(II) CHLORIDE AND IRON(III) CHLORIDE. THEN, SIO2 SHELL WAS COATED ON THE COFE2O4 MAGNETIC NANOPARTICLES. THESE MAGNETIC NANOPARTICLES WERE FUNCTIONALIZED WITH 3-CHLOROPROPYLTRIMETHOXYSILANE (CPTMS) IN ORDER TO ENHANCE THE PERFORMANCE [1]. IN THE NEXT STEP, IMINE COMPLEX OF CU WAS PREPARED AND ANCHORED ONTO THE COFE2O4/SIO2/CPTMS. THE CHARACTERIZATION OF THE COMPOUNDS WAS STUDIED BY FOURIER TRANSFORM INFRARED SPECTROMETER (FT-IR), X-RAY DIFFRACTION (XRD), VIBRATING-SAMPLE MAGNETOMETERY (VSM), FIELD EMISSION SCANNING ELECTRON MICROSCOPY (FESEM), ENERGY-DISPERSIVE X-RAY SPECTROSCOPY (EDX), UV-VIS AND ATOMIC ABSORBTION TECHNIQUES. THE PREPARED COMPOUND AS A CATALYST WAS ABLE TO USE FOR ORGANIC REACTIONS, FOR EXAMPLE OXIDATION OF ALCOHOLS [2].

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

MAGNETITE NANOPARTICLES (MNPS) ARE MAGNETIC IRON OXIDES THAT HAVE A SUPER PARAMAGNETIC BEHAVIOR UNDER CERTAIN PARTICLE SIZES, WHICH CAN BE EASILY MAGNETIZED WITH AN EXTERNAL MAGNETIC FIELD AND REDISPERSED IMMEDIATELY, ONCE THE MAGNETIC FIELD IS REMOVED [1]. MNPS HAVE BEEN USED IN VARIOUS SCIENTIFIC FIELDS SUCH AS BIOTECHNOLOGY, ENGINEERING, BIOMEDICAL, ENVIRONMENTAL, SEPARATION AND MATERIAL SCIENCE [2-5]. BECAUSE OF THE IMPORTANCE AND VERY WIDE APPLICATION OF MNPS, IN THIS RESEARCH, ACID FOLIC COATED MAGNETITE NANOPARTICLES WERE PREPARED AND USED FOR THE FIRS TIME FOR SOLID PHASE EXTRACTION AND DETERMINATION OF ULTRA TRACE AMOUNTS OF PB (II) IN ENVIRONMENTAL SAMPLES. LEAD IS CLASSIFIED AS PREVALENT TOXIC METAL, WHICH CONSTITUTES A MAJOR ENVIRONMENTAL HEALTH PROBLEM. MAGNETITE NANOPARTICLES WERE PREPARED BY COPRECIPITATION METHOD, THEN WERE SILICA COATED WITH TETRAETHYLORTOSILICATE TO FORM WELL-DISPERSED MAGNETIC SILICA NANO SPHERES. IN THE NEXT STEP, FUNCTIONALIZATION WITH 3-AMINOPROPYL TRIMETHOXYSILANE WAS PERFORMED AND THEN FOLIC ACID WAS BONDED TO AMINE FUNCTIONALIZED MNPS. THE RESULTED NANOMATERIAL WAS CHARACTERIZED WITH DIFFERENT PHYSICOCHEMICAL TECHNIQUES SUCH AS FT-IR, VIBRATING SAMPLE MAGNETOMETRY (VSM) AND SCANNING ELECTRON MICROSCOPY (SEM). THIS NANOMATERIAL WAS USED IN SOLID PHASE EXTRACTION-AAS DETERMINATION OF PB (II) IONS IN ENVIRONMENTAL SAMPLES. 1.0 M HNO3 SOLUTION WAS USED AS PROPER DESORPTION SOLUTION. THE EFFECT OF VARIOUS PARAMETERS ON ADSORPTION OF THE IONS (PH, ADSORPTION AND DESORPTION TIME, ELUTION SOLUTION, …) WAS INVESTIGATED AND PERFORMANCE CHARACTERISTICS OF THE PROPOSED METHOD WERE OBTAINED (DETECTION LIMIT, ENRICHMENT FACTOR, PRECISION, ACCURACY, DYNAMIC LINEAR RANGE, …). THE RESULTS INDICATED THAT THIS MODIFIED MNPS CAN BE USED AS AN EFFICIENT ADSORBENT (WITH 98% REMOVAL PERCENTAGE) FOR PB (II) IONS IN PH =7.