Controlled release study of an anti-carcinogenic agent, gallate from the surface of magnetite nanoparticles Mohammad Yeganeh Ghotbi a,n , Mohd Zobir bin Hussein b a Nanomaterials and Nanotechnology Program, Ceramic Engineering Department, Faculty of Engineering, Malayer University, Malayer, Iran b Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia article info Article history: Received 23 February 2011 Received in revised form 12 February 2012 Accepted 19 February 2012 Available online 24 February 2012 Keywords: A. Magnetic materials A. Nanostructures B. Chemical synthesis C. X-ray diffraction abstract Immobilization of gallate anion, an anti-carcinogenic, anti-mutagenic, and anti-microbial agent on the surface of magnetite nanoparticles was accomplished by adsorption technique for the formation of a core–shell nanocomposite. A simple co-precipitation technique in the presence of poly vinyl pyrroli- done was successfully applied for the preparation of magnetite nanoparticles as core beads with narrow size distribution. The powders were characterized by X-ray diffraction, particle size analysis, magnetic measurements, atomic force microscope and also infrared spectroscopy. FTIR and CHNS results indicated that the gallate anion was actually adsorbed onto the surface of the magnetite nanoparticles. The release of the anion from the surface of the nanocomposite was found to be controllable by the selection of the release media. & 2012 Elsevier Ltd. All rights reserved. 1. Introduction Nanosized magnetic materials such as magnetite have been used frequently as carrier surfaces for functional materials due to its ability to deliver useful functional materials to specific sites by an external magnetic field. Also, it has been applied in special medical techniques such as MRI and drug delivery. The develop- ment of organic–inorganic nanocomposite material containing these core–shell systems can be achieved by the adsorption of functional materials such as drugs on uniform inorganic cores to obtain nanosized bioactive materials [1–5]. Magnetite (Fe 3 O 4 ) has an inverse spinel structure, which contains iron cations in mixed oxidation states with Fe 3 þ (Fe 2 þ Fe 3 þ )O 4 formula. The oxygen forms a face-centered cubic close-packed array and the Fe 2 þ and half of the Fe 3 þ ions are in octahedral sites and the remaining half of the Fe 3 þ cations occupy tetrahedral sites. The electrons can jump between Fe 2 þ and Fe 3 þ in the octahedral sites at room temperature, rendering magnetite an important class of half- metallic materials. With proper surface coating, these magnetic nanoparticles can be dispersed into suitable solvents, forming homogeneous suspensions and can be positioned to a specific area for targeting purposes [6,7]. Non-toxicity, biocompatibility, higher chemical stability and high-level accumulation in the target area are amongst the most crucial characteristics of these superparamagnetic iron oxide nanoparticles for medical purposes [8,9]. Gallic acid (3,4,5-trihydroxybenzoic acid) is an anti-mutagenic, anti-carcinogenic, anti-inflammatory and antimicrobial agent. Gallnut, sumac, black tea and some other plants are just handful examples of natural products in which gallic acid can be traced in noticeable amount [10–12]. In the present study, the immobilization of gallate anion on the surface of magnetite nanoparticles, pre-prepared using poly vinyl pyrrolidone (PVP) as a stabilizer and size controlling agent will be discussed. PVP acts as a polymeric stabilizer, which has been frequently used to reduce the nanoparticles size and improve the size distribution of particles [13]. In this study, magnetite was chosen as a core and gallate anion (GA) as a shell to be adsorbed on the surface of the core. Results from the XRD, magnetic studies, particle size analysis and FTIR as well as release property of gallate anion from the magnetite–gallate nanocom- posites into the aqueous media are discussed in this paper. 2. Materials and methods All solutions were prepared using de-ionized water. The magnetite nanoparticles were synthesized by co-precipitating Fe þ 2 and Fe þ 3 as previously reported by Chen and Liao [14], but with the addition of a polymer, PVP as stabilizer at various percentages, 0.5–2.5% (w/v). Fe 2 (SO 4 ) 3  6H 2 O and FeCl 2  4H 2 O and PVP were dissolved in de-ionized water with Fe þ 3 /Fe þ 2 , R i ¼ 2 and ([Fe þ3 ] þ [Fe þ 2 ]) ¼ 0.15 M. The solution was brought at pH Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/jpcs Journal of Physics and Chemistry of Solids 0022-3697/$ - see front matter & 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.jpcs.2012.02.031 n Corresponding author: Tel.: þ98 851 223 2346; fax: þ98 851 222 1977. E-mail addresses: yeganehghotbi@gmail.com, m.yeganeh@malayeru.ac.ir (M.Y. Ghotbi). Journal of Physics and Chemistry of Solids 73 (2012) 936–942