Vol.:(0123456789) 1 3 Chemistry Africa https://doi.org/10.1007/s42250-019-00097-4 ORIGINAL ARTICLE Structured Magnetic Core/Silica Internal Shell Layer and Protein Out Layer Shell (BSA@SiO 2 @SME): Preparation and Characterization Mohamad Tarhini 1  · Jaime Vega‑Chacón 1,2  · Miguel Jafelicci Jr. 2  · Nadia Zine 3  · Abdelhamid Errachid 3  · Hatem Fessi 1  · Abdelhamid Elaissari 1 Received: 11 July 2019 / Accepted: 1 October 2019 © The Tunisian Chemical Society and Springer Nature Switzerland AG 2019 Abstract Purpose Magnetic nanoparticles are an interesting approach in the biomedical and biotechnological feld. They can be used as a drug delivery system or in magnetic resonance imaging. However, these particles have the disadvantage of being colloidally instable, easily oxidized, and sufer from partial toxicity. To overcome these problems, magnetic nanoparticles were coated by diferent types of coats such as silica, polymer, etc. the purpose of this study is to develop a coated iron oxide nanoparticle system. Methods Seed magnetic emulsion particles (SME) were frst prepared and characterized before inducing silica layer using sol–gel process. The obtained SiO 2 @SME particles are then encapsulated using bovine serum albumin (BSA) layer. This proteins layer was performed via nanoprecipitation of BSA molecules on the SME. Particles were characterized by electron microscopy, FTIR, TGA, and zeta potential measurement. Results Characterization studies confrm the successful coating of BSA on the surface of amino-functionalized silica shell and magnetic core. Conclusion The used process leads to the preparation of highly magnetic particles encapsulated with silica layer ad then coated with proteins shell. The presence of silica shell will enhance the chemical stability of the magnetic core, whereas, the presence of proteins shell will improve low cytotoxicity and good biocompatibility in the contact with biological samples. Keywords Bovine serum albumin · Nanoparticle · Iron-oxide · Core–shell · Coating · Encapsulation · Nanoprecipitation 1 Introduction Magnetic nanoparticles have gained much attention in the biomedical feld, targeted drug delivery, and bio-imaging due to their ability to respond to magnetic feld [1]. Magnetic particles made from iron oxide are particularly important because of their availability and manufacturing simplic- ity. In addition, these particles feature a superparamagnetic behavior. Briefy, they are only magnetized in the presence of a magnetic feld. While their magnetization is zero in the absence of the latter. This property gives the nanoparticles an extra stability when dispersed in solution [2]. Magnetic nanoparticles were prepared via various tech- niques such as co-precipitation, micelle synthesis, hydro- thermal synthesis, thermal decomposition, etc. [3–7]. Nano- particles were produced with a low size range (2–100 nm) allowing the easy penetrability through biological barriers [8, 9]. However, particles in this size range sufer from col- loidal and chemical instability at a long term. These particles tend to form agglomerates to reduce the energy of the sys- tem caused by the high surface area/volume ratio. In addi- tion, metallic nanoparticles in general are chemically highly active, and can be easily oxidized in air which may lead to the loss of magnetization and dispersibility [10]. Solutions were suggested to solve this problem, such as coating the particles with diferent materials, organic or inorganic, such as surfactants, polymer, or silica [10]. This coating step, can chemically stabilize magnetic particles against degradation as a function of time. In addition, coating can be used for * Abdelhamid Elaissari abdelhamid.elaissari@univ-lyon1.fr 1 Univ Lyon, University Claude Bernard Lyon-1, CNRS, LAGEP-UMR 5007, 69622 Lyon, France 2 Institute of Chemistry, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil 3 Institute of Analytical Sciences, UMR 5280, Claude Bernard Lyon 1 University, University of Lyon, Villeurbanne, France