Research paper Effect of cell media on polymer coated superparamagnetic iron oxide nanoparticles (SPIONs): Colloidal stability, cytotoxicity, and cellular uptake studies Alke Petri-Fink a, * ,1 , Benedikt Steitz a,b,1 , Andrija Finka a,c,1 , Jatuporn Salaklang a , Heinrich Hofmann a a Laboratory of Powder Technology, Ecole Polytechnique Fe ´de ´rale de Lausanne (EPFL), Lausanne, Switzerland b Microsystems Laboratory 4, Ecole Polytechnique Fe ´de ´ rale de Lausanne (EPFL), Lausanne, Switzerland c Regenerative Medicine and Pharmacobiology Laboratory, Ecole Polytechnique Fe ´de ´rale de Lausanne (EPFL), Lausanne, Switzerland Received 15 November 2006; accepted in revised form 2 February 2007 Available online 13 July 2007 Abstract The influence of the composition of the polymer coated polyvinyl alcohol (PVA), vinyl alcohol/vinyl amine copolymer (A-PVA) and polyethylenimine (PEI) coated superparamagnetic iron oxide nanoparticles (SPIONs) on the colloidal stability, cytotoxicity and cellular uptake of these particles in different cell media is reported in this paper. Although all examined polymer coated SPIONs were stable in water and PBS buffer these colloidal systems had different stabilities in DMEM or RPMI media without and supplemented with fetal calf serum (FCS). We found that A-PVA coating onto the surface of the SPIONs decreased the cytotoxicity of the polymer compared to the same concentration of A-PVA alone. As well, polyplexes of PEI-SPIONs with DNA in concentration used for transfection experiments showed no cytotoxicity compared to PEI and PEI-SPIONs. Our data show that the choice of medium largely influences the uptake of these particles by HeLa cells. The optimal medium is different for the different examined polymer coated SPIONs and it should be deter- mined in each case, individually. Ó 2007 Elsevier B.V. All rights reserved. Keywords: Superparamagnetism; Iron oxide; Nanoparticles; PVA; PEI; Colloidal stability; Cytotoxicity 1. Introduction The synthesis and characterization of nanoparticles have been a focus of intensive research for more than 10 years since they play an important role in electronics, catalysis, biology and medicine. Nanoparticles that can be biochem- ically functionalized are potential medical device systems that can be used in many different biological and medical fields of application. Beside the unique physical properties induced by surface or quantum effects, the size of the pri- mary particles is with 2–30 nm comparable to the size of biological building blocks and allows investigation of the cellular functioning or direct interaction with biological targets. Well described examples are inorganic photolumi- nescent particles (quantum dots) as markers or nanosized superparamagnetic iron oxide particles. Superparamagnet- ic particles with a diameter of around 10 nm have been used for many years for e.g. non-viral gene delivery, as MRI contrast agents, or for typical separation applications [1]. Those applications are relatively well established on the market, whereas targeted particle delivery is still in the development stage. It has been shown that magnetic parti- cles are physiologically well tolerated and that the surface 0939-6411/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.ejpb.2007.02.024 * Corresponding author. Laboratory of Powder Technology, Ecole Polytechnique Fe ´de ´rale de Lausanne (EPFL), EPFL-STI-IMX-LTP, Station 12, 1015 Lausanne, Switzerland. Tel.: +41 0 21 693 5107; fax: +41 021 693 3089. E-mail address: alke.fink@epfl.ch (A. Petri-Fink). 1 These authors contributed equally to this work. www.elsevier.com/locate/ejpb European Journal of Pharmaceutics and Biopharmaceutics 68 (2008) 129–137