Please cite this article in press as: Perret, F., et al., Preparation and characterization of CK2 inhibitor-loaded cyclodextrin nanoparticles for drug delivery. Int J Pharmaceut (2012), http://dx.doi.org/10.1016/j.ijpharm.2012.11.004 ARTICLE IN PRESS G Model IJP-12957; No. of Pages 8 International Journal of Pharmaceutics xxx (2012) xxx–xxx Contents lists available at SciVerse ScienceDirect International Journal of Pharmaceutics jo ur nal homep a ge: www.elsevier.com/locate/ijpharm Preparation and characterization of CK2 inhibitor-loaded cyclodextrin nanoparticles for drug delivery Florent Perret a,∗ , Christelle Marminon b , Wael Zeinyeh b , Pascal Nebois b , Andre Bollacke c , Joachim Jose c , Hélène Parrot-Lopez a , Marc Le Borgne b a Université de Lyon, Université Lyon 1, CSAp, Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, Bâtiment Raulin, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France b Université de Lyon, Université Lyon 1, Faculté de Pharmacie - ISPB, EA 4446 Biomolécules Cancer et Chimiorésistances, SFR Santé Lyon-Est CNRS UMS3453 - INSERM US7, 8 avenue Rockefeller, F-69373 Lyon Cedex 8, France c Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität Münster, Hittorfstraße 58-62, 48149 Münster, Germany a r t i c l e i n f o Article history: Received 28 August 2012 Received in revised form 31 October 2012 Accepted 3 November 2012 Available online xxx Keywords: CK2 inhibitor Indeno[1,2-b]indole derivative Amphiphilic cyclodextrins Drug delivery Nanoparticles Encapsulation a b s t r a c t Casein Kinase 2 (CK2) is a ubiquitous kinase protein currently targeted for the treatment of some can- cers. Recently, the series of indeno[1,2-b]indoles has revealed great interest as potent and selective CK 2 ATP-competitive inhibitors. Among them, 1-amino-5-isopropyl-5,6,7,8-tetrahydroindeno[1,2-b]indole- 9,10-dione (CM1) was selected for an encapsulation study in order to improve its biodisponibility. Its complexation was evaluated at the molecular scale, with a series of fluorinated or hydrocarbon- ated amphiphilic cyclodextrins (CDs). Then the encapsulation of CM1 within CD nanoparticles at the supramolecular level was achieved. Nanoparticles formed between CM1 and hexakis[6-deoxy-6-(3- perfluorohexylpropanethio)-2,3-di-O-methyl]--cyclodextrin, a fluorinated amphiphilic -cyclodextrin, gave the best results in terms of encapsulation rate, stability and drug release. These nanospheres showed an encapsulation efficiency of 65% and a sustained release of the entrapped drug over 3 h. Based on these results, encapsulation within fluorinated amphiphilic CD nanoparticles could be considered as a potential drug delivery system for indenoindole-type CK2 inhibitors, allowing better biodisponibility and offering perspectives for tumor targeting development. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Protein kinase CK2 is a ubiquitous serine/threonine kinase found in all eukaryotic cells. Known since 1954, CK2 is a newly validated therapeutic target, ideally suited for drug design, and has become for next decades a major target for inhibition (Dobrowolska et al., 1999). Up to date more than 400 substrates (Salvi et al., 2009) were identified as its substrate but its connection to any specific metabolic event in the cell has not been known clearly. Human CK2 includes two catalytic subunits / ′ and two regulatory sub- units . It could work either lonely in monomeric / ′ or in the heterotetrameric form (22), ( ′ 22) or ( ′ 2). Catalytic sub- unit possesses a great number of basic residues within the substrate recognition site (Cozza et al., 2011). The  subunits play a role in stabilizing the tetrameric conformation and recruiting substrate (Graham and Litchfield, 2000). Unlike other kinases, CK2 is consti- tutively active (Sarno et al., 2002). For this reason, phosphorylation is not an essential event for CK2 full activation as other protein ∗ Corresponding author. Tel.: +33 426 234 404; fax: +33 472 448 438. E-mail address: florent.perret@univ-lyon1.fr (F. Perret). kinases. A high activity of this protein has been reported in many human diseases (Guerra and Issinger, 2008) such as inflammatory processes, neurodegenerative disorders, viral infections, cardiovas- cular diseases. Moreover, protein kinase CK2 activity is associated with the proliferative status of several tumor cells such as glioblas- toma (Kaminska et al., 2009), breast carcinoma (Giusiano et al., 2011), prostate carcinoma (Götz et al., 2012), pancreatic cancer (Hamacher et al., 2007; Giroux et al., 2009), leukemia (Piazza et al., 2012) and hepatocellular carcinoma (Yu et al., 2009; Sass et al., 2011). In most cases a remarkable hyperactivity of CK2 has been observed. It seems to be linked to an overexpression of the kinase considering that no protein mutations have been found until now. To date numerous ATP-competitive inhibitors have been iden- tified, which consist of small and planar heterocyclic scaffolds, able to fit into the nucleotide-binding pocket of CK2 and dis- place the ATP (Cozza et al., 2009). Among these inhibitors, there are (i) polyhalogenated benzimidazoles and related derivatives, (ii) flavonoids, (iii) anthraquinones, (iv) coumarins, (v) indolo- quinazolines, (vi) pyrazolo-triazines and (vii) carboxylic acid derivatives (e.g. CX-4945). A new class of CK2 inhibitors, the series of indeno[1,2-b]indole derivatives, have revealed a great interest as ATP-competitive inhibitors (Hundsdörfer et al., 2012a, 2012b). 0378-5173/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ijpharm.2012.11.004