Carbohydrate Polymers 142 (2016) 149–157 Contents lists available at ScienceDirect Carbohydrate Polymers j ourna l ho me page: www.elsevier.com/locate/carbpol Preparation and characterization of soluble branched ionic -cyclodextrins and their inclusion complexes with triclosan Flor Gómez-Galván a , Leyre Pérez-Álvarez a,b,∗ , Janire Matas a , Arturo Álvarez-Bautista c,d , Joana Poejo c,d , Catarina M. Duarte c,d , Leire Ruiz-Rubio a , Jose Luis Vila-Vilela a , Luis M. León a,b a Departamento de Química Física (Laboratorio de Química Macromolecular), Universidad del País Vasco (UPV/EHU), B ◦ Sarriena s/n, 48940 Leioa, Vizcaya, Spain b BCMaterials, Building 500-1st Floor, Bizkaia Science and Technology Park, 48160 Derio, Spain c Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal d iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901 Oeiras, Portugal a r t i c l e i n f o Article history: Received 24 September 2015 Received in revised form 19 January 2016 Accepted 21 January 2016 Available online 23 January 2016 Keywords: Branched ionic cyclodextrins Epichlorohydrin Cytotoxicity Water solubility a b s t r a c t This study aims to synthesize, characterize and investigate the water solubility and cytotoxicity of branched anionic/cationic -cyclodextrins (bCDs) obtained by reaction with epichlorohydrin and chloroacetic acid or choline chloride, respectively, by a single step polycondensation reaction. Obtained ionic bCDs were investigated as an attempt to comparatively study anionic and cationic bCDs. Water solubility of both ionic derivatives was similar (400 mg/mL) at neutral and basic pHs and remarkably higher than that of their neutral homologues. Additionally, a pH-dependent solubility of anionic bCDs was observed. Cytotoxicity of ionic bCDs was evaluated on Human colon carcinoma Caco-2 cells and high cell viability (>99%) was observed in the range of 0–100 mg/mL for anionic and cationic samples, in the same range of that of neutral and parent -CDs. Additionally, complexes formation capacity with triclosan, a poor water soluble antimicrobial agent, was confirmed by several techniques observing a complexation limit around 4 mg/mL for both systems and higher stability constant for anionic bCDs than cationic derivatives. © 2016 Published by Elsevier Ltd. 1. Introduction Cyclodextrins (CDs) are cyclic oligosaccharides produced from starch and which contain six (-CDs), seven (-CDs) or eight (-CDs) glucopyranose units linked by -1,4 glucosidic bonds (Breslow, 2010, chap. 2). The -form is the most accessible and widely used cyclodextrin. As a result of the restricted rota- tion of linked glucopyranose units CDs are toroidal or truncated cone shaped molecules with an internal cavity whose size is around 6.0–7.0 ˚ A for -CDs (Loftsson & Brewster, 1996). CDs have hydrophilic hydroxyl groups on their outer surface, which is hydrophilic, but a hydrophobic cavity in the center, which provides an apolar matrix. As a result, CDs have a special capability to entrap ∗ Corresponding author at: Departamento de Química Física, Facultad de Ciencia y Tecnología (Laboratorio de Química Macromolecular), Universidad del País Vasco (UPV/EHU), B ◦ Sarriena s/n, 48940 Leioa, Bizkaia, Spain. E-mail address: leyre.perez@ehu.es (L. Pérez-Álvarez). hydrophobic guests (Szejtli, 1988, chap. 2; Singh, Bharti, Madan, & Hiremath, 2010). This property has received increasing atten- tion in the last years and has been extensively exploited to form host–guest inclusion complexes with a variety of drugs (Uekama, Hirayama, & Irie, 1998), food additives (Kayaci & Uyar, 2012), and antibacterial agents (Hill, Gomes, & Taylor, 2013), in different fields such as analytical chemistry (Szente & Szeman, 2013), catalysis (Easton, 2007), pharmacy (Davis & Brewster, 2004), food industries (Astray, Gonzalez-Barreiro, Mejuto, Rial-Otero, & Simal-Gándara, 2009) and the treatment of wastewater (Crinia & Morcellet, 2002). Over the last decades, CDs have been used as drug and antimicro- bials carriers showing that they are able to enhance water solubility, chemical stability, bioavailability and decrease unfavorable side- effects of the active agents (Blomberg, Kumpulainen, David, & Amiel, 2004). However, parent -CDs have poor water solubility as a conse- quence of the intra molecular hydrogen bonding of the secondary hydroxyl groups which limits their further applications. To over- come this drawback, various CDs derivatives have been developed http://dx.doi.org/10.1016/j.carbpol.2016.01.046 0144-8617/© 2016 Published by Elsevier Ltd.