Short communication Synthesis and antibacterial activity evaluation of a novel cotton fiber (Gossypium barbadense) ampicillin derivative Roberta Cassano * , Sonia Trombino, Teresa Ferrarelli, Rita Muzzalupo, Lorena Tavano, Nevio Picci Department of Pharmaceutical Sciences, University of Calabria, Arcavacata di Rende, 87036 Cosenza, Italy article info Article history: Received 15 April 2009 Received in revised form 22 May 2009 Accepted 29 May 2009 Available online 7 June 2009 Keywords: Biopolymers Cotton fibers (Gossypium barbadense) Ampicillin Antibacterial activity abstract We prepared cellulose cotton fibers containing ampicillin moieties and evaluated their antibacterial activity. In spite of recent progress in experimental and clinical medicine, the problem of chronic wounds treatment remains to be solved. In fact conventional methods are based on solutions of antibiotics and antiseptics and ointment bandages but the efficacy of this method is low and so the idea to use modified cotton gauzes would have to prevent infections insorgence during wounds healing. Ampicillin, a large spectrum antibiotic, was covalently coupled to cellulose backbone of hydrophilic cotton fibers by a het- erogeneous synthesis to produce a functionalized biopolymer with a satisfactory degree of substitution (DS) and antibacterial activity. The obtained biopolymer was characterized by infrared spectroscopy (FT-IR). Finally, the antibacterial activity in inhibiting microorganism growth in Petri dishes, was evalu- ated. The results suggested that these biomaterials posses an excellent ‘‘in vitro” antibacterial activity and so they can be efficiently employed in biomedical fields for chronic wounds management to ensure a valid protection against infections and contaminations. Biopolymers so functionalized were found to be very efficient to contrast sensible bacteria growth. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Wound dressing before the 1960s were considered to be only the so-called passive products having a minimal role in the healing process. The pioneering researches in the last decade introduced the concept of an active involvement of a wound dressing in estab- lishing and maintaining an optimal environment for wound repair (Deg ˘im, 2008). The new advances in wound healing resulted in the development of dressing from traditional passive materials to functional active dressing which, through the interaction with the wounds they cover, create and maintain a moist and healing environment (Huang & Yang, 2008). An ideal wound dressing should protect the wound from bacterial infection, provide a moist and healing environment, and be biocompatible (Lou, 2008). Re- cently blends made by natural polymers such as starch, cellulose, chitin, chitosan, cotton, gelatin, alginate and dextran have been re- ported for the development of wounds dressings (Edwards, How- ley, & Cohen, 2004; Kim et al., 2007; Lin et al., 2007; Mi et al., 2001; Muzzarelli et al., 2005). New fibrous and wound dressing media have been developed to encourage wound occlusion, exu- date transport and drug dispensation on demand with much re- duced distress to the patient (Miraftaba, Qiaoa, Kennedyb, Ananda, & Groocockc, 2003). However, natural fibers are presently under investigation as materials for the controlled release of bioac- tive molecules to contrast the progression of infection in chronic wounds management. On the other hand, literature reports on bio- materials in which the antibacterial molecules were simply ab- sorbed on the polymer surface by the adsorption methodology (Adamopoulos et al., 2007) and not covalently grafted. In this way only medicated soaked gauzes have been prepared (Denkbas, Öztürk, Özdemir, Kekeci, & Agalar, 2004; Zilberman & Elsner, 2008). Cellulose is the most important constituent of natural fibers and it can be functionalized with bioactive molecules using its primary hydroxylic groups; natural fibers are biocompatible, biodegradable and non-toxic so they can be used to cover infected wounds. In the present work, ampicillin moieties have been covalently linked to cotton fibers to produce a functionalized biomaterial that is able to protect wounds from infections thanks to the presence of the ac- tive molecules. This study showed that the designed systems pre- serve the antibiotic activity of ampicillin moieties also compared with the non-functionalized cotton dishes. The synthesis of this biomaterial has been conducted under mild conditions using thio- nyl chloride in dry THF. The evaluation of antibacterial activity has been demonstrated by ‘‘in vitro” tests using Petri dishes of the type ‘‘Mueller–Hinton Agar”. Furthermore Infrared Spectroscopy showed the presence of the covalent bond with ampicillin and the degree of substitution was determined by saponification and then volumetric analysis. 0144-8617/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.carbpol.2009.05.030 * Corresponding author. Tel.: +39 0984493296; fax: +39 0984493163. E-mail address: roberta.cassano@unical.it (R. Cassano). Carbohydrate Polymers 78 (2009) 639–641 Contents lists available at ScienceDirect Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol