Macromolecular Nanotechnology PVA–clay nanocomposite hydrogels for wound dressing Mehrdad Kokabi a, * , Mohammad Sirousazar b,1 , Zuhair Muhammad Hassan c a Polymer Engineering Group, Faculty of Engineering, Tarbiat Modares University, P.O. Box 14155-143, Tehran, Islamic Republic of Iran b Chemical Engineering Group, Faculty of Engineering, Tarbiat Modares University, P.O. Box 14155-143, Tehran, Islamic Republic of Iran c Immunology Group, Faculty of Medical Science, Tarbiat Modares University, P.O. Box 14155-331, Tehran, Islamic Republic of Iran Received 20 June 2006; received in revised form 25 November 2006; accepted 28 November 2006 Available online 11 January 2007 Abstract Polymer gels as soft biomaterials have found diverse applications in biomedical field, e.g. in management and care of wound as wound dressing. The recent researches on nanocomposite materials have shown that some properties of polymers and gels significantly improve by adding organoclay into polymeric matrix. In this work, in order to obtain wound dressing with better prop- erties, nanocomposite hydrogel wound dressing was prepared using combination of polyvinyl alcohol hydogel and organo- clay, i.e. Na-montmorillonite, via the freezing–thawing method. The effect of organoclay quantity on the structural, swelling, physical and mechanical properties of nanocomposite hydrogel wound dressing was investigated. The results showed that the nanocomposite hydrogels could meet the essential requirements for the reasonable wound dressing with some desirable characteristics such as relatively good swelling, appreciated vapour transmission rate, excellent barrierity against microbe penetration and mechanical properties. The results also indicated that the quantity of the clay added to the nanocomposite hydrogel is the key factor in obtaining such suitable properties required for wound dressing. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Wound dressing; Nanocomposite hydrogel; Polyvinyl alcohol; Montmorillonite; Freezing–thawing 1. Introduction The primary objective in wound care is the pro- motion of rapid wound healing with the best func- tional and cosmetic results. Wound healing may be considered as a specific biological process related to the general phenomenon of growth and regener- ation [1]. It is a dynamic process in which normally involves systematic, coordinated and balanced activity of inflammatory, vascular, connective tissue and epithelial cells. The process of wound healing is orchestrated by the extra cellular matrix, while interleukins and other growth factors play a major role in the regulation of cellular processes [2]. Wound dressings are usually used to encourage the various stages of wound healing and create bet- ter healing conditions. They often cover the wound surface to accelerate its healing. 0014-3057/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.eurpolymj.2006.11.030 * Corresponding author. Tel.: +98 21 8801 1001; fax: +98 21 8800 6544. E-mail address: mehrir@modares.ac.ir (M. Kokabi). 1 Present address: Chemical Engineering Group, Faculty of Engineering, University of Mohaghegh Ardabili, P.O. Box 56199- 11367, Ardabil, Islamic Republic of Iran. European Polymer Journal 43 (2007) 773–781 www.elsevier.com/locate/europolj EUROPEAN POLYMER JOURNAL MACROMOLECULAR NANOTECHNOLOGY