The Effect of Glutaraldehyde on the Properties of Gelatin Films A. Talebian, a,* S. S. Kordestani, b A. Rashidi, c F. Dadashian, d and M. Montazer d a Islamic Azad University, Shahre Rey Branch, Faculty of Technical Engineering, Textile Dep., b Tehran-Qom freeway, Tehran, Iran b Amir Kabir University of Technology, Faculty of Biomedical Engineering, Hafez st., Tehran, Iran c Islamic Azad University, Science-Research Branch, Faculty of Technical Engineering, Textile Laboratory, * Hesarak, Ponak sq., Tehran, Iran d Amir Kabir University of Technology, Faculty of Textile Engineering, Hafez st., Tehran, Iran In this work gelatin film was prepared from cow’s bone. In order to increase mechanical stability of the prepared transparent film as well as decrease its swelling, glutaraldehyde (GTA) was used. Different mass fractions of GTA were utilized. It was observed that at w = 0.18 % of GTA the load at break of the film is d = 53.7 N and the solubility decreased. The solubility of the film was measured as a dependant parameter of the swelling behavior. In this case it was decreased from 389 % to 156 % at 5 min for gelatin films without GTA and with 0.18 % GTA, respectively. FTIR spectroscopy results showed a peak for crosslinked gelatin at ~ n = 1650 cm –1 . It means the crosslinking between gelatin and GTA has taken place. SEM micrographs confirm the porosity has decreased by increasing the GTA fraction, which is an indication of higher strength. Key words: Gelatin, glutaraldehyde, mechanical properties, FTIR, SEM Introduction In recent years, the development of environment-friendly and biodegradable materials based on natural polymers has received increasing attention. This is due to attempt to sub- stitute petroleum-based plastics, which present concerns in terms of pollution and sustainability. 1 Among other bio- polymers, gelatin has been extensively studied due to its low cost, biodegradability, biocompatibility and non-im- munogenic. Gelatin is obtained by thermal denaturation or physical and chemical degradation of collagen from animal skin and bones. 2–4 Four processes are used: Acid, Alkaline, Enzymatic and Heat/Pressure process. Among all of these processes, heat/pressure process is done at a short time and no chemicals, but the extracted gelatin has low bloom in- dex. 5,6 Gelatin is widely used in food, pharmaceutical indu- stries as well as in the biomedical field: hard and soft capsules, microspheres, sealants for vascular prostheses, wound dressing, adsorbent pads for surgical use and im- plantable devices. 2,3,5,7 In spite of gelatin advantages, gelatin films have poor mechanical properties and are dissolvable in aqueous solutions very fast, which limit their possible ap- plications as a biomaterial especially for long-term applica- tions. 2,3 Thus, to modify mechanical properties and delay the solubility of gelatin films, the formation of crosslinks among the macromolecular chains has been proposed. 8 Al- dehydes, such as formaldehyde and glyoxal, 9 glutaralde- hyde 3 and other crosslinking agents like genipin 2 and trans- glutaminase, 9 were used to produce modified gelatin films. Among the chemical crosslinking agents, glutaraldehyde (GTA) is by far the most widely used chemical because it is inexpensive, easily available and its aqueous solutions can effectively crosslink collagenous tissues in a relatively short period 3 that the crosslinking reaction between GTA and protein (like gelatin) is shown in Fig. 1. 10,11 A. TALEBIAN et al.: Glutaraldehyde and the Properties of Gelatin Films, Kem. Ind. 56 (11) 537–541 (2007) 537 KUI – 27/2007 Received January 29, 2007 Accepted October 1, 2007 * Correspondent author: Aazam Talebian, e-mail: safazam@yahoo.com, a_talebian@iausr.ac.ir F i g. 1 – The crosslinking reaction between glutaraldehyde and protein 10,11 Slika 1 – Reakcija umreÞavanja izmeðu glutaraldehida i protei- na 10,11