VOL. 11, NO. 24, DECEMBER 2016 ISSN 1819-6608 ARPN Journal of Engineering and Applied Sciences ©2006-2016 Asian Research Publishing Network (ARPN). All rights reserved. www.arpnjournals.com 14052 FABRICATION AND CHARACTERIZATION OF CHITOSAN COATED AND UNCOATED PCL/HA/PPY COMPOSITE SCAFFOLDSUSING FREEZE DRYING TECHNIQUE Sharon Kalu Joseph Ufere 1 and Naznin Sultana 1,2 1 Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, Skudai Johor, Malaysia 2 Advanced Membrane Technology Research Center, Universiti Teknologi Malaysia, Skudai Johor, Malaysia E-Mail: naznin@biomedical.utm ABSTRACT Chitosan is an abundantly common, naturally occurring, polysaccharide biopolymer. In this study, chitosan was used to coat previously fabricated conductive Polycaprolactone/Hydroxyapatite/Polypyrrole (PCL/HA/PPY) composite scaffold and the properties of the coated and non-coated scaffolds were investigated and compared. The morphology of the chitosan coated and non-coated scaffolds were characterized using a scanning electron microscope (SEM). The wettability was determined using a water contact angle measuring system. Furthermore, water uptake was determined by measuring the water absorption of each sample before and after coated with chitosan. Water contact angle result revealed an increase in wettability of the scaffolds ranging from 108º ± 4.2 down to 59.4º ± 0.7. On the other hand, the coated sample showed a higher water uptake than the non-coated sample. The results indicated that coating with chitosan was important to increase water absorption of composite scaffold, rendering it more hydrophilic. Keywords: chitosan, coated, 3D scaffolds, bone tissue engineering. 1. INTRODUCTION The use of absorbable orthopedic implants in recent decades has been on the upsurge, which in turn has prompted extensive research in the field of bone tissue engineering. In orthopedic applications, tissue engineering approach is based on the fabrication of three-dimensional (3D) scaffolds that support, strengthen, and consolidate the regenerating tissue. The scaffold utilized in bone tissue engineering manipulates the functions of osteoblasts and guides new bone development in the desired forms[1]. A perfect scaffold material must fulfill a few conditions and possesses some qualities. The scaffold must be capable of being fabricated in precise shapes. It must possess a measured porous architecture to permit cell penetration. Also, the scaffold material must aid cell attachment, development, tissue restoration, and vascularization. It must have good mechanical properties, particularly at large deformations, to protect structural reliability during culture and utilization [2-4]. Furthermore, the scaffolds must be osteoconductive. Chitosan, being one of the extensively studied polymers and promising for use as scaffold material in bone tissue engineering application, is the copolymer of D- glucosamine and N-acetyl-Dglucosamine [5]. It is biodegradable, biocompatible, non-toxic and also possesses antibacterial properties. In this study, chitosan because of its several advantages was used in coating already fabricated conductive PCL/HA/PPY composite scaffold which was fabricated using freeze drying technique. 2. MATERIALS AND METHODS The materials used were already fabricated scaffolds Polycaprolactone/ Hydroxyapatite/ Polypyrrole (PCL/HA/PPY), 0.2g chitosan, 50ml distilled water and 1ml of 2% acetic acid. 2.1 Method: Coating of scaffolds with chitosan: To prepare chitosan solution, 0.2g chitosan was dissolved in 50ml distilled water containing 1ml of 2% acetic acid with the aid of magnetic stirrer. After the chitosan solution was prepared, the scaffold, 10% PCL/HA/PPY was selected and dipped inside the chitosan solution for 5 minutes before it wasfreezed at low temperature for 6 hours. 2.2 Characterization of samples 2.2.1 Scanning electron microscope and energy dispersive x-ray (EDX) analysis: The surface morphology of all the fabricated scaffolds were examined with a scanning electron microscope (SEM, Table Top TM3000) and Field Emission Scanning Electron Microscope (FESEM, SU8020, Hitachi) to study their morphology and structures. 2.2.2 Contact angle measurement: The wettability of composite scaffolds was determined by measuring water contact angle using video contact angle system (VCA Optima, AST Product, Inc). The measurements were done after 5 seconds of dropping deionized water of 1μl size onto the composite surface for each sample. Contact angle values of the water droplet at the left and right side were measured and average values were calculated. Five measurements were performed for each sample at different locations of the scaffold surface and was analyzed using VCA Optima software. Contact angle values reported were the average of three measurements taken at different locations of the fibers. 2.2.3 Water uptake: Water uptake was also determined by measuring the water absorption of each sample before and after coated with chitosan. Each of the samples are weighted and then immersed in distilled water for 5