Mad Jin and Sultana / Malaysian Journal of Fundamental and Applied Sciences Vol. 14, No. 4 (2018) 495-499 495 Osteoblast adhesion and proliferation on porous chitosan / polycaprolactone scaffolds for bone tissue engineering application Rashid Mad Jin b , Naznin Sultana, a, b,* a Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia b Biomaterial Laboratory, Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Bahru, Malaysia * Corresponding author: naznin@biomedical.utm.my Article history Received 5 May 2018 Revised 1 June 2018 Accepted 2 July 2018 Published Online 16 December 2018 Graphical abstract Abstract Tissue engineering is an evolving technique to reduce the limitations of the bone graft. It provides diversity to improve the healing process of bone fractures and defect by combining the use of 3D scaffolds, healing promoting factors, gene therapy and different drugs. Flexibility to use a different technique to fabricate scaffolds lead to the new insight of bone healing future. A bone graft is defined as promoted bone healing through osteogenesis, osteoinduction, and osteoconduction by the implanted material alone or with other materials. Ideal bone graft depends on several factors such as biomechanical characteristic, tissue viability, the morphological structure as well as biological characteristics. In this work, we have investigated adhesion, proliferation, and differentiation of poly (ɛ- caprolactone) / chitosan scaffolds with the incorporation of hydroxyapatite and tetracycline HCl on normal human osteoblast cells. Both of the polymers were blended without a cross-linking agent to form porous scaffolds by freeze-drying technique. From the results, it was observed that the compressive modulus increased from 4.0 MPa to 12.5 MPa and the yield strength increased from 0.48 MPa to 0.75 MPa for the PCL/CS scaffold and nHA/PCL/CS scaffold, respectively. Scanning electron microscopy study revealed that the cells successfully adhered to the surface of scaffolds after 24 hours incubation. Proliferation analysis exhibited increasing trend of growth of cells. This study indicated that the scaffold fabricated using this technique was able to promote adhesion, proliferation, and differentiation of normal human osteoblast cells. Keywords: Tissue engineering, bone graft, normal human osteoblast cell, freeze drying technique, scaffolds. © 2018 Penerbit UTM Press. All rights reserved INTRODUCTION Bone tissue engineering in the field of regenerative medicine has been extensively studied over the past two decades. In the recent years, the development of scaffolds-based tissue engineering provides alternatives to bone grafting for restoring the form and function of defect bones. In this technique, a combination of scaffolds, living cells, and bioactive factors are the fundamental to graft the engineering functional bone (Jan, H. et al., 2013). Bone tissue engineering required a biocompatible scaffold that mimics the natural bone extracellular matrix (ECM) (Ami, R. A. et al., 2012). This characteristic was crucial as ECM in natural tissue support for cell attachment, proliferation as well as cell differentiation (Shuilin, W., et al., 2014). Other than that, it should have an ability to support the normal cellular activity such as molecular signaling system without any toxic effect on the host tissues (Shuilin, W. et al., 2014). Biomaterials for bone tissue engineering should possess physical, chemical and biological properties to support the growth of new cell formation (Ami, R. A. et al., 2012). Osteoinductive biomaterials have excellent characteristics as they are able to instructing its surrounding in vivo environment to induce ectopic bone formation (Ami, R. A. et al., 2012). One of the bioceramics, hydroxyapatite (HA) that is chemically similar to the inorganic component of bone matrix. It is biocompatible, bioactive and highly osteoconductive either in natural or synthetic form. Different available methods to construct scaffolds with suitable properties have been extensively studied such as solid freeform fabrication (SFF) (Dietmar, W. H. et al., 2004), porogen leaching (Chun-Jie, L. et al., 2001), electrospinning (Muhammad, I., H. et al., 2014), gas foaming (Yoon, S. N. et al., 1999) freeze drying (Naznin, S. et al., 2012, Jin, R. M, et al., 2015) and many others. Different technique shall have different advantages and disadvantages. Two polymers that will be studied in this research are chitosan and polycaprolactone (PCL). Chitosan is a natural polysaccharide that contains glucosamine and N-acetylglucosamine, with a structure similar to that of glycosaminoglycans. Glycosaminoglycans are a major component of the native ECM. For this reason, chitosan shows excellent cell adhesion, proliferation, and differentiation. Besides, chitosan is known for its antibacterial properties (Croisier, F., & Jérôme, C. 2013 and Dash, M., et al., 2011). However, as a single polymer, chitosan shows a lack of mechanical strength as well as a high degradation rate that makes it unstable to be used in tissue engineering applications. Another polymer is PCL, which is a synthetic polymer that has a good mechanical strength and a low biodegradation rate, and has also been used in tissue engineering. Despite that, its hydrophobicity causes poor cell adhesion and proliferation (Pitt, C. G., 1990). It is expected that blending both of the polymers will enhance its properties for bone tissue engineering applications. In this experiment, freeze drying technique was utilized to fabricate PCL/CS composite scaffolds. Freeze drying or also known as RESEARCH ARTICLE