Applied Surface Science 256 (2010) 5882–5887 Contents lists available at ScienceDirect Applied Surface Science journal homepage: www.elsevier.com/locate/apsusc Modified titanium surface with gelatin nano gold composite increases osteoblast cell biocompatibility Young-Hee Lee a,1 , Govinda Bhattarai a,1 , Santosh Aryal b , Nan-Hee Lee a , Min-Ho Lee c , Tae-Gun Kim d , Eun-Chung Jhee a , Hak-Yong Kim b , Ho-Keun Yi a,∗ a Department of Oral Biochemistry, School of Dentistry and Institute of Oral Bioscience, BK21 program, Chonbuk National University, Jeonju, Republic of Korea b Department of Bionanosystem Engineering, Chonbuk National University, Jeonju, Republic of Korea c Department of Dental Biomaterials, School of Dentistry and Institute of Oral Bioscience, BK21 program, Chonbuk National University, Jeonju, Republic of Korea d Department of Conservative Dentistry, School of Dentistry, Chonbuk National University, Jeonju, Republic of Korea article info Article history: Received 27 January 2010 Received in revised form 12 March 2010 Accepted 12 March 2010 Available online 19 March 2010 Keywords: Gelatin nano gold composite Titanium modification Cell signaling Cell adherent molecules Biocompatibility Dental implant abstract This study examined the gelatin nano gold (GnG) composite for surface modification of titanium in addi- tion to insure biocompatibility on dental implants or biomaterials. The GnG composite was constructed by gelatin and hydrogen tetrachloroaurate in presence of reducing agent, sodium borohydrate (NabH 4 ). The GnG composite was confirmed by UV–VIS spectroscopy and transmission electron microscopy (TEM). A dipping method was used to modify the titanium surface by GnG composite. Surface was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The MC-3T3 E1 cell viabil- ity was assessed by trypan blue and the expression of proteins to biocompatibility were analyzed by Western blotting. The GnG composite showed well dispersed character, the strong absorption at 530 nm, roughness, regular crystal and clear C, Na, Cl, P, and Au signals onto titanium. Further, this composite allowed MC-3T3 E1 growth and viability compared to gelatin and pure titanium. It induced ERK activa- tion and the expression of cell adherent molecules, FAK and SPARC, and growth factor, VEGF. However, GnG decreased the level of SAPK/JNK. This shows that GnG composite coated titanium surfaces have a good biocompatibility for osteoblast growth and attachment than in intact by simple and versatile dipping method. Furthermore, it offers good communication between cell and implant surfaces by regulating cell signaling and adherent molecules, which are useful to enhance the biocompatibility of titanium surfaces. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Titanium as a biomaterial has a strong character cross link with the bone and has been used extensively in dental implants. Titanium shows excellent biocompatibility and high corrosion resistance. However, an unmodified titanium surface is unsuitable for osseointegration [1]. Various surface modification techniques, such as roughness modified, topography, chemistry and electrical charge, etc., have been carried out to improve dental implants [2]. In contrast to physicochemical modification, biological molecules were applied to the surface of an implant to stimulate osteogenic cell growth, proliferation and differentiation [3]. Significant effort has been made to develop an artificial extracellular matrix (ECM) to ∗ Corresponding author at: Department of Oral Biochemistry, School of Dentistry, Chonbuk National University, 634-18, Deokjin-dong, Deokjin-gu, Jeonju, Jeonbuk 561-712, Republic of Korea. Tel.: +82 63 270 44033. E-mail address: yihokn@chonbuk.ac.kr (H.-K. Yi). 1 These two authors contributed equally to this work. promote cell growth and differentiation. Among the biomaterials proposed, the composites of hydroxyl apatite (HA) and biodegrad- able polymers have great potential due to their similar composition to the hard tissue ECM [4]. Gelatin is a natural biodegradable poly- mer derived from the hydrolysis of collagen [5]. It is completely resorbable in vivo and can imitate the ECM for biocompatibility [6]. In other hand gelatin behaves as stabilizing and reducing agents to prepare gold nano particles. The major advantage for gelatin as a stabilizing agent is that it can be used to tailor the nanocompos- ite properties and also to provide long-term stability of the nano particles by preventing particles agglomeration [7]. Recently, it was reported that a nano scale or nano structure has a higher biocompatibility than structures on a larger scale [8,9]. Functionalized gold nanoparticles have long been used as tools in bioscience, such as immunostaining marker particles for elec- tron microscopy, chromophores for immune reaction, and nucleic acid hybridization [10–12]. The development of metal nano parti- cles with a well defined shape, size, toxicity, biocompatibility and suitable composition is challenging in the field of nanotechnol- ogy. Several methods for the preparation of metal nanoparticles 0169-4332/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.apsusc.2010.03.069