title: Effect of heparin and alendronate coating on titanium surfaces on inhibition of osteoclast and enhancement of osteoblast function.
abstract: The failure of orthopedic and dental implants has been attributed mainly to loosening of the implant from host bone, which may be due to weak bonding of the implant material to bone tissue. Titanium (Ti) is used in the field of orthopedic and dental implants because of its excellent biocompatibility and outstanding mechanical properties. Therefore, in the field of materials science and tissue engineering, there has been extensive research to immobilize bioactive molecules on the surface of implant materials in order to provide the implants with improved adhesion to the host bone tissue. In this study, chemically active functional groups were introduced on the surface of Ti by a grafting reaction with heparin and then the Ti was functionalized by immobilizing alendronate onto the heparin-grafted surface. In the MC3T3-E1 cell osteogenic differentiation study, the alendronate-immobilized Ti substrates significantly enhanced alkaline phosphatase activity (ALP) and calcium content. Additionally, nuclear factor kappa B ligand (RANKL)-induced osteoclast differentiation of RAW264.7 cells was inhibited with the alendronate-immobilized Ti as confirmed by TRAP analysis. Real time PCR analysis showed that mRNA expressions of osteocalcin and osteopontin, which are markers for osteogenesis, were upregulated in MC3T3-E1 cells cultured on alendronate-immobilized Ti. The mRNA expressions of TRAP and Cathepsin K, markers for osteoclastogenesis, in RAW264.7 cells cultured on alendronate-immobilized Ti were down-regulated. Our study suggests that alendronate-immobilized Ti may be a bioactive implant with dual functions to enhance osteoblast differentiation and to inhibit osteoclast differentiation simultaneously.
authors: Department of Maxillofacial Biomedical Engineering, School of Dentistry, Kyung Hee University, Seoul 130-701, Republic of Korea.
authors: Ho-Jin
authors: HJ
authors: Moon
authors: Young-Pil
authors: YP
authors: Yun
authors: Choong-Wan
authors: CW
authors: Han
authors: Min Sung
authors: MS
authors: Kim
authors: Sung Eun
authors: SE
authors: Kim
authors: Min Soo
authors: MS
authors: Bae
authors: Gyu-Tae
authors: GT
authors: Kim
authors: Yong-Suk
authors: YS
authors: Choi
authors: Eui-Hwan
authors: EH
authors: Hwang
authors: Joon Woo
authors: JW
authors: Lee
authors: Jin-Moo
authors: JM
authors: Lee
authors: Chang-Hoon
authors: CH
authors: Lee
authors: Duck-Su
authors: DS
authors: Kim
authors: Il Keun
authors: IK
authors: Kwon
mesh_terms: D019386:Alendronate / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology*; D006493:Heparin / Q000737:chemistry / Q000494:pharmacology*; D051379:Mice; D010006:Osteoblasts / Q000187:drug effects*; D010010:Osteoclasts / Q000187:drug effects*; D053245:RANK Ligand / Q000494:pharmacology; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D053245:RANK Ligand; D006493:Heparin; D014025:Titanium; D019386:Alendronate