title: Osteogenic ability of Cu-bearing stainless steel.
abstract: A newly developed copper-bearing stainless steel (Cu-SS) by directly immobilizing proper amount of Cu into a medical stainless steel (317L SS) during the metallurgical process could enable continuous release of trace amount of Cu(2+) ions, which play the key role to offer the multi-biofunctions of the stainless steel, including the osteogenic ability in the present study. The results of in vitro experiments clearly demonstrated that Cu(2+) ions from Cu-SS could promote the osteogenic differentiation by stimulating the Alkaline phosphatase enzyme activity and the osteogenic gene expressions (Col1a1, Opn, and Runx2), and enhancing the adhesion and proliferation of osteoblasts cultured on its surface. The in vivo test further proved that more new bone tissue formed around the Cu-SS implant with more stable bone-to-implant contact in comparison with the 317L SS. In addition, Cu-SS showed satisfied biocompatibility according to the results of in vitro cytotoxicity and in vivo histocompatibility, and its daily released amount of Cu(2+) ions in physiological saline solution was at trace level of ppb order (1.4 ppb/cm(2) ), which is rather safe to human health. Apart from these results, it was also found that Cu-SS could inhibit the happening of inflammation with lower TNF-α expression in the bone tissue post implantation compared with 317L SS. In addition to good biocompatibility, the overall findings demonstrated that the Cu-SS possessed obvious ability of promoting osteogenesis, indicating a unique application advantage in orthopedics.
authors.affiliation: Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Ren
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong, China.|Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma, The University of Hong Kong Shenzhen Hospital, Shenzhen, China.
authors.forename: Hoi Man
authors.initials: HM
authors.lastname: Wong
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong, China.|Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma, The University of Hong Kong Shenzhen Hospital, Shenzhen, China.
authors.forename: Chun Hoi
authors.initials: CH
authors.lastname: Yan
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong, China.|Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma, The University of Hong Kong Shenzhen Hospital, Shenzhen, China.
authors.forename: Kelvin W K
authors.initials: KW
authors.lastname: Yeung
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Yang
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis; D018786:Bone Substitutes / Q000737:chemistry / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D003300:Copper / Q000737:chemistry / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis / Q000187:drug effects*; D013193:Stainless Steel / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000943:Antigens, Differentiation; D018786:Bone Substitutes; D013193:Stainless Steel; D003300:Copper
keywords: bioactive material; bone; metal ions; osteogenesis; stainless steel