title: Investigation of the histology and interfacial bonding between carbonated hydroxyapatite cement and bone.
abstract: An ideal bone implant should facilitate the formation of a new bone layer as an osteo-integrated interface between bone and the implanted biomaterials. In the present work, the interface between carbonated hydroxyapatite (CHA) cement and bone was evaluated by interfacial bonding strength measurements and histological characterizations. CHA cement was implanted into a mongrel dog's femoral supracondylar and below the tibial plateau area, and was then tested ex vivo by, respectively, detaching and pullout experiments. Polymethylmethacrylate (PMMA) was used as a control. CHA cement could be directly injected and solidified in situ to repair bone defects. Histology results showed that CHA bonded with bone through gradual remodeling and was replaced by new bone tissue, which is an attribute for excellent biocompatibility. The interfacial bonding strength increased with implantation time. After 16 weeks implantation, the measured detaching force and the pullout force between CHA and bone were 281 +/- 16 N and 512.5 +/- 14.5 N, respectively. These values were several times higher compared to 5 days implantation. In contrast, the control showed a fibrous microstructure between PMMA and bone, and the detaching force and the pullout force decreased with implantation time. The results strongly suggest that CHA can form a better osteo-integrated interface compared to PMMA, and could be used as an ideal biomaterial for bone defect repair.
authors.affiliation: Department of Orthopedics, General Hospital of People's Liberation Army, 28 Fuxing Road, Beijing 100853, People's Republic of China.
authors.forename: Keya
authors.initials: K
authors.lastname: Mao
authors.forename: Yun
authors.initials: Y
authors.lastname: Yang
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Li
authors.forename: Libo
authors.initials: L
authors.lastname: Hao
authors.forename: Peifu
authors.initials: P
authors.lastname: Tang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Ning
authors.initials: N
authors.lastname: Wen
authors.forename: Mingkui
authors.initials: M
authors.lastname: Du
authors.forename: Jifang
authors.initials: J
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001842:Bone and Bones / Q000473:pathology* / Q000648:ultrastructure; D002254:Carbonates; D004285:Dogs; D017886:Durapatite; D005269:Femur / Q000503:physiopathology*; D006882:Hydroxyapatites; D008297:Male; D019904:Polymethyl Methacrylate / Q000737:chemistry* / Q000627:therapeutic use*; D019736:Prostheses and Implants; D013977:Tibia / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D001672:Biocompatible Materials; D002254:Carbonates; D006882:Hydroxyapatites; C475044:hydroxyapatite cement; D019904:Polymethyl Methacrylate; D017886:Durapatite