title: Microstructure and biocompatibility of composite biomaterials fabricated from titanium and tricalcium phosphate by spark plasma sintering.
abstract: Important issues in developing hydroxyapatite (HAp)- and titanium (Ti)-based composite biomaterials for orthopedic or dental devices include the dissociation of HAp during fabrication and its influences in the microstructure and biocompatibility of the final composite. During the densification by sintering of HAp/Ti composites, Ti reacts with -OH freed from HAp to form TiO2 thus dissociated HAp into Ca3(PO4)2, CaO, CaTiO3, TiP, and so forth. To inhibit this reaction, composites were fabricated with Ti and 30, 50, and 70 vol % β-tricalcium phosphate (β-TCP) instead of HAp by spark plasma sintering at 1200°C. It has been observed that after sintering at 1200°C, Ti also reacted with TCP, but unlike HAp/Ti composites, the final TCP/Ti composites contained significant amounts of unreacted TCP and Ti phases. The initial 70 vol % TCP/Ti composite showed compressive strength of 388.5 MPa, Young's modulus of 3.23 GPa, and Vickers hardness of 361.9 HV after sintering. The in vitro cytotoxicity and proliferation of osteoblast cells on the composites surfaces showed that the addition of a higher amount of TCP with Ti was beneficial by increasing cell viability, cell-composite attachment and proliferation. Osteopontin and collagen type II protein expression from osteoblasts cultured onto the 70% TCP-Ti composite was also higher than other composites and pure Ti. In vivo study verified that within 3 months of implantation in an animal body, 70% TCP-Ti had an excellent bone-implant interface compared with a pure Ti metal implant.
authors.affiliation: Department of Biomedical Engineering and Materials, College of Medicine, Soonchunhyang University, Cheonan 330-090, Korea.
authors.forename: Dibakar
authors.initials: D
authors.lastname: Mondal
authors.forename: Linh
authors.initials: L
authors.lastname: Nguyen
authors.forename: Ik-Hyun
authors.initials: IH
authors.lastname: Oh
authors.forename: Byong-Taek
authors.initials: BT
authors.lastname: Lee
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry* / Q000378:metabolism; D002130:Calcium Phosphates / Q000737:chemistry* / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D055119:Elastic Modulus; D005269:Femur / Q000601:surgery; D006244:Hardness; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008422:Materials Testing; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D019736:Prostheses and Implants; D011817:Rabbits; D014025:Titanium / Q000737:chemistry* / Q000378:metabolism
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate; D014025:Titanium