title: Electrostatic surface charge acceleration of bone ingrowth of porous hydroxyapatite/beta-tricalcium phosphate ceramics.
abstract: Bone ingrowth enhancement by the surface induced charges of the electrically polarized hydroxyapatite (HA)/beta-tricalcium phosphate (beta-TCP) ceramics was histologically investigated to clarify the early stage events of ossification. The HA/beta-TCP specimens with a relatively low porosity of 45% for bone ingrowth were polarized in a dc electric field at 400 degrees C for 1 h. The large preserved charges of 8 muC cm(-2) significantly promoted the bone ingrowth process of the porous ceramics implanted in femoral diaphyses of New Zealand white rabbits. The bone formation in the pores of the polarized HA/beta-TCP specimens was observed within 1 week after surgery. The bone occupancy of the polarized HA/beta-TCP pores reached more than 90% at as early as 2 weeks and significantly higher than that of the nonpolarized. The electrical polarization was proved to be effective for bone penetration improvement of low porosity ceramics. The electrically polarized HA/beta-TCP bone grafts with a lower porosity and a higher mechanical strength combined high osteoconductivity generated by the induced surface charges.
authors.affiliation: Division of Inorganic Materials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakamura
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Miho
authors.initials: M
authors.lastname: Nakamura
authors.forename: Soichiro
authors.initials: S
authors.lastname: Itoh
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Yamashita
mesh_terms: D000818:Animals; D002130:Calcium Phosphates / Q000494:pharmacology*; D002516:Ceramics / Q000494:pharmacology*; D017886:Durapatite / Q000494:pharmacology*; D020007:Implants, Experimental; D010012:Osteogenesis / Q000187:drug effects*; D016062:Porosity / Q000187:drug effects; D011817:Rabbits; D055672:Static Electricity; D013499:Surface Properties / Q000187:drug effects; D013696:Temperature
chemical_list: D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate; D017886:Durapatite