title: Enhanced bone ingrowth into hydroxyapatite with interconnected pores by Electrical Polarization.
abstract: Hydroxyapatite (HA) ceramics are used as implants to repair damaged/removed bone, and negative or positive electrical polarization enhances osteoblast and decreases osteoclast activity, respectively, in vivo. We compared the ability of electrically polarized and non-polarized HA with interconnected pores (IPHA) implants to promote bone growth. Polarized or non-treated IPHAs were implanted into the right or left femoral condyle of rabbits (N = 10 in each group), and we performed histological examination, including enzymatic staining for osteoblasts and osteoclasts, 3 and 6 weeks after implantation. We observed improved bone ingrowth and increased osteoblast activity in polarized implants with complete bone penetration into polarized implants occurring as early as 3 weeks after surgery. In contrast, non-polarized implants were not fully ossified at 6 weeks after surgery. Furthermore, positively charged implant regions had decreased osteoclast activity compared to negatively charged or uncharged regions. We propose two different models to explain these observations.
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8519, Japan. itoso.gene@cmn.tmd.ac.jp
authors.forename: Soichiro
authors.initials: S
authors.lastname: Itoh
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakamura
authors.forename: Miho
authors.initials: M
authors.lastname: Nakamura
authors.forename: Kenichi
authors.initials: K
authors.lastname: Shinomiya
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Yamashita
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology*; D001842:Bone and Bones / Q000737:chemistry / Q000166:cytology* / Q000187:drug effects*; D002452:Cell Count; D048430:Cell Shape; D017886:Durapatite / Q000378:metabolism*; D004563:Electrochemistry; D020007:Implants, Experimental; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects; D010012:Osteogenesis; D016062:Porosity; D011817:Rabbits; D013057:Spectrum Analysis
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite