title: Influence of bioresorbable, unsintered hydroxyapatite/poly-L-lactide composite films on spinal cord, nerve roots, and epidural space.
abstract: The effect of forged unsintered hydroxyapatite/poly-L-lactide (u-HA/PLLA) composite films on spinal cord and nerve roots and its degradation behavior and osteoconductivity in epidural space were compared with those of calcined HA (c-HA)/PLLA and unfilled PLLA films. Partial laminectomy was performed on 20 rabbits, and u-HA/PLLA and PLLA films were implanted in the intervertebral space. Total laminectomy was performed on 30 rabbits to implant u-HA/PLLA, c-HA/PLLA, and PLLA films in both epidural and subcutaneous spaces. For up to 50 weeks, there were no histological changes in the spinal cord or nerve root, and no inflammatory cell infiltration into the epidural space around the films. The rate of decrease in viscosity average molecular weight of both composite films was initially higher than that of PLLA but eventually became lower, although there was no difference in the degradation behavior of the three films in either the epidural or subcutaneous spaces after 50 weeks. Scanning electron microscopic and energy-dispersive X-ray analysis indicated calcium phosphate deposits on the surface of composite films with new bone formation from 4 weeks. The u-HA/PLLA composite film therefore has good biocompatibility, osteoconductivity, and fast primary degradation rate, which may prove compatible with application to spinal surgery.
authors.affiliation: Department of Orthopedics, Miyazaki Medical College, 5200, Kiwara, Kiyotake-cho, Miyazaki 889-1692, Japan. tomo-m@athena.ocn.ne.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Etsuo
authors.initials: E
authors.lastname: Chosa
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nabeshima
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Shikinami
authors.forename: Naoya
authors.initials: N
authors.lastname: Tajima
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D001842:Bone and Bones / Q000502:physiology; D017886:Durapatite / Q000737:chemistry / Q000494:pharmacology*; D004553:Electric Conductivity; D004824:Epidural Space / Q000166:cytology* / Q000187:drug effects*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D011091:Polyesters / Q000494:pharmacology*; D011817:Rabbits; D013116:Spinal Cord / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D013126:Spinal Nerve Roots / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D016707:Tissue Fixation; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; C033616:poly(lactide); D017886:Durapatite