title: Evaluation of polylactic acid homopolymers as carriers for bone morphogenetic protein.
abstract: Polylactic acid (PLA) homopolymers with molecular weights of 105,000; 21,000; 3300; 650; and 160d (PLA105000, PLA21000, PLA3300, PLA650, and PLA160, respectively) were prepared and evaluated as carriers for bone morphogenetic protein (BMP). Composites consisting of 4 mg of water-soluble, semipurified BMP and 100 mg of one of the PLA homopolymers were implanted into the dorsal muscles of mice. PLA105000/BMP, PLA21000/BMP, PLA3300/BMP, and PLA160/BMP composites failed to induce new bone formation; PLA105000, PLA21000, and PLA3300 elicited foreign-body reactions or chronic inflammation (or both), and PLA160 produced tissue necrosis. PLA650/BMP composites induced cartilage formation within one week and induced bone with hematopoietic marrow at three weeks postimplantation. PLA650/BMP composites were completely absorbed and replaced by new bone. The results suggest that within this group of PLA homopolymers, PLA650 may be the only type suitable for use as a BMP carrier.
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Medical School, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Miyamoto
authors.forename: K
authors.initials: K
authors.lastname: Takaoka
authors.forename: T
authors.initials: T
authors.lastname: Okada
authors.forename: H
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: J
authors.initials: J
authors.lastname: Hashimoto
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Ono
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D001846:Bone Development / Q000187:drug effects; D019485:Bone Morphogenetic Proteins; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005549:Foreign-Body Reaction / Q000139:chemically induced; D007773:Lactates / Q000378:metabolism*; D019344:Lactic Acid; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008970:Molecular Weight; D011091:Polyesters; D011108:Polymers / Q000378:metabolism*; D011506:Proteins / Q000008:administration & dosage* / Q000493:pharmacokinetics
chemical_list: D019485:Bone Morphogenetic Proteins; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D007773:Lactates; D011091:Polyesters; D011108:Polymers; D011506:Proteins; D019344:Lactic Acid; C033616:poly(lactide)