title: Salicylic acid-derived poly(anhydride-esters) inhibit bone resorption and formation in vivo.
abstract: The objective of this study was to investigate the effects of a novel polymer that biodegrades into salicylic acid (SA) on the healing of critical sized long bone defects. Microspheres of the homopolymer, or a copolymer containing 50% less of the SA, were packed into 5-mm mid-diaphyseal defects in rat femurs. Control animals received collagen sponge implants. After 4 and 8 weeks of implantation, bone healing was evaluated using microradiography and quantitative histomorphometry. Four weeks postsurgery, significantly less new bone was formed in both of the polymer groups (p<0.038). Reduced bone loss was also noted with the polymers at this time, although it was not statistically significant. However, at 8 weeks postsurgery, a statistically significant reduction in bone loss was observed in both of the polymer groups compared with controls (p<0.0072). Both polymers seemed to elicit identical tissue responses because there were no differences detected between the homopolymer and copolymer materials at either time point. These results indicate that locally released SA can significantly reduce both bone loss and bone formation in this animal model.
authors.affiliation: Department of Orthopaedics, UMDNJ-New Jersey Medical School, Newark, New Jersey 07103, USA. hartenr@synthes.com
authors.forename: Robert D
authors.initials: RD
authors.lastname: Harten
authors.forename: David J
authors.initials: DJ
authors.lastname: Svach
authors.forename: Robert
authors.initials: R
authors.lastname: Schmeltzer
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Uhrich
mesh_terms: D000812:Anhydrides; D000818:Animals; D001672:Biocompatible Materials; D001673:Biodegradation, Environmental; D001861:Bone Regeneration / Q000187:drug effects; D001862:Bone Resorption / Q000188:drug therapy*; D001842:Bone and Bones / Q000293:injuries; D004952:Esters; D005269:Femur; D020007:Implants, Experimental; D008297:Male; D008863:Microspheres; D023421:Models, Animal; D010012:Osteogenesis / Q000187:drug effects*; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020156:Salicylic Acid / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000812:Anhydrides; D001672:Biocompatible Materials; D004952:Esters; D011108:Polymers; D020156:Salicylic Acid