title: In vivo and in vitro evaluation of flexible, cottonwool-like nanocomposites as bone substitute material for complex defects.
abstract: The easy clinical handling and applicability of biomaterials has become a focus of materials research due to rapidly increasing time and cost pressures in the public health sector. The present study assesses the in vitro and in vivo performance of a flexible, mouldable, cottonwool-like nanocomposite based on poly(lactide-co-glycolide) and amorphous tricalcium phosphate nanoparticles (PLGA/TCP 60:40). Immersion in simulated body fluid showed exceptional in vitro bioactivity for TCP-containing fibres (mass gain: 18%, 2 days, HAp deposition). Bone regeneration was quantitatively investigated by creating four circular non-critical-size calvarial defects in New Zealand White rabbits. The defects were filled with the easy applicable cottonwool-like PLGA/TCP fibres or PLGA alone. Porous bovine-derived mineral (Bio-Oss) was used as a positive control and cavities left empty served as a negative control. The area fraction of newly formed bone (4 weeks implantation) was significantly increased for TCP-containing fibres compared to pure PLGA (histological and micro-computed tomographic analysis). A spongiosa-like structure of the newly formed bone tissue was observed for PLGA/TCP nanocomposites, whereas Bio-Oss-treated defects afforded a solid cortical bone.
authors.affiliation: Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Oliver D
authors.initials: OD
authors.lastname: Schneider
authors.forename: Franz
authors.initials: F
authors.lastname: Weber
authors.forename: Tobias J
authors.initials: TJ
authors.lastname: Brunner
authors.forename: Stefan
authors.initials: S
authors.lastname: Loher
authors.forename: Martin
authors.initials: M
authors.lastname: Ehrbar
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Schmidlin
authors.forename: Wendelin J
authors.initials: WJ
authors.lastname: Stark
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D001826:Body Fluids; D018786:Bone Substitutes / Q000494:pharmacology*; D002113:Calcification, Physiologic / Q000187:drug effects; D002130:Calcium Phosphates / Q000138:chemical synthesis; D032561:Cotton Fiber; D019344:Lactic Acid / Q000138:chemical synthesis; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry*; D010012:Osteogenesis / Q000187:drug effects; D018583:Pliability / Q000187:drug effects; D011100:Polyglycolic Acid / Q000138:chemical synthesis; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D012886:Skull / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology* / Q000601:surgery; D013696:Temperature; D054457:Tissue Scaffolds; D055114:X-Ray Microtomography
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C018392:tricalcium phosphate