title: An in vivo evaluation of PLLA/PLLA-gHA nano-composite for internal fixation of mandibular bone fractures.
abstract: Internal fixation of bone fractures using biodegradable poly(L-lactic-acid) (PLLA)-based materials has attracted the attention of many researchers. In the present study, 36 male beagle dogs were randomly assigned to two groups: PLLA/PLLA-gHA (PLLA-grafted hydroxyapatite) group and PLLA group. PLLA/PLLA-gHA and PLLA plates were embedded in the muscular bags of the erector spinae and also implanted to fix mandibular bone fractures in respective groups. At 1, 2, 3, 6, 9, and 12 months postoperatively, the PLLA/PLLA-gHA and PLLA plates were evaluated by adsorption and degradation tests, and the mandibles were examined through radiographic analysis, biomechanical testing, and histological analysis. The PLLA/PLLA-gHA plates were non-transparent and showed a creamy white color, and the PLLA plates were transparent and faint yellow in color. At all time points following surgery, adsorption and degradation of the PLLA/PLLA-gHA plates were significantly less than those of the PLLA plates, and the lateral and longitudinal bending strengths of the surgically treated mandibles of the beagle dogs in the PLLA/PLLA-gHA group were significantly greater than those of the PLLA group and reached almost the value of intact mandibles at 12 months postoperatively. Additionally, relatively rapid bone healing was observed in the PLLA/PLLA-gHA group with the formation of new lamellar bone tissues at 12 months after the surgery. The PLLA/PLLA-gHA nano-composite can be employed as a biodegradable material for internal fixation of mandibular bone fractures.
authors.affiliation: Department of Plastic and Reconstructive Surgery, The 1st Hospital of Jilin University, 71 Xinmin Street, Changchun, Jilin Province, 130021, People's Republic of China.
authors.forename: Weihai
authors.initials: W
authors.lastname: Peng
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Kai
authors.initials: K
authors.lastname: Shi
authors.forename: Wangshu
authors.initials: W
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Shao
authors.forename: Duo
authors.initials: D
authors.lastname: Zhang
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D018786:Bone Substitutes / Q000008:administration & dosage* / Q000138:chemical synthesis; D004285:Dogs; D017886:Durapatite / Q000737:chemistry*; D019544:Equipment Failure Analysis; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods; D016268:Internal Fixators; D019344:Lactic Acid / Q000737:chemistry*; D008297:Male; D008337:Mandibular Fractures / Q000473:pathology / Q000628:therapy*; D008422:Materials Testing; D053761:Nanocomposites / Q000008:administration & dosage / Q000737:chemistry; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D011474:Prosthesis Design; D016896:Treatment Outcome
chemical_list: D018786:Bone Substitutes; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D017886:Durapatite