title: Three-dimensional porous poly-DL-lactide/basic fibroblast growth factor composites for bone defect repair: an experimental study.
abstract: OBJECTIVE
  To investigate the osteoinductive ability of the composites consisting of basic fibroblast growth factor (bFGF) and porous poly-DL-lactide (PDLLA) for the development of a new absorbable osteosynthesis material.
  
  
  METHODS
  Highly porous foams of PDLLA with the pore size ranging from 150 to 300 microm were prepared by a solvent-casting, particulate-leaching technique with NaCl as the leachable component. Animal models of radial diaphyseal defects of 1.0 cm with complete removal of the periosteum were induced in 45 rabbits, which were randomly divided into 3 groups to receive the defect repair with PDLLA and PDLLA/bFGF respectively, leaving one group untreated to serve as the control group. The implant specimens were harvested at 2, 4, 8, and 12 weeks respectively after the surgery and X-ray, histological and scanning electron microscopic (SEM) examinations were performed to evaluate the effectiveness of defect repair. At 8 and 12 weeks after implantation, biomechanical test (for three-point bending strength) was employed to study the quality of bone formation.
  
  
  RESULTS
  PDLLA/bFGF composite stimulated more bone formation and had higher bending strength than PDLLA (P<0.05), and the bone formation induced by both materials was significantly more than that observed in the control group in every postoperative stage (P<0.05).
  
  
  CONCLUSIONS
  PDLLA possesses good biocompatibility and absorbability, and when prepared into a porous material, it exhibits good osteoconductibility. As a good bFGF carrier, the foam of PDLLA with three- dimensional structure shows good osteoinductive ability with regard to the rapidity, quantity and quality of the bone formation.
authors.affiliation: Department of Orthopedics and Spine, Zhujiang Hospital, First Military Medical University, Guangzhou 510282, China. msxbear24@yahoo.com.cn
authors.forename: Shao-xiong
authors.initials: SX
authors.lastname: Min
authors.forename: An-min
authors.initials: AM
authors.lastname: Jin
authors.forename: Bin-hui
authors.initials: BH
authors.lastname: Tong
authors.forename: Li-xin
authors.initials: LX
authors.lastname: Zhu
authors.forename: Jing
authors.initials: J
authors.lastname: Tian
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001861:Bone Regeneration / Q000187:drug effects* / Q000502:physiology; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D008297:Male; D010012:Osteogenesis / Q000187:drug effects* / Q000502:physiology; D011091:Polyesters / Q000737:chemistry*; D016062:Porosity; D011817:Rabbits
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D016222:Fibroblast Growth Factor 2; C033616:poly(lactide)