title: Promoted healing of femoral defects with in situ grown fibrous composites of hydroxyapatite and poly(DL-lactide).
abstract: Although, electrospun composite fibers have shown promise in enhancing growth, differentiation, and mineralization of osteoblasts in vitro, bone repairing capabilities have not been clarified after in vivo implantation up to now. In situ grown composites (IGC) of hydroxyapatite (HA) and poly(DL-lactide) (PDLLA) were obtained from electrospun fibers grafted with gelatin as the induction sites for HA growth. The presence and location of HA nanoparticles within electrospun fibers were proposed to affect the degradation and repairing process of femoral defects. Subcutaneous implantation of IGC led to around 90% of mass loss and 75% of molecular weight reduction during 16 weeks, which were significantly higher than those after in vitro degradation in buffer solutions. In vitro tests on MC3T3-E1 cells indicated that IGC acted as a better cell support to provide favorable conditions for cell proliferation and to stimulate the osteogenic differentiation as compared with electrospun PDLLA fibers, and blend electrospun fibrous composites. Femoral defects were created for in vivo evaluation of bone repairing, indicating that the entire defect was filled by newly formed bone with compact structure after 16 week implantation of IGC. Histological and SEM observations demonstrated a successful bridging of the critical-sized defect with rapid mineralization, continual remodeling, and abundant vasculature. The in situ grown HA nanoparticles on the surface of electrospun fibers improved the biocompatibility with defect sites, promoted the bone formation within fibrous scaffolds and enhanced the bone remodeling, indicating potentials for bone regeneration and repairing of bone defects.
authors.affiliation: Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zou
authors.forename: Xian
authors.initials: X
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Zhi
authors.forename: Yaowen
authors.initials: Y
authors.lastname: Liu
authors.forename: Wenguo
authors.initials: W
authors.lastname: Cui
authors.forename: Shuchun
authors.initials: S
authors.lastname: Hu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Li
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000378:metabolism; D049109:Cell Proliferation; D004285:Dogs; D017886:Durapatite / Q000737:chemistry* / Q000378:metabolism; D005269:Femur / Q000293:injuries* / Q000473:pathology; D017102:Fracture Healing; D008297:Male; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry; D010012:Osteogenesis; D011091:Polyesters / Q000737:chemistry* / Q000378:metabolism; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; C033616:poly(lactide); D017886:Durapatite