title: Enhanced in Vitro Mineralization and in Vivo Osteogenesis of Composite Scaffolds through Controlled Surface Grafting of L-Lactic Acid Oligomer on Nanohydroxyapatite.
abstract: Nanocomposite of hydroxyapatite (HA) surface grafted with L-lactic acid oligomer (LAc oligomer) (op-HA) showed improved interface compatibility, mechanical property, and biocompatibility in our previous study. In this paper, composite scaffolds of op-HA with controlled grafting different amounts of LAc oligomer (1.1, 5.2, and 9.1 wt %) were fabricated and implanted to repair rabbit radius defects. The dispersion of op-HA nanoparticles was more uniform than n-HA in chloroform and nanocomposites scaffold. Calcium and phosphorus exposure, in vitro biomineralization ability, and cell proliferation were much higher in the op-HA1.1 wt %/PLGA scaffolds than the other groups. The osteodifferentiation and bone fusion in animal tests were significantly enhanced for op-HA5.2 wt %/PLGA scaffolds. The results indicated that the grafted LAc oligomer of 5.2 or 9.1 wt %, which formed a barrier layer on the HA surface, prevented the exposure of nucleation sites. The shielded nucleation sites of op-HA particles (5.2 wt %) might be easily exposed as the grafted LAc oligomer was decomposed easily by enzyme systems in vivo. Findings from this study have revealed that grafting 1.1 wt % amount of LAc oligomer on hydroxyapatite could improve in vitro mineralization, and 5.2 wt % could promote in vivo osteogenesis capacity of composite scaffolds.
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, PR China.|University of Chinese Academy of Sciences, Beijing 100039, PR China.
authors.forename: Zongliang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Medical Cosmetology, The First Affiliated Hospital of Xiamen University , Xiamen 361003, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, PR China.
authors.forename: Peibiao
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, PR China.
authors.forename: Xuesi
authors.initials: X
authors.lastname: Chen
mesh_terms: D000818:Animals; D001861:Bone Regeneration; D000069343:Bone-Implant Interface; D002113:Calcification, Physiologic; D002460:Cell Line; D017886:Durapatite / Q000737:chemistry*; D048091:Guided Tissue Regeneration / Q000379:methods; D019344:Lactic Acid / Q000737:chemistry*; D051379:Mice; D053761:Nanocomposites / Q000009:adverse effects / Q000737:chemistry*; D053758:Nanoparticles / Q000009:adverse effects / Q000737:chemistry; D010012:Osteogenesis; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D054457:Tissue Scaffolds / Q000009:adverse effects / Q000737:chemistry*
chemical_list: D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017886:Durapatite