title: Selective laser sintering fabrication of nano-hydroxyapatite/poly-ε-caprolactone scaffolds for bone tissue engineering applications.
abstract: The regeneration of functional tissue in osseous defects is a formidable challenge in orthopedic surgery. In the present study, a novel biomimetic composite scaffold, here called nano-hydroxyapatite (HA)/poly-ε-caprolactone (PCL) was fabricated using a selective laser sintering technique. The macrostructure, morphology, and mechanical strength of the scaffolds were characterized. Scanning electronic microscopy (SEM) showed that the nano-HA/PCL scaffolds exhibited predesigned, well-ordered macropores and interconnected micropores. The scaffolds have a range of porosity from 78.54% to 70.31%, and a corresponding compressive strength of 1.38 MPa to 3.17 MPa. Human bone marrow stromal cells were seeded onto the nano-HA/PCL or PCL scaffolds and cultured for 28 days in vitro. As indicated by the level of cell attachment and proliferation, the nano-HA/PCL showed excellent biocompatibility, comparable to that of PCL scaffolds. The hydrophilicity, mineralization, alkaline phosphatase activity, and Alizarin Red S staining indicated that the nano-HA/PCL scaffolds are more bioactive than the PCL scaffolds in vitro. Measurements of recombinant human bone morphogenetic protein-2 (rhBMP-2) release kinetics showed that after nano-HA was added, the material increased the rate of rhBMP-2 release. To investigate the in vivo biocompatibility and osteogenesis of the composite scaffolds, both nano-HA/PCL scaffolds and PCL scaffolds were implanted in rabbit femur defects for 3, 6, and 9 weeks. The wounds were studied radiographically and histologically. The in vivo results showed that both nano-HA/PCL composite scaffolds and PCL scaffolds exhibited good biocompatibility. However, the nano-HA/PCL scaffolds enhanced the efficiency of new bone formation more than PCL scaffolds and fulfilled all the basic requirements of bone tissue engineering scaffolds. Thus, they show large potential for use in orthopedic and reconstructive surgery.
authors.affiliation: Department of Orthopedics, Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xia
authors.forename: Panyu
authors.initials: P
authors.lastname: Zhou
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Cheng
authors.forename: Yang
authors.initials: Y
authors.lastname: Xie
authors.forename: Chong
authors.initials: C
authors.lastname: Liang
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.forename: Shuogui
authors.initials: S
authors.lastname: Xu
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D001861:Bone Regeneration / Q000187:drug effects*; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D017886:Durapatite / Q000737:chemistry* / Q000494:pharmacology; D017102:Fracture Healing / Q000187:drug effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D059630:Mesenchymal Stem Cells; D049329:Nanostructures / Q000737:chemistry*; D010012:Osteogenesis / Q000187:drug effects; D011091:Polyesters / Q000737:chemistry* / Q000494:pharmacology; D011817:Rabbits; D023822:Tissue Engineering / Q000295:instrumentation* / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: C525718:BMP2 protein, human; D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D011091:Polyesters; C016240:polycaprolactone; D017886:Durapatite
keywords: biomimetic composite scaffold; orthopedic surgery; osseous defects; reconstructive surgery