title: Guided bone regeneration with tripolyphosphate cross-linked asymmetric chitosan membrane.
abstract: OBJECTIVE
  The objective of this study was to prepare a novel asymmetric chitosan guided bone regeneration (GBR) membrane, which is composed of a dense layer isolating the bone defect from the invasion of surrounding connective fibrous tissue and a loose layer which can improve cell adhesion and stabilize blood clots, thus guided bone regeneration.
  
  
  METHODS
  The chitosan membrane was fabricated through liquid nitrogen quencher combined with lyophilization and cross-linked by sodium tripolyphosphate (TPP). The physical properties of asymmetric chitosan membrane were measured by scanning electron microscope (SEM), Fourier-transform infrared (FTIR), x-ray diffraction (XRD) and tensile test machine. MTT assay and Live/Dead cell staining for MC3T3-E1 osteoblasts cultured on the membrane were used to characterize the biocompatibility of the membrane. In animal experiments, full-thickness and critical sized skull defects were made to evaluate the effect of the membrane on bone regeneration.
  
  
  RESULTS
  The results of this study indicate that the asymmetric chitosan membrane can be built and cross-linked by TPP to enhance the tensile strength of the membrane. In vitro experiment showed that no significant numbers of dead cells were detected on the chitosan membrane, indicating that the membrane had good biocompatibility. In animal experiments, the chitosan membrane had faster new bone formation, showing the capability to enhance bone regeneration.
  
  
  CONCLUSIONS
  The chitosan membrane prepared in this study has an asymmetric structure; its tensile strength, biodegradation and biocompatibility fulfil the requirements of guided bone regeneration. Therefore, the asymmetric chitosan membrane is a promising GBR membrane for bone regeneration.
  
  
  CONCLUSIONS
  Guided bone regeneration (GBR) is an effective method for healing bone defects caused by periodontitis and implantitis, in which GBR membrane is a key biomaterial.
authors.affiliation: School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin 300070, PR China.
authors.forename: Shiqing
authors.initials: S
authors.lastname: Ma
authors.affiliation: School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin 300070, PR China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Chen
authors.affiliation: School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin 300070, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qiao
authors.affiliation: School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin 300070, PR China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Sun
authors.affiliation: The Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer, Beijing University of Chemical Technology, Beijing 100029, PR China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, PR China.
authors.forename: Xuliang
authors.initials: X
authors.lastname: Deng
authors.affiliation: National Tissue Engineering Center of China, No. 68, East Jiang Chuan Road, Shanghai 200241, PR China; School of Chemical Engineering, East China University of Science and Technology, No. 130, Mei Long Road, Shanghai 200237, PR China.
authors.forename: Lian
authors.initials: L
authors.lastname: Cen
authors.affiliation: The Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer, Beijing University of Chemical Technology, Beijing 100029, PR China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Cai
authors.affiliation: School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin 300070, PR China.
authors.forename: Mingyao
authors.initials: M
authors.lastname: Wu
authors.affiliation: School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin 300070, PR China. Electronic address: zhxden@gmail.com.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School and Hospital of Stomatology, Tianjin Medical University, 12 Observatory Road, Tianjin 300070, PR China. Electronic address: gptj@sina.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Gao
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001847:Bone Diseases / Q000601:surgery; D001861:Bone Regeneration / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D048091:Guided Tissue Regeneration / Q000295:instrumentation*; D008297:Male; D008567:Membranes, Artificial; D051379:Mice; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology; D010294:Parietal Bone / Q000601:surgery; D011122:Polyphosphates / Q000737:chemistry*; D016062:Porosity; D051381:Rats; D017207:Rats, Sprague-Dawley; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D008567:Membranes, Artificial; D011122:Polyphosphates; D048271:Chitosan; C005692:triphosphoric acid
keywords: Asymmetric; Chitosan membrane; Guided bone regeneration; Sodium tripolyphosphate