title: Amorphous Silica: A New Antioxidant Role for Rapid Critical-Sized Bone Defect Healing.
abstract: Traumatic fractures cause structurally unstable sites due to severe bone loss. Such fractures generate a high yield of reactive oxygen species (ROS) that can lead to oxidative stress. Excessive and prolonged ROS activity impedes osteoblast differentiation and instigates long healing times. Stimulation of antioxidants such as superoxide dismutase (SOD1), are crucial to reduce ROS, stimulate osteogenesis, and strengthen collagen and mineral formation. Yet, no current fixative devices have shown an ability to enhance collagen matrix formation through antioxidant expression. This study reports plasma-enhanced chemical vapor deposition based amorphous silicon oxynitride (Si(ON)x) as a potential new fracture healing biomaterial that adheres well to the implant surface, releases Si(+4) to enhance osteogenesis, and forms a surface hydroxyapatite for collagen mineral attachment. These materials provide a sustained release of Si(+4) in physiological environment for extended times. The dissolution rate partially depends on the film chemistry and can be controlled by varying O/N ratio. The presence of Si(+4) enhances SOD1, which stimulates other osteogenic markers downstream and leads to rapid mineral formation. In vivo testing using a rat critical-sized calvarial defect model shows a more rapid bone-regeneration for these biomaterials as compared to control groups, that implies the clinical significance of the presented biomaterial.
authors.affiliation: Department of Biomedical Sciences, Texas A&M University, Baylor College of Dentistry, Dallas, TX, 75246, USA.
authors.forename: Azhar
authors.initials: A
authors.lastname: Ilyas
authors.affiliation: Department of Biomedical Sciences, Texas A&M University, Baylor College of Dentistry, Dallas, TX, 75246, USA.|Department of Applied Prosthodontics, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1, Sakamoto, Nagasaki, 852-8588, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Odatsu
authors.affiliation: Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, TX, 76019, USA.
authors.forename: Ami
authors.initials: A
authors.lastname: Shah
authors.affiliation: Department of Bioengineering, University of Texas at Arlington, Arlington, TX, 76019, USA.|Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital, Dallas, TX, 75219, USA.
authors.forename: Felipe
authors.initials: F
authors.lastname: Monte
authors.affiliation: Center for Excellence in Hip Disorders, Texas Scottish Rite Hospital, Dallas, TX, 75219, USA.|Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390, USA.
authors.forename: Harry K W
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Department of Biomedical Sciences, Texas A&M University, Baylor College of Dentistry, Dallas, TX, 75246, USA.
authors.forename: Philip
authors.initials: P
authors.lastname: Kramer
authors.affiliation: Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, TX, 76019, USA.
authors.forename: Pranesh B
authors.initials: PB
authors.lastname: Aswath
authors.affiliation: Department of Biomedical Sciences, Texas A&M University, Baylor College of Dentistry, Dallas, TX, 75246, USA. varanasi@bcd.tamhsc.edu.
authors.forename: Venu G
authors.initials: VG
authors.lastname: Varanasi
mesh_terms: D000818:Animals; D002460:Cell Line; D017102:Fracture Healing; D050723:Fractures, Bone / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D008297:Male; D051379:Mice; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012822:Silicon Dioxide / Q000737:chemistry / Q000494:pharmacology; D000072105:Superoxide Dismutase-1 / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D012822:Silicon Dioxide; C000606291:Sod1 protein, mouse; C000606292:Sod1 protein, rat; D000072105:Superoxide Dismutase-1
keywords: PECVD; antioxidants; blood vessel formation; bone formation; superoxide dismutase