title: N-acetyl cysteine alleviates cytotoxicity of bone substitute.
abstract: Lack of cytocompatibility in bone substitutes impairs healing in surrounding bone. Adverse biological events around biomaterials may be associated with oxidative stress. We hypothesized that a clinically used inorganic bone substitute is cytotoxic to osteoblasts due to oxidative stress and that N-acetyl cysteine (NAC), an antioxidant amino acid derivative, would detoxify such material. Only 20% of rat calvaria osteoblasts were viable when cultured on commercial deproteinized bovine bone particles for 24 hr, whereas this percentage doubled on bone substitute containing NAC. Intracellular ROS levels markedly increased on and under bone substitutes, which were reduced by prior addition of NAC to materials. NAC restored suppressed alkaline phosphatase activity in the bone substitute. Proinflammatory cytokine levels from human osteoblasts on the bone substitute decreased by one-third or more with addition of NAC. NAC alleviated cytotoxicity of the bone substitute to osteoblastic viability and function, implying enhanced bone regeneration around NAC-treated inorganic biomaterials.
authors.affiliation: Laboratory for Bone and Implant Sciences (LBIS), The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA. masayamada@tdc.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Yamada
authors.forename: T
authors.initials: T
authors.lastname: Ueno
authors.forename: H
authors.initials: H
authors.lastname: Minamikawa
authors.forename: N
authors.initials: N
authors.lastname: Sato
authors.forename: F
authors.initials: F
authors.lastname: Iwasa
authors.forename: N
authors.initials: N
authors.lastname: Hori
authors.forename: T
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects; D018786:Bone Substitutes / Q000633:toxicity*; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005978:Glutathione / Q000096:biosynthesis; D006801:Humans; D007378:Interleukins / Q000096:biosynthesis; D008297:Male; D008903:Minerals / Q000633:toxicity*; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D016166:Free Radical Scavengers; D007378:Interleukins; D008903:Minerals; D017382:Reactive Oxygen Species; D005978:Glutathione; D000111:Acetylcysteine