title: Nanocrystallinity effects on osteoblast and osteoclast response to silicon substituted hydroxyapatite.
abstract: OBJECTIVE
  Silicon substituted hydroxyapatites (SiHA) are highly crystalline bioceramics treated at high temperatures (about 1200°C) which have been approved for clinical use with spinal, orthopedic, periodontal, oral and craniomaxillofacial applications. The preparation of SiHA with lower temperature methods (about 700°C) provides nanocrystalline SiHA (nano-SiHA) with enhanced bioreactivity due to higher surface area and smaller crystal size. The aim of this study has been to know the nanocrystallinity effects on the response of both osteoblasts and osteoclasts (the two main cell types involved in bone remodelling) to silicon substituted hydroxyapatite.
  
  
  METHODS
  Saos-2 osteoblasts and osteoclast-like cells (differentiated from RAW-264.7 macrophages) have been cultured on the surface of nano-SiHA and SiHA disks and different cell parameters have been evaluated: cell adhesion, proliferation, viability, intracellular content of reactive oxygen species, cell cycle phases, apoptosis, cell morphology, osteoclast-like cell differentiation and resorptive activity.
  
  
  RESULTS
  This comparative in vitro study evidences that nanocrystallinity of SiHA affects the cell/biomaterial interface inducing bone cell apoptosis by loss of cell anchorage (anoikis), delaying osteoclast-like cell differentiation and decreasing the resorptive activity of this cell type. These results suggest the potential use of nano-SiHA biomaterial for preventing bone resorption in treatment of osteoporotic bone.
authors: Department of Biochemistry and Molecular Biology I, Faculty of Chemistry, Universidad Complutense de Madrid, Spain; Instituto de Investigación Sanitaria San Carlos IdISSC, Spain. Electronic address: arualanilom@hotmail.com.
authors: Laura
authors: L
authors: Casarrubios
authors: Department of Biochemistry and Molecular Biology I, Faculty of Chemistry, Universidad Complutense de Madrid, Spain. Electronic address: conchitamatesanz@hotmail.com.
authors: María Concepción
authors: MC
authors: Matesanz
authors: Department of Inorganic and Bioinorganic Chemistry, Faculty of Pharmacy, Universidad Complutense de Madrid, Instituto de Investigación Hospital 12 de Octubre i+12, Spain; Networking Research Center on Bioengineering/Biomaterials and Nanomedicine, CIBER-BBN, Spain. Electronic address: sansanch@ucm.es.
authors: Sandra
authors: S
authors: Sánchez-Salcedo
authors: Department of Inorganic and Bioinorganic Chemistry, Faculty of Pharmacy, Universidad Complutense de Madrid, Instituto de Investigación Hospital 12 de Octubre i+12, Spain; Networking Research Center on Bioengineering/Biomaterials and Nanomedicine, CIBER-BBN, Spain. Electronic address: arcosd@ucm.es.
authors: Daniel
authors: D
authors: Arcos
authors: Department of Inorganic and Bioinorganic Chemistry, Faculty of Pharmacy, Universidad Complutense de Madrid, Instituto de Investigación Hospital 12 de Octubre i+12, Spain; Networking Research Center on Bioengineering/Biomaterials and Nanomedicine, CIBER-BBN, Spain. Electronic address: vallet@ucm.es.
authors: María
authors: M
authors: Vallet-Regí
authors: Department of Biochemistry and Molecular Biology I, Faculty of Chemistry, Universidad Complutense de Madrid, Spain; Instituto de Investigación Sanitaria San Carlos IdISSC, Spain. Electronic address: portoles@quim.ucm.es.
authors: María Teresa
authors: MT
authors: Portolés
mesh_terms: D000818:Animals; D023102:Anoikis / Q000187:drug effects; D018786:Bone Substitutes / Q000737:chemistry* / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003460:Crystallization; D017886:Durapatite / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012825:Silicon / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D018786:Bone Substitutes; D017382:Reactive Oxygen Species; D017886:Durapatite; D012825:Silicon
keywords: Anoikis; Apoptosis; Cell adhesion; Cell cycle; Hydroxyapatite; Nanocrystallinity; Osteoblast; Osteoclast; Osteoporosis; Silicon