title: Cytocompatibility and biocompatibility of nanostructured carbonated hydroxyapatite spheres for bone repair.
abstract: OBJECTIVE
  The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA) microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA).
  
  
  METHODS
  The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group) (n=5/period/group). After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance.
  
  
  RESULTS
  The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p<0.05) indicating greater biosorption. An increase in the RANKL/OPG ratio was observed in the CHA group on the 7th day.
  
  
  CONCLUSIONS
  CHA spheres were osteoconductive and presented earlier biosorption, inducing early increases in the levels of proteins involved in resorption.
authors.affiliation: Departamento de Cirurgia Oral, Faculdade de Odontologia, Universidade Federal Fluminense, Niteroi, RJ, Brazil.
authors.forename: Mônica Diuana
authors.initials: MD
authors.lastname: Calasans-Maia
authors.affiliation: Faculdade de Odontologia, Universidade Federal Fluminense, Niteroi, RJ, Brazil.
authors.forename: Bruno Raposo de
authors.initials: BR
authors.lastname: Melo
authors.affiliation: Faculdade de Odontologia, Universidade Federal Fluminense, Niteroi, RJ, Brazil.
authors.forename: Adriana Terezinha Neves Novellino
authors.initials: AT
authors.lastname: Alves
authors.affiliation: Faculdade de Odontologia, Universidade Federal Fluminense, Niteroi, RJ, Brazil.
authors.forename: Rodrigo Figueiredo de Brito
authors.initials: RF
authors.lastname: Resende
authors.affiliation: Departamento de Cirurgia Oral, Faculdade de Odontologia, Universidade Federal Fluminense, Niteroi, RJ, Brazil.
authors.forename: Rafael Seabra
authors.initials: RS
authors.lastname: Louro
authors.affiliation: Faculdade de Odontologia, Universidade Federal Fluminense, Niteroi, RJ, Brazil.
authors.forename: Suelen Cristina
authors.initials: SC
authors.lastname: Sartoretto
authors.affiliation: Instituto Nacional de Metrologia, Qualidade e Tecnologia, Duque de Caxias, Rio de Janeiro, Brazil.
authors.forename: José Mauro
authors.initials: JM
authors.lastname: Granjeiro
authors.affiliation: Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, Niteroi, RJ, Brazil.
authors.forename: Gutemberg Gomes
authors.initials: GG
authors.lastname: Alves
mesh_terms: D000464:Alginates / Q000494:pharmacology*; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D001861:Bone Regeneration / Q000187:drug effects*; D002452:Cell Count; D017886:Durapatite / Q000494:pharmacology*; D020723:Glucuronic Acid / Q000494:pharmacology; D006603:Hexuronic Acids / Q000494:pharmacology; D006801:Humans; D008297:Male; D008422:Materials Testing; D049329:Nanostructures / Q000627:therapeutic use*; D010006:Osteoblasts / Q000187:drug effects; D053244:Osteoprotegerin / Q000097:blood; D017208:Rats, Wistar; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000097:blood; D015203:Reproducibility of Results; D013997:Time Factors; D020390:Tooth Socket / Q000187:drug effects; D014961:X-Ray Diffraction
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D006603:Hexuronic Acids; D053244:Osteoprotegerin; D053246:Receptor Activator of Nuclear Factor-kappa B; D020723:Glucuronic Acid; D017886:Durapatite
references.citation: Bone. 2002 Apr;30(4):533-40
references.pmid: 11934642
references.citation: Crit Rev Eukaryot Gene Expr. 2009;19(1):61-72
references.pmid: 19191757
references.citation: J Biomed Mater Res A. 2005 Dec 1;75(3):567-79
references.pmid: 16094665
references.citation: Mater Sci Eng C Mater Biol Appl. 2014 Aug 1;41:309-19
references.pmid: 24907765
references.citation: J Biomed Mater Res B Appl Biomater. 2016 Feb;104(2):274-82
references.pmid: 25716009
references.citation: J Biomed Mater Res B Appl Biomater. 2012 Nov;100(8):2316-26
references.pmid: 23015272
references.citation: Philos Trans A Math Phys Eng Sci. 2004 Dec 15;362(1825):2821-50
references.pmid: 15539372
references.citation: Skeletal Radiol. 2007 Dec;36(12):1105-7
references.pmid: 17912519
references.citation: J Biomed Mater Res A. 2007 Jun 15;81(4):930-8
references.pmid: 17252547
references.citation: Clin Oral Investig. 2013 Dec;17(9):2003-10
references.pmid: 23358705
references.citation: J Biomed Mater Res A. 2013 Jul;101(7):1986-93
references.pmid: 23239606
references.citation: Curr Pharm Des. 2013;19(19):3446-55
references.pmid: 23432675
references.citation: Clin Oral Investig. 2013 Mar;17(2):423-30
references.pmid: 22552592
references.citation: J Biomed Mater Res B Appl Biomater. 2013 Feb;101(2):387-97
references.pmid: 23281143
references.citation: J Am Acad Orthop Surg. 2013 Jan;21(1):51-60
references.pmid: 23281471
references.citation: FEBS Lett. 2013 Jan 4;587(1):48-53
references.pmid: 23183242
references.citation: IEEE Trans Nanobioscience. 2012 Dec;11(4):336-40
references.pmid: 22438516
references.citation: Dent Mater J. 2012;31(4):549-57
references.pmid: 22864207
references.citation: Artif Organs. 2012 Jun;36(6):535-42
references.pmid: 22372877
references.citation: J Mater Sci Mater Med. 2012 Mar;23(3):781-8
references.pmid: 22201029
references.citation: Br J Oral Maxillofac Surg. 2011 Sep;49(6):469-73
references.pmid: 20970227
references.citation: J Biomed Mater Res A. 2011 Sep 1;98(3):351-8
references.pmid: 21626666
references.citation: Tissue Eng Part A. 2010 Dec;16(12):3687-95
references.pmid: 20673025
references.citation: Clin Oral Implants Res. 2010 Dec;21(12):1334-44
references.pmid: 20626421
references.citation: Calcif Tissue Int. 2010 Nov;87(5):450-60
references.pmid: 20730582
references.citation: Acta Biomater. 2010 Aug;6(8):2863-73
references.pmid: 20123046
references.citation: J Mater Sci Mater Med. 2010 Jan;21(1):283-94
references.pmid: 19885643
references.citation: J Endod. 2009 Oct;35(10):1387-90
references.pmid: 19801236
references.citation: Dent Traumatol. 2009 Feb;25(1):2-11
references.pmid: 19208005