title: Biological monitoring of a promissory xenogenic pin for biomedical applications: a preliminary intraosseous study in rats.
abstract: OBJECTIVE
  Over the last years, it is known that in some cases metal devices for biomedical applications present some disadvantages suggesting absorbable materials (natural or synthetic) as an alternative of choice. Here, our goal was to evaluate the biological response of a xenogenic pin, derived from bovine cortical bone, intraosseously implanted in the femur of rats.
  
  
  METHODS
  After 10, 14, 30 and 60 days from implantation, the animals (n=5/period) were killed and the femurs carefully collected and dissected out under histological demands. For identifying the osteoclastogenesis level at 60 days, we performed the immunohistochemisty approach using antibody against RANKL.
  
  
  RESULTS
  Interestingly, our results showed that the incidence of neutrophils and leukocytes was observed only at the beginning (10 days). Clear evidences of pin degradation by host cells started at 14 days and it was more intensive at 60 days, when we detected the majority of the presence of giant multinucleated cells, which were very similar to osteoclast cells contacting the implanted pin. To check osteoclastogenesis at 60 days, we evaluated RANKL expression and it was positive for those resident multinucleated cells while a new bone deposition was verified surrounding the pins in all evaluated periods.
  
  
  CONCLUSIONS
  Altogether, our results showed that pins from fully processed bovine bone are biocompatible and absorbable, allowing bone neoformation and it is a promissory device for biomedical applications.
authors.affiliation: Cell Therapy Center (UPC), University Hospital Antonio Pedro, Fluminense Federal University, Niterói, Rio de Janeiro.
authors.forename: Willian Fernando
authors.initials: WF
authors.lastname: Zambuzzi
authors.forename: Rodrigo Cardoso
authors.initials: RC
authors.lastname: Oliveira
authors.forename: Bruno Leite
authors.initials: BL
authors.lastname: Subitoni
authors.forename: Renato
authors.initials: R
authors.lastname: Menezes
authors.forename: Rumio
authors.initials: R
authors.lastname: Taga
authors.forename: José Mauro
authors.initials: JM
authors.lastname: Granjeiro
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001858:Bone Nails; D002417:Cattle; D005269:Femur / Q000601:surgery*; D007124:Immunoenzyme Techniques; D020007:Implants, Experimental; D010012:Osteogenesis / Q000502:physiology*; D010784:Photomicrography; D053245:RANK Ligand / Q000378:metabolism; D051381:Rats; D018709:Statistics, Nonparametric; D014183:Transplantation, Heterologous
chemical_list: D001672:Biocompatible Materials; D053245:RANK Ligand