title: Biocompatibility of single-walled carbon nanotube composites for bone regeneration.
abstract: OBJECTIVE
  The purpose of this study was to evaluate in vivo biocompatibility of novel single-walled carbon nanotubes (SWCNT)/poly(lactic-co-glycolic acid) (PLAGA) composites for applications in bone and tissue regeneration.
  
  
  METHODS
  A total of 60 Sprague-Dawley rats (125 g to 149 g) were implanted subcutaneously with SWCNT/PLAGA composites (10 mg SWCNT and 1gm PLAGA 12 mm diameter two-dimensional disks), and at two, four, eight and 12 weeks post-implantation were compared with control (Sham) and PLAGA (five rats per group/point in time). Rats were observed for signs of morbidity, overt toxicity, weight gain and food consumption, while haematology, urinalysis and histopathology were completed when the animals were killed.
  
  
  RESULTS
  No mortality and clinical signs were observed. All groups showed consistent weight gain, and the rate of gain for each group was similar. All groups exhibited a similar pattern for food consumption. No difference in urinalysis, haematology, and absolute and relative organ weight was observed. A mild to moderate increase in the summary toxicity (sumtox) score was observed for PLAGA and SWCNT/PLAGA implanted animals, whereas the control animals did not show any response. Both PLAGA and SWCNT/PLAGA showed a significantly higher sumtox score compared with the control group at all time intervals. However, there was no significant difference between PLAGA and SWCNT/PLAGA groups.
  
  
  CONCLUSIONS
  Our results demonstrate that SWCNT/PLAGA composites exhibited in vivo biocompatibility similar to the Food and Drug Administration approved biocompatible polymer, PLAGA, over a period of 12 weeks. These results showed potential of SWCNT/PLAGA composites for bone regeneration as the low percentage of SWCNT did not elicit a localised or general overt toxicity. Following the 12-week exposure, the material was considered to have an acceptable biocompatibility to warrant further long-term and more invasive in vivo studies. Cite this article: Bone Joint Res 2015;4:70-7.
authors.affiliation: Southern Illinois University School of Medicine, 701 N First Street, Springfield, Illinois 62794-9679, USA.
authors.forename: A
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Southern Illinois University School of Medicine, 701 N First Street, Springfield, Illinois 62794-9679, USA.
authors.forename: T A
authors.initials: TA
authors.lastname: Liberati
authors.affiliation: Southern Illinois University School of Medicine, 701 N First Street, Springfield, Illinois 62794-9679, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Verhulst
authors.affiliation: Southern Illinois University School of Medicine, 701 N First Street, Springfield, Illinois 62794-9679, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Main
authors.affiliation: Southern Illinois University School of Medicine, 701 N First Street, Springfield, Illinois 62794-9679, USA.
authors.forename: M H
authors.initials: MH
authors.lastname: Roberts
authors.affiliation: Southern Illinois University School of Medicine, 701 N First Street, Springfield, Illinois 62794-9679, USA.
authors.forename: A G R
authors.initials: AG
authors.lastname: Potty
authors.affiliation: Southern Illinois University School of Medicine, 701 N First Street, Springfield, Illinois 62794-9679, USA.
authors.forename: T K
authors.initials: TK
authors.lastname: Pylawka
authors.affiliation: Southern Illinois University School of Medicine, 701 N First Street, Springfield, Illinois 62794-9679, USA.
authors.forename: S F
authors.initials: SF
authors.lastname: El-Amin Iii
keywords: Biocompatibility; Bone regeneration; Bone tissue engineering; Carbon nanotubes; SWCNT/PLAGA composites