title: Decreased Staphylococcus aureus and increased osteoblast density on nanostructured electrophoretic-deposited hydroxyapatite on titanium without the use of pharmaceuticals.
abstract: BACKGROUND
  Plasma-spray deposition of hydroxyapatite on titanium (Ti) has proven to be a suboptimal solution to improve orthopedic-implant success rates, as demonstrated by the increasing number of orthopedic revision surgeries due to infection, implant loosening, and a myriad of other reasons. This could be in part due to the high heat involved during plasma-spray deposition, which significantly increases hydroxyapatite crystal growth into the nonbiologically inspired micron regime. There has been a push to create nanotopographies on implant surfaces to mimic the physiological nanostructure of native bone and, thus, improve osteoblast (bone-forming cell) functions and inhibit bacteria functions. Among the several techniques that have been adopted to develop nanocoatings, electrophoretic deposition (EPD) is an attractive, versatile, and effective material-processing technique.
  
  
  OBJECTIVE
  The in vitro study reported here aimed to determine for the first time bacteria responses to hydroxyapatite coated on Ti via EPD.
  
  
  RESULTS
  There were six and three times more osteoblasts on the electrophoretic-deposited hydroxyapatite on Ti compared with Ti (control) and plasma-spray-deposited hydroxyapatite on Ti after 5 days of culture, respectively. Impressively, there were 2.9 and 31.7 times less Staphylococcus aureus on electrophoretic-deposited hydroxyapatite on Ti compared with Ti (control) and plasma-spray-deposited hydroxyapatite on Ti after 18 hours of culture, respectively.
  
  
  CONCLUSIONS
  Compared with uncoated Ti and plasma-sprayed hydroxyapatite coated on Ti, the results provided significant promise for the use of EPD to improve bone-cell density and be used as an antibacterial coating without resorting to the use of antibiotics.
authors.affiliation: Department of Biomedical Engineering, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Dennis
authors.initials: D
authors.lastname: Mathew
authors.affiliation: Department of Biomedical Engineering, VIT University, Vellore, Tamil Nadu, India ; Centre for Biomaterials Science and Technology, School of Mechanical and Building Sciences, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Garima
authors.initials: G
authors.lastname: Bhardwaj
authors.affiliation: Department of Chemical Engineering and Program in Bioengineering, Northeastern University, Boston, MA, USA.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Chemical Engineering and Program in Bioengineering, Northeastern University, Boston, MA, USA.
authors.forename: Linlin
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Chemical Engineering and Program in Bioengineering, Northeastern University, Boston, MA, USA.
authors.forename: Batur
authors.initials: B
authors.lastname: Ercan
authors.affiliation: Department of Biomedical Engineering, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Manisavagam
authors.initials: M
authors.lastname: Geetha
authors.affiliation: Department of Chemical Engineering and Program in Bioengineering, Northeastern University, Boston, MA, USA ; Center of Excellence for Advanced Materials Research, University of King Abdulaziz, Jeddah, Saudi Arabia.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Webster
mesh_terms: D000497:Alloys; D002452:Cell Count; D002460:Cell Line; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000494:pharmacology*; D017886:Durapatite / Q000737:chemistry*; D004586:Electrophoresis / Q000379:methods; D004595:Electroplating / Q000379:methods*; D006801:Humans; D008422:Materials Testing; D010006:Osteoblasts / Q000187:drug effects / Q000502:physiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000502:physiology*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; C031462:titanium alloy (TiAl6V4); D017886:Durapatite; D014025:Titanium
keywords: bacteria; electrophoretic deposition; inhibition; nanotechnology
references.citation: Nanotechnology. 2011 Jul 22;22(29):295102
references.pmid: 21673387
references.citation: Biomaterials. 2006 Apr;27(11):2331-9
references.pmid: 16364434
references.citation: Nano Lett. 2007 Jun;7(6):1686-91
references.pmid: 17503870
references.citation: Biomaterials. 2005 Apr;26(12):1349-57
references.pmid: 15482822
references.citation: Clin Orthop Relat Res. 2010 Jan;468(1):52-6
references.pmid: 19669386
references.citation: Med J Aust. 2002 Jun 17;176(12):609-15
references.pmid: 12064963
references.citation: Biomaterials. 2003 Nov;24(25):4663-70
references.pmid: 12951009
references.citation: J Biomed Mater Res A. 2010 Mar 1;92(3):1218-24
references.pmid: 19343780
references.citation: Int J Nanomedicine. 2008;3(2):229-41
references.pmid: 18686782
references.citation: J Biomed Mater Res B Appl Biomater. 2009 Apr;89(1):165-71
references.pmid: 18780361
references.citation: J Bone Joint Surg Am. 2009 Jan;91(1):128-33
references.pmid: 19122087
references.citation: Int J Nanomedicine. 2011;6:1765-71
references.pmid: 21980239
references.citation: Clin Orthop Relat Res. 2010 Jan;468(1):45-51
references.pmid: 19554385
references.citation: J Biomed Mater Res A. 2010 Sep 15;94(4):1012-22
references.pmid: 20694968
references.citation: Proc Natl Acad Sci U S A. 2009 Feb 17;106(7):2130-5
references.pmid: 19179282
references.citation: J Antimicrob Chemother. 1997 May;39 Suppl A:1-6
references.pmid: 9511055
references.citation: Acta Biomater. 2010 Jun;6(6):2352-62
references.pmid: 20005310
references.citation: Biomaterials. 2000 Sep;21(17):1755-61
references.pmid: 10905457
references.citation: J Mater Sci Mater Med. 1997 Apr;8(4):213-9
references.pmid: 15348761
references.citation: Acta Biomater. 2011 Jul;7(7):3003-12
references.pmid: 21515421
references.citation: Biomaterials. 2010 Feb;31(4):706-13
references.pmid: 19879645
references.citation: Int J Nanomedicine. 2011;6:219-25
references.pmid: 21499419
references.citation: J R Soc Interface. 2010 Oct 6;7 Suppl 5:S581-613
references.pmid: 20504802