title: Improved osseointegration of PTFEP-coated titanium implants.
abstract: BACKGROUND
  Clinical success of bone implants is critically related to the interaction between the implant surface and the surrounding tissue. The polymer poly(bis(trifluoroethoxy)phosphazene) (PTFEP) is a promising, highly biocompatible surface coating which also inhibits the adsorption of granulocytes, macrophages, inflammatory cells, bacteria, and platelets. However, there is limited clinical experience of PTFEP as a coating for bone implants. Therefore PTFEP-coated titanium implants in an animal model were examined.
  
  
  METHODS
  PTFEP-coated titanium cylinders were implanted into the lateral femoral condyles of rabbits. Osseointegration was examined six weeks and six months after implantation using a non-destructive mechanical pull-out measurement and a histological analysis.
  
  
  RESULTS
  The results indicate improved osseointegration of PTFEP-coated implants. Six weeks after implantation, the PTFEP-coated implants showed a higher stiffness (pull-out length [pol]=7.1+/-2.0 microm) compared with uncoated cylinders (pol=10.2+/-3.4 microm, p<0.05). Six months after implantation, the mechanical properties of both implants had adjusted, and histological analysis revealed an increased bone-implant interface of PTFEP-coated cylinders compared with the first 6 weeks (17.5% vs. 8.2% in controls, p<0.05).
  
  
  CONCLUSIONS
  Taken together, the results of this preliminary study indicate promising applications of PTFEP as a coating material for bone implants.
authors.affiliation: Department of Orthopedic Surgery, University of Heidelberg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Zeifang
authors.forename: Michael
authors.initials: M
authors.lastname: Grunze
authors.forename: Gunter
authors.initials: G
authors.lastname: Delling
authors.forename: Helga
authors.initials: H
authors.lastname: Lorenz
authors.forename: Christian
authors.initials: C
authors.lastname: Heisel
authors.forename: Georgios
authors.initials: G
authors.lastname: Tosounidis
authors.forename: Desiderius
authors.initials: D
authors.lastname: Sabo
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Simank
authors.forename: Joerg H
authors.initials: JH
authors.lastname: Holstein
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D020099:Coated Materials, Biocompatible; D005260:Female; D005269:Femur / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D008422:Materials Testing; D009943:Organophosphorus Compounds; D016348:Osseointegration / Q000502:physiology; D011108:Polymers; D019736:Prostheses and Implants; D011817:Rabbits; D013997:Time Factors; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D009943:Organophosphorus Compounds; D011108:Polymers; C081660:poly(bis(trifluoroethoxy)phosphazene); D014025:Titanium