title: Influence of Silver-hydroxyapatite Nanocomposite Coating on Biofilm Formation of Joint Prosthesis and Its Mechanism.
abstract: The main reason for biomaterial related refractory infections is biofilm formation caused by bacterial adhesion on the surface of materials. Silver-hydroxyapatite (Ag/HA) nanocomposite coating can inhibit the formation of biofilm, but its mechanism is not clear.
  
  
  
  In order to clarify the mechanism, the amounts of biofilm on the Ag/HA composite coating and HA coating were determined, the release rates of silver nanoparticles in simulated body fluid (SBF) were detected by atomic absorption spectrometry, and the expression values ofatlE,fbe,sap,iapBgenes ofStaphylococcus aureuswere studied when they grew on Ag/HA composite coating and HA coating.
  
  
  
  The amount of the biofilm on the Ag/HA composite coating was significantly less than that on the HA coating, and the bacterial adhesion was decreased. The silver nanoparticles were released continuously in SBF and the release rate decreased gradually with time. The expression values ofatlE,fbeandsapwere high in the initial stage of adhesion and the expression value ofiapBwas high in the colonies-gathering stage in the control group, but they were all significantly inhibited in the presence of Ag.
  
  
  
  These results indicated that the main antibacterial effect of Ag/HA composite coating was achieved by the release of silver nanoparticles. The addition of Ag inhibited the expression of genes related to biofilm formation, which in turn inhibited the formation of biofilms. This provided theoretical support for the clinical application of Ag/HA composite coating.
authors.affiliation: Department of Orthopaedics, The Second Affiliated Hospital of Soochow University, Jiangsu 215000, China. E-mail: sudazhaolei@hotmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Faculty of Science and Natural Resources, Universiti Malaysia, Sabah 88400, Kota Kinabalu, Sabah, Malaysia.
authors.forename: M A
authors.initials: MA
authors.lastname: Ashraf