title: On the determining role of network structure titania in silicone against bacterial colonization: mechanism and disruption of biofilm.
abstract: Silicone-based biomedical devices are prone to microbial adhesion, which is the primary cause of concern in the functioning of the artificial device. Silicone exhibiting long-term and effective antibacterial ability is highly desirable to prevent implant related infections. In this regard, nanophase titania was incorporated in silicone as an integral part of the silicone network structure through cross-link mechanism, with the objective to reduce bacterial adhesion to a minimum. The bacterial adhesion was studied using crystal violet assay, while the mechanism of inhibition of biofilm formation was studied via electron microscopy. The incorporation of nanophase titania in silicone dramatically reduced the viability of Staphylococcus aureus (S. aureus) and the capability to adhere on the surface of hybrid silicone by ~93% in relation to stand alone silicone. The conclusion of dramatic reduction in the viability of S. aureus is corroborated by different experimental approaches including biofilm inhibition assay, zone of inhibition, and through a novel experiment that involved incubation of biofilm with titania nanoparticles. It is proposed that the mechanism of disruption of bacterial film in the presence of titania involves puncturing of the bacterial cell membrane.
authors.affiliation: Biomaterials and Biomedical Engineering Research Laboratory, Center for Structural and Functional Materials, University of Louisiana at Lafayette, P.O. Box 44130, Lafayette, LA 70504-4130, USA.
authors.forename: D
authors.initials: D
authors.lastname: Depan
authors.forename: R D K
authors.initials: RD
authors.lastname: Misra
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D015169:Colony Count, Microbial; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D053758:Nanoparticles / Q000648:ultrastructure; D012828:Silicones / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D013499:Surface Properties; D013718:Tensile Strength / Q000187:drug effects; D014025:Titanium / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D012828:Silicones; C009495:titanium dioxide; D014025:Titanium
keywords: Antimicrobial; Biofilm; Silicone; Titania