title: Inhibition of bacterial and leukocyte adhesion under shear stress conditions by material surface chemistry.
abstract: Biomaterial-centered infections, initiated by bacterial adhesion, persist due to a compromised host immune response. Altering implant materials with surface modifying endgroups (SMEs) may enhance their biocompatibility by reducing bacterial and inflammatory cell adhesion. A rotating disc model, which generates shear stress within physiological ranges, was used to characterize adhesion of leukocytes and Staphylococcus epidermidis on polycarbonate-urethanes and polyetherurethanes modified with SMEs (polyethylene oxide, fluorocarbon and dimethylsiloxane) under dynamic flow conditions. Bacterial adhesion in the absence of serum was found to be mediated by shear stress and surface chemistry, with reduced adhesion exhibited on materials modified with polydimethylsiloxane and polyethylene oxide SMEs. In contrast, bacterial adhesion was enhanced on materials modified with fluorocarbon SMEs. In the presence of serum, bacterial adhesion was primarily neither material nor shear dependent. However, bacterial adhesion in serum was significantly reduced to < or = 10% compared to adhesion in serum-free media. Leukocyte adhesion in serum exhibited a shear dependency with increased adhesion occurring in regions exposed to lower shear-stress levels of < or = 7 dyne/cm2. Additionally, polydimethylsiloxane and polyethylene oxide SMEs reduced leukocyte adhesion on polyether-urethanes. In conclusion, these results suggest that surface chemistry and shear stress can mediate bacterial and cellular adhesion. Furthermore, materials modified with polyethylene oxide SMEs are capable of inhibiting bacterial adhesion, consequently minimizing the probability of biomaterial-centered infections.
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
authors.forename: Jasmine D
authors.initials: JD
authors.lastname: Patel
authors.forename: Michael
authors.initials: M
authors.lastname: Ebert
authors.forename: Ken
authors.initials: K
authors.lastname: Stokes
authors.forename: Robert
authors.initials: R
authors.lastname: Ward
authors.forename: James M
authors.initials: JM
authors.lastname: Anderson
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects / Q000502:physiology*; D001672:Biocompatible Materials / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007962:Leukocytes / Q000187:drug effects / Q000502:physiology*; D008422:Materials Testing / Q000379:methods*; D013212:Staphylococcus epidermidis / Q000502:physiology; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials