The use of immunoliposomes for specific delivery of antimicrobial agents to oral bacteria immobilized on polystyrene.

Antibacterial immunoliposomes have been prepared using covalently bound antibody, raised to the cell surface of the bacterium Streptococcus oralis (S. oralis), and incorporating the bactericides chlorhexidine and Triclosan. A regrowth assay, in which the ability of a bacterial biofilm immobilised on polystyrene to grow after exposure to a test solution, was undertaken to study the action of the antibacterial immunoliposomes. The antibacterial anti-oralis immunoliposomes show enhanced growth inhibition of S. oralis, compared to free bactericide, using low bactericide concentrations. For short exposure times to the biofilms, antibacterial anti-oralis immunoliposomes can show several times enhanced growth inhibition of S. oralis compared to free bactericide. Antibacterial anti-oralis immunoliposomes inhibit the growth of S. oralis more than that of other oral bacteria. The extent of growth inhibition by antibacterial anti-oralis immunoliposomes is linearly related to the number of immunoliposomes targeted to the biofilm surface.