Antibacterial activities and release kinetics of a newly developed recoverable controlled agent-release system

We attempted to develop a resin with a recoverable antibacterial activity b ased on the desorption/adsorption of a cationic bactericide by the ion-exch ange mechanism. The aims of this study were to investigate the release kine tics of the agent and the antibacterial activity of this newly designed res in system. An experimental resin was prepared by the addition of methacryli c acid as a cation-exchanger and a cationic antibacterial agent, cetylpyrid inium chloride (CPC), to triethyleneglycol dimethacrylate. The amount of CP C desorbed from the experimental resin into buffer solutions at pH 4-8 was measured. The adsorption of CPC to control resin and re-adsorption of CPC t o the experimental resin, which had once desorbed the agent, were also dete rmined. The antibacterial activity of experimental resin against Streptococ cus mutans was evaluated, and the relationship between bacterial acid produ ction and antibacterial effect was assessed. The experimental resin desorbe d CPC at pH less than or equal to 6, and the amount of agent desorbed incre ased with increasing acidity. The control resin adsorbed CPC when immersed in CPC aqueous solution at a rate determined by the concentration of the ag ent and immersion time. The experimental resin, once desorbed CPC, could re -adsorb the bactericide by being exposed to a solution of the agent. Less p laque formed on the experimental resin, and the growth and survival of S. m utans was inhibited in the condition in which acid was produced. These resu lts demonstrate that the resin system proposed was able to desorb and re-ad sorb the cationic bactericide by an ion-exchange mechanism and could show a n inhibitory effect on S. mutans growth and plaque formation.