• Biomedical Science Letters
• /
• v.13 no.3
• /
• pp.175-182
• /
• 2007

In vitro ciprofloxacin (CFX)-release study and bioassay using microorganisms were performed to estimate the retention of the antimicrobial activity of the CFX-incorporated central venous catheters (CFX-CVCs). The release experiments were carried out under the optional CFX-release conditions to mimic the in vivo environment. The release of CFX experienced an initial burst followed by a slow and steady matrix-diffusion controlled release. The 1.0CP (polyurethane catheter containing 1.0% (w/w) of CFX) under dynamic condition showed a near zero-order CFX release profile, which is beneficial for the long-tenn antimicrobial activity. The modified Kirby-Bauer method was performed employing S. aureus and E. coli to evaluate the retention of antimicrobial activity of the catheters retrieved from the release experiments. The 1.0CP showed the long-term antimicrobial activity (${\geq}\;21$ days) against both S. aureus and E. coli. These results indicate that 1.0CP is useful as a long-tenn indwelling CVC.

• Biomedical Science Letters
• /
• v.10 no.3
• /
• pp.245-251
• /
• 2004

Microbial infection provokes one of the most serious complications to the patients with indwelling catheters. Ciprofloxacin (CFX) was added into the catheter materials (polyurethane or silicone) during the manufacturing process to avoid the microbial infection. Efficacy of the catheters containing CFX was investigated by using the in vitro zone of growth inhibition test method. The catheters made of polyurethane or silicone exhibited a strong antimicrobial activity against the major catheter-related microorganisms (S. aureus, S. epidermidis, P. aeruginosa and E. coli), when CFX was incorporated into the catheters. Fetal bovine serum (FBS) did not affected antimicrobial activities of the polyurethane catheters with CFX loading of 0.5 and 1.0％ (W/W) against S. aureus and S. epidermidis. However, the polyurethane catheters with 1.0％ (W/W) of CFX loading showed a significantly (P<0.05) reduced antimicrobial activity against E. coli when the catheters were exposed to FBS. Silicone catheters with 1.0 and 1.5％ (W/W) of CFX loading demonstrated effective antimicrobial activity against S. epidermidis for at least 2 weeks. These results suggest that the use of catheters containing ciprofloxacin could be effective in preventing catheter-related infections.

• Biomedical Science Letters
• /
• v.15 no.1
• /
• pp.73-80
• /
• 2009

Bloodstream infections (BSI) are caused by planktonic microorganisms, sometimes leading to serious infections such as bacteremia and sepsis. BSI occurs more frequently to the patients wearing the central venous catheter (CVC). The ciprofloxacin-incorporated CVC (CFX-CVC) has been reported previously to possess antimicrobial activity. In this study, the antibacterial activity of CFX-CVC and its mechanism against planktonic BSI cells were explored by using the shake flask test and by examining the release rate of 260 nm-absorbing substances from the bacterial cells indicative of the membrane damage of the bacterial cells. CFX-CVC reduced more than 99.9% of the viable planktonic BSI cells demonstrating its potent antibacterial activity. It provoked bacteriolysis causing leakage of a large amount of 260 nm-absorbing materials from the planktonic bacterial cells like S. aureus and E. coli. These results provide evidence that the antibacterial activity of CFX-CVC came from the inhibition of the stability of the planktonic bacterial cells.