Chitosan-based rechargeable long-term antimicrobial and biofilm-controlling systems.

Chitosan, a natural cationic polymer, strongly binds anionic antibiotics (e.g., rifampin) through the formation of ionic complexes. The new system shows sustained rifampin release, leading to potent antimicrobial and biofilm-controlling functions against gram-positive bacteria including Staphylococcus epidermidis and Staphylococcus aureus, which are responsible for a wide range of medical device-related infections, for longer than 30 days. Moreover, the released drugs can be recharged to further extend antimicrobial durations. Drug release mechanisms and potential applications of the new system are also discussed. Copyright 2008 Wiley Periodicals, Inc.