Thromboresistant/anti-biofilm catheters via electrochemically modulated nitric oxide release

• Electrochemical NO release from a nitrite reservoir is demonstrated in a catheter.
• NO release from the catheter surface can be turned “on” and “off”.
• These catheters reduce surface thrombus in vivo by up to 67%.
• The NO release catheters reduce S. aureus and E. coli biofilm formation by > 99.9%.

Inexpensive nitric oxide (NO) release strategies to prevent thrombosis and bacterial infections are desirable for implantable medical devices. Herein, we demonstrate the utility of electrochemically modulated NO release from a catheter model using an inner copper wire working electrode and an inorganic nitrite salt solution reservoir. These catheters generate NO surface fluxes of > 1.0 × 10− 10 mol min− 1 cm− 2 for more than 60 h. Catheters with an NO flux of 1.1 × 10− 10 mol min− 1 cm− 2 are shown to significantly reduce surface thrombus formation when implanted in rabbit veins for 7 h. Further, the ability of these catheters to exhibit anti-biofilm properties against bacterial species commonly causing bloodstream and urinary catheter infections is examined. Catheters releasing NO continuously during the 2 d growth of Staphylococcus aureus exhibit a 6 log-unit reduction in viable surface bacteria. We also demonstrate that catheters generating NO for only 3 h at a flux of 1.0 × 10− 10 mol min− 1 cm− 2 lower the live bacterial counts of both 2 d and 4 d pre-formed Escherichia coli biofilms by > 99.9%. Overall, the new electrochemical NO-release devices could provide a cost-effective strategy to greatly enhance the biocompatibility and antimicrobial properties of intravascular and urinary catheters, as well as other implantable medical devices.

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