# Nitric Oxide-Releasing Thixotropic Hydrogels as Antibacterial and Hemocompatible Catheter Locks

## TL;DR

This paper introduces a new gel-based catheter lock that prevents bacterial contamination and blood clots using nitric oxide.

## Contribution

The first gel-based catheter lock is developed, combining thixotropic hydrogel with nitric oxide for antibacterial and hemocompatible properties.

## Key findings

- The hydrogel provides a physical barrier to slow bacterial migration and reduce drug loss.
- Nitric oxide released from the gel effectively prevents biofilm formation on catheter surfaces.
- The gel demonstrates excellent hemocompatibility and reduces clot adhesion.

## Abstract

Catheters are indispensable
medical tools for accessing blood vessels,
hollow organs, and body cavities to facilitate medication delivery
and fluid drainage. However, they also serve as major entry points
for bacterial contamination and trigger foreign body responses, necessitating
locking strategies that are both bactericidal and biocompatible. This
study introduces the first gel-based catheter lock, in contrast to
conventional liquid locks. The gel is a poloxamer-based hydrogel formulated
with 2-hydroxypropyl α-cyclodextrin (HP-αCD). HP-αCD
forms supramolecular complexes with the poloxamer to enhance gelation
and with the nitric oxide (NO) donor to modulate NO release kinetics.
This thixotropic gel can be injected into the catheter lumen when
the catheter is not in use and withdrawn when vascular access is needed.
The gel matrix provides a physical barrier that slows bacterial migration
and minimizes drug loss. Simultaneously, the released NO functions
as a broad-spectrum antimicrobial agent, effectively preventing biofilm
formation on both the internal and external surfaces of the catheter.
The NO-releasing hydrogel also demonstrates excellent hemocompatibility
and reduces clot adhesion. Together, the gel-based lock offers a promising
strategy for more effective catheter maintenance and represents a
new application of hydrogels.