Catheter locks are used to prevent infection and clotting in indwelling catheters, but most current locks are simple liquids. These liquid formulations can spill into the bloodstream during instillation due to the parabolic flow pattern and subsequently mix with blood due to the absence of a defined interface between the lock solution and blood. When the lock solution contains drugs such as antimicrobial and anticoagulant agents, this spillage can lead to systemic toxicity and reduced therapeutic efficacy. In contrast, the use of a hemocompatible thixotropic hydrogel as a catheter lock significantly minimizes spillage and mixing by 2–5 folds, thereby slowing drug loss.
Nitric oxide (NO)-releasing thixotropic hydrogels, utilizing poloxamers and 2-hydroxypropyl α-cyclodextrin (HP-αCD), are advanced, shear-thinning materials designed for catheter locks and wound dressings. They provide a physical barrier while releasing NO to kill bacteria (biofilm reduction) and prevent clotting (hemocompatibility). This thixotropic gel can be injected into the catheter lumen when the catheter is not in use and withdrawn when vascular access is needed.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.
Li W, Liebrecht L, Poudel S, Goodhart R, More S, Montano J, Lust D, Xu Q, Mangino M, Wang X. Nitric Oxide-Releasing Thixotropic Hydrogels as Antibacterial and Hemocompatible Catheter Locks. ACS Biomater Sci Eng. 2026 Jan 12;12(1):655-667. doi: 10.1021/acsbiomaterials.5c01661