The goal of this work is to develop a catheter end cap with an antimicrobial luminal insert to reduce risk of blood stream infections (BSI) in hemodialysis (HD) patients. The Gatekeeper™ antimicrobial barrier cap (GCAP) acts as a barrier and delivery device to kill infection-causing microorganisms inside hemodialysis (HD) catheter hubs. Infections are the second leading cause of hospitalization and death in HD patients with 70% of all BSI due to catheter use.1,2 Catheter related BSI necessitate catheter locking with high dose antibiotics, removal and replacement of the catheter at a new site, or exchange of the catheter for a new one which preserves the venous site but with increased risk of infection recurrence.3 Replacement of long-term catheters is a major problem with high morbidity, high costs and risk for vein damage in patients where it is critical to preserve insertion sites. GCAP can reduce infections, excessive antibiotic use, and the need for catheter replacement. The proposed cap is a short (5 cm) guidewire that extends from the end cap and is inserted in the catheter extension line upon cap placement on the hub. This guidewire is loaded with a novel antimicrobial peptide called ASP-2 that has broad spectrum efficacy against infection causing microbes and their associated biofilms. When screwed into place, the peptide is released into the lock solution eliminating microbes and preventing catheter biofilms from accumulating. Standard practice dictates replacement of caps with each hemodialysis session, typically once every three days. The caps replenish ASP-2 with each access event to provide protection over the catheter lifetime, overcoming the limited activity duration of antimicrobial coated catheters.4 This Phase I project builds on strong existing data establishing the safety and broad-spectrum activity of ASP-2, including its capacity to eradicate biofilms on device surfaces and under conditions relevant to vascular access. The objectives are to (1) develop the coating composition and process to apply ASP-2 to end caps, (2) manufacture and characterize prototypes, including ASP-2 delivery and stability to sterilization, (3) demonstrate efficacy in a challenging ex vivo hemodialysis model, and (4) verify end caps meet minimal safety requirements by measuring particulate development, metal ion leaching, and the strength of the wire to cap bond. The proposed caps are expected to provide a safe and simple solution that does not require additional steps or nursing time to reduce infection risks. There is a large and growing market for infection control consumables in the setting of dialysis and vascular access. GCAP has substantial commercial potential and will benefit multiple stakeholders including patients, hemodialysis centers, hospitals, and insurers.