Continuous subcutaneous insulin infusion (CSII) using pumps is a widely used method for insulin therapy in patients with diabetes mellitus. Among the major factors that usually lead to the discontinuation of CSII are CSII set-related issues, including infection at the infusion site. The American Diabetic Association currently recommends rotating sites every 2 to 3 days. This recommendation adds cost and creates inconvenience. Therefore, in order to prevent infections and extend the duration between insertion site changes, we developed a Teflon cannula coated with a combination of gentian violet and chlorhexidine (gendine) and tested its antimicrobial efficacy against different pathogens. The cannulas were coated with gendine on the exterior surface and dried. The efficacy and durability of gendine-coated cannulas were determined against methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, methicillin-susceptible S. aureus, Streptococcus pyogenes, vancomycin-resistant enterococci, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Candida glabrata using a biofilm colonization method. The cytotoxicity of gendine was assessed against mouse fibroblast cell lines. The gendine-coated cannulas showed complete prevention of biofilm colonization of all organisms tested for up to 2 weeks (P < 0.0001) compared to that with the uncoated control. A gendine-coated catheter against mouse fibroblast cells was shown to be noncytotoxic. Our in vitro results show that a novel gendine cannula is highly effective in completely inhibiting the biofilm of multidrug-resistant pathogens for up to 2 weeks and may have potential clinical applications, such as prolonged use, cost reduction, and lower infection rate. C ontinuous subcutaneous insulin infusion (CSII), a universally approved method, is used by an increasing number of both children and adults with diabetes (1). Technical advancements in insulin pump fabrication and the use of rapid-acting insulin analogs in recent years have increased the safety and efficacy of CSII to successfully attain normoglycemia (2). It is estimated that Ͼ500,000 patients worldwide are currently using CSII (3). Among the major factors that usually lead to the discontinuation of CSII therapy are CSII set-related issues, such as those related to the inconvenience of CSII therapy, which includes the need for frequent set changes, mechanical issues with infusion sets, skin problems at the site associated with pain and skin irritation from needle sticks, and infection at the infusion site (4-6). The use of CSII pumps by diabetic cancer patients while undergoing chemotherapy might improve their glycemic control and therapeutic outcomes; however, this frequently immunosuppressed and immunocompromised population has heightened susceptibility to infections (7,8).The American Diabetic Association (ADA) recommends changing the infusion set catheter at least every 3 days. Longer use of CSII is associated with microbial colonization and may consequently lead to infection. These recomme...