Polymyxin B nonapeptide (TFA) is widely used in research and pharmaceutical applications due to its ability to disrupt bacterial membranes. It is particularly valuable in studying the mechanisms of antibiotic resistance, as it mimics the action of polymyxin antibiotics without the full toxicity. This compound is also employed in the development of novel antimicrobial agents, helping researchers design more effective treatments against multidrug-resistant bacteria. Additionally, it serves as a tool in membrane biology studies, aiding in understanding the interactions between antimicrobial peptides and bacterial cell walls. Its application extends to drug delivery systems, where it is used to enhance the permeability of therapeutic agents across cellular barriers.