Study on Antibacterial Function of Polyurethane Surface Modified with Endothelializable -Peptide Polymer

Vascular grafts are prone to cause risks of endothelial damage and microbial infection during implantation, so there is an urgent need to find multifunctional biomaterials with endothelializable and antibacterial functions to reduce these risks. Host defense peptides (HDPs) have broad-spectrum antimicrobial activity and are widely used to inhibit microbial infections. However, the application of these peptides is limited due to their low stability, expensive and time-consuming synthesis. Therefore, in order to meet the multifunctional requirements of vascular grafts and address these limitations, endothelializable beta-peptide polymer NM40CH60 was used as HDPs mimics for antibacterial functional studies in this work. beta-Peptide polymer NM40CH60 was grafted to the surface of thermoplastic polyurethane (TPU), commonly used in artificial vascular grafts, via a process of O-2 plasma activation followed by brominated modification. The effective functionalization of TPU surface was confirmed by ellipsometry, X-ray photoelectron spectroscopy and water contact angle characterization. Antibacterial studies showed that NM40CH60-modified TPU surface exhibited broad-spectrum antibacterial activity against multi-drug resistant Gram-positive and Gram-negative bacteria, as well as efficient contact-killing ability. Antimicrobial mechanism study indicated that NM40CH60-modified TPU surface killed bacteria by interacting with bacterial membrane. Meanwhile, the functionalized TPU surface displayed excellent blood compatibility. In addition, beta-peptide polymer NM40CH60-modified TPU surface maintained superior endothelial-selective cell adhesion, which can effectively reduce the risk of microbial infection and endothelial damage of vascular grafts, implying great potential in the treatment of cardiovascular disease. [GRAPHICS] .