Antifouling PUs

In the following sections, antifouling and antimicrobial PUs will be presented in relation to their application for preventing intravascular device-related infections. 

Recently, to obtain antifouling materials, segmented PUs having the same hard domain but a variable soft domain have been synthesized. The soft phase was constituted by polypropylene oxide (PPO), polycaprolactone (PCL), or poly-L-lactide (PLA). PCL- and PLA-containing PUs reduced the adhesion of S. epidermidis compared to the PPO-containing PU this ability is presumably related to their greater hydrophilicity. 

PEG is widely known for its resistance to protein adsorption, nonimmunogenicity, and antithrombogenicity. It is believed that PEG S antifouling ability is related to hydration and steric effects. Several studies have been focused on PEG grafting onto PUs. Particularly, PEG was either introduced in the polymer backbone, 2" by Michael addition onto main chain double bonds and click chemistry, or grafted in the polymer side chain by urethane or allophanate linkages. ... 

Another hydrophilic polymer studied as antifouling coating is poly-A-vinylpyrrolidone (Hydromer ). PU catheters coated with Hydromer significantly reduced the adhesion of five strains of S. epidermidis and one strain of S. aureusMore recently, a PVP coating was applied to PU for application as urinary tract biomaterial. While enaustation was less on the PVP-coated PU than on the uncoated PU and silicone catheters, E. coli and E. faecalis adhesion was similar on the coated and uncoated PUs. 

---