Disruption and activation of blood platelets in contact with an antimicrobial composite coating consisting of a pyridinium polymer and AgBr nanoparticles.

Composite materials made up from a pyridinium polymer matrix and silver bromide nanoparticles embedded therein feature excellent antimicrobial properties. Most probably, the antimicrobial activity is related to the membrane-disrupting effect of both the polymer matrix and Ag+ ions; both may work synergistically. One of the most important applications of antimicrobial materials would be their use as surface coatings for percutaneous (skin-penetrating) catheters, such as central venous catheters (CVCs). These are commonly used in critical care, and serious complications due to bacterial infection occur frequently. This study aimed at examining the possible effects of a highly antimicrobial pyridinium polymer/AgBr composite on the blood coagulation system, i.e., (i) on the coagulation cascade, leading to the formation of thrombin and a fibrin cross-linked network, and (ii) on blood platelets. Evidently, pyridinium/AgBr composites could not qualify as coatings for CVCs if they trigger blood coagulation. Using...