Biomedical Applications of Nitric Oxide-Releasing/Generating Polymers

Nitric oxide is secreted by vascular endothelium and can inhibit the activation and adhesion of platelets, prevent inflammation and induce vasodilation. Polymers that continuously produces NO at their surfaces are expected to exhibit enhanced biocompatibility. In this work, the biocompatibility of novel NO-releasing/generating materials has been evaluated via both in vitro and in vivo studies. An in vitro platelet adhesion assay has been designed to quantify platelet adhesion on polymer surfaces via their lactate dehydrogenase content. Such an assay can be employed as a preliminary screening tool in the assessment of new NO-releasing/generating materials. In addition, the first in vivo evaluation of NO-generating polymers was conducted. The generation of NO via the decomposition of endogenous S-nitrosothiols (RSNOs) showed enhanced biocompatibility. NO-generating polymers can also be utilized to electrochemically detect RSNO based on the decomposition to yield NO. The advantage of the RSNO sensor is that measurement can be made in whole blood samples without any pretreatment, thereby minimizing any artifacts associated with sample processing.