Flow Cell System for Evaluating the Stability of non-Fouling Medical Coatings

Typically, blood-contacting devices with commercial coatings begin to clot after about 2 weeks of implantation/attachment. The failure modes of many of these non-fouling coatings may be due 1) slow-paced protein fouling and 2) coating erosion due to sheer stress. Therefore a flow system, comprising flow cells and Tygon tubing circuits, suitable for studying flow effects on non-fouling coatings has been developed and is being used to evaluate non-fouling coatings. The flow cells feature dual chambers (top and bottom), which assembles to affix any substrate coated or uncoated and allow variable flow rates over the substrate’s surface. Blood perfusion pumps are used to re-circulate blood simulants through the flow system to impose sheer stresses typically present on blood-contacting devices. The system designed to help evaluate the effect of coating erosion due to sheer stress on coating biocompatibility.  The dual chamber feature of the flow cells makes the system also suitable for studying material properties such as gas transfer, polymer gas release dynamics and the role of various gases on bacteria and may cell lines. For example it can be used to study the bactericidal effect of nitric oxide flux levels that are non-toxic to fibroblasts.