Profiling of time-dependent human plasma protein adsorption on non-coated and heparin-coated oxygenator membranes.

Patients with severe lung diseases are highly dependent on lung support systems. Despite many improvements, long-term use is not possible, mainly because of the strong body defence reactions (e.g.

Development of a novel low-background noise blood loop model for testing blood-contacting biomaterials and medical devices in fresh human blood.

A novel low volume blood loop model (Ension Triad System [ETS]) incorporating pulsatile flow and a proprietary low-activation blood-contacting surface (Ension bioactive surface [EBS]) enabling high signal-to-noise performance is described. The ETS system incorporates a test chamber that allows direct comparison of material samples or finished medical devices such as catheters with varying compositions and/or surface treatments. ETS performance is presented from two independent organizations (Medtronic and MLM Labs) and includes results for hemolysis (pfHgb), platelet count, platelet activation (βTG), coagulation (TAT), inflammation (PMN Elastase, PMN CD112b, and monocyte CD112b) and immune response (SC5b-9) were made on: (1) the EBS-treated system itself without a test material (No Material, NM); (2) the EBS-treated system with an idealized untreated catheter (UC); and (3) the EBS-treated system with the prototype catheter treated with the EBS surface treatment (CC).

Development and in vitro evaluation of infection resistant materials: A novel surface modification process for silicone and Dacron.

Silicone and Dacron are used in a wide spectrum of implantable and indwelling medical products. They elicit a foreign body response, which results in a chronic inflammatory environment and collagenous encapsulation of the medical device that compromises the immune system's ability to effectively fight infections at the biomaterial surface. The objective of this work is to evaluate a novel process to modify silicone and Dacron with a bioactive collagen surface coupled to a gentamicin impregnated hydrogel graft and assess the surface's cytocompatibility and infection resistance properties.

Effects of surface-bound and intravenously administered heparin on cell-surface interactions: inflammation and coagulation.

Intravenous administration of heparin and heparin-bonded extracorporeal circuits are frequently used to mitigate the deleterious effects of blood contact with synthetic materials. The work described here utilized human blood in a micro-perfusion circuit to experimentally examine the effects of intravenous and surface-bound heparin on cellular activation. Activation markers of coagulation and of the inflammatory response were examined using flow cytometry; specifically, markers of platelet, monocyte, polymorphonuclear leukocyte (PMN), and lymphocyte activation were quantified.

In vitro assessment of blood compatibility: residual and dynamic markers of cellular activation.

The blood compatibility of materials and surfaces used for medical device fabrication is a crucial factor in their function and effectiveness. Expansion of device use into more sensitive and longer term applications warrants increasingly detailed evaluations of blood compatibility that reach beyond the customary measures mandated by regulatory requirements. A panel of tests that assess both deposition on the surface and activation of circulating blood in contact with the surface has been developed.