Effect of Immobilized Antithrombin III on the Thromboresistance of Polycarbonate Urethane.

The surface of foils and vascular grafts made from a thermoplastic polycarbonate urethanes (PCU) (Chronoflex AR) were chemically modified using gas plasma treatment, binding of hydrogels-(1) polyethylene glycol bisdiamine and carboxymethyl dextran (PEG-DEX) and (2) polyethyleneimine (PEI)-and immobilization of human antithrombin III (AT). Their biological impact was tested in vitro under static and dynamic conditions. Static test methods showed a significantly reduced adhesion of endothelial cells, platelets, and bacteria, compared to untreated PCU.

An aptamer-based protein biochip.

The establishment of an aptamer-based biochip for protein detection is described. Using a model system comprising human IgE as the analyte and single-stranded DNA aptamers specific for IgE or anti-IgE antibodies as immobilized ligands on chips, we could demonstrate that aptamers were equivalent or superior to antibodies in terms of specificity and sensitivity, respectively. Aptamer-based analyte detection on glass slides could clearly be demonstrated at minimum concentrations of 10 ng/mL IgE.

Affinity measurements of biological molecules by a quartz crystal microbalance (QCM) biosensor.

We present a immunosensing system based on a quartz crystal microbalance (QCM) that allows detection and evaluation of a broad range of molecules relevant to medicine and biology. Soluble analyte is applied by injection into a flow-through chamber where receptor molecules are immobilized, thus enabling real-time measurement of the specific intermolecular interactions. This system can be used for detection purposes, e.