Research Project
2225774
Polyurethanes are used in a variety of biomedical devices including artificial hearts, pacemaker leads, intra-aortic balloons and catheters. Most commercially-available polyurethanes are blends of a base polymer and one or more additives, including catalysts, antioxidants, light stabilizers, particulate fillers and surface-active processing aids (e.g. lubricants and surface modifiers). The presence of these additives, which are usually proprietary to the manufacturer, seriously complicates the study of polyurethanes as biomaterials. This proposal involves the synthesis, fabrication and characterization of four polyurethaneurea (PUU) Primary Reference Materials (PRM). Three PRMs will be additive-free PUUs, virtually identical except for soft segment chemistry. High-purity PUUs from polyethyleneoxide, polytetramethyleneoxide (PTMO) and polydimethylsiloxane will be synthesized in solution. Half the PTMO PUU solution will be used to prepare a fourth PRM (an analog of Biomer(R)) by adding an antioxidant and a hindered-amine-containing methacrylate copolymer. Polymer solutions that are free of unwanted surface-active contaminants, as determined by ESCA and static SIMS, will be fabricated into film and tubing samples, and will be packaged, sterilized and thoroughly characterized in several laboratories. The characterized PRM will be offered with handling instructions, as inter-laboratory standards to biomaterials researchers and manufacturers of medical devices. PROPOSED COMMERCIAL APPLICATION: The Polyurethaneurea Primary Reference Materials will be commercialized as standards for calibration of physicochemical and biological tests. The fabrication of PRM provides a source of well characterized, stable polyurethaneurea reference materials, with different levels of hydrophobicity/hydrophilicity, to investigators interested in studying the effect of bulk properties on blood-materials interactions.
