Patent EP-2151253-A1 (EP)
Inventor: OTT MATTHIAS
IPC: C23C16/30
Filed: 2008-07-31
Abstract: The layer consists of Si, O, C, H and optionally nitrogen. It comprises e.g. silicon-organic fluid, cross-linked by plasma polymerization or ultraviolet irradiation. The UV wavelength is below 250 nm. No metals of atomic number exceeding 14 are used. The atomic ratio of oxygen to silicon is 0.75-2.2 and the atomic ratio of carbon to silicon of 0.1-2.5. These values are measured by x-ray photoelectron spectroscopy (XPS). The surface of the layer is non-genotoxic. This property can be imparted to a surface. In addition, the layer controls the degree of adhesion of bio-molecules, cells, prokaryotes and eukaryotes, i.e. it enhances or reduces their adhesion in a controlled manner. Where adhesion is reduced the layer is not comprised of carbon, silicon, oxygen and hydrogen and if appropriate the usual impurities. Using electron spectroscopy for chemical analysis (ESCA) of the layer, calibration is undertaken at the aliphatic part of the C 1s peak at 285.00 eV. Comparison is made with a trimethylsiloxy-terminated polydimethyl siloxane (PDMS) having a kinematic viscosity of 350 mm 2>/s at 25[deg] C and a density of 0.97 g/ml at 25[deg] C. The Si 2p peak is associated with bonding energy displaced higher or lower by 0.45 eV at most. The O 1s peak has a bonding energy displaced by at most 0.50 eV to higher or lower values. The coating is used to make a non-genotoxic object: a membrane, pipe or flexible tubing. It is especially an oxygenation membrane, catheter, angioplasty balloon, stent, cannula, sensor or probe. It is an intentionally-implanted rod, clamp, clip, thread or screw. It is e.g. a bone-fixation rod, stent or vessel prosthesis, an injection system, catheter, cardio-vascular implant or artificial organ. It is a pacemaker and/or associated current source. The object is a prosthesis or orthopedic implant. It is an artificial joint, especially a ball and socket for the hip. It is a knee joint, spinal prosthesis, a cochlea implant, an artificial heart valve and ring, an intra-ocular lens or an artificial cornea. It forms a pump of other device releasing substances in the body. It is used to make a container to receive and/or transport bodily fluid, tissues or other organs of a living being. It carries bio-molecules, preferably peptides, proteins, lipids, carbohydrates, nucleic acids or active materials made from them. The layer is used in a covering for the skin or mucous membranes. It covers wounds especially. Further provisions concern contact with specific bodily substances and fluids, water contact angle, limits on components determined by XPS analysis. In manufacture, methyl siloxane precursors are cross-linked especially by low pressure- or atmospheric plasma-polymerization. Silicon oil with no chemically-reactive groups is cross-linked by plasma or UV, especially excimer radiation. The layer is at least partially oxidized by plasma action, flaming, oxy-fluorination, laser treatment or treatment with excimer lamps, following its formation. Maximum silicon-containing layer thicknesses lie at specified values in the range 2 mu m to 15 nm. The layer produced is oxidized, optionally with masking. The mask is self-adhesive and/or printed. It is detachable, soluble and/or dispersible, preferably in water. Independent claims are included for the following: (A) a non genotoxic object; (B) a membrane, pipe or flexible tubing; (C) a container; (D) and a covering .