Self-supporting laminated films, structural materials and medical devices manufactured therefrom and methods of making same
Metal foils, wires, and seamless tubes with increased mechanical strength are provided. As opposed to wrought materials that are made of a single metal or alloy, these materials are made of two or more layers forming a laminate structure. Laminate structures are known to increase mechanical strength of sheet materials such as wood and paper products and are used in the area of thin films to increase film hardness, as well as toughness. Laminate metal foils have not been used or developed because the standard metal forming technologies, such as rolling and extrusion, for example, do not lend themselves to the production of laminate structures.
1. An implantable medical graft comprising an abluminal film composed of biocompatible metal layers and a self-supporting luminal film concentrically positioned within the abluminal film, wherein the self-supporting luminal film is composed of biocompatible metal layers, wherein an interfacial region is defined where the abluminal film and luminal film are in immediate juxtaposition and co-extensive with one another; and the interfacial region has a thermodynamic parameter change relative to a thermodynamic parameter of the abluminal film or the luminal film, each of the abluminal film and luminal film having a plurality of openings passing there through, wherein each opening of the plurality of openings are dimensioned to be capable of permitting cellular migration without permitting fluid flow there through.
2. The implantable medical graft according to claim 1 , wherein the biocompatible metal layers are selected from the group consisting of titanium, vanadium, aluminum, nickel, tantalum, zirconium, chromium, silver, gold, silicon, magnesium, niobium, scandium, platinum, cobalt, palladium, manganese, molybdenum and alloys thereof, zirconium-titanium-tantalum alloys, nitinol, and stainless steel.
3. The implantable medical graft according to claim 1 , wherein a first plurality of openings are positioned through the abluminal film and a second plurality of openings are positioned through the luminal film.
4. The implantable medical graft according to claim 3 , wherein the first and second plurality of openings are positioned out of phase with one another.
5. The implantable medical graft according to claim 3 , wherein the size of the plurality of openings in the luminal film are different than the size of the plurality of openings in the abluminal film.
6. The implantable medical graft according to claim 3 , wherein the interfacial region has a microroughness with a peak-to-valley depth between about 10μ to 15μ.
7. The implantable medical graft according to claim 6 , wherein the interfacial region has a microroughness that spans a surface area region between adjacent pairs of the first plurality of openings or the second plurality of openings.
8. The implantable medical graft according to claim 1 , wherein a plurality of spacing members project into the interfacial region maintaining the abluminal film and the luminal film in a concentric spaced-apart relationship.
9. The implantable medical graft according to claim 1 , further comprising a plurality of microgrooves in an interfacial region surface of at least one of the abluminal film or the luminal film.