MXPA00006485A - Method of producing elastin, elastin-based biomaterials and tropoelastin materials - Google Patents

Abstract

A method is provided for producing elastin or elastin-based materials or tropoelastin materials which have a substantially reduced level of calcification. These materials are typically capable of being formed into a fused layer. The subject method comprises providing unreacted elastin or elastin-based biomaterials or tropoelastin materials, and pretreating the unreacted elastin or elastin-based biomaterials or tropoelastin materials with an aliphatic alcohol prior to reaction thereof. In this way, when the pretreated unreacted elastin or elastin-based biomaterials or tropoelastin materials is reacted subsequently, elastin or elastin-based materials or tropoelastin materials are produced which have a substantially reduced level of calcification as compared with elastin or elastin-based materials or tropoelastin materials produced from non-pretreated counterpart unreacted elastin or elastin-based biomaterials or tropoelastin materials.

Description

METHOD FOR THE PRODUCTION OF ELAS INA, MATERIALS BASED ON ELASTIN AND TROPOELASTINE MATERIALS FIELD OF THE INVENTION The present invention relates to the elastin and elastin-based biomaterials, to the tub tropoela materials, particularly to the methods for the production of such materials, and more particularly to the methods for using same in the repair and replacement of tissues. .

BACKGROUND OF THE INVENTION Elastic fibers are responsible for the elastic properties of various tissues such as the skin and lung, as well as the arteries, and are composed of two morphologically distinct components, elastin and microfibrils. The microfibrils constitute the quantitatively smaller component of the fibers and play an important role in the structure and assembly of the elastic fibers. The most abundant component of elastic fibers is elastin. The entropy of relaxation REF.121377 of elastin is responsible for the elasticity similar to rubber elastic fibers. Elastin is an extracellular matrix protein that is ubiquitous in mammals. Elastin is found, for example, in the skin, in blood vessels, and in lung tissues where it imparts strength, elasticity and flexibility. In addition, elastin, which is common in the internal elastic lamina (IEL), and in the external elastic lamina (EEL) of the normal artery, can inhibit the migration of smooth muscle cells within the intima. Elastin in the form of solubilized peptides has been shown to inhibit the migration of smooth muscle cells in response to 'platelet derived factors' (Ooyama et al., Arteriosclerosis 7: 593 (1987).) The repeated hexapeptides of elastin attract the bovine aortic endothelial cells (Long et al., J. Cell, Physiol., 140: 512 (1989)) and the elastin nonapeptides have been shown to attract fibroblasts (USP 4,976,734) The present invention takes advantage of these physical and biochemical properties of elastin: Thirty to forty percent of atherosclerotic stenoses are open with balloon angioplasty restenosis as a result of internal development of the median cells.Inner development of smooth muscle within the intima appears to be more common in sections of the artery where the IEL of the artery is torn, broken, or missing, as in damage with severe dilatation from balloon angioplasty, anastomosis s of vessels, 11 other traumas - to the vessels that result in tearing or removal of the elastic lamina. While repair of the arterial wall occurs after damage, the elastin structures IEL and EEL do not pre-organize. Since these components play larger structural and regulatory roles, their destruction is accompanied by migration of muscle cells. There are also diseases that are associated with weakness in the wall of the vessels that result in aneurysms that may eventually break down, as well as other events that are, at least in part, related to elastin abnormalities. In vertebrates, elastin is formed through the secretion and cross-linking of tropoelastin, the 72 kDa biosynthetic precursor for elastin. This is discussed, for example, in an article entitled "Oxidation, Cross-linking, and Insolubilization of Recombinant Crosslinked Tropoelastin by Purified Lysyl Oxidase" by Bedell-Hogan, et al. in the Journal of Biological Chemistry, Vol. 268, No. 14, pages 10345-10350 (1993). In vascular replacement and repair, the best option today is to implant autologous veins and arteries where the obvious limit is the supply of vessels that can be sacrificed from the tissues they were serving. Replacements of autologous veins for damaged arteries also tend to be only a temporary measure, since they can deteriorate within a few years in the high-pressure arterial circulation. When autologous graft material is not available, the surgeon must choose between sacrificing the vessel, and potentially the tissue he subdivided, or replacing the vessel with synthetic materials such as Dacron or Gore-tex. Intravascular compatibility indicates that several "biocompatible polymers" including Dacron, invoke the hyperplastic response, with inflammation particularly at the interface between the native tissue and the synthetic implant. Incomplete healing is also due, in part, to poor fit in performance between newly used synthetic biomaterials and native tissues.

As described in the prior co-pending patent applications described above (US Serial No. 08 / 341,881, filed November 15, 1994, USSN 08 / 658,855, filed May 31, 1996, US Serial No. 08 / 797,770, filed February 7, 1997, US Serial No. 08 / 798,425, filed February 7, 1997, US Serial No. 08 / 798,426, filed February 7, 1997) which are incorporated by reference in the present, elastin and elastin-based biomaterials, or tub-tip materials, can be used in a number of medical applications. For example, these materials can be used to provide a method for performing repair or replacement or support of a section of a body tissue, such as a stent, such as a vascular stent, or as a duct replacement, or as an artery. , vein or a ureter replacement, or as a stent or tube that covers or covers or covers. It can also provide a suitable graft for use in the repair of a lumen wall, or in tissue replacement or repair, for example in the replacement or repair of the internal bladder, bowel, tubular replacement or repair such as fallopian tubes, esophagus such as esophageal varices, ureter, artery such as aneurysm, veins, stomach, lung, heart such as congenital heart repair, or colon repair or replacement, or repair or replacement of the skin, or as a cosmetic implant or breast implant.

BRIEF DESCRIPTION OF THE INVENTION A problem with the use of elastin or materials based on elastin or tropoelastin materials in the aforementioned applications is that when they are implanted in vi, the calcification of them will occur. The effect of the calcification of the implanted materials is that it prevents the effective and efficient operation of this material for its intended use. This can happen, for example, when one of the first and second outer surfaces of the elastin or materials based on the elastin or tropoelastin material, and a tissue substrate, are fused together. The present invention also relates to a method for the pretreatment of elastin and materials based on elastin or tropoelastin materials that can be used in the repair, replacement or support of a section of a tissue-body. There is thus provided a method for producing j-la-s-ti-aa -o m.ataniaJ._e-s -based ja -lastiria or tropoelastin materials, which, after implantation, have a substantially reduced level of calcification in vi compared to elastin or elastin-based materials or tropoelastin materials produced from the non-pretreated counterpart of unreacted elastin or biomaterials based on elastin or tropoelastin materials. These materials are typically capable of being formed into a fused layer. The present method comprises the provision of unreacted elastin or biomaterials based on unreacted elastin or unreacted tropoelastin materials, and pretreating the unreacted materials with an aliphatic alcohol prior to reaction thereof. When elastin or elastin-based biomaterials or unreacted, pretreated tropoelastin materials are subsequently reacted, elastin or elastin-based materials or tropoelastin materials are implanted, they show a substantially reduced level of calcification in vitro. Compared to the level of calcification in vi for elastin or elastin-based materials or tropoelastin materials produced from non-pretreated, unreacted, elastin or elastin-based biomaterials or tropoelastin materials. The aliphatic alcohol employed in the present invention is typically a lower aliphatic alcohol, preferably a lower aliphatic alcohol comprising from 1 to 8 carbon atoms, more preferably a lower aliphatic alcohol comprising from 2 to 4 carbon atoms, with the most preferred lower aliphatic alcohol being ethanol. The method of this invention may comprise the placement of elastin and elastin-based materials or tropoelastin materials at the site of the section and joining the biomaterial to the site or the tissue surrounding the site. The union is effected by contacting the elastin material and the site, or the tissue that xodes the site, at the point where the joint is to be made, with a .ene-rgia absorbing agent. . The agent is then exposed to an amount of energy absorbable by the agent, sufficient to bind the elastin material to the site or to the tissue surrounding the site. The absorbent material may comprise a biocompatible dye, more preferably an energy absorber. In one form of the present invention, the energy absorbing material is substantially dissipated when the elastin or the elastin-based materials or the tropoelastin material and the tissue substrate are fused together. In another form of this invention, the energy absorbing material comprises a material for dyeing the first or second surface of the elastin or the elastin-based materials or the tropoelastin material. The energy absorbing material can also be applied to one of the outer surfaces of the biomaterial by impurifying a separate elastin layer with an energy absorbing material and then fusing the separate, doped elastin layer to the elastin or to the based materials. in elastin or tropoelastin materials. In either case, the energy absorbing layer is preferably substantially uniformly applied to at least one of the outer surfaces, typically in a manner where the energy absorbing material substantially covers the entire outer surface of the elastin or the elastin-based materials. or the tropoelastin material. Some of the key properties that effect the method of the present invention with respect to the fusion of elastin or elastin-based materials or tropoelastin materials and the tissue substrate, include the magnitude of the wavelength, the energy level , the absorption, and the intensity of light during the irradiation with light energy of the energy absorbing material, and the concentration of the energy absorbing material. These properties are designed so that the. temperature during irradiation with light energy, for a period of time which will cause the one or the other of the outer surfaces of the elastin or of the materials based on elastin or the tropoelastin material and the tissue substrate to merge with one another, it is about 40 to 140 degrees centigrade, and more preferably 50 to 100 ° C, but if it is well localized to the biomaterial tissue interface it can be as high as 600 degrees C. In addition, the average thickness of the absorber material energy in the preferred method of this invention is from about 0.5 to 300 microns. The additional objects and advantages of the invention will be clear from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1. Application of laser energy to biomaterial and exposed native tissue. Figure 2. Placement of the elastin biomaterial within the artery. Figure 3. Use of the biomaterial as an intestinal patch. Figure 4. Elastin based biomaterial scanning electron micrograph (prepared according to Rabaud et al using elastin, fibrinogen and thrombin) fused to porcine aorta using continuous wave diode laser. Figure 5. Microscopic image of elastin-based biomaterial light fused to porcine aorta using a pulsed diode laser. E = elastin biomaterial; A = aorta. Figure 6. Light microscope micrograph of biomaterial based on elastin derived from arterial digestion welded to porcine carotid artery. E = elastin biomaterial; A = aorta. Figure 7. Histological examination of the elastin heterograph, without pretreatment, after 30 days of subcutaneous implantation in rats. Figure 8. Histological examination of the elastin heterograph, with pretreatment with aliphatic alcohol, after 30 days of subcutaneous implantation in rats. Figure 9. Light microscopy of implanted elastin tissue, without pretreatment, after six months of subdermal implantation in mice. Figure 10. Light microscopy of implanted elastin tissue, with pretreatment with aliphatic alcohol, after six months of subdermal implantation in mice.

DETAILED DESCRIPTION OF A PREFERRED MODALITY The present invention relates to elastin or elastin-based materials or tropoelastin materials having a substantially reduced level of calcification. Elastin-based biomaterials suitable for use in the present invention can be prepared, for example, from elastin, (e.g. from bovine neck ligament), fibrinogen and thrombin as described by Rabaud et al. to (USP 5,223,420). (See also Apraha ian et al., J. Biomed, Mat Res. 21: 965 (1987), Rabaud et al., Thromb Res. 43: 205 (1986), Martin, Biomaterials 9: 519 (1988)). Such biomaterials may have associated thrombogenic property that may be advantageous in certain types of tissue repair. Elastin-based biomaterials, suitable for use in the invention, can also be prepared from elastin and collagen type III, also as described by Rabaud et al. (Lefebvre et al., Biomaterials 12 (1): 28-33). (1992) - Such preparations are not thrombogenic and thus can be used for vascular stents, etc. A further type of elastin-based biomaterial, suitable for use in the present invention, is prepared as described by Urry et al. (see, for example, USP 4,132,746 and 4,500,700) (See also USP 's 4,187,852, 4,589,882, 4,693,718, 4,783,523, 4,870,055, 5,064,430, 5,336,256) Elastin matrices resulting from the digestion of elastin-containing tissues (eg arteries) can also be used Digestion results in the elimination of cells, proteins and fats, but the maintenance of the elastin matrix intact The biomaterial used will depend on the application The elastin-based biomaterial of the present invention, prepared from soluble elastin (see Rabaud et al. above) can be molded to make it of a suitable size and shape for any specific purpose. The molded biomaterial can be prepared as follows. Elastin (for example soluble elastin (molecular weight of 12-32,000 daltons) is washed and swelled in buffer.

Fibrinogen or cryoglobulins (prepared for example according to Pool et al., New Engl. J. Med. 273 (1965)) are added to swollen elastin, followed by thiourea, with or without a protease inhibitor (such as aprotinin), and collagen. The thrombin is added with agitation and the resulting mixture is immediately emptied into an appropriate mold. The mold is then incubated (for example at 37 ° C) while the polymerization of the fibrin material / elas is allowed to proceed, advantageously, from 15 minutes to 1 hour, with 30 minutes being preferred. The reaction can be carried out at temperatures lower than 37 ° C, but the reaction proceeds more rapidly at 77 ° C. Heating the reaction above 40 ° C, however, can result in thrombin denaturation. Cooling the mixture while stirring allows more time for mixing to occur. For polymerization to occur, it is important to have calcium and magnesium in the buffer and to use undenatured thrombin. After the polymerization in the mold, the resulting biomaterial can be further cross-linked using gamma radiation or an agent such as glutaraldehyde (a solution of glutaraldehyde, formic acid and picric acid which is preferred). When radiation is used, the samples are advantageously subjected to gamma irradiation from a source of cobalt 60. The amount of irradiation may be in the range, for example, from 10 to 100 MRAD, with MRAD being preferred. It has been shown that the amount of gamma irradiation can affect the strength of the material (Aprahamian, J. Biomed, Mat. Res. 21: 965 (1987).) Biomaterial sheets can be prepared which are of a controlled thickness by the use of molds. The sheets of the biomaterial can be processed in thicknesses in the range of, for example, 200 microns to 5 mm.The sheets are generally made as thin as possible to allow the penetration of laser energy while maintaining sufficient strength. By way of example, a sheet suitable for use as an intestinal patch may be in the thickness range of 200 micrometers to 5 mm, with approximately 2 mm being preferred.A patch that requires greater strength, such as a patch for use in the bladder is typically thicker, stents or arterial patches may be thinner (eg 100 μm - 1000 μm) .The biomatérial prepared from elastic fragments Soluble or insoluble elastin, can also be molded into tubular segments, for example, by injecting the material into tubular molds. The crosslinking of the elastin solution, present between the inner and outer tubes, can be carried out before the removal of the biomaterial from the mold or after the tubes are removed. The tubular segments of different internal and external diameters, as well as of different lengths, can be prepared using this procedure, by varying the diameters of the internal and external tubes. A mold of this type can be made of virtually any size, with internal and external tubes that vary in diameter. A small tube can be used for a coronary arterial stent. A large tube of 2.54 to 12.7 cm (1 to 5 inches) in diameter can be developed and used as an angularly welded patch for the anastomosis of the small intestine or colon. Various molding techniques and molding materials can be used; The above is merely an example. As indicated above, the biomaterial suitable for use in the present invention can be prepared from tissue digestions containing an elastin matrix. Suitable tissues for use as an initial material include arteries (e.g., coronary or femoral arteries, e.g., swine), umbilical cords, intestines, ureters, etc. Preferably, the matrix material is derived from the species of animal in which the implant is to be made, so that biocompatibility is increased. Any method of removal (digestion) of cellular material, proteins and fats from the native matrix while leaving the extracellular elastin matrix intact, can be used. These methods may involve a combination of acidic, basic, detergent, enzymatic, thermal or erosive media, as well as the use of organic solvents. This may include incubation in solutions of sodium hydroxide, formic acid, trypsin, guanidine, ethanol, diethyl ether, acetone, t-butanol, and sonication. Typically, digestion proceeds more quickly at higher temperatures. The optimal temperature and time of incubation depend on the initial material and the digestive agent used, and can be easily determined. A person skilled in the art will appreciate that while the tubular segments result from the digestion of the initial tubular materials, those segments can be opened and shaped to produce sheets suitable for use as tissue grafts. Alternatively, such segments can be opened and then reconstructed as tubular segments having a different diameter from the initial tissue. Preferably, however, when the tubular products are searched, the initial material is selected to produce a tubular segment after digestion, which has the appropriate diameter, so that subsequent manipulations (different from the length adjustment) can be avoided. . The biomaterial of the invention, whether prepared from elastin powder or from tissue digestions, is normally secured to the existing tissue. Various techniques can be used to effect such coupling, including recognized techniques in the art. However, it is preferred that the biomaterial be secured using an energy source for tissue welding and an agent that absorbs energy emitted by that source. Advantageously, the energy source is a source of electromagnetic energy, such as a laser, and the absorbing agent is a dye having an absorption peak at a wavelength corresponding to that of the laser. The elastin biomaterial and the tissue to be welded have much lower absorption of light at this wavelength and the effect is therefore confined to an area around the dye layer. A preferred energy source is a laser diode having a dominant wavelength at about 808 nm and a preferred dye is indocyanine green (ICG) of maximum absorbance 795-805 nm (see WO 91/4073).

Other laser / dye combinations can also be used. It is preferred that the colorant be applied to that portion of the biomaterial that is to be contacted and secured to the existing tissue. The dye can also be applied to the surface of the structure to which the elastin biomaterial is going to be welded or secured. The dye can be applied directly to the biomaterial or the surface of the biomaterial can be first treated or coated (eg sizing) with a composition that controls the absorption of the dye within the biomaterial, so that the dye is maintained as a discrete layer or coating . Alternatively, the dye can be attached to the elastin biomaterial so that it is secured to the surface and prevented from leaking into the material. The dye can be applied in the form of a solution or the dye can be dissolved in or suspended in a medium which can then be applied as a thin layer or film, preferably of uniform thickness and dye concentration. The techniques of joining or welding of fabrics using a welding agent can be used. Such techniques are known (WO 91/04073). Any protein material that is thermally denatured after heating can be used as the soldering agent (eg, any serum protein), such as albumin, fibronectin, von Willebrand factor, vitronectin, or any mixture of proteins or peptides). Welders comprising fibrinogens polymerized by thrombin are preferred, except where such materials could cause undesirable thrombosis or coagulation such as within vascular lumens. The welders. they are selected for their ability to impart greater adhesive strength between the biomaterial and the tissue. The soldering iron must be non-toxic and generally biocompatible. In accordance with the present invention, the laser energy can be directed to the target site (eg, the dye) directly from the laser by exposure of the tissue (eg, during a surgical procedure). In some cases, for example, endovascular catheter-based treatments where open surgical exposure does not occur, laser energy is directed to the binding site via optical fibers. When ICG is used as the dye, wavelengths of the target media of about 800 nm can be used. Such wavelengths are not well absorbed by many tissues, particularly vascular tissues, therefore, there will be a negligible effect on these tissues and the thermal effects will be confined to the dye layer. The biomaterial of the invention has similarly little optical absorbance in this waveband, as compared to the energy absorbing dye. In this way, the laser energy can pass either through the elastin / elastin biomaterial or the native tissue and be absorbed by the energy absorbing material, for example, the dye layer as shown in Figure 1. A Once the surgeon has exposed the surface or vessel where reinforcement or replacement of the biomaterial has to be effected, the surface containing the biomaterial dye is placed in contact with the tissue at the site and laser energy is distributed to the tissue. direct the laser beam to the desired location. The absorbance of the dye layer (for example ICG) is ideally pre-or concurrently determined, so that the optimum amount of light for the optimal bond can be distributed. Pressure can be used to ensure adequate approximation of the tissue and the biomaterial. With a diode laser source, the diode laser itself, or a capacitor or an optic distribution system based on optical fiber, can be placed against the material to ensure distribution of uniform use. In cases where a new elastin coating or a new internal elastic lamina is required, for example, after an open surgical endarterectum, once the artery has been surgically cleared of the atheroma or other injury, the biomaterial is then placed in its site, with the dye down (see Figure 2). The biomaterial can be deployed as a flat patch or as a tubular segment. A tubular segment can be hollow or filled by a material that supports the lumen during placement, and that is fused with low-grade heat or dissolved or removed with a variety of means. When necessary, a small number of surgical structures (eg fixation points) may be used to juxtapose the edges of the vessel with each other or to sew the vessel. Once the biomaterial is in place, laser energy is directed through the vessel wall or through the biomaterial to the absorption dye, having been the appropriate laser energy previously determined based on the absorbance measured in the biomaterial. Alternatively, the dye can be applied at the time of surgery to the biomaterial or the vessel wall or both, and then laser energy is distributed. In this modality, the absorbance can be determined at the time of surgery to the biomaterial or the vessel wall or both, and then the laser energy is distributed or with a feedback device that evaluates the adequacy of the union or the thermal effect (Figure 4 is a SEM of biomaterial based on elastin fused to porcine aorta). In addition to the above, the biomaterial of the invention can be used as a patch material for use in intestinal or colon repairs that often do not heal well with current techniques, particularly when the patient has nutritional or other problems, or when the patient is in shock, such as multiple gunshot wounds or other abdominal injuries (see Figure 3). The use of such a patch can, for example, seal the intestinal contents and thereby reduce the likelihood of peritonitis. In addition, a patch can be used on a solid organ, such as the liver, when lacerations have occurred. Similarly, the biomaterial of the invention can be used to repair or replace portions of the urinary system, for example, from the calyces of the kidney down to the urethra. The patch can also be used to seal a defect in a cardiac chamber, such as an atrial septal defect, as well as bronchial or rectal fistulas. The biomaterial can also be used as a cerebrovascular patch for an aneurysm. The biomaterial can be sealed in place with laser-directed fusion. For applications where direct exposure is not possible or not desirable, a variety of catheter or endoscopic systems can be used to direct laser energy to the target site. The elastin-based biomaterials to which the invention relates can be used in a variety of other clinical and surgical settings to effect the tissue repair graft. For the distribution of the biomaterial in the form of an intravascular stent, the biomaterial can be preassembled on a deflated balloon catheter. The balloon catheter can be maneuvered into the desired arterial or venous site using standard techniques. The balloon can then be inflated by compressing the stent (biomaterial) against the vessel wall and then laser light is distributed through the balloon to seal the stent in place (the dye may be present on the outside of the biomaterial). The balloon can then be deflated and removed leaving the stent in place. A sleeve or protective sleeve (eg, plastic) may be used to protect the stent during its passage into the vessel and then removed once the stent is in the desired location. The biomaterial of the invention can also be used as a biocompatible cover for a scaffolding or metal or synthetic stent. In such cases, simple mechanical unfolding can be used without the need for laser bonding. Laser binding can be employed, however, depending on the specific demands, for example, where inadequate mechanical bonding occurs, such as in the deployment of the stent for abdominal aortic aneurysms. An alternative catheter-based vascular stent deployment strategy employs a temporary mechanical stent with or without a balloon delivery device. An additional catheter-based vascular stent deployment strategy employs a scaffold or stent or metal coating (such as nitinol or other metal of a similar type) deformable by heat, which is incorporated into the catheter tubing beneath the stent biomaterial. . The stent is maneuvered at the desired site, after which the deformable metal of the stent is activated such that the stent is juxtaposed against the vessel wall. The laser light is then distributed a system based on optical fiber, also incorporated in the catheter assembly. The elastin-based biomaterial can also be used to replace portions of diseased or damaged vascular or non-vascular tissue, such as the esophagus, pericardium, pulmonary pleura, etc. The biomaterial can also be used as a skin layer replacement, for example, in treatments for burns or wounds. As such, the biomaterial serves as a permanent dressing or bandage that acts as a scaffold for the re-growth of epithelial cells. The biomaterial can include antibiotics, coagulants or other desirable drugs for various treatments that provide high local concentrations with minimum levels of systemic drug. A drug can be incorporated into the biomaterial, thereby decreasing the need for intravenous or systemic oral medications. The elastin biomaterial can be deployed with a dye on the side of the tissue and then fused with the appropriate wavelength and the appropriate laser energy. In addition, a drug can be incorporated into the elastin or elastin biomaterial layer, thereby decreasing the need for intravenous or oral systemic medications. Also, drugs for photodynamic therapy ("PDT") that are activated with light can be used in the present. In addition to repairing tubular body structures, the biomaterial of the present invention can also be used in organ reconstruction. For example, the biomaterial can be molded or otherwise shaped into a bag suitable for use in the reconstruction of the bladder. The biomaterial of the invention can also be molded or otherwise shaped to be suitable for esophageal replacement. Again, metal or synthetic mesh could also be associated with the implant if extra support of the wall is needed to control the passage of food from the pharynx into the stomach. This could be used for stenosis of the esophagus, as a cover for bleeding esophageal varices, to prevent bleeding or to treat bleeding, for the repair of acid reflux for erosive esophagitis or, more preferably, to reconstruct damaged esophageal segments during or after surgery or chemotherapy for esophageal carcinoma. For certain applications, it may be desirable to use the biomaterial of the invention in combination with a support material having strong mechanical properties. For those applications, the biomaterial can be coated on the support material (see the stent description below), for example, using the molding techniques described herein. Suitable support materials include polymers, such as woven polyethylene terephthalate (Dacron), Teflon, polyolefin copolymer, polyurethane-polyvinyl alcohol polymer or other. In addition, a polymer that is a hybrid between a natural polymer, such as fibrin and elastin, and a non-natural polymer such as a polyurethane, polyacrylic acid or polyvinyl alcohol, can be used (see Giusti et al., Trends in Polymer Science 1 : 261 (1993) .This hybrid material has the advantageous mechanical properties of the polymer and the desired biocompatibility of the elastin-based material.Examples of other prostheses that can be made from synthetic materials or metals coated with the elastin biomaterial or from of synthetic / biomaterial hybrids include heart valve rings and esophageal stents The elastin-based prostheses of the invention can be prepared to include a drug, which can be administered, via prostheses, to particular sites in the body. vascular stents should be produced to include drugs that prevent coagulation, such as heparin, drugs that prevent the internal development of smooth muscle or drugs that stimulate endothelial regrowth. Vasodilators may also be included. The prostheses formed from the elastin-based biomaterial can also be coated with viable cells, preferably cells originating from the receptor of the prosthetic device. Endothelial cells, preferably autologous (for example harvested during liposuction), can be seeded on elastin bioprostheses before implantation (for example for vascular stent indications). Alternatively, the elastin biomaterial can be used as a skin replacement or repair means where the cultured skin cells can be placed on the biomaterial before implantation. The skin cells can thus be used to coat the elastin biomaterial. The elastin structures that constitute a structure or framework for a three-dimensional multilayer cell culture system will provide intact elastic structures not constructed by stromal cells that populate the synthetic matrices. The production of elastin in vi is thought to occur only during development and ceases during childhood (the only exceptions being hypertension and restenosis). Elastogenesis is a complex process and the formation of mature elastic structures is probably not achieved relatively simply in cell culture systems in vi tro. However, it has been reported that such three-dimensional cell culture systems can organize elastin into coherent fibrous matrices analogous to those found in elastic tissues. A method by which a graft of living tissue with elastic structure and function more similar to the tissue that is high in elastin content is produced by the cultivation of cells in three-dimensional frames made of elastin or elastin-based biomaterials. This ensures the presence of biologically important elastic structures in the grafts of living tissue. One method for organizing elastin and fibrils of elastin-based biomaterials, and the provision of a support for the development of fibroblasts, is by coacervation of elastin monomers in solution with fibroblasts. Elastin monomers mixed with stromal cells (fibroblasts) in an aggregate of physiological buffer in the fibers (coacervation) after raising the temperature of the solution. By doing this, the fibroblasts become trapped in a loose matrix of elastin fibers. The contraction of the fibroblasts bound to the coacervated elastin monomers preferentially align the elastin fibrils before crosslinking.

Certain aspects of the invention are described in greater detail in the following non-limiting Examples.

Example 1. Preparation of Elastin-based Biomaterial Sheets from Soluble Peptides Materials used for the production of biomaterial: Phosphate buffer: The phosphate buffer used contained 1 mM sodium phosphate, 150 mM sodium chloride, 2 mM calcium chloride, 1 mM magnesium chloride, pH 7.4. Soluble elastin peptides: The elastin powder of the neck of the bovine ligament is obtained from Sigma, Saint Louis, Missouri. The following procedure was used to obtain the soluble elastin peptides: 2.7 g elastin powder was suspended in 35 ml of a 1 M KOH solution in 80% ethanol. The suspension was stirred at 50 ° C for 2.5 hours. Then, 10 ml of deionized water were added and the solution was neutralized with 12 M concentrated hydrochloric acid to pH 7.4. The solution was cooled to 4 ° C for 12 hours. The clear solution was decanted from the salt crystals, and the supernatant was centrifuged for 15 minutes at 2000 rpm. The solution was then dialyzed against three changes of tap water at 2 hour intervals and a 15 hour interval using a 10,000 molecular weight cut dialysis tube. Dialysis was continued with six changes of deionized water at two hour intervals and one for 15 hours. The resulting dialysate was lyophilized and stored at -20 ° C. The yield was 40%. Preparation of cryoglobulin: A modification of the Pool and Shannon method was used to Produce cryoglobulins (New Engl. J. Med. 273 (1965). The cryoglobulins are mainly fibrinogen (40 mg / ml) and fibronectin (10 mg / ml) (The concentrations of fibrinogen and fibronectin will vary). Briefly, pig blood was collected in a 500 ml blood collection bag containing adenine, citrate and dextrose as an anticoagulant. The blood was transferred to twelve tubes for 50 ml plastic centrifuge and centrifuged for 15 minutes at 1500 rpm. Plasma was decanted from the erythrocyte layer and frozen at -70 ° C for 12 hours. The plasma was then thawed at 4 ° C. The cryoglobulins were harvested by centrifugation of the plasma at 4 ° C for 15 minutes at 1500 rpm. The supernatant was decanted and the cryoglobulins were collected by removing the precipitate with a pasteur pipette. Each tube was also rinsed with 3 ml of a sodium citrate solution containing 0.9% sodium chloride and 0.66% sodium citrate. The cryoglobulins were combined, frozen at -70 ° C, lyophilized and stored at -20 ° C until use. Thiourea: Thiourea reactive grade, was obtained from Sigma Saint Louis Missouri. A 0.5 mg / ml solution was used. Collagen type I: Type I collagen soluble in Sigma acid was obtained. This was preferred from the rat tail tendon by a modification of the Bornstein method. Two mg of collagen was heated in 0.6 ml of phosphate buffer at 60 ° C for 10 minutes until the collagen dissolved. This was then cooled to 37 ° C and used. Thrombin: Bovine plasma thrombin was obtained from Sigma in lyophilized form. When reconstituted with 1 ml, the solution contained 106 NIH units per ml.

Aprotinin: Aprotinin from bovine lung was obtained from Sigma. This contained 15 to 30 trypsin inhibitory units (TIU) per ml.

Preparation: Six molds were made by gluing a 620 μm quartz fiber to one side of a glass plate of approximately 40 mm x 25 mm and attaching a second glass plate to the first, using a rubber band. Each mold thus constructed maintained approximately 0.5 ml. The biomaterial was prepared by successively adding and mixing the following: 200 g of soluble kappa-elastin or of kappa-elastin powder in 2 ml of phosphate buffer (PB) (P043 + 1 mM, 150 mM NaCl, 2 mM Ca2 +, Mg2 + 1 mM, pH 7.4) at 37 ° C. 160 mg of cryoglobin in 1 ml P: B (37 ° C). 2 mg of collagen in 0.6 ml of PB (60 ° C 37 ° C) 200 μl of thiourea (0.5 mg / ml) 200 IU of aprotinin (5 Units) An aliquot of 0.6 ml of the above solution was loaded into a tube of trial and they were added 50 μl of the thrombin solution (approximately 6 units). The resulting solution was immediately loaded into the mold. Some of the resulting leaves were cross-linked with glutaraldehyde for 2 minutes. Results: The leaves prepared as described above were slightly yellowish and opaque. The sheets fixed with glutaraldehyde were less stretchable and were torn more easily than the unfixed sheets. The leaves fixed with glutaraldehyde were subjected to electron microscopy. These sheets or sheets had a cohesive surface appearance, smooth at 100X and 1000X.

Example 2. Fabric Welding of Elastin-Based Biomaterial Sheets Pre-weld procedure: A 1 mg / ml ICG solution was applied to fresh pork aorta that had been carefully trimmed from the adventitia tunic, washed in a sterile 0.9% NaCl solution, and cut into 1 cm2 squares . 1 mg / ml of the ICG solution was applied to the lumenal side of the aorta for approximately 3 minutes and was removed by rubbing (ICG was obtained from Sigma and contained 90% dye and 10% sodium iodide). The absorption coefficient measured at 780 nm with a 7.25 X 10 ~ 6 M solution was found to be 175,000 M_1cm_1. The maximum adsorption is shifted to 805 nm when the ICG binds to the whey proteins (Landsman et al., J. Appl. Physiol.40 (1976) .A small amount of cryoglobulins, containing approximately 40 mg / ml of fibrinogen and 10 mg / ml of fibronectin doped with ICG, was also applied and the biomaterial was placed on it The two materials were placed between two glass slides, which were immersed in a 0.9% saline solution. of biomaterial prepared as described in Example 1 were equilibrated in phosphate buffer, pH 7.4, and were welded to porcine aorta stained with ICG, using an aluminum and gallium arsenide diode laser.The maximum yield was 808 +. / - 1.5 nm The laser was coupled to a 1 μm quartz fiber with polyethylene plating material The laser energy was collimated with a focusing lens and coupled to the quartz fiber The size of the point at the end The distal length of the fiber could be varied from 1 mm to 4 mm by adjusting the distance between the focus lens and the proximal end of the fiber. The laser operated continuously, CW, and the performance measured at the distal end of the fiber was 1.5 W. The quartz fiber was placed directly above the glass slide, the biomaterial, and the aorta. Before welding, the size of the laser spot was measured. The welding seemed to occur under saline at 0.85 W but not at 1.32 W. Twenty seconds was enough time to weld and 40 seconds caused a browning and scorching of the biomaterial.

Example 3. Preparation of Elastin-based Biomaterial from Arteries Digestion Fresh pieces of 4 cm porcine carotid artery were dissected and cleaned and washed in two changes of 0.9% saline overnight. The vessels were placed in 0.5 M NaOH and sonicated for 120 minutes (a modified method of Crissman, R. 1987) (Crissman, Rogert S. "Comparison of Two Digestive Techniques for Preparation of Vascular Elastic Networks by SEM Observation", Journal of Electron Microscopy Techniques 6: 335-348 (1987) The digested vessels were then washed in distilled water and autoclaved at 105 ° C (225 ° F) for 30 minutes.The digested vessels appeared translucent, pearly white and they collapsed when they were removed from the water, indicating the absence of collagen and other structural support proteins.The welding of the digestions of the arteries to the porcine aorta was achieved through the following methods: fresh porcine aorta was coated with 5 mJ / ml of ICG for 5 minutes The excess ICG solution was transferred Sections of 1 cm x 1 cm of digested carotid artery elastin segments, sonicated with NaOH, were placed on fresh aortas. An arrangement of pulsed aluminum and gallium arsenide diode lasers (Star Medical Technologies) was used to weld the segments. Pulses of five milliseconds were emitted at 790-810 light at 2 joules, and were applied to the tissue with a capacitor that created a uniform beam of 4X4 mm which was placed on the elastin digest covered by a glass coverslip. Good welds were achieved with up to 10 pulses. A light microscope photograph of the elastin digest welded to the porcine aorta is shown in Figure 6.

Example 4 Preparation of Elastin-Based Biomaterial and Porcine Aorta Fusion Materials: Bovine neck elastin powder (Sigma, Saint Louis, MO) was siphoned with a 40 μm sieve and swelled with phosphate buffer. The elastin fragments were then reacted with 67 mg of fibrinogen (Sigma), in phosphate buffer, type I collagen soluble in 2 m acid (Sigma), thiourea 2.8 mg, Ca 2 + 2 mM, Mg 2 + 1 mM and 75 units of thrombin and injected into molds and heated to 77 ° C. 1 mm thick sheets and tubes of this biomaterial were removed and stored in 33% ethanol for later use. Indiumcyanine green dye was dissolved in deionized water to provide a 1% solution and applied to the lumenal surface of fresh porcine aorta. The dye was in that site for 5 minutes and then the residual dye was transferred. The elastin biomaterial was placed on aorta stained with ICG and covered with a glass coverslip. Laser energy was applied with a condenser that collected the output of an array of lasers of gallium arsenide diode emitting light at 800 nm in pulses of 5 milliseconds.

Points of six mm2 were irradiated with 2.89 joules for 1-10 pulses, which provided adequate welds. The samples were then bisected and fixed in formalin for the microscopic study. Figure 5 is a photograph of the light microscope of such a weld, stained with an elastin stain. Excellent welding of the elastin biomaterial to the porcine aorta without detectable thermal damage or other damage to the biomaterial or the aorta is noted.

Example 5. Preparation of Elastin-Based Biomaterial and Porcine Aorta Fusion Materials: Bovine ligament nape elastin, porcine plasma fibrinogen, and acid-soluble type I collagen from the rat tail tendon were obtained from Sigma Chemical Corp. (Saint Louis, Missouri). Elastin was solubilized in 1 M KOH / 80% ethanol at 50 ° C for 2.5 hours (Hornebreck). Cryoprecipitates were obtained from porcine plasma according to the method of Pool and Shannon (Pool and Shannon). Fresh porcine aorta was obtained from Carlton Packaging Co. (Carlton, Pray) and stored at -20 ° C until thawed for use.

Elastin-fibrin biomaterials were prepared similarly to the methods developed by Rabaud (Rabaud). Oxygenated and cryoprecipitated elastin patches were prepared by successive addition with a perfect mixture of 200 mg of soluble elastin dissolved in 2 ml of buffer, 160 mg of freeze-dried cryoprecipitate dissolved in 1 ml of buffer, 2 mg of type I collagen dissolved in 0.6 ml of buffer, and 0.2 ml of thiourea solution (0.5 mg / ml H20). 6 units of thrombin were added to 0.5 ml aliquots of the mixture, mixed thoroughly in a 1 ml syringe, and injected into 4 cm2 glass molds. The molds were incubated at 37 ° C for 30 minutes, and were subjected to 25 mrad of radiation g (cobalt source). The biomaterial was stored at 4 ° C in 33% ethanol. Before use, the biomaterial was washed several times with saline. Patches were also made with insoluble elastin and fibrinogen. The lyophilized elastin from Sigma was passed through a No. 4000 mesh (Tyler) American screen before use. Only 40 μm or smaller particles were used. 28-0 mg of filtered elastin were swollen and washed overnight in an excess of phosphate buffer, the mixture was centrifuged (1000 rpm, 10 minutes) and the excess buffer was discarded. The swollen elastin was suspended in 2 ml of phosphate buffer. Successively added to this suspension are 67 mg of lyophilized fibrinogen dissolved in 1 ml of buffer, 2 mg of type I collagen dissolved in 0.6 ml of buffer, and 0.2 ml of thiourea solution (0.5 mg / ml of H20).

Finally, 33 units of thrombin were added and the mixture was vortexed perfectly and quickly emptied into 3 cm x 7 cm molds. The molds were incubated at 37 ° C for ~ 30 minutes, the biomaterial was stored at 4 ° C in 33% ethanol. Before use, the biomaterial was washed several times with saline. The soluble patch, cryoprecipitated with elastin, was fused to the porcine aorta using an aluminum and Gallium Arsenide diode array laser that emits 808 nm continuous wave optical radiation. The fresh porcine aorta was washed in 0.9% NaCl and cut into 2 cm2 portions. Indiumcyanine green (Sigma) was applied in aqueous concentrate of 1 or 5 mg / ml, via a pasteur pipette, allowed to stand for 5 minutes and then transferred. The tissue was then equilibrated in a 0.9% saline solution for 15 minutes to remove any unbound dye. The biomaterial was then applied to the lumenal surface of the aorta. The laser beam was directed to the surface of the biomaterial via a fused silica fiber of 1 μm (Polymicro Technologies Phoenix, Az) through a glass coverslip as shown in Figure 1. The spot size of the laser beam varied between 1 and 4 mm. The laser performance measured from the tip of the fiber was 1.5 Watts and the exposure times varied from 5 to 4 seconds. The insoluble elastin-fibrinogen patch was fused to the porcine aorta using a diode array laser of Aluminum and Gallium Arsenide emitting 790-810 nm pulsed optical radiation (Star Medical Technologies). The thawed porcine aorta was prepared and stained with 5 mg / ml aqueous ICG solution as previously described for the fresh aorta. After application of the biomaterial to the stained luminal surface of the aorta, laser radiation was directed to the biomaterial via a copper-coated condenser placed against a glass coverslip. Laser performance was adjusted to 2 J and pulse durations of 5 milliseconds.

Example 6. Preparation of Elastin-based Biomaterials and Fusion of the Same Bovine elastin from the nape of the neck, porcine plasma fibrinogen and acid-soluble type I collagen from rat tail tendon were obtained from Sigma Chemical Corp. (Saint Louis, Mo). 1 mg of indigocyanine green is dissolved in 1 ml of 24% human serum albumin. 67 mg of fibrinogen was dissolved in 1 ml of phosphate buffer at 37 ° C. Just before mixing, 16.6 units of thrombin are added to the indiumcyanine green solution. The mixtures were cooled to 4 ° C. The two mixtures are rapidly mixed and injected, or emptied, into a 3 X 7 cm mold and incubated for 30 minutes at 37 ° C. The lyophilized elastin from Sigma was passed through a No. 400 mesh (Tyler) US sieve before use. Only 40 μm or smaller particles were used. 210 mg of the filtered elastin were swollen and washed overnight in an excess of phosphate buffer. The mixture was centrifuged (1000 rpm, 10 Al minutes) and the excess buffer was discarded. The swollen elastin was suspended in 1.5 ml of phosphate buffer. Successively added to this suspension were 67 mg of lyophilized fibrinogen dissolved in 0.75 ml of buffer, 2 mg of type I collagen dissolved in 0.45 ml of buffer, and 0.15 ml of thiourea solution (0.5 mg / ml of H20). Finally, 26 units of thrombin were added and the mixture was vortexed perfectly and quickly emptied onto the fibrin matrix impurified with indigocyanine green in the 3 X 7 cm molds. The molds were again incubated at 37 ° C for 30 minutes. When they were removed from the mold, the two layers are inseparable and the preparation produces a simple patch.

Example 7. Welding of Fibrin and Elastin Biomaterial to Porcine Intestine Fresh pig intestine was obtained from Carlton Packing Co. (Carlton, OR). The intestine was rinsed with tap water and stored at -20 ° C in Ziploc freezer bags. Before use, the intestine is thawed in ambient air and kept on gauze soaked with saline to prevent drying out. The tina-fibrin biomaterial prepared as described in Example 4 was fused to the porcine intestine using an aluminum and Gallium Arsenide diode array laser (Star Medical Technologies) as follows: Indiumcyanine green was applied in aqueous concentrations of 5 mg / ml to the swine intestine serosa thawed with a pasteur pipette, allowed to stand for 5 minutes and then transferred with a Kimwipe EXL swab. The elastin-fibrin biomaterial was cut into patches of 1 X 1 cm and the excess moisture was removed with a Kimwipe EXL wiper. The biomaterial was then placed on top of the serosa stained with ICG of the intestine, and a glass microscope cover was placed on top of the biomaterial. A scale rule was placed below the intestine. The laser radiation was directed to the biomaterial by means of a 4 X 4 mm copper-coated condenser, placed against the glass coverslip. The laser performance was adjusted to 1.99-2.19 joules and pulses of 5 milliseconds. During laser exposure, manual force was applied to the glass coverslip with the condenser. The amount of pressure applied was checked periodically on the scale placed below the intestine. 5 pulses and 500 to 1600 grams of force resulted in successful adhesion of the elastin-fibrin biomaterial to the intestine. Figure 6 (Figure 14 of the proposed army grant) is a light microscope slide of the elastin-fibrin biomaterial, soldered to porcine intestine (1.99 joules per pulse, 10 pulses, 500 g force).

Example Preparation and Welding of Coronary Vessel Digests Coronary artery left anterior descending, right major, and circumflex, fresh, were removed from a porcine heart. Excess fat and thrombi were removed from the excised vessels. The vessels were cut in half and the distal halves were washed in saline and sonicated in 0.5 M sodium hydroxide for 45 minutes at 65 ° C. The distal halves were then removed from the alkali, submerged in 500 ml of distilled water for 30 minutes, and finally immersed in boiling distilled water for another 30 minutes. The vessels sonicated with NaOH are referred to hereafter as heteroinj erts. The proximal half of the vessels was stored and stored on gauze soaked with saline until use. The right main coronary heteroinj ects were welded to the right main and left anterior descending arteries with a pulsed diode laser of Aluminum and Gallium Arsenide that emits 790-810 nm of optical radiation (Star Medical Technologies). 5 mg of indigocyanine green (ICG) were dissolved in 1 ml of distilled water. This solution was then diluted with 4 ml of 25% human serum albumin (HSA) with careful mixing avoiding the formation of excessive air bubbles. The heteroinj ects were coated on a balloon for percutaneous transluminal coronary angioplasty measuring 3.0 mm in diameter when inflated. The balloon coated by heteroinjection was inflated at 0.28 kg / cm2 (4 psi) and immersed in the ICG-HSA for 5 minutes to stain the heteroinj erto. After removing the heteroinjured and balloon from the staining solution, the balloon was deflated and inserted into the untreated proximal half of a right main coronary artery or LAD. After insertion, the balloon was inflated to 0.56 kg / cm2 (8 psi). The balloon / inflated balloon was placed on a laboratory table and a coverslip was placed over the region to be welded. A 4 X 4 mm copper-coated condenser was placed against the coverslip. The laser performance was adjusted by 2.3 joules of energy and pulse durations of 5 milliseconds. After 5 pulses, the balloon is rotated approximately 30 degrees and another region is illuminated with 5 pulses. This procedure is repeated until the entire circumference of the balloon has been illuminated. The balloon is then deflated, leaving behind the heteroinj ect, now fused to the luminal surface of the artery.

Example 9. Preparation of Elastin-Based Materials With and Without Pretreatment The following example describes the experiments that compare the effectiveness of the pretreatment of the elastin materials with an aliphatic alcohol to inhibit the calcification in vi, compared to the counterpart elastin materials, not pretreated.

Carotid artery of pig. were obtained for testing purposes. Specimens were stored on ice during transport for the test. The foreign adiposis of the vessels was carefully removed using Metzenbaum dissection scissors. The arteries incubated in ethanol were immersed for 72 hours at 25 degrees C, in 500 ml of 80% ethanol / phosphate buffered saline, pH 7.4 (PBS). After incubation with ethanol, the vessels were rinsed twice in 500 ml of 0.9% sodium chloride and then each vessel was individually immersed in 200 ml of pre-warmed 0.5 M NaOH at 65 degrees C. The vessels not incubated in ethanol were they were washed overnight in PBS, and then individually immersed in 200 ml of 0.5 M NaOH preheated to 65 degrees C. All vessels were sonicated for 60 minutes in 0.5 M sodium hydroxide at 65 degrees C. After sonication, the digested vessels (heteroinj ertos) were removed from 0.5 M sodium hydroxide and washed twice for 30 minutes in 1000 ml deionized water. A punch for dermal biopsy (Miltex Instrument Co., New York) was used to cut uniform "disks" of the wall of each heteroinj erto. The diameter of each disc was 2 mm. The disks were immersed in flasks containing 15 ml of deionized water and heated in an autoclave at 107 ° C (225 ° F) for 30 minutes. A sterile 16 gauge needle was used to make incisions in the right flanks of BALB / c mice. A sterile cannula, preloaded with an elastin biomaterial disc, was inserted through the incision in the skin of a mouse and placed subcutaneously. One obturator ejected each elastin biomaterial disk from the needle into the subcutaneous layer. The mice were followed to evaluate any acute or chronic rejection symptoms of the implants. The implants i n vi ve were harvested at 30 days, 60 days, and at six months. Each disk of implanted heteroinjection was fixed, sectioned and mounted for histological examination. The classic method of von Kossa was used to demonstrate the calcification of the assembled heteroinjection sections. The calcium deposits were stained again using the von Kossa silver method.

Elastin heterografts implanted in the subcutaneous layer of BALB / c mice that are not incubated in ethanol before implantation, begin to calcify in as little as thirty days, and are severely calcified at six months. The elastin heterointes that have been incubated in ethanol, before digestion in sodium hydroxide, showed no signs of calcification at 30 days, 60 days, or at six months. In Figures 7 and 8, photomicrographs at a magnification of 125 X describe the histological examination of elastin heteroinj, without pretreatment, after 30 days of subcutaneous implantation in rats. In Figures 9 and 10, microphotographs at a 125 X amplification describe an elastin heteroinjustment, without pretreatment, after six months of subdermal in vitro implantation in mice. More specifically, calcification was observed in 5 of 6 heteroinjections implanted for 30 days (see Figure 8) and observed in all heteroinjections implanted for sixty days. (n = 6) and 6 months (n = 12) (see Figure 10). None of the heteroinj tates pretreated with ethanol calcified in vi vo. This includes heteroinj etches pretreated with ethanol (see Figures 7 and 9) implanted for 30 days (n = 3), 60 days (n = 3), and 6 months (n = 2). Thus, this example clearly demonstrates that the pretreatment of the elastin materials with an aliphatic alcohol substantially reduces the level of calcification in vi such elastin materials, as compared to the elastin materials produced from the counterpart elastin materials, not pretreated All the documents cited above are incorporated by reference in their entirety herein. A person skilled in the art will appreciate from a reading of this description that various changes in form and detail can be made without departing from the true scope of the invention.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (33)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A method for producing elastin or materials based on elastin or tropoelastin materials that have a substantially reduced level of calcification, and which are capable of being formed into a fused layer, characterized in the method because it comprises: the provision of elastin or biomaterials based in elastin or tropoelastin materials, unreacted; and the pretreatment of elastin or elastin-based biomaterials or unreacted tro.poelastin materials with an aliphatic alcohol prior to reaction thereof; and the reaction of elastin or biomaterials based on elastin or tropoelastin materials, unreacted, pretreated, to produce elastin or materials based on elastin or tropoelastin materials, which, after implantation, have a Substantially reduced level of in vivo Calcification compared to elastin or elastin-based materials or tropoelastin materials produced from the non-pretreated counterpart of elastin or biomaterials based on elastin or unreacted tropoelastin materials.

2. The method according to claim 1, characterized in that the aliphatic alcohol is a lower aliphatic alcohol.

3. The method according to claim 2, characterized in that the lower aliphatic alcohol comprises from one to eight carbon atoms.

4. The method according to claim 3, characterized in that the lower aliphatic alcohol comprises from two to four carbon atoms.

5. The method according to claim 1, characterized in that the lower aliphatic alcohol comprises ethanol.

6. A method for producing elastin or materials based on elastin or tropoelastin materials having a substantially reduced level of calcification, characterized in that it comprises: the provision of elastin or materials based on elastin or tropoelastin materials, unreacted; and the pretreatment of elastin or biomaterials based on elastin or tropoelastin materials, without reacting, with an aliphatic alcohol prior to the reaction thereof; and the reaction of elastin or biomaterials based on elastin or tropoelastin materials, unreacted, pretreated, to produce elastin or materials based on elastin or tropoelastin materials, which, after implantation, have a substantially reduced level of calcification in vi compared to elastin or elastin-based materials or tropoelastin materials produced from the non-pretreated counterpart of elastin or biomaterials based on elastin or tropoelastin materials, unreacted.

7. The method according to claim 6, characterized in that the aliphatic alcohol is a lower aliphatic alcohol.

8. The method according to claim 7, characterized in that the lower aliphatic alcohol comprises from one to eight carbon atoms.

9. The method according to claim 8, characterized in that the lower aliphatic alcohol comprises from two to four carbon atoms.

10. The method according to claim 6, characterized in that the lower aliphatic alcohol comprises ethanol.

11. A method for producing elastin or materials based on elastin or tropoelastin materials having a substantially reduced level of calcification, and which are capable of being formed into a fused layer, characterized in that the method comprises: the provision of elastin or biomaterials based on elastin or tropoelastin materials, unreacted; the pretreatment of elastin or biomaterials based on elastin or tropoelastin materials, without reacting, with an aliphatic alcohol prior to the reaction thereof; the reaction of elastin or biomaterials based on elastin or tropoelastin materials, unreacted, pretreated, to produce elastin or materials based on elastin or tropoelastin materials, which, after implantation, have a high level substantially reduced calcification in vi compared to elastin or elastin-based materials or tropoelastin materials produced from the non-pretreated counterpart of elastin or biomaterials based on elastin or tropoelastin materials, unreacted. the formation of an elastin layer or materials based on elastin or tropoelastin materials; and the fusion of the elastin layer or materials based on elastin or tropoelastin materials.

12. The method according to claim 11, characterized in that the aliphatic alcohol is a lower aliphatic alcohol.

13. The method according to claim 12, characterized in that the lower aliphatic alcohol comprises from one to eight carbon atoms.

14. The method according to claim 13, characterized in that the lower aliphatic alcohol comprises from two to four carbon atoms.

15. The method according to claim 11, characterized in that the lower aliphatic alcohol comprises ethanol.

16. A method for producing elastin or elastin-based materials or tropoelastin materials which, after implantation, have a substantially reduced level of viral calcification, and which can be fused to a tissue substrate, characterized in that the method comprises: the provision of an elastin sheet or sheet or materials based on elastin or tropoelastin materials having a first and second outer major surface, and a tissue substrate having a first and a second outer major surface that has been pretreated with an aliphatic alcohol; and the application of an energy absorbing material, which absorbs the energy within a predetermined range of wavelengths of light, to a selected one of the first and second outer surfaces of the pre-treated sheet of elastin or of elastin-based materials or of pretreated tropoelastin materials, in an amount that will cause fusion of one of the first and second outer surfaces of the elastin or materials based on elastin or tropoelastin materials, pretreated, and an outer surface of the tissue substrate. , the energy absorbing material penetrates into the interstices of the elastin or elastin-based materials or tropoelastin materials, pretreated, the irradiation of the energy absorbing material with light energy in the predetermined wavelength range with sufficient intensity to fuse together one of the first and second outer surfaces of the ela stina or materials based on elastin or tropoelastin materials, pretreated, and the tissue substrate; and fusing together one of the first and second outer surfaces of the preformed sheet of elastin or elastin-based materials or tropoelastin materials, pretreated, and the tissue substrate.

17. The method according to claim 16, characterized in that the aliphatic alcohol is a lower aliphatic alcohol.

18. The method according to claim 17, characterized in that the lower aliphatic alcohol comprises from one to eight carbon atoms.

19. The method according to claim 17, characterized in that the lower aliphatic alcohol comprises from two to four carbon atoms.

20. The method according to claim 17, characterized in that the lower aliphatic alcohol comprises ethanol.

21. The method according to claim 16, characterized in that the step of irradiating the energy-absorbing material comprises indirectly irradiating the energy-absorbing material by directing the first light energy through the elastin or the elastin-based materials or the elastin-based materials. tropoelastin materials or the tissue substrate, and then to the energy absorbing material.

22. The method according to claim 16, characterized in that the energy absorbing material comprises a biocompatible chromophore.

23. The method according to claim 16, characterized in that the energy absorbing material comprises an energy absorbing dye.

24. The method according to claim 16, further characterized in that it includes the step of substantially dissipating the energy absorbing material when the elastin or the elastin-based materials or the tropoelastin materials and the tissue substrate are fused together.

25. The method according to claim 16, characterized in that it also includes the step of dyeing the first or second surface of the elastin or the materials based on elastin or tropoelastin materials with the energy absorbing material.

26. The method according to claim 16, characterized in that it also includes the step of applying the energy absorbing material to one of the outer surfaces of the biomaterial, by impurifying a separate elastin layer, with an energy-absorbing material, and then by fusing the separated, contaminated elastin layer to the elastin or elastin-based material.

27. The method according to claim 16, characterized in that the energy absorbing layer is substantially uniformly applied to a selected one of the first and second outer surfaces of the elastin materials or materials based on elastin or tropoelastin materials.

28. The method according to claim 16, characterized in that it further includes the step of substantially covering the entire outer surface of the elastin or of the elastin-based materials or of the tropoelastin materials with the energy-absorbing material.

29. The method according to claim 16, characterized in that it also includes the step of irradiating the energy absorbing material with light energy at a localized temperature of about 40 to 600 degrees C, for a period of time sufficient to cause the fusion to each other. one of the first and second outer surfaces of elastin or materials based on elastin or tropoelastin material, and one of the first and second outer surfaces of the tissue substrate.

30. The method according to claim 16, characterized in that it also includes the step of irradiating the energy absorbing material with light energy, resulting in a temperature located at the interface of the elastin or elastin-based materials or the materials of tropoelastin, and the tissue substrate which is approximately 50 to 100 degrees C, for a duration sufficient to fuse together one of the first and second outer surfaces of the elastin or of the materials based on elastin or the tropoelastin materials and the substrate of woven.

31. The method according to claim 16, characterized in that the average thickness of the energy absorbing material that penetrates into the interstices of the elastin or of the materials based on elastin or tropoelastin material is approximately 0.5 to 300 meters.

32. The method according to claim 16, characterized in that it also includes the step of accommodating the magnitude of the wavelength, the energy level, the absorption, and the intensity of the light during irradiation with light energy of the energy absorbing material , and the concentration of the energy absorbing material, such that the temperature located at the interface of the first and second outer surfaces of the elastin or of the elastin-based materials or of the tropoelastin materials and the tissue substrate are maintained at about 40 to 140 ° C, whereby elastin or elastin-based materials or tropoelastin materials and the tissue substrate are fused together.

33. The method according to claim 16, characterized in that the tissue substrate is a living tissue substrate.