DE102008042576A1 - Medical implant for use as vascular implant, preferably cardiovascular implant or orthopedic implants for fixing human or animal tissue, vessels, bones or bone fragments, comprises bio-corrosive alloy composition - Google Patents

Abstract

A medical implant comprises a bio-corrosive alloy composition. A medical implant comprises a bio-corrosive alloy composition of general formula (I). Mg-A-B (I) A : one or multiple elements selected from a group consisting of copper, nickel or zinc; and B : one or multiple elements selected from a group consisting of lanthanides, aluminum or calcium.

Description

The The present invention relates to a medical implant made of a biocorrodible magnesium alloy.

medical Implants of various uses for use in the human or animal body are in great Diversity known in the art. A common goal in the realization of modern medical implants is a high Biocompatibility, that is a high degree Tissue compatibility of the inserted into the body Medical device.

in the Field of vascular surgery and cardiology, Angiography and radiology find permanent metallic implants often application. These permanent implants include for example intraluminal vascular supports (Endoprostheses, stents) for the treatment of lesions. These Supports serve, for example, for expansion and lumen maintenance from constricted vessels by moving from the vessel lumen starting with a balloon catheter or self-expanding the vessel lumen hold on a correspondingly optimal inner diameter. In many Cases, however, is a permanent support function not required by the implant. Rather, it can be in some Use cases by the diseased vessel biological repair processes on their own recover that the intraluminal implant is no longer needed is. This is generally the case about 4 weeks after implantation.

Of the permanent retention of a metallic implant can with some Disadvantages connected. The implant leads as a foreign body to local and possibly also systemic reactions. So showed Over time, for example, stents come from medical Although steel (316L) is highly biocompatible, it has medium and long periods partly a thrombosis formation and partly an adhesion of biomolecules on their surface promote. Another limitation of biocompatibility permanent stents is the permanent mechanical irritation of the vessel wall, which is also a cascade of cellular molecular Can trigger processes.

One Approach to solve the above problem exists in it, the implant in whole or in part of a biocorrodible To form material.

Under Biocorrosion in the living organism in the present case become microbial Processes or simply by the presence of body fluids conditioned hydrolytic, enzymatic and other metabolic-related Deterioration processes understood, leading to a gradual reduction which consist of the material structure. As a synonym Often the term "biodegradation" is used. The term bioresorption additionally includes the following Absorption of the decomposition products. Losing at a certain time the implant or at least the part of the implant that is made of the biocorrodible material, its mechanical integrity. The degradation products are absorbed by the body, with low Residues are tolerable.

biocorrodible Among other things, materials based on polymers were more synthetic Developed from nature or natural origin. To preferred Plastic materials include polymethyl methacrylate, polylactide and polyglycolic acid esters. Their mechanical properties on the one hand, and the subsequent foreign body reaction during On the other hand, biodegradation causes them to become sole material are unsuitable for implantation. For example, orthopedic implants often withstand high mechanical stresses and vascular implants, e.g. As stents, depending on the design a lot special requirements for modulus of elasticity, breaking strength and malleability suffice.

One promising solution is the use of biocorrodible metal alloys. So will in the DE 197 31 021 A1 proposed to form medical implants of a metallic material whose main component is selected from the group of alkali metals, alkaline earth metals, iron, zinc and aluminum. Particularly suitable alloys based on magnesium, iron and zinc are described. Secondary constituents of the alloys may be manganese, cobalt, nickel, chromium, copper, cadmium, lead, tin, thorium, zirconium, silver, gold, palladium, platinum, silicon, calcium, lithium, aluminum, zinc and iron. Furthermore, from the DE 102 53 634 A1 the use of a biocorrodible magnesium alloy with a share of magnesium> 90%, yttrium 3.7-5.5%, rare earth metals 1.5-4.4% and remainder <1% known in particular for the preparation of an endoprosthesis, z. In the form of a self-expanding or balloon-expandable stent.

Notwithstanding the advances made in the field of biocorrodible metal alloys, too the previously known alloys due to their material properties, such as strength and corrosion behavior, only limited operational.

So showed that metallic bone implants made of magnesium alloys in vivo depending on the composition of their Although alloying elements dissolve quickly and increased Bone regeneration around corrosive magnesium implants show, however, was in all alloys used one observed temporary formation of subcutaneous gas pockets. These are due to the still too high corrosion rate and the so related gas evolution of magnesium alloys. The gas pockets formed in the corrosion of the magnesium alloy can lead to a reduction of bone density, to implant loosening and even lead to implant failure.

Also At other implantation sites, the permanent education of Gas volumes not desirable. In vascular Implants can increase the risk of gas embolism after a certain volume of gas not be excluded. At implantation sites, where no transport system is available, such as in the abdomen leads the gas accumulation to swelling.

Experimental investigations into the corrosion properties of magnesium alloys result in increasing the dissolution rate of magnesium with increasing anodic polarization. In accordance with electrochemical expectations, the cathodic reaction rate of hydrogen evolution should be slowed in anodic polarization. However, unlike expected, the hydrogen evolution rate is also increasing. This unusual behavior is referred to as Negative Difference Effect (NDE) [ G. Song et al., Corrosion Science 1997, Vol. 5, 855-875 ; G. Song, Advanced Engineering Materials 2005, no. 7, 563-586 ].

Of the The present invention is therefore based on the object, a To provide material, the one in particular with the known biocorrodible magnesium alloys have comparably high biocompatibility but has improved material properties for the Use as an implant, especially with regard to on the strength and corrosion resistance, and the in the biodegradation a greatly reduced hydrogen evolution shows or even prevents them.

The The task is performed by the medical implant 1 mentioned features solved.

It was surprisingly found to be a biocorrodible Magnesium alloy of composition Mg-A-B, wherein A is for one or more elements selected from the group copper (Cu), nickel (Ni), zinc (Zn) and B for one or more Elements selected from the group of lanthanides (Ln), aluminum (Al) and calcium (Ca), and a proportion of A in the alloy 32-37% and a share of B in the alloy 2-10% is an increased strength and a delayed in vivo corrosion behavior as well as greatly reduced to near has complete suppressed hydrogen evolution.

Under the collective name "lanthanides" are present the 14 elements following lanthanum, namely cerium (58), Praseodymium (59), neodymium (60), promethium (61), samarium (62), europium (63), gadolinium (64), terbium (65), dysprosium (66), holmium (67), Erbium (68), thulium (69), ytterbium (70) and lutetium (71). The symbol Ln is used for the lanthanides.

The Alloy according to the invention contains magnesium as the main component. Under main component of an alloy becomes understood the alloy component according to the invention, whose atomic proportion of the alloy is highest. In the the following preferred alloy compositions described in more detail all other proportions of the alloy components must always be specified that each magnesium has the highest atomic proportion. Accordingly are all percentage statements on the composition of Alloy in atomic percent.

at the alloy according to the invention is an amorphous alloy. Amorphous alloys in the invention Senses are characterized by the fact that they have no crystal structure train and the material in a kind of arrangement without periodicity, d. H. without long distance order, similar to the atoms in a melt, remains. A particular class of amorphous alloys are metallic ones Glasses (narrow metallic glasses, glassy metals, amorphous metals). Even if the alloys are called amorphous, they always have a pronounced sense of order, both topologically and chemically.

By various known from the prior art manufacturing process can be prevented be that forms a crystal structure and the material remains in the amorphous state. Massively shaped semi-finished and finished goods made of amorphous alloys (also called solid glasses, Engl. Bulk metallic glasses (BMG)) can be produced for example by rapid quenching of a melt. In so-called melt spinning, the liquid metal is fed to a rapidly rotating, cooled cylinder. In particular, by quenching in Cu molds massive glasses can be produced with several millimeters thickness.

Material properties and manufacturing processes for magnesium-containing amorphous alloys describe (i) A. Inoue and T. Masumoto, Materials Science and Engineering, A173 (1993) pp. 1 to 8 ; (Ii) G. Yuan, T. Zhang and A. Inoue, Materials Transactions, Vol. 11 (2003) pp. 2271 to 2275 and (iii) WM Rainforth and H. Jones, Scripta Materialia, Vol. 3 (1997) pp. 311 to 314 ,

Theoretically, any alloy can be obtained by suitable process control in amorphous modification. In practice and for the purposes of the invention particularly suitable alloys are characterized by a high ratio of glass transition temperature T _g and melting temperature T _l (as a result of the known Turnbull criterion: D. Turnbull, Metall Trans B (1981) 271 ), which is predominantly the case with low-melting eutectic compositions. It is also known that increased chemical and topological differences between the individual alloying components, eg. B. in atomic size and in the bonding behavior, crystal formation during the cooling of the melt can prevent.

at Investigations with Mg-based metallic glasses has further shown that small amounts of silver elements (Ag), palladium (Pd) and platinum (Pt) the glass forming properties and can improve the ductility of the glasses. Specifically, such alloying elements can prevent Partially crystallize glasses over time and so on completely embrittled. Proved to be particularly suitable have (alloying dependent) contents of 0.5 up to 10% platinum, 0.5 to 10% palladium or 5 to 20% silver, as well as combinations of the three elements with a total of less than 15%.

In order to find suitable alloy systems, data collections of phase diagrams of binary or ternary alloys can be used ( Massalski TB, Okamoto H., Subramanian PR, Kacprizak L., Binary alloy phase diagrams, vols. 1 to 3, Materials Park (OH): ASM International, 1990/1 ; Villars P., Prince A., Okamoto H., Handbook of ternary alloy phase diagrams, vols. 1 to 10, Materials Park (OH): ASM International, 1995 ). Another approach is to slowly cool melts with the alloy components in question in the presence of high gravimetric forces. This can be accomplished by providing the melts in pots received from a centrifuge and slowly lowering the temperature during centrifugation ( Löffler JF, Johnson WL, Intermetallics 10 (2002), pp. 1167 to 1175 ; Löffler JF, Intermetallics 11 (2003), pp. 529 to 540 ; Löffler JF, Peker A., Bossuyt S., Johnson WL, Materials Science and Engineering A 375-377 (2004) pp. 341 to 345 ). Accordingly, it is readily possible for a person skilled in the art, with reference to the literature values or the abovementioned gravimetric examination methods, to identify eutectics or compositions which are close to the eutectics and which can form particularly stable amorphous alloys.

The amorphous alloys are to be chosen in their composition, that they are biocorrodible. As biocorrodible in the sense of Invention alloys are referred to, in which physiological environment a degradation takes place, which ultimately leads to the entire implant or the part formed from the material of the implant loses its mechanical integrity.

Preferably are vascular implants in the form of stents in such terms the biocorrodible amorphous alloys used, that a mechanical integrity of the implant for 2-20 weeks is maintained. orthopedic Implants for osteosynthesis are in terms of biocorrodible amorphous alloy composition so that the mechanical integrity of the implant for 6-36 months is maintained.

In a particularly preferred embodiment is in the biocorrodible magnesium alloy of the composition Mg-A-B around an alloy, where A is zinc and B is Calcium is and where the proportion of Zn in the alloy is 32-37% and the proportion of Ca in the alloy is 2-10%. These alloys are characterized by the alloy components like calcium due to a high degree of biocompatibility and have an increased compared to other alloy systems Strength, a delayed in vivo corrosion behavior and a greatly reduced to almost completely suppressed Hydrogen evolution on.

In In another preferred embodiment, the biocorrodible Magnesium alloy of the composition Mg-Zn-Ca a share of Zn of 34-37% and a proportion of Ca in the alloy from 2-10%.

In In another preferred embodiment, the biocorrodible Magnesium alloy of the composition Mg-Zn-Ca a share of Zn of 34-37% and a proportion of Ca in the alloy from 2-6%.

In In another preferred embodiment, the biocorrodible Magnesium alloy of the composition Mg-Zn-Ca a share of Zn of 34-37% and a proportion of Ca in the alloy from 5% up.

In In a particularly preferred embodiment, the biocorrodible Magnesium alloy of the composition Mg-Zn-Ca a share of Zn of 35% and the proportion of Ca in the alloy 5%.

The According to the invention medical implants can be designed as vascular implants. So can For example, in vascular surgery in vascular surgery Implants such as intraluminal vascular supports used for the treatment of lesions. Prefers Stents are used in this area, because such an expansion and lumen maintenance of narrowed vessels to one according to optimal inner diameter is possible.

To Another preferred embodiment is the medical one Implant as orthopedic implant, in particular for Osteosynthesis formed. Thus, biocorrodible orthopedic ones are available Implants, in particular in oral and maxillofacial surgery, hand surgery and as fixation implants and nails for fractures. In particular, the medical implant designed as a plate, wire, screw, pin or staple to Combine bones or bone fragments.

To Another preferred embodiment is the medical one Implant as a clip, clip or other device for fixation or to combine human or animal Tissue or vessels formed.

To Another preferred embodiment is the medical one Implant for fixation or joining of human or animal tissue or bone to other implants.

Of the Advantage compared to permanent implants lies among other things in that no renewed surgical procedure is required for removal is and the amorphous materials compared to crystalline materials have the same composition better material properties. Compared with the known biocorrodible metallic Implants are a higher strength and a delayed one Corrosion kinetics expected. In addition, opposite comparable crystalline alloys of the alloy area in be varied in a wide range of amorphous systems and so for example better on requirements of biocompatibility To be received.

In Another preferred embodiment has the surface of the medical implant additionally one or more pharmaceutical active ingredients, wherein the one or more pharmaceutical Active ingredients optionally in one or more biostable and / or biodegradable polymer layers are contained and released.

One Pharmaceutical agent is a compound that binds to the surrounding Tissue or to the vessel wall, in which the medical implant is introduced. there it is preferred that the active ingredient be released at very low rates becomes. The pharmaceutical agent is preferably of the following Drug classes selected: antimicrobial, antimitotic, antimyotic, antineoplastic, antiphlogistic, antiproliferative, antithrombotic and vasodilatory agents.

The biostable and / or biodegradable polymer layer within the scope of the present invention Invention is composed of polymers selected from the group consisting of non-resorbable, permanent polymers and / or absorbable biodegradable polymers.

The biostable and / or biodegradable polymer layer is particularly preferably composed of polymers selected from the group of polyolefins, polyether ketones, polyethers, polyvinyl alcohols, polyvi nyl halides, polyvinyl esters, polyacrylates, polyhalo-olefins, polyamides, polyamide-imides, polysulfones, polyesters, polyurethanes, silicones, polyphosphazenes, polyphenylene, polymer foams (of styrenes and carbonates), polydioxanones, polyglycolides, polylactides, poly-ε-caprolactone, ethylvinylacetate, polyethyleneoxide, polyphosphorylcholine, Polyhydroxybutyric acids, lipids, polysaccharides, proteins, polypeptides and copolymers, blends and derivatives of these compounds.

All particularly preferred is the biostable and / or biodegradable polymer layer composed of polymers selected from the group consisting of polypropylene, polyethylene, polyisobutylene, polybutylene, Polyetheretherketone, polyethylene glycol, polypropylene glycol, polyvinyl alcohols, Polyvinyl chloride, polyvinyl fluoride, polyvinyl acetate, polyethyl acrylate, Polymethyl acrylate, polytetrafluoroethylene, polychlorotrifluoroethylene, PA11, PA12, PA46, PA66, polyamide-imides, polyethersulfone, polyphenylsulfone, Polycarbonates, polybutylene terephthalate, polyethylene terephthalate, Elastanes, pellethanes, silicones, polyphosphazenes, polyphenylene, polymer foams (from styrenes and carbonates), polydioxanones, polyglycolides, poly-L-, Poly-D-, and poly-D, L-lactide, as well as poly-ε-caprolactone, Ethyl vinyl acetate, polyethylene oxide, polyphosphorylcholine, polyhydroxyvalerate, Cholesterol, cholesterol ester, alginate, chitosan, levan, hyaluronic acid, Uronides, heparin, dextran, cellulose, fibrin, albumin, polypeptides and copolymers, blends and derivatives of these compounds.

The Biostable and / or biodegradable polymer layer is preferred after the desired elution rate and the individual characteristics of the various active ingredients used and after the different absorption or degradation rate at the site of action of the medical implant.

following the invention is based on embodiments and explained in more detail in the accompanying drawings. Show it:

1 a graphical representation of the hydrogen evolution of different biocorrodible magnesium alloys;

2 a graph of polarization resistance versus time of different biocorrodible magnesium alloys;

3 a graph of free corrosion potential versus time of different biocorrodible magnesium alloys; and

4a . 4b Cross sections of magnesium platelets of different alloy composition after 70 hours storage in artificial plasma.

The amorphous magnesium alloys of the present invention, having sufficiently good glass forming properties to produce samples several millimeters thick, exist in several alloy systems which can be described with Mg-AB. In the course of the investigations, the amorphous alloys of the Mg-Zn-Ca system listed in Table 1 were investigated by way of example, the proportion of calcium in the alloy being 5% in each case. Table 1: Amorphous magnesium alloys of the system Mg-Zn-Ca Mg AB Mg ₇₅ Zn ₂₀ Ca ₅ Comparative example Mg ₇₂ Zn ₂₃ Ca ₅ Comparative example Mg ₆₉ Zn ₂₆ Ca ₅ Comparative example Mg ₆₆ Zn ₂₉ Ca ₅ Comparative example Mg ₆₃ Zn ₃₂ Ca ₅ inventively Mg ₆₀ Zn ₃₅ Ca ₅ inventively

In addition, crystalline materials such as technically pure magnesium and Mg ₉₈ Zn _{2 were} investigated as further comparative examples.

As a test medium for testing the corrosion behavior of various magnesium alloys As of crystalline magnesium and Mg ₉₈ Zn ₂ , artificial plasma is used as it is EN ISO 10993-15: 2000 for biocorrosion tests (composition NaCl 6.8 g / l, CaCl ₂ 0.2 g / l, KCl 0.4 g / l, MgSO ₄ 0.1 g / l, NaHCO ₃ 2.2 g / l, Na ₂ HPO ₄ 0.126 g / l, NaH ₂ PO ₄ 0.026 g / l). A sample of the alloy to be examined is stored in a sealed sample container with a defined amount of the test medium at 37 ° C. At intervals - adjusted to the expected corrosion behavior - from a few hours to several days (or months), the samples are taken and examined in a known manner for traces of corrosion.

Determination of the released Hydrogen concentration

1 represents the graph of hydrogen evolution of the various biocorrodible magnesium alloys as well as in crystalline technically pure magnesium and Mg ₉₈ Zn ₂ at the following measurement times: 5, 24 and 70 hours. At measuring times of 24 h, it can be assumed that a stationary state of material dissolution and hydrogen evolution has set. Table 2 summarizes the released hydrogen concentrations. Table 2 Mg AB Vol H ₂ / cm ² after 5 h [ml] Vol H ₂ / cm ² after 24 h [ml] Vol H ₂ / cm ² after 70 h [ml] Mg _99.95 2.27 4:45 7.25 Mg ₉₈ Zn ₂ 1.7 5.75 17.65 Mg ₇₅ Zn ₂₀ Ca ₅ 0.27622 4.88367 8.88639 Mg ₇₂ Zn ₂₃ Ca ₅ 0.25245 1.09215 4.98094 Mg ₆₉ Zn ₂₆ Ca ₅ 0174 0.6906 2.26382 Mg ₆₆ Zn ₂₉ Ca ₅ 0.10427 0.23765 0.5611 Mg ₆₃ Zn ₃₂ Ca ₅ 0.01964 0.04904 0.12314 Mg ₆₀ Zn ₃₅ Ca ₅ 0.09304 0.09304 0.10971

The Measurements show that after 24 h at a proportion of Zn in the alloy between 0 and 20% hydrogen in high concentration is released. From a Zn content in the alloy of 20% increases Although the hydrogen evolution from nonlinear, but the released hydrogen concentration continues to be significantly high. Because of these properties, these alloys are for the use as medical implants little suitable. First in the alloys according to the invention, in which the proportion of Zn in the alloy is 32 and 35% the released concentration of hydrogen extremely low.

in the Comparison to the magnesium alloy with a Zn content of 20% the concentration of released hydrogen at a Zn content of 32% lower by a factor of 100 at 24 h and by a factor of 72 lower after 70 h.

It was surprisingly found that the amount of hydrogen formed decreases strongly nonlinearly with increasing Zn content. If the released hydrogen concentration for technically pure magnesium and the alloys Mg ₉₈ Zn ₂ and Mg ₇₅ Zn ₂₀ Ca ₅ at high values, a significant drop in the amount of hydrogen released was determined with increasing Zn content, wherein in the alloys according to the invention the evolution of hydrogen almost completely comes to a halt. The biocorrodible magnesium alloys according to the invention are therefore particularly suitable as medical implants, since the formation of gas pockets within the human or animal organism is avoided due to the low corrosion rate and the associated low evolution of hydrogen.

Determination of the polarization resistance

2 shows the polarization resistances with free corrosion potential (open circuit potential, OCP) recorded for the alloys MgZn ₃₅ Ca, MgZn ₂₈ Ca ₅ and MgZn ₂₁ Ca ₅ under comparable experimental conditions.

The detection of the linear polarization resistance, ie the ratio of current and voltage of the corroding sample, in a small range of plus / minus 10 mV around the free corrosion potential tial is proportional to the corrosion rate, was carried out with a measuring system consisting of a potentiostat and a measuring cell with three electrodes: working, counter and reference electrode. Measurements were taken over a long period of time in Simulated Body Fluid (SBF) at Free Corrosion Potential (OCP), which sets itself up without external influence (voltage, current).

in the Comparison to the comparative examples with a Zn content of 21 and 28%, has the alloy of the invention with a Zn of 35% an increased polarization resistance on. This situation could be considered in view of the decreasing concentration expect at first hydrogen released.

Indeed increases the polarization resistance for the alloy a share of Zn of 35% over time, whereas the two Comparative Examples decreasing or constant values for show the polarization resistance. When comparing the absolute Values of the polarization resistance after approx. 3 h shows the alloy with a share of Zn of 35% a value 32 times higher as the alloy with a Zn content of 21%. Accordingly would be a decrease in the volume of hydrogen formed also about to expect the factor 32. Taking into account the previously described NDE's that the experimentally observed amount of hydrogen is always greater than the theoretically calculated, is a decrease in the volume of hydrogen formed by clearly expect less than a factor of 32. Actually reduced However, the amount of hydrogen formed completely surprising about a factor of 100.

Determination of free corrosion potential

Furthermore, the free corrosion potential of the alloys Mg ₆₀ Zn ₃₅ Ca ₅ , Mg ₆₇ Zn ₂₈ Ca ₅ and Mg ₇₄ Zn ₂₁ Ca _{5 was} measured ( 3 ).

in the Comparison to the comparative examples with a Zn content of 21 and 28%, has the alloy of the invention with a share of Zn of 35% a significantly increased free Corrosion potential.

4a and 4b each represent cross sections of platelets consisting of a magnesium alloy of the composition Mg ₆₉ Zn ₂₆ Ca ₅ and Mg ₆₀ Zn ₃₅ Ca ₅ , which were stored for 70 hours in artificial plasma.

In order to analyze the samples better, the plates were cut in half and placed on top of each other. These stacks were then embedded to make cross sections. These cross sections were analyzed by electron microscopy. 4a shows the transverse section of a magnesium alloy according to the invention with a Zn content of 35%; 4b shows as a comparative example a magnesium alloy with a Zn content of 26%. In the middle of the two images, the two halves of the samples are placed one on top of the other. Therefore, a similar image is observed below and above the midline. Compared to the alloy of the composition Mg ₆₉ Zn ₂₆ Ca ₅ , the alloy according to the invention in 4a a much thinner and also much denser layer on. The alloy in 4b On the other hand, it has strong corrosion attacks, leaving behind a pore-like structure. The biocorrodible magnesium alloy according to the invention with a content of Zn in the alloy of 35% thus has a denser and significantly thinner layer in artificial plasma than the comparative example Mg ₆₉ Zn ₂₆ Ca ₅ . The formation of a continuous, thin and dense surface layer in the inventive alloy Mg ₆₀ Zn ₃₅ Ca _{5 also} explains the increased free corrosion potential. While the free corrosion potential of alloys with thick and porous layers changes only very slightly in comparison, it increases significantly for the alloy with a dense layer.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 19731021 A1 [0008]
• - DE 10253634 A1 [0008]

Cited non-patent literature

• G. Song et al., Corrosion Science 1997, Vol. 5, 855-875 [0012]
• - G. Song, Advanced Engineering Materials 2005, no. 7, 563-586 [0012]
• A. Inoue and T. Masumoto, Materials Science and Engineering, A173 (1993) pp. 1 to 8 [0020]
• G. Yuan, T. Zhang and A. Inoue, Materials Transactions, Vol. 11 (2003) pp. 2271 to 2275 [0020]
• - WM Rainforth and H. Jones, Scripta Materialia, Vol. 3 (1997) pp. 311 to 314 [0020]
• D. Turnbull, Metall Trans B (1981) 271 [0021]
• Massalski TB, Okamoto H., Subramanian PR, Kacprizak L., Binary alloy phase diagrams, vols. 1 to 3, Materials Park (OH): ASM International, 1990/1 [0023]
• Villars P., Prince A., Okamoto H., Handbook of ternary alloy phase diagrams, vols. 1 to 10, Materials Park (OH): ASM International, 1995 [0023]
• - Löffler JF, Johnson WL, Intermetallics 10 (2002), pp. 1167 to 1175 [0023]
• - Löffler JF, Intermetallics 11 (2003), pp. 529 to 540 [0023]
• Löffler JF, Peker A., Bossuyt S., Johnson WL, Materials Science and Engineering A 375-377 (2004) pp. 341 to 345 [0023]
• - EN ISO 10993-15: 2000 [0049]

Claims (17)

Medical implant in whole or in part of a biocorrodible alloy of the composition Mg-A-B, in which A selected for one or more elements from the group copper, nickel, zinc and B for one or several elements selected from the group of lanthanides, Aluminum and calcium stands, as well a share of A in the Alloy 32-37% and a share of B in the alloy 2-10%, to the hydrogen evolution from the alloy to reduce or completely prevent. Implant according to claim 1 with an alloy of Composition Mg-Zn-Ca. Implant according to claim 1 or 2, characterized that a share of A in the alloy 34-37% and a share of B on the alloy is 2-10%. Implant according to claim 3, characterized in that that a share of A in the alloy 34-37% and a share of B on the alloy is 2-6%. Implant according to claim 4, characterized in that that a share of A in the alloy 34-37% and a share of B on the alloy is 5%. Implant according to claim 5, characterized in that a proportion of A in the alloy is 35%. Implant according to one of the preceding claims, characterized in that the alloy additionally comprises platinum, Palladium, silver or combinations of these elements. Implant according to one of claims 1 to 7 designed as a vascular implant. An implant according to claim 8, wherein the vascular Implant is a stent. Implant according to one of claims 1 to 7 designed as a cardiovascular implant. An implant according to claim 10, wherein the cardiovascular Implant is a stent. Implant according to one of claims 1 to 7 designed as an orthopedic implant. An implant according to claim 12, wherein the orthopedic Implant is designed for osteosynthesis. Implant according to one of claims 1 to 7 formed as a clip, clip or a device for fixing or to combine human or animal Tissues or vessels. Implant according to one of claims 1 to 7 formed as a plate, wire, screw, pin or clip for Assembly of bones or bone fragments. Implant according to one of claims 1 to 7 designed for fixing of human or animal tissue or bones to other implants. Implant according to one of claims 1 to 7, characterized in that the surface of the implant additionally one or more active pharmaceutical ingredients optionally, wherein the or the pharmaceutical active ingredients in one or more biostable and / or biodegradable polymer layers are included and released.