MXPA99009919A

MXPA99009919A - Stents with a radioactive surface coating, processes for producing the same and their use for restenosis prevention

Info

Publication number: MXPA99009919A
Application number: MXPA/A/1999/009919A
Authority: MX
Inventors: Heldmann Dieter; Platzek Johannes; Dinkelborg Ludger; Blume Friedhelm; Hilger Christophstephan; Niedballa Ulrich; Miklautz Heribert
Original assignee: Blume Friedhelm; Dinkelborg Ludger; Duda Stephan; Goerner Heidemarie; Heldmann Dieter; Hilger Christophstephan; Miklautz Heribert; Niedballa Ulrich; Noll Bernhard; Platzek Johannes; Schering Aktiengesellschaft; Speck Ulrich; Tepe Gunnar
Priority date: 1997-04-30
Filing date: 1999-10-28
Publication date: 2000-07-01

Abstract

Radioactive stents are characterised in that the surface of the stent is coated with a radioactive isotope. Also disclosed are processes for producing the same.

Description

STENTS WITH A RADIOACTIVE SURFACE COVER Description of the invention The invention relates to stents having a radioactive surface coating, processes for their manufacture and their use for the prophylaxis of restenosis. STATE OF THE ART Radioactive stents belong to the state of the art (EP 0433011, WO 94/26205, US 5176617). Stents are stents that allow open structures to be maintained as passages in the bodies of humans and animals (for example, stent of the vascular conduit, esophagus duct, tracheal duct, bile duct). They are used as a palliative measure in the case of constrictions due to occlusions (for example arteriosclerosis) or external pressures (for example in the case of tumors). Radioactive stents are used, for example, after vascular surgical interventions or interventional radiological interventions (for example, globular angioplasty) for the prophylaxis of restenosis. Such radioactive stents can be manufactured for example by activation of a non-radioactive stent by means of radiation with protons or deuterons of a cyclotron (WO 94/26205). This method of manufacturing radioactive stents is called ion implantation. There is now the problem that, on the one hand, a cyclotron is not available at the site of use of the stent in order to carry out a stent activation, and that on the other hand the activated stent can not be stored and transported at will. , by virtue of the short half-life of the activated isotopes, and for reasons of protection against radiation. Accordingly, the task of the present invention is to provide stents that can be activated independently of a cyclotron, and new processes for its manufacture. In particular it is the task of the invention to provide stents that can be coated with a previously selected isotope irrespective of a cyclotron. This task is solved by the stents and processes for their manufacture that are described below, as they are characterized in the patent claims. DESCRIPTION OF THE INVENTION The task described above is solved by the manufacturing processes for radioactive stents described below. Contrary to ion implantation, the processes according to the invention for the manufacture of radioactive stents are based on chemical and electrochemical methods. Within the framework of the present application the expressions "" X and X-.nn (X: symbol of the element, nn number of mass) will be considered synonymous (Example: 110Ag is equivalent to Ag-110). The task described above is solved in a first variant by a process for the manufacture of a radioactive stent in which a chemical deposition of the radioactive isotope is carried out on the stent. For this purpose, the selected stent is immersed in a solution containing the radioactive isotope. The isotoporadioactive is then deposited chemically on the stent. Depending on the materials chosen for the stent on the one hand and the radioactive isotope to be deposed on the other hand, two possibilities of deposition are considered: 1) Chemical reduction In the case of chemical reduction to the solution containing the radioactive isotope in dissolved form as well as the stent is added a reducing agent (for example SnCl2, KBH4, dimethyl borane, formaldehyde, sodium hypophosphite).

Synoptic table: M2 + + 2e "(of the reducing agent)? Catalytic surface? M ° Hypophosphite reducing agent (in the case of Ni) H2P02" + H20? catalytic surface - HPO32"+ 2H + + H" 2H "+ Ni2? Ni H2 Addition of citrate, acetate, fluoride, succinate, lactate, propionate pH = 4 - 11 Reducing agent NaBH4 (in the case of Au, Ni) BH4" + H20? BH3OH "+ H2 BH3OH" + 3Au (CN) 2"+ 30H" - > catalytic surface? B02"+ 1.5 H2 + 3Au ° + 6CN" + 2H20 2Ni2 + + NaBH4 + 2H20 - catalytic surface? 2Ni ° + 2H2 + 4H + + NaB02 Additions of dimethylammonium borane, boric acid, citric acid, malonic acid, glycine, pyrophosphate, malic acid, pH = 4 - 10 Reducing agent formaldehyde: (in the case of Cu) Cu2 + + 2 HCOH + 40H "? catalytic surface? Cu0 + H2 + 2H20 + 2HC00"under addition of NKa tartrate, NaOH Hydrazine reducing agent: (in the case of Pd, Pt) Pd, Pt with addition of NH4OH, EDTA, Dimethylaminoborane reducing agent (Cr NH'Br (in the case of Au, Ag) (CH3) 2NH »BH3 + OH- -> catalytic surface? BH3OH ~ + (CH3) 2NH Au and Ag of cyanidic baths After 1 minute to 10 hours the stent is removed from the respective solution and washed.The surface of the stent is coated with the radioactive isotope.This way it is possible to deposit on metal stents (for example steel, nitinol ), for example, isotopes of the elements Ag, Au, Bi, Co, Cr, Cu, Fe, Gd, Hg, Ho, In, Go, Lu, Mn, Ni, P, Pb, Pd, Pm, Pt, Re, Rh, Ru, Se, Sm, Tb, Te or Y. 2) Chemical precipitation In the case of chemical precipitation to the solution containing the radioactive isotope in dissolved form as well as the stent is added a precipitating agent (eg oxalic acid, phosphoric acid or its salts or NH2CO3). In this way it is possible to deposit on metal stents (for example steel, nitinol), for example, isotopes of the elements Ag, Au, Bi, Co, Cr, Cu, Fe, Gd, Hg, Ho, In, Ir, Lu, Mn, Ni, Pb, Pd, Pm, Pt, Re, Rh, Ru, Se, Sm, Tb, Te or Y.

The aforementioned task is solved in a second variant proceeding in such a way that the radioactive isotope is fixed on the surface of the stent by means of an adhesive. Accordingly, the device according to the invention comprises a metallic base body of the stent, an adhesive on the surface of the stent and a radioactive isotope that adheres thereto. As a base body, the commercially available vascular implants can be used, for example a Wiktor stent, a Strecker stent or a Palmaz-Schatz stent. Peptides, fats or gold are used as adhesives in combination with a complexing agent containing thiol groups. It is thus possible, for example, to use modified polyurethanes which, in turn, contain complexing agents. But as adhesives, peptides can also be used which, on the one hand, carry a complexing agent and, on the other hand, bind specifically to the metal of the stent. Examples of these compounds are the endothelin-labeled derivatives such as those described, for example, in EP 606683, DE 4425778, DE 43 37 600, DE 4337599 and DE 19652374 (for example Tc-99m-Asp-Gli-Gli). -Cis-Gli-Cis-P e- (Dr-Trp) -Leu-As? -Ile-Ile-Tr?).

They can also be used as greasy adhesives that carry a complexing agent. Examples of this are the complexing agents which carry lipophilic radicals which are mentioned in DE 43 40 809, EP 450742, EP 438206, EP 413405 or WO 96/26182. In addition to the foregoing, it is also possible to use gold as a glue in combination with a complex former which contains thiol groups. It is known that compounds containing thiol groups show an increased affinity to gold-coated surfaces (H. Schonherr et al., J. Am. Chem. Soc. 118 (1996), 13051-13057). Surprisingly, the elemental gold that is on the surface of the stent also has the ability to specifically fix complexing agents, as long as they contain thiol groups. The complex formers in turn fix the radioactive isotopes. In the sense of this document, the complex formers are, for example, DTPA, DOTA, D03A, EDTA, TTHA, Amides MAG2, Amides MAG3 and their derivatives. Radioactive isotopes can be used isotopes of the elements Ag, Au, Ba, Bi, C, Co, Cr, Cu, Fe, Gd, Hg, Ho, In, Ir, Lu, Mn, Ni, P, Pb, Pd, Pm, Pt, Re, Rh, Ru, S, Sb, Se, Sm, Tb, Te or Y. Accordingly, the invention relates to radioactive stents characterized in that the radioactive isotope is fixed on the surface of the stent by means of an adhesive. The stents according to the invention can be exemplarily manufactured in the following manner: A. Peptide as adhesive A. First a peptide is selected which in turn has the ability to complex with heavy metal ions. This is activated by the reaction with the radioactive isotope (for example 186 Re or 188 Re) eventually together with a reducing agent. The radioactively labeled peptide is dissolved in a solvent (for example, water, phosphate buffer), and the stent is immersed in the peptide solution. After removing the stent from the peptide solution it is dried in a chamber dried at room temperature. After washing the stent is ready to be used. A2. In one variant of the process the uncoated stent is first coated with the non-activated peptide. The stent coated in this way is then immersed in a solution containing the radioactive metal (for example 186 Re or 188 Re) optionally together with a reducing agent (for example SnCl 2) and is thus charged with the isotope. After washing the stent is ready to be used.

B. Grease as an adhesive Bl An uncoated stent is first coated with a lipophilic compound (for example, diacid 3,9-bis (carboxymethyl) -6-bis (octadecyl) -aminocarbonylmethyl-3,6-9-triazaundecanoic, WO 96 / 26182) as an adhesive. This lipophilic compound carries a DTPA radical as a complex former. The stent can be immersed directly in the compound or in a solution thereof. After coating the stent with the compound, it is placed in a solution of the radioactive metal (for example 90YC13). After washing the stent is ready to be used. B.2 In a variant of this process the coating of the stent is carried out in two stages. For this purpose, the stent is first treated with a lipophilic compound that carries amino groups. The amino groups are then reacted with DTPA monoanhydride, as described in the literature. Now the stent has a coating that carries complex formers (in this case DTPA). The stent of this coated mode is then placed in a solution of the radioactive metal (for example 90YC13). After washing the stent is ready to be used. C. Gold / complex former containing thiol groups as an adhesive. C. An uncoated stent is first coated electrochemically (by internal electrolysis, cementation) with elemental gold. The gold-coated stent is then immersed in an aqueous solution of a complex former containing thiol groups (for example N, N-dimethyl-2- (3, 3, 5, 11, 13, 13-hexamethyl-1, 2-dithia-5, 8, 11-triazacyclylotridecan-8-yl) -ethylamine or the product of the coupling of 11-amino-undecyl thiol with bis-anhydride of DTPA). The complex former containing thiol groups is adhered to the gold-coated stent. The stent prepared in this way is now mixed with the radioactive metal solution (for example 67CuS04). After washing the stent is ready to be used. The complex former can be synthesized on the surface of the stent. It is possible to apply on the gold-coated stent only one component of the complex former first, and then to continue coupling this component with other partial units. This procedure is described in detail in the examples. C.2 In a variant of this process, the gold-coated stent is mixed with a solution of the complex former that contains thiol groups, which in turn already complex a radioactive isotope. After washing the stent is ready to be used. C.3 In a variant of this process the gold-coated stent is mixed with a solution of the complex former that contains thiol groups which in turn contains 35s- After washing the stent is ready to be used. C.4 In another variant of this process, the gold-coated stent is mixed with a solution of the complexing agent containing thiol groups, with the thiol group being labeled 35s and the complexing agent already complexing a radioactive isotope (for example 67CuS04). After washing the stent is ready to be used. The processes described above are usually carried out at temperatures of 0-100 ° C. When coating the stent with the adhesive, solvents can be used depending on the respective adhesive. In the case of using a non-aqueous solvent, it must be removed before implantation. The stents can also be coated with two or more different isotopes. In particular, it is possible to apply isotopes of short and long life together on a stent (eg 55Co with 55Fe, 35S with 67Cu or 99Mo with 57Co). The steps necessary to carry out the processes described above in principle are known to the expert. The special embodiments are described in detail in the examples. In a third variant the invention also relates to a process for manufacturing radioactive stents characterized in that a non-radioactive stent is immersed in a solution containing at least one radioactive isotope in ionic form, the isotope is then deposited chemically on the stent. According to the invention, the task described above is solved by an electrochemical deposition of the isotope of radioactive metal on the stent. For this purpose, the chosen stent is immersed in a solution containing the radioactive metal isotope. The radioactive isotope is then deposited electrochemically. Depending on the materials selected for the stent on the one hand and the radioactive isotope to be deposited on the other hand, two possibilities of deposition are considered: I) Galvanized (external electolysis) In the case of galvanizing the dissolved radioactive isotope is reductively deposited by the application of direct electric current to the stent connected as a cathode.

In this way it is possible to deposit for example copper, tecnetium, rhenium, silver or indium on electrically conductive stents (for example steel, nitinol). II) Cementation (internal electrolysis) In the case of cementation the most noble dissolved radioactive isotope is deposited without applying current to the less noble material of the stent by virtue of the position of the materials in the scale of polarity of the metals. In this way it is possible to deposit, for example gold, silver or copper on metal stents (for example steel, nitinol). DETAILED DESCRIPTION OF THE INVENTION For the coating of metal stents, two electrochemical processes are particularly suitable: galvanizing (electrolytic coating) and cementing (internal electrolysis). The most widespread application process is galvanizing, by virtue of which it also allows the coating with an electrochemically more negative material than that of the stent. The coating also allows chemical reactions - for example, reducing processes. From the point of view of the goodness for which it applies, cementation is the best process: the stent is introduced into the solution of an electrochemically more positive element and the coating proceeds without external (electrical) current. By means of a suitable form of the cells the excess coating material can be reduced. The necessary agitation can be carried out by means of a magnetic stirrer or by moving the stent by hand. Because only small amounts of material are spent with these processes, hand-shaking is justified. The same is true for reactions at high temperature: due to the short time a thermostatization is not essential (automatic temperature control), but preheating is sufficient. The loading of the cells (figures 1, 2) can be carried out with injectors for injections or, in the case of larger stents, with the help of dosing pumps. In the case of these larger cells it is convenient to separate the used electrolytic solution (active) and the washing liquid (inactive) in order to reduce the volume of active liquid. In the case of the cells described in figures 1, 2, the stent is placed with its carrier in the container, where a higher point with a concavity takes care of the positioning. In the case of a galvanized cell this concavity contains a Pt sheet as a contact for the stent connected as a cathode. On the wall of the cell is a grid of Pt as anode. By inserting an annular sheet of another metal electrically conductively connected to the anode, it is also possible to work with a tin, zinc or copper anode. The introduction of the stent with its carrier has the advantage that the inner side of the stent is covered and consequently no coating takes place there. The coating only takes place at those points that are oriented against the container. Since a restenosis is suppressed by the coating, it is possible to dispense with the electrophoresis of the crude stent, particularly in the case of stainless steel. Possibilities of the electrochemical marking of stents: Galvanostatic deposition: For this purpose, a battery (1.5 to 12 V) connected with a variable resistance and two electrode terminals is sufficient. The metal to be coated is connected as a cathode. As an anode, a noble metal, preferably platinum, should be used. The duration of electrolysis is from 20 seconds to 30 minutes. It is worked at temperatures of 0 ° - 80 ° C, however preferably at room temperature. Cu: (for example Cu-67 and rays?, T »» = 6.19 h) of pyrophosphate baths of the following composition: Cu2 +: 20-40 g (P207) 4-: 15-250 g N03-: 5 - 10 g NH3: 1 - 3 g (HPO4) 2": <110 g pH: 8 - 9 I: 1 - 8 A / dm2 of alkaline baths of CuCN at pH 12.2 - 12.8 acid baths • sulfate-oxalate-acid boric • CuCl / sodium thiosulfate • fluorborate, fluorsilicate, formate • CuII / gluconate, lactate, maleate, tartrate I = 1 - 2.5 A / dm2 U = 0.2 - 6 V pH = 1.2 Au: (Au-199, t », = 3 d, ß and y-rays) of cyanidic baths under the addition of phosphate and citrate at pH 5-12, of NH4CIKAUCN2 baths with the addition of thiourea at pH 6. 5 - 7, I = 0.1 - 0.6 A / dm2 In: from cyanidic baths to pH = 0 - 1 of fluorophore baths with addition of tartaric acid at pH 1 In2 (S04) 3, pH 2-3 / or sulfamate and tartrate Re: of perrhenate Re-186 Citrate + H2SO4, pH 1-5 I = 1 - 15 A / dm2 Ni: of NiS04 / boric acid, or of baths of acetate, fluoroborate or sulphamate, pH 1-5 I = 2 - 30 A / dm2 Pt, Rh, Pd, Ru: (Pt-197, tH = ß-rays) I = 1 - 4 A / dm2 Ru of (NH3) 4 (Ru2NCi8 (H2?) 2 or Rh sulfate or low phosphate sulfate addition of H2SO4, pH = 1-2 Pd of Pd (NH3) 4Br2, ETDA Pt of H2Pt (N02) 2S04 under addition of NH4NO2 sulfamate, NH3 H2Pt (N02) 2S04 under the addition of H2SO4, K2Pt (OH) 6 with the addition of KOH and / or ethylamine H2PtCl6 in acidic baths with addition of Ag HCl: (Ag-110, tH = 250 d) cyanidic baths under addition of KOH Electrochemical deposition The marking of the stent is carried out by electrochemical deposition of the radioactive metal correspondingly to its electrochemical potential with respect to the metal potential of the stent. The deposition is carried out in a suitable electrolyte and selected reaction conditions. A particularly suitable electrolyte is hydrochloric acid in concentrations of 0.75N to 1N. In this way it is possible to deposit all the radioisotopes of metals whose electric potential is more positive than that of the stent metal. It has been shown that after electrochemical deposition of the radioactive metal, non-specifically bound activity is still attached to the stent. To eliminate this, the stent is treated with a solution containing an electrolyte (for example NaCl), a reducing agent and a hydroxycarbonic acid (for example SnCl2 and gentisin acid) or a lipophilic alcohol and cations (for example an alcoholic bromide solution). of tetrabutylammonium). The stent thus produced can still be sealed with a polymer. As the polymer, for example, a polyacrylate is suitable. It is also possible to coat all the stents with two or several different isotopes. In particular it is possible to apply short-lived and long-lived isotopes together on a stent (for example 55Co with 55Fe or 99Mo with 57Co). With the described process it is possible to manufacture radioactive stents that contain on the surface at least one radioisotope of the elements Ag, Au, Bi, Co, Cr, Cu, Fe, Gd, Hg, Ho, In, Ir, Lu, Mn, Ni , Pb, Pd, Pm, Pt, Re, Rh, Ru, Se, Sm, Tb, Te or Y. Therefore the invention relates to stents of this nature as well as processes for their manufacture. The steps necessary to carry out the processes described above in principle are known to the person skilled in the art. The special embodiments are described in detail in the examples. The stents according to the invention solve the task mentioned in the introduction. By means of the revealed processes it is possible to radioactively mark the stents without problems and with a precise dosage. The stents according to the invention are physiologically tolerable. As could be demonstrated in the animal model, restenosis after a globular denudation is significantly inhibited by the implantation of the stents according to the invention. The particular advantage of the stents according to the invention is that the doctor can select a stent (non-radioactive) according to his needs at the scene and can then activate the stent chosen by the described process. The few substances and solutions necessary for this can be sent correspondingly prepared, so that the respective physician only has to immerse the uncoated stent in the individual solutions in the prescribed sequence. Accordingly, the invention also relates to those substances, solutions and preparations (kits) prepared for the processes according to the invention. EXAMPLES OF EMBODIMENT The following examples should explain the object of the invention without, however, limiting it to them. Example 1 Direct Marking of Y-90 from a Wiktor-stent A Wiktor-stent (22, 85 mg, model 6570, Medtronic) is coated with 2 ml of a saturated solution of sodium oxalate. 37MBq of yttrium-90 trichloride solution is added and heated for 30 minutes at 60 ° C. The stent is then removed and washed 3 x with 5 ml of a 0.9% solution of sodium chloride. The Wiktor-stent marked in this way carries an activity of 0.88MBq Y-90.

Example 2 Coating of Strecker-stents with Tc-99m One Strecker-stent (6.51 mg, SS / 5-4, Boston Scientific) is coated with 726 μl of sodium pertechnetate solution (231.9 MBq). 100 μl of a solution of tin (II) chloride dihydrate (5 mg SnCl) is added • 2H20 / 1 ml of 0.01 M HCl), the reaction mixture is placed for 5 minutes in an ultrasonic bath and finally incubated for 25 minutes at room temperature. The stent is dried and washed 3 x for 15 minutes with 726 μl of a 0.9% sodium chloride solution.

Finally, it is recoated with 726 μl of 0.9% sodium chloride solution and the reaction mixture is placed in an ultrasonic bath for 5 minutes. The dry Strecker-stent carries an activity of 1.1 MBq-Tc- 99m / 6.51 mg (= 29.7 μCi / 6.51 mg = 4.6 μCi / 1 mg). Example 3 Coating of Strecker-stents with Re-186 A Strecker-stent (6.60 mg, SS / 5-4, Boston Scientific) is coated with 736 μl of sodium perrhenate solution (240.2 MBq). 100 μl of a solution of tin (II) chloride dihydrate (5 mg SnCl • 2 H20 / 1 ml of 0.01 M HCl) is added, the reaction mixture is placed for 5 minutes in an ultrasonic bath and finally incubated for 25 minutes at room temperature. The stent is dried and washed 3 x for 15 minutes with 736 μl of a 0.9% sodium chloride solution. Finally, it is recoated with 736 μl of 0.9% sodium chloride solution and the reaction mixture is placed in an ultrasonic bath for 5 minutes. The dry Strecker-stent carries an activity of 1.0 MBq-Re-186 / 6.6 mg (= 27 μCi / 6.6 mg = 4.1 μCi / 1 mg). EXAMPLE 4 Coating of Wiktor-stents with Tc-99m A Wiktor-stent (22.92 mg, model 6570, Medtronic) is coated with 2.56 ml of sodium pertechnetate solution (911.5 MBq). 256 μl of a solution of tin (II) chloride dihydrate (5 mg SnCl • 2H20 / 1 ml of 0.01 M HCl) are added, the reaction mixture is placed for 5 minutes in an ultrasonic bath and finally incubated for 25 minutes at room temperature. The stent is dried and washed 3 x for 15 minutes with 2.56 ml of a 0.9% sodium chloride solution. Finally, it is recoated with 2.56 ml of 0.9% sodium chloride solution and the reaction mixture is placed in an ultrasonic bath for 5 minutes. The dry Wiktor-stent carries an activity of 5.9 MBq-Tc-99m / 2.92 mg (= 159.5 μCi / 22.92 mg s 6.9 μCi / 1 mg). EXAMPLE 5 Coating of Wiktor-stents with Re-186 A Wiktor-stent (22.31 mg, model 6570, Medtronic) is coated with 2.5 ml of sodium perrhenate solution (884.1 MBq). 249 μl of a solution of tin (II) chloride dihydrate (5 mg SnCl • 2H20 / 1 ml of 0.01 M HCl) are added, the reaction mixture is placed for 5 minutes in an ultrasonic bath and finally incubated for 25 minutes at room temperature. The stent is dried and washed 3 x for 15 minutes with 2.5 ml of a 0.9% sodium chloride solution. Finally, it is recoated with 2.5 ml of 0.9% sodium chloride solution and the reaction mixture is placed in an ultrasonic bath for 5 minutes. The dry Wiktor-stent carries an activity of 5.2 MBq-Re-186 / 22.31 mg (s 140.5 μCi / 22.31 mg = 6.3 μCi / 1 mg). Example 6 Application of a Tc-99m coated Wiktor-stent in the abdominal aorta of rabbits The Wiktor-stent (model 6570, Medtronic) was coated with Tc.99m as described in example 4. To a white rabbit from New Zealand (3.2 kg of body weight) narcotized (rompun / cetavet 1: 2) was exposed to the artery-femoralis. Through a 5 F gate, the marked Wiktor-stent was introduced into the vessel and fixed to the infrarenal aorta by inflation of the globular catheter. The catheter was then removed and both a. femoralis as well as the wound. Full-body gammagrams were made for a period of 8 hours after the application of the stent with the aid of a commercial gamma camera. 5 hours after the application of the stent, a gammagram was made. Only activity could be detected in the region of the stent that was inside the infrarenal aorta of the animal. During the entire period of the investigation, no detectable activity of the stent was delayed. After 8 hours the rabbit was sacrificed, the stent was removed and the activity in the gamma counter was measured. The activity adhered to the stent was exactly as high as at the beginning of the test taking into account the radioactive decay of 99mTc to 99Tc. Example 7 Marking of Strecker-Stent with Cu-67 In a cementing cell (Figure 2a) a Strecker-stent (1993 mg) is introduced into an alkaline solution of copper sulfate / potassium tartrate. sodium with a 47.3 MBq ctivity. After the addition of formaldehyde solution, the deposition of elemental copper occurs. The active solution is removed and the stent is washed 4 times with a physiological solution of sodium chloride. It shows an activity of 1.63 MBq. CuS04 • 5H20 500mg / 100ml KNaC4H406 • 4H20 2500mg / 100ml NaOH 700mg / 100ml HCOH (37%) lml / lOOml T 20 ° C Example 8 Marking of a nitinol stent with Au-199 In a cementing cell (figure 2b) introduces a nitinol stent (496 mg) is a solution composed of potassium aurocyanide (K [9Au (CN) 4] with an activity of 137.8 MBq, potassium cyanide and potassium hydroxide.After heating to 75 ° C is added potassium borohydride and stirred for 3 minutes.After 4 minutes the solution is purged and the stent is washed 4 times with a physiological sodium chloride solution.Its activity is 1.31 MBq. [Au (CN) 2] 580mg / 100ml K CN 1300mg / 100ml K OH 1120mg / 100ml K BH4 2160mg / 100ml Example 9 Marking a Strecker-stent with Ag-110 In a cementing cell, a Strecker-stent (997 mg) is introduced into a solution composed of cyanide of sodium and silver (Na Ag (CN) 2) with an activity of 40 MBq / mg of stent, sodium cyanide and sodium hydroxide. When heating to 55 ° C, dimethyl borane is added. It is stirred for 4 minutes at 55 ° C, then the solution is purged, the stent is washed 4 times with a physiological sodium chloride solution and the activity is defined. It is 1.34 MBq. Na [Ag (CN) 2] 183mg / 100ml Na CN lOOmg / lOOml Na OH 75mg / 100ml Na BH4 200mg / 100ml Na [Ag (CN) 2]: 134mg AgCN + 49 mg NaCN Example 10 Marking a Strecker-stent with Pd / P-32 In a cementing cell (figure 2a) a Strecker-stent (1996 mg) is introduced into a solution of palladium chloride, hydrochloric acid, ammonia and ammonium chloride. The solution has a temperature of 55 ° C and is stirred. To the solution are added by mixing 9 mg of sodium hypophosphite monohydrate having an activity of 36.4 MBq. A palladium-phosphorus alloy having an activity of 1.31 MBq is deposited on the stent. Pd Cl2 200mg / 100ml HCl (38%) 0.4ml / 100ml NH4OH (28%) 16ml / 100ml NH4CI 2.7g / 100ml NaH2P02H20 lg / 100 ml T 55 ° C 3 g of hypophosphite produce 1 g of Pd alloy with 1.5 % of P Example 11 Marking of a stainless steel stent with Pd / P-32 In a cementing cell (figure 2b) a stainless steel stent (498 mg) is introduced into a solution of palladium chloride, hydrochloric acid, ammonia and ammonium chloride. The solution has a temperature of 55 ° C and is stirred. To the solution are added by mixing 6 mg of sodium hypophosphite monohydrate having an activity of 37.8 MBq. A palladium-phosphorus alloy having an activity of 1.16 MBq is deposited on the stent. Pd Cl 200mg / 100ml HCl (38%) 0.4ml / 100ml NH40H (28%) 16ml / 100ml NH4CI 2.7g / 100ml NaH2P02H20 lg / 100 ml T 55 ° C 3 g of hypophosphite produce 1 g of Pd alloy with 1.5 % D.E.P Example 12 Marking of a nitinol stent with Pd / P-32 In a cementation cell (Figure 2b), a nitinol stent (96 mg) is introduced into a solution of palladium chloride, hydrochloric acid, ammonia and ammonium chloride. The solution has a temperature of 55 ° C and is stirred. To the solution are added by mixing 3 mg of sodium hypophosphite monohydrate having an activity of 39.4 MBq. A palladium-phosphorus alloy having an activity of 1.37 MBq is deposited on the stent. Pd Cl2 200mg / 100ml HCl (38%) 0.4ml / 100ml NH4OH (28%) 16ml / 100ml NH4CI 2.7g / 100ml NaH2P02H20 lg / 100 ml T 55 ° C 3 g of hypophosphite produce 1 g of Pd alloy with 1.5 % D.E.P Example 13 Marking of a stainless steel stent with P-32 In a galvanizing cell (figure 1) a stainless steel stent (1992 mg) is introduced into a phosphoric acid solution with a 32P activity of 41.4 MBq heated to 50 °. C. The stent is connected as an anode and electrolyzed for 2 minutes at 2 V. The solution is then purged, the stent is washed 4 times with a physiological solution of sodium chloride and the activity of the stent is measured. It is 0.93 MBq.

Example 14a Coating of a Wiktor-stent with l-. { 3- [N- (2-methoxyethyl) -octadecylsulfamoyl] -2-hydroxypropyl} -4,7,10-tris- (hydroxycarbonylmethyl) -1,4,7,10-tetraazacyclododecane 50 mg l-. { 3- [N- (2-methoxyethyl) -octadecylsulfamoyl] -2-hydroxypropyl} 4, 7, 10-tris- (hydroxycarbonylmethyl) -1,4,7,10-tetraazacyclododecane (prepared according to DE 43 40 809.5) are dissolved in 1 ml of ethanol. The Wiktor-stent (22.82 mg, model 6570, Medtronic) is coated with the solution prepared in this way. Then 2 ml of water are added and incubated for 15 minutes in the ultrasonic bath. The Wiktor-stent is removed and dried. Example 14b Marking of In-111 of a Wiktor-stent coated with l-. { 3- [N- (2-methoxyethyl) -octadecylsulfamoyl] -2-hydroxypropyl} -4,7, 10-tris- (hydroxycarbonylmethyl) -1, 4, 7, 10-tetraaza-cyclo-dodecane A Wiktor-coated stent with l-. { 3- [N- (2-methoxyethyl) -octadecylsulfamoyl] -2-hydroxypropyl} -4,7, 10-tris- (hydroxycarbonylmethyl) -1,4,7,7,10-tetraazacyclododecane (produced according to DE 43 40 809.5) as in example 14a is coated with 2 ml of a 0.9 sodium chloride solution. %. After adding 37MBq of indium trichloride solution, the reaction mixture is placed for 15 minutes in an ultrasonic bath. The stent is removed, washed 3 times with 5 ml of 0.9% sodium chloride solution and dried. The Wiktor-stent marked in this way carries an activity of 1.49 MBq of In-111. Example 14c Marking of Y-90 of a Wiktor-stent coated with l-. { 3- [N- (2-methoxyethyl) -octadecylsulfamoyl] -2-hydroxypropyl} -4,7, 10-tris- (hydroxycarbonylmethyl) -1,4,7,10-tetraaza-cyclododecane A Wiktor-stent coated with l-. { 3- [N- (2-methoxyethyl) -octadecylsulfamoyl] -2-hydroxypropyl} -4, 7, 10-tris- (hydroxycarbonylmethyl) -1,4,7, 10-tetraazacyclododecane (produced according to DE 43 40 809.5) as in example 14a is coated with 2 ml of a 0.9 sodium chloride solution. %. After adding 37MBq of yttrium trichloride solution, the reaction mixture is placed for 15 minutes in an ultrasonic bath. The stent is removed, washed 3 times with 5 ml of 0.9% sodium chloride solution and dried. The Wiktor-stent marked in this way carries an activity of 1.12 MBq of Y-90. Example 15a Complete Y-90 of l-. { 3- [N- (2-methoxyethyl) -octadecyl-sulfamoyl] -2-hydroxypropyl} -4, 7, 10-tris- (hydroxycarbonylmethyl) -1,4,7, 10-tetraazacyclododecane 50 mg of l-. { 3- [N- (2-methoxyethyl) -octadecyl-sulfamoyl] -2-hydroxypropyl} -4,7, 10-tris- (hydroxycarbonylmethyl) -1,4,7,10-tetraazacyclododecane (produced according to DE 4340809.5) are dissolved in 1 ml of ethanol. After the addition of 37MBq of yttrium-90 trichloride solution, the reaction mixture is heated at reflux for 10 minutes. The complex solution of Y-90 thus prepared can be used without further purification to coat a Wiktor-stent. Example 15b Marking of Y-90 from a Wiktor-stent with the Y-90 complex of l-. { 3- [N- (2-methoxyethyl) -octadecylsulfamoyl] -2-hydroxypropyl} -4, 7, 10-tris- (hydroxycarbonyl-methyl) -1,4,7, 10-tetraazacyclododecane in 900 μl of the solution of the l- complex. { 3- [N- (2-methoxyethyl) -octadecyl-sulfamoyl] -2-hydroxypropyl} 4, 7, 10-tris- (hydroxycarbonylmethyl) -1,4,7,10-tetraazacyclo-dodecane-Y90 prepared according to example 15a is introduced a Wiktor-stent (22.89 mg, model 6570, Medtronic). After adding 2 ml of water, the reaction mixture is placed in an ultrasonic bath for 15 minutes. The Wiktor-stent is then removed and washed 3 times with 5 ml of 0.9% sodium chloride solution and dried. The Wiktor-stent marked in this way carries an activity of 0.98 MBq of Y-90.

Example 16a N, N'-bisundecyl-diethylenetriamine pentaacetic acid diamide 3.57 g (10 mmol) of diethylene triamine pentaacetic acid bisanhydride are suspended together with 4.05 g (40 mmol) of triethylamine in 100 ml of absolute dimethylformamide . Then, a solution of 3.42 g (20 mmol) of undecylamine dissolved in 50 ml of absolute dichloromethane is added dropwise to the reaction mixture at room temperature. The reaction mixture is stirred for 6 hours at room temperature, filtered and concentrated by evaporation in a high vacuum. The residue is dissolved three times in 100 ml of dimethylformamide and concentrated in each case by evaporation under high vacuum. To the foam product of the reaction, 50 ml of absolute diethyl ether are added and the mixture is stirred overnight. It is filtered and dried in a high vacuum. Yield: 6.3 g (90%), white powder Elemental analysis: Calculated: C 61.77 H 9.94 N 10.01 O 18.86 Found: C 61.52 H 9.63 N 9.91 O Example 16b Coating of a Wiktor-stent with N, N '- acid diamide bisundecyl-diethylene-triamino penta-acetic acid 50 mg of N, N'-bisundecyl-diethylenetriamine pentaacetic acid diamide (prepared according to example 16a) are dissolved in 1 ml of ethanol. The Wiktor-stent (22.93 mg, model 6570, Medtronic) is coated with the solution prepared in this way. Then 2 ml of water are added and incubated for 15 minutes in the ultrasonic bath. The Wiktor-stent is removed and dried. Example 16c Marking of In-111 of a Wiktor-stent coated with N, N '-bisundecyl-diethylene-triamino penta-acetic acid diamide A Wiktor-stent coated with N, N' -bisundecyl-diethylene-triamino penta acid diamide -acetic as in example 16b is coated with 2ml of a 0.9% sodium chloride solution. After adding 37MBq of indium trichloride solution, the reaction mixture is placed for 15 minutes in an ultrasonic bath. The stent is removed, washed 3 times with 5 ml of 0.9% sodium chloride solution and dried. The Wiktor-stent marked in this way carries an activity of 1.34 MBq of In-111. Example 16d Marking Y-90 of a Wiktor-stent coated with N, N'-bisundecyl-diethylenetriamine pentaacetic acid diamide A Wiktor-stent coated with N, N'-bisundecyl-diethylenetriamine pentaacetic acid diamide as in example 16b, it is coated with 2 ml of a 0.9% sodium chloride solution. After adding 37MBq of yttrium trichloride solution, the reaction mixture is placed for 15 minutes in an ultrasonic bath. The stent is removed, washed 3 times with 5 ml of 0.9% sodium chloride solution and dried. The Wiktor-stent marked in this way carries an activity of 1.11 MBq of Y- 0. Example 17a Complete Y-90 complex of N, N'-bisundecyl-diethylene triamine penta-acetic acid diamide 50 mg of acid diamide N, N'-bisundecyl-diethylenetriamine pentaacetic (example 16a) are dissolved in 1 ml of ethanol. After the addition of 37MBq of yttrium-90 trichloride solution, the reaction mixture is heated for 10 minutes at 60 ° C. The complex solution of Y-90 thus prepared can be used without further purification to coat a Wiktor-stent . Example 17b Marking of Y-90 from a Wiktor-stent with the Y-90 complex of N, N'-bisundecyl-diethylene-triamino-penta-acetic acid diamide In 900 μl of the solution of the Y-90 complex of the N, N'-bisundecyl-diethylenetriamine pentaacetic acid diamide prepared according to example 17a is introduced a Wiktor-stent (22.87 mg, model 6570, Medtronic). After adding 2 ml of water, the reaction mixture is placed in an ultrasonic bath for 15 minutes. The Wiktor-stent is then removed and washed 3 times with 5 ml of 0.9% sodium chloride solution. The Wiktor-stent marked in this way carries an activity of 0.99 MBq of Y-90. Example 18a N-benzyloxycarbonyl-glycyl-N'-undecyl-glycinamide 3.63 g (10 mmol) of the N-benzyloxycarbonyl-glycyl-glycine-N-hydroxysuccinimide ester and 1.71 g (10 mmol) of undecylamine are dissolved in 100 ml of absolute dichloromethane. The reaction mixture is stirred for 6 hours at room temperature. It is then diluted with 100 ml of dichloromethane, the organic phase is washed 2 x with 50 ml of a saturated solution of sodium hydrocarbonate and 1 x with 50 ml of water. Dry over magnesium sulfate and the solvent is evaporated in vacuo. The crude product is purified by chromatography on silica gel (eluents: dichloromethane / methanol 95: 5). Yield: 3.8 g (90.6%), white powder Elemental analysis: Calculated: C 65.84 H 8.89 N 10.01 O 15.25 Found: C 65.71 H 9.02 N 10.10 O Example 18b Glycyl-N '-undecyl-glycinamide 3 g (7.15 mmoles) of N-benzyloxycarbonyl-glycyl-N '-undecyl-glycinamide (example 18a) are dissolved in 100 ml of absolute ethanol. After the addition of 300 mg of palladium on carbon (10%) it is hydrated for 2 hours at room temperature (1 atmosphere of hydrogen). It is filtered and concentrated by evaporation in vacuo. The resulting amine is used without further purification for the subsequent reaction. Yield: 1.92 g (94.1%), white foam Elemental analysis: Calculated: C 63.12 H 10.95 N 14.72 O 11.21 Found: C 63.03 H 11.04 N 14.57 0 Example 18c N- (S-Acetyl-mercaptoacetyl) -glycyl-N '- Go undecyl glycine 285.4 mg (1 mmol) of glycyl-N '-undecyl-glycinamide (example 18b) and 231.2 mg (1 mmol) of the N-hydroxy succinic ester of S-acetyl mercaptoacetic acid are dissolved together my absolute dichloromethane. The reaction mixture is stirred for 6 hours at room temperature. It is then diluted with 20 ml of dichloromethane, the organic phase is washed 2 × with 5 ml of a half-saturated solution of sodium hydrocarbonate and 1 × 5 ml of water. Dry over magnesium sulfate and the solvent is evaporated in vacuo. The crude product is purified by chromatography on silica gel (eluents: dichloromethane / methanol 93: 7). Yield: 362 mg (90.1%), white powder Elemental analysis: Calculated: C 56.83 H 8.79 N 10.46 O 15.94 S 7.98 Found: C 56.67 H 8.93 N 10.18 OS 7.72 Example 18d N- (mercaptoacetyl) -glycyl-N '-undecyl Glycinamide 201 mg (0.5 mmoles) of the N- (S-acetyl-mercaptoacetyl) -glycyl-N '-undecyl-glycinamide (example 18c) are dissolved in 15 ml of absolute ethanol. It is saturated with argon and a stream of ammonia is passed through the solution for 30 minutes. It is then concentrated by evaporation and the residue is taken up in 20 ml of dichloromethane. The organic phase is stirred 1 x with 2% aqueous citric acid and dried over sodium sulfate. The solvent is evaporated in vacuo and the residue is chromatographed on silica gel (eluents: dichloromethane / methanol 9: 1). Yield: 153 mg (85.1%), white powder Elemental analysis: Calculated: C 56.79 H 9.25 N 11.69 O 13.35 S 8.92 Found: C 56.67 H 9.43 N 11.48 OS 8.71 Example 18e Coating of a Wiktor-stent with N- (mercaptoacetyl) -glycyl-N '-undecyl-glycinamide 50 mg of N- (mercaptoacetyl) -glycyl-N' -undecyl-glycinamide (example 18d) are dissolved in 1 ml of ethanol. The Wiktor-stent (22.89 mg, model 6570, Medtronic) is coated with the solution prepared in this way. Then 2 ml of water are added and incubated for 15 minutes in the ultrasonic bath. The Wiktor-stent is removed and dried. Example 18f Labeling of Re-186 of a Wiktor-stent coated with N- (mercaptoacetyl) -glycyl-N '-undecyl-glycinamide A Wiktor-stent coated with N- (mercaptoacetyl) -glycyl-N' -undecyl-glycinamide as in Example 18e is coated with 2 ml of a disodium hydrophosphate buffer (0.1 M, pH = 8.5). After adding 37 MBq of perrhenate solution, 100 μl of a dihydrate solution of tin dichloride (5 mg SnC12x2H20 / l ml of 0.1 M HCl) is added to the reaction mixture. The reaction mixture is placed for 15 minutes in an ultrasonic bath. The stent is removed, washed 3 times with 5 ml of 0.9% sodium chloride solution and dried. The Wiktor-stent marked in this way carries an activity of 1.31 MBq of Re-186.

Example 18g Complex Re-186 of N- (mercaptoacetyl) -glycyl-N '-undecyl-glycinamide 5 mg of N- (mercaptoacetyl) -glycyl-N' -undecyl-glycinamide (example 18d) are dissolved in 800 μl of ethanol . After adding 5 mg of disodium tartrate L, 50 μl of 0.1 M sodium hydrophosphate buffer (pH = 8.5), 37 MBq of perrhenate and 100 μl of a dihydrate solution of tin dichloride (5 mg SnC12x2H20 / l ml of HCl) are added. 0.1 M). The reaction mixture is heated for 5 minutes at 60 ° C. The solution of the Re-186 complex of the N- (mercaptoacetyl) -glycyl-N '-undecyl-glycinamide thus prepared can be used without directly for the labeling of a Wiktor-stent Example 18h Marking of a Wiktor-stent with the Re-186 complex of N- (mercaptoacetyl) -glycyl-N '-undecyl-glycinamide In 900 μl of the solution of the Re-186 complex of N- (mercaptoacetyl) -glycyl-N '-undecyl-glycinamide prepared according to example 18g is introduced a Wiktor-stent (22.99 mg, model 6570, Medtronic). After adding 2 ml of water, the reaction mixture is placed in an ultrasonic bath for 15 minutes. The Wiktor-stent is then removed and washed 3 times with 5 ml of 0.9% sodium chloride solution. The Wiktor-stent marked in this way carries an activity of 1.13 MBq of Re-186. Example 19 Direct Marking of Y-90 from a Wiktor-Stent A Wiktor-stent (22.85 mg, model 6570, Medtronic) is coated with 2 ml of a saturated solution of sodium oxalate. 37MBq of yttrium-90 trichloride solution is added and heated for 30 minutes at 60 ° C. The stent is then removed and washed 3 x with 5 ml of a 0.9% solution of sodium chloride. The Wiktor-stent marked in this way carries an activity of 0.88MBq Y-90. Example 20 Use of bisdecyloyl hydrazino-diethylenetriamine pentaacetate to coat stents. Example 20a Preparation of bisdecyloyl hydrazino-diethylene triamine pentaacetate 17.5 g of decanoic acid methyl ester are dissolved in 11% absolute ethanol and mixed with 350 ml of hydrazine hydrate. It is heated at reflux for 3 hours and then stirred overnight at room temperature. The solution is concentrated to approximately 300 ml and left to stand until the product is separated by crystallization. After separating by filtration and drying, 16.6 g (= 94% of theory) of decanoic acid hydrazide are obtained. Elemental analysis Calculated: C 64.5% H 11.9% N 15.0% O 8.6% Found: C 65.4% H 11.9% N 14.5% 3.6 g of diethylenetriamine pentaacetic acid bisanhydride are dissolved in 500 ml of DMF and are mixed under hydrogen atmosphere with 4.2 ml of triethylamine and 3.7 g of decanoic acid hydrazide. The mixture is stirred at room temperature for 24 hours and the undissolved components are then filtered off. The solution is concentrated and the oily residue is taken up in 500 ml of ether. After adding 500 ml of hexane and continuing stirring the product precipitates in crystalline form. After drying, 7.2 g (= 95% of theory) of bisdecyl-hydrazino-diethylenetriamine-pentaacetate are obtained. Example 20b Coating of Strecker-stents with bisdecyl-hydrazino-diethylenetriamine-pentaacetate 2mg of bisdecyl-hydrazino-diethylenetriamine-pentaacetate are dissolved in 1 ml of methanol and precipitated by the addition of 2 ml of hexane. In this solution, a Strecker-stent (SS / 5-4, Boston Scientific) of 0.5 cm length is immersed and incubated for 15 minutes by ultrasound. The stent was then removed and dried. This process was repeated 5 times and finally the excess coating material was removed by washing in the ultrasound with physiological sodium chloride solution. Example 20c Marking of the bisdecyl-hydrazino-diethylenetriamine-pentaacetate coated Strecker-stent For its labeling, the stent thus treated was immersed in a solution of the radioactive metal isotope (In-111, Y-90, respectively 74 MBq) acquired in the Commerce, and incubated for 15 minutes on ultrasound. It was then washed for 20 minutes in the ultrasound in a physiological saline solution. 0.3 MBq of residual activity remained in the stent. Example 20d Coating of the Strecker-stents with bisdecyl-hydrazino-diethylenetriamine-pentaacetate labeled 2 mg of bisdecyloyl-hydrazino-diethylenetriamine-pentaacetate are dissolved in 1 ml of methanol and labeled with a solution of the radioactive metal isotope (In-111, Y-90, respectively 74 MBq) acquired in commerce. In this solution, a Strecker-stent (SS / 5-4, Boston Scientific) of 0.5 cm length is immersed and incubated for 15 minutes by ultrasound. The stent was then removed and dried. This process was repeated 5 times and finally the dissolved activity was eliminated by washing in the ultrasound with physiological sodium chloride solution. There remained 0.1 MBq of residual activity in the stent. Example 21a Use of thioacetyl-gly-gly-amidoethyl-PEG-methyl ether to coat stents. Preparation of thioacetyl-gly-gly-amidoethyl-PEG-methyl ether 50 mg of aminoethyl-polyethylene glycol methyl ether with a molecular weight of about 5000 is stirred for 24 hours at room temperature with 3.6 g of N-hydroxysuccinimide N-benzyloxycarbonyl ester. glycylglycine (Z-Gli-Gli-OSu) in 100 ml of DMF. The solution is concentrated and the residue is reacted without further purification. The residue is dissolved in a 1: 1 methanol / water mixture, mixed with 2 g of palladium on active carbon and hydrated under a hydrogen atmosphere (pressure: 1 bar) until approximately 230 ml of hydrogen was absorbed. The catalyst is then filtered off and the remaining mixture is purified after concentration by means of gel filtration. After drying, 49 g (= 96% of theory) of glycyl-glycyl-amidoethyl-PEG-methyl ether are obtained. This product is dissolved in 100 ml of DMF and mixed by stirring for 24 hours at room temperature with 2.2 g of N-hydroxysuccinimide ester of S-acetyl thioglycolic acid. The mixture is then mixed with 20 ml of aqueous ammonia solution and stirred for a further 2 hours. The product is acidified to pH 4 with 6 n aqueous hydrochloric acid and concentrated. The purification is carried out by means of a gel filtration column. 42 g (= 85% of theory) of thioacetyl-glycyl-glycyl-amidoethyl-polyethylene glycol methyl ether are obtained. Example 21b Coating of Strecker-stents with thioacetyl-gly-gly-amidoethyl-PEG-methyl ether and subsequent radioactive labeling. 2 mg of thioacetyl-gly-gly-amidoethyl-PEG-methyl ether with a molecular weight of about 5300 were dissolved in 2 ml of methanol and precipitated by the addition of 1 ml of hexane. In this suspension a Strecker-stent (SS / 5-4, Boston Scientific) of 0.5 cm length is immersed and incubated for 15 minutes on ultrasound. The stent was then removed and dried. This process was repeated 5 times and finally the excess coating material was removed by washing in the ultrasound with physiological sodium chloride solution. For its marking, the stent treated in this way was immersed in a radioactive metal isotope solution (Tc-99m, Re-186) consisting of 5 ml of the solution (Tc-99m from the generator, commercially-purchased Re-186, containing approximately 3 MBq of activity), 200 μl of phosphate buffer (Na2HP04, 0.5 mol / 1, pH 8.5), 50 μl of a 0.15 molar disodium tartrate solution, as well as 2.5 μl of 0.2 molar SnCl2 solution and incubated for 15 minutes on ultrasound. It was then washed for 20 minutes in the ultrasound in a physiological saline solution. There remained 0.1 MBq of residual activity in the stent. Example 21c Coating of Strecker-stents with thioacetyl-gly-gly-amidoethyl-PEG-methyl ether radioactively labeled 0.5 mg of thioacetyl-gly-gly-amidoethyl-PEG-methyl ether with a molecular weight of approximately 5300 were dissolved in 300 μl of regulator. phosphate (Na2HP? 4, 0.5 mol / 1, pH 8.5) and 50 μl of a 0.15 molar disodium tartrate solution, as well as 2.5 μl of a 0.2 molar SnCl 2 solution were added. The mixture was mixed with a pertechnetate solution (2 MBq) of a Tc-99m generator, and incubated for 15 minutes at 60 ° C. Analogously a solution could be made with polyethylene glycols labeled with Re-186. In this suspension a Strecker-stent (SS / 5-4, Boston Scientific) of 0.5 cm length is immersed and incubated for 15 minutes on ultrasound. The stent was then removed and dried. This process was repeated several successive times until the adhered activity reached 0.3 adhered reached 0.3 MBq. After that, it was washed twice for 60 minutes in physiological saline. The remaining activity was 100 MBq. EXAMPLE 22 Coating of the Strecker-Stent with Tc-99m-Asp-Gli-Gli-Cis-Gli-Cis-Phe- (Dr-Trp) -Leu-Asp-Ile-Ile-Trp 0.5 mg of the Asp-Gli-Gli- Cis-Gli-Cis-Phe- (Dr-Trp) -Leu-Asp-Ile-Ile-Trp elaborated analogously to Barany and Marrifield, The Peptides; Analysis, Biology, Academic Press, New York, 1990; Stewart and Young, Solid-Phase Peptide Synthesis, 2a. Edition, Pierce Chemical Co., Rockford, IL, 1984 are dissolved in 300 ml of phosphate buffer (Na2HP04, 0.5 mol / 1, pH 8.5) and mixed with 50 μl of a 0.15 molar disodium tartrate solution, and 2.5 μl of a 0.2 molar solution of tin chloride II dihydrate. The mixture was mixed with a pertechnetate solution (50 mCi = 1.85 MBq) of a Mo-99 / Tc-99m generator, and incubated for 10 minutes at room temperature. A Strecker-stent (SS / 5-4, Boston Scientific) of0. 5 cm in length and incubated five successive times in each case for 15 minutes in the Tc-99m peptide solution. After each incubation the activity adhered to the stent was defined with the help of a commercial gamma counter. As shown in the figure, after a single incubation there remained a remnant of 230 μCi of activity on the Strecker-stent. Repetitions of this incubation do not lead to a substantially greater remaining activity on the stent. The stent coated with the Tc-99m peptide solution was then washed four times in each case for 1 minute and twice for 60 minutes in a physiological saline solution. After the first wash, 81 μCi remained on the stent. The other washing processes do not lead to a substantial reduction of the activity bound on the stent. EXAMPLE 23 Coating of Wiktor-stents with Tc-99m A Wiktor-stent (22.92 mg, model 6570, Medtronic) is coated with 2.56 ml of sodium pertechnetate solution (911.5 MBq). 256 μl of a solution of tin (II) chloride dihydrate (5 mg SnCl • 2H20 / 1 ml of 0.01 M HCl) are added, the reaction mixture is placed for 5 minutes in an ultrasonic bath and finally incubated for 25 minutes at room temperature. The stent is dried and washed 3 x for 15 minutes with 2.56 ml of a 0.9% sodium chloride solution. Finally, it is recoated with 2.56 ml of 0.9% sodium chloride solution and the reaction mixture is placed in an ultrasonic bath for 5 minutes. The dry Wiktor-stent carries an activity of 5.9 MBq-Tc-99m / 2.92 mg (= 159.5 μCi / 22.92 mg s 6.9 μCi / 1 mg). Example 24 Wiktor-stents coating with Re-186 A Wiktor-stent (22.31 mg, model 6570, Medtronic) is coated with 2.5 ml of sodium perrhenate solution (884.1 MBq). 249 μl of a solution of tin (II) chloride dihydrate (5 mg SnCl • 2H20 / 1 ml of 0.01 M HCl) are added, the reaction mixture is placed for 5 minutes in an ultrasonic bath and finally incubated for 25 minutes at room temperature. The stent is dried and washed 3 x for 15 minutes with 2.5 ml of a 0.9% sodium chloride solution. Finally, it is recoated with 2.5 ml of 0.9% sodium chloride solution and the reaction mixture is placed in an ultrasonic bath for 5 minutes. The dry Wiktor-stent carries an activity of 5.2 MBq-Re-186 / 22.31 mg (== 140.5 μCi / 22.31 mg s 6.3 μCi / 1 mg). Example 25 Application of a Tc-99m coated Wiktor-stent in the abdominal aorta of rabbits The Wiktor-stent (model 6570, Medtronic) was coated with Tc.99m as described in example 4. To a white rabbit from New Zealand (3.2 kg of body weight) narcotized (rompun / cetavet 1: 2) was exposed to the artery-femoralis. Through a gate 5 F the marked Wiktor-stent was introduced into the vessel and fixed in the infrarenal aorta by inflation of the globular catheter. The catheter was then removed and both the femoralis artery and the wound were sewn. Full-body gammagrams were made for a period of 8 hours after the application of the stent with the aid of a commercial gamma camera. Figure XI shows a gamma made 5 hours after the application of the stent. Only activity could be detected in the region of the stent that was inside the infrarenal aorta of the animal. During the entire period of the investigation, no detectable activity of the stent was delayed. After 8 hours the rabbit was sacrificed, the stent was removed and the activity in the gamma counter was measured. The activity adhered to the stent was exactly as high as at the beginning of the test. Example 26a Cementing a Strecker-stent with gold A Strecker-stent (approximately 200 mg) is coated with gold in a cementing vessel (figure 2a) (2 minutes, 30 mg of gold (III) chloride in 30 ml of hydrochloric acid) aqueous at 5%). The stent thus obtained is washed 3 times with 10% aqueous nitric acid and 2 times with water. Then 2 times with acetonitrile and dried.

Example 26b Linkage of 11-aminoundecyl-thiol to the surface 500 mg of 11-aminoundecyl-1-thiol are dissolved in a solution consisting of 10 ml of 7.5% aqueous nitric acid / 5 ml of tetrahydrofuran / 3 ml of 1 , 2-dichloromethane. In this solution, the Strecker-stent produced according to example 26a is immersed under protective gas (in the ultrasonic bath / 37 ° C). The ultrasound is subjected to approximately 15 minutes. The stent is washed 3 times with ethanol, then 2 times with acetonitrile. Example 26c DTPA bis-anhydride binding The stent described in example 26b is immersed in a 7.5% aqueous solution of sodium carbonate, and under stirring at 0 ° C 500 mg of DTPA bis-anhydride are added in 5 portions of respectively 100 mg. It is stirred for 10 minutes at 0 ° C. The stent is washed 2 times with 5% aqueous hydrochloric acid, then 3 times with water and 2 times with acetonitrile. Example 26d Indium-111 labeling of the stent derived from the amide DTPA. The stent described in Example 26c is immersed in an acetate buffer solution (0.001 mole, pH 5.5) and In-111 solution (initial activity: 48.8 MBq) is added. It is stirred for 5 minutes at room temperature. The stent is washed 3 times with a 3% aqueous solution of sodium carbonate, then 2 times with a physiological solution of sodium chloride. The stent can be used directly for the implant. The stent shows a quantity of radioactivity of 1.2 MBq. Example 27a Linking of DOTA to the stent of example 26b The stent obtained according to example 26b is immersed in a phosphate buffer (0.1 mol / 1, pH 7.4) and 150 mg of 1, 4,7, 1? (carboxymethyl) -1,4,7,10-tetraazacyclododecane (DOTA). It is cooled to 0 ° C and 200 mg of N-hydroxysulfosuccinimide (sulfo-NHS) and 200 mg of l-ethyl-3- (dimethylaminopropyl) -carbodiimide HCl (EDC) are added. It is stirred for 30 minutes at 0 ° C. The stent is washed 2 times with water, 2 times with a physiological solution of sodium chloride. Example 27b Marking with In-111 The stent described in example 27a is immersed in an acetate buffer solution (0.01 mol, pH 5) and In-111 solution is added (initial activity: 37.3 MBq). It is heated for 30 minutes at 50 ° C. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate, then 3 times with a physiological solution of sodium chloride. The stent shows a quantity of radioactivity of 1.45 MBq. Example 28a Linkage of 4-isothiocyanato-benzyl-DTPA to the stent of example 26b A stent prepared as in example 26b is immersed in a buffer solution of sodium carbonate (0.1 mol / 1, pH 9) and 100 mg of sodium carbonate is added. -isothiocyanate-benzyl-DTPA (Gansow, O. WO 91/14459). It is stirred for 30 minutes at room temperature. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate and then 3 times with a physiological solution of sodium chloride. Example 28b Marking of Cu-67 The stent described in example 28a is immersed in an acetate buffer solution (0.01 mol, pH 5) and Cu-67 solution (initial activity: 34.5 MBq) is added.

It is stirred for 5 minutes at room temperature. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate, then 3 times with a physiological solution of sodium chloride. The stent shows a radioactivity amount of 0.98 MBq. Example 29a Linkage of 4-isothiocyanato-benzyl-DOTA to the stent of example 26b A stent prepared as in example 26b is immersed in a buffer solution of sodium carbonate (0.1 mol / 1, pH 9) and 100 mg of sodium carbonate is added. -isothiocyanatobenzyl-DOTA (Gansow, O. US 4,923,985). It is stirred for 30 minutes at room temperature. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate and then 3 times with a physiological solution of sodium chloride. Example 29b Marking of Cu-67 The stent described in example 29a is immersed in a buffer solution of acetate (0.01 mole), pH 5) and Cu-67 solution is added (initial activity: 28.6 MBq). It is stirred for 15 minutes at 40 ° C. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate, then 3 times with a physiological solution of sodium chloride. The stent shows an amount of radioactivity of 0.77 MBq. Example 30a Cystamine Bisamide with DTPA 10 g (28 mmol) of DTPA bis-anhydride are suspended in 100 ml of dimethyl sulfoxide. It is cooled to 0 ° C and 5.7 g (56 mmoles) of triethylamine are added. Then add 1.58 g (7 mmol) of cystamine dihydrochloride and stir for 24 hours at room temperature. 20 ml of formic acid and 1000 ml of diethyl ether are added. The precipitated solid is filtered off and chromatographed on RP18 (eluent: acetonitrile / THF / water gradient). The product obtained after concentrating the main fractions by evaporation is recrystallized from methanol. Yield: 1.96 g (31% of theory with respect to cystamine) of a colorless hygroscopic solid. Water content: 6.8% Elemental analysis: (calculated on the anhydrous substance) Calculated: C 42.57 H 6.03 N 12.41 S 7.10 Found: C 42.39 H 5.97 N 12.53 S 7.03 Example 30b Linkage of cistaminamide from DTPA to a cemented Strecker-stent gold (26a) The Strecker-stent described in example 26a is fixed in an electrolytic cell (figure 1) and a phosphate buffer (0.1 mol / 1, pH 5) is added. To the solution is added 100 mg of the title compound of example 26a and a voltage of 3 V is applied. It is electrolyzed for 15 minutes at room temperature. The stent is washed 4 times with water and can be used directly for labeling.

Example 30c Marking with In-111 The stent described in Example 30b is immersed in an acetate buffer solution (0.01 mole, pH 5) and In-111 solution is added (initial activity: 34.7 MBq). It is stirred for 5 minutes at room temperature. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate, then 3 times with a physiological solution of sodium chloride. The stent shows a quantity of radioactivity of 1.11 MBq. Example 31 Marking with Cu-67 The stent described in Example 30b is immersed in an acetate buffer solution (0.01 mol, pH 5) and Cu-67 solution is added (initial activity: 41.2 MBq).

It is stirred for 3 minutes at room temperature. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate, then 3 times with a physiological solution of sodium chloride. The stent shows a radioactivity amount of 0.97 MBq. Example 32a Linkage of N, N-dimethyl-2- (3, 3, 5, 11, 13, 13-hexamethyl-l, 2-dithia-5, 8, 11-triazacyclotide-8-yl) -ethylamine to a Strecker -stent gold cemented The Strecker-stent described in example 26a is fixed in an electrolytic cell (figure 1) and a phosphate buffer (0.1 mol / 1, pH 5) is added. To the solution is added 100 mg of N, N-dimethyl-2- (3,3,5,11, 13, 13-hexamethyl-l, 2-dithia-5, 8, 11-triazacyclo-tridecan-8- il) -ethylamine (prepared according to WO 96/11918, example 27) and a voltage of 3.5 V is applied. It is electrolyzed for 15 minutes at room temperature. The stent is washed 4 times with water and can be used directly for labeling. Example 32b Marking with Re-186 The stent described in example 32a is immersed in a solution composed of acetate buffer (0.01 mol, pH 5) and 100 mg of tin (II) chloride, and Re-186 solution is added ( initial activity: 48.3 MBq). It is stirred for 3 minutes at room temperature. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate, then 3 times with a physiological solution of sodium chloride. The stent shows a quantity of radioactivity of 1.44 MBq. EXAMPLE 33 Marking of a gold-cemented stent with In-111 under in situ ligation of the title compound of example 30a by chemical reduction The Strecker-stent described in example 26a is fixed in an electrolytic cell (FIG. 1) and a Phosphate buffer solution (0.1 mol / 1, pH 5). To the solution is added 10 mg of the title compound of example 30a, In-111 solution (initial activity: 34.6 MBq) and a voltage of 3 V is applied. It is electrolyzed for 15 minutes at room temperature. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate, 2 times with water and can be implanted directly. The stent showed a radioactivity amount of 0.77 MBq. Example 34 Marking of a gold-cemented stent with Cu-67 under in situ ligation of the title compound of example 30a by chemical reduction The Strecker-stent described in example 26a is fixed in an electrolytic cell (figure 1) and a Citric acid buffer solution (0.1 mol / 1, pH 5). To the solution is added 10 mg of the title compound of Example 30a, Cu-67 solution (initial activity: 36.7 MBq) and a voltage of 1.8 V is applied. It is electrolyzed for 15 minutes at room temperature. The stent is washed 2 times with a 3% aqueous solution of sodium carbonate, 2 times with water and can be implanted directly. The stent showed a radioactivity amount of 0.98 MBq.

Example 35 Marking with S-35 A stent produced according to 26a is placed in a 5% aqueous hydrochloric acid solution and a solution of S-35-cysteine (initial activity 37.5 MBq) is added. It is stirred for 5 minutes at room temperature. The stent is washed 4 times with a physiological solution of sodium chloride. A quantity of radioactivity of 1.35 MBq is measured. Example 36 Marking a Strecker-stent with Cu-67 A Strecker-stent (93 mg) is fixed in an electrolytic cell as described in figure 1. The cell is then filled with a 5% aqueous hydrochloric acid solution and add a Cu-67 solution (initial activity 47.4 MBq). Then a voltage of 2 V is applied. It is electrolyzed for 5 minutes at room temperature. The radioactive solution is evacuated through a valve and the stent is washed 4 times with a physiological solution of sodium chloride. A Strecker-stent marked on its surface in this way contains a quantity of radioactivity of 1.56 MBq and can be used directly as an implant. Example 37 Marking of a nitinol stent with Cu-67 A nitinol stent (approximately 500 mg) was set analogously to that described in example 1. However, it was electrolyzed for 10 minutes at 1.5 V. The stent showed an amount of radioactivity of 3.21 MBq. Example 38 Labeling of a nitinol stent with Re-186 A nitinol stent (approximately 1000 mg) is fixed in an electrolytic cell as described in figure 1. A phosphate buffer is then added (0.1 mol / 1)., pH 5). Then a solution of Re-186 (initial activity 51.4 MBq) is added and a voltage of 2.5 V is applied. It is electrolyzed for 10 minutes at room temperature. The radioactive solution is separated and the stent is washed 4 times with a physiological solution of sodium chloride. The stent showed a radioactivity amount of 2.44 MBq. Example 39 Marking of a Palmaz-Schatz stent (316 stainless steel) with Re-186 A Pal az stent (approximately 200 mg) is fixed in an electrolytic cell (Figure 1) and a 5% aqueous nitric acid solution is added to the which is dissolved 150 mg / ml of sodium chloride. A solution of Re-186 (initial activity 37.4 MBq) is added and a voltage of 2.3 V is applied. It is electrolyzed for 5 minutes at room temperature. The radioactive solution is separated and the stent is washed 4 times with a physiological solution of sodium chloride. The stent showed a radioactivity amount of 1.98 MBq. Example 40 Marking of a Strecker-stent with Au-199 A Strecker-stent (approximately 150 mg) is placed in an electrolytic cell (Figure 1) and a 7.5% aqueous hydrochloric acid solution is added. Then a solution of Au-199 (initial activity 45.2 MBq) is added and a voltage of 1.5 V is applied. It is electrolyzed for 5 minutes at room temperature. The radioactive solution is separated and the stent is washed 4 times with a physiological solution of sodium chloride. The stent showed an amount of radioactivity of 2.13 MBq. Example 41 Marking of a Strecker-stent with Au-199 A Strecker-stent (approximately 350 mg) is placed in an electrolytic cell (Figure 1), and a solution of 2.5% aqueous hydrochloric acid in which it is dissolved is added. 100 mg / ml of tetramethylammonium chloride. Then a solution of Au-199 (initial activity 55.6 MBq) is added and a voltage of 1.2 V is applied. It is electrolyzed for 4 minutes at room temperature. The radioactive solution is separated and the stent is washed 4 times with a physiological solution of sodium chloride. The stent showed a quantity of radioactivity of 1.81 MBq. Example 42 Marking of a Z stent (304 stainless steel) with Au-199 A Z stent (approximately 250 mg) is placed in an electrolytic cell (Figure 1), and a 2.5% aqueous nitric acid solution is added in which 100 mg / ml of tetramethylammonium chloride are dissolved. Then a solution of Au-199 (initial activity 38.6 MBq) is added and a voltage of 1.2 V is applied. It is electrolyzed for 3 minutes at room temperature. The radioactive solution is separated and the stent is washed 4 times with a physiological solution of sodium chloride. The stent showed a quantity of radioactivity of 1.13 MBq. Example 43 Marking of a Z stent (304 stainless steel) with Ag-110 A Z stent (approximately 250 mg) is placed in an electrolytic cell (Figure 1), and a 5% aqueous nitric acid solution is added in which 100 mg / ml of tetramethylammonium nitrate are dissolved. Then a solution of Ag-110 (initial activity 56.8 MBq) is added and a voltage of 1.5 V is applied. It is electrolyzed for 2 minutes at room temperature. The radioactive solution is separated and the stent is washed 4 times with a physiological solution of sodium chloride. The stent showed a quantity of radioactivity of 1.54 MBq. Example 44 Labeling of a nitinol stent (304 stainless steel) with Ag-110 A nitinol stent (approximately 1500 mg) is placed in an electrolytic cell (Figure 1), and a 7.5% aqueous nitric acid solution is added to the which is dissolved 150 mg / ml of tetramethylammonium nitrate. Then a solution of Ag-110 (initial activity 39.4 MBq) is added and a voltage of 1.4 V is applied. It is electrolyzed for 10 minutes at room temperature. The radioactive solution is separated and the stent is washed 4 times with water and 2 times with a physiological solution of sodium chloride. The stent showed a radioactivity amount of 1.78 MBq. Example 45 Marking of a nitinol stent with In-111 A nitinol stent (approximately 1500 mg) is placed in an electrolytic cell (figure 1)and a solution of 5% aqueous citric acid in which 150 mg / ml of tetramethylammonium chloride are dissolved is added. Then a solution of In-111 is added (initial activity 51.3 MBq) and a voltage of 3.5 is applied V. Electrolyze for 7 minutes at room temperature. The radioactive solution is separated and the stent is washed 2 times with water and 2 times with a physiological solution of sodium chloride. The stent showed a quantity of radioactivity of 1.45 MBq. Example 46 Marking of a Z-stent with In-111 A Z-stent (approximately 500 mg) is placed in an electrolytic cell (Figure 1), and a solution of 5% aqueous citric acid in which 150 mg are dissolved is added. / ml of tetramethylammonium chloride. Then a solution of In-111 is added (initial activity 36.9 MBq) and a voltage of 3.8 is applied V. Electrolyze for 12 minutes at room temperature. The radioactive solution is separated and the stent is washed 2 times with water and 2 times with a physiological solution of sodium chloride. The stent showed a quantity of radioactivity of 1.77 MBq. Example 47 Labeling of a Strecker-stent with Au-199 In a cementing vessel (Figure 2b) a Strecker-stent (approximately 93 mg) is mixed with an aqueous solution of hydrochloric acid (pH 3). Au-199 chloride solution is added (initial activity: 32.6 MBq) and stirred for 10 minutes at room temperature. The stent is washed 4 times with a physiological solution of sodium chloride. The stent can be used directly for the implant. The stent shows a quantity of radioactivity of 1.22 MBq. Example 48 Labeling of a Strecker-stent with Ag-110 In a cementing vessel (figure 2a) a Strecker-stent (approximately 496 mg) is mixed with an aqueous solution of nitric acid (pH 4). Ag-110 nitrate solution (initial activity: 37.6 MBq) is added and stirred for 10 minutes at room temperature. The stent is washed 4 times with diluted nitric acid (pH 3), 2 times with water and can be used directly for the implant. The stent shows a quantity of radioactivity of 1.02 MBq. Example 49 Marking of a Z-stent with Au-199 In a cementing vessel (Figure 2a) a Z-stent (approximately 987 mg) is mixed with an aqueous solution of hydrochloric acid (pH 3). Au-199 chloride solution is added (initial activity: 41.5 MBq) and stirred for 10 minutes at room temperature. The stent is washed 4 times with a physiological solution of sodium chloride. The stent can be used directly for the implant. The stent shows a quantity of radioactivity of 1.13 MBq. Example 50 Labeling of a nitinol stent with Au-199 In a cementing vessel (Figure 2b) a nitinol stent (approximately 488 mg) is mixed with an aqueous solution of hydrochloric acid (pH 3). Au-199 chloride solution is added (initial activity: 39.7 MBq) and stirred for 10 minutes at room temperature. The stent is washed 4 times with a physiological solution of sodium chloride. The stent can be used directly for the implant. The stent shows a radioactivity amount of 0.98 MBq. Example 51 Marking of a Strecker-stent with Re-186 A Strecker-stent is introduced into an electrolytic cell (Figure 1) and a solution of sulphurous zinc sulfate solution (50 mg / ml, pH 5) is added. After introducing a zinc anode, it is electrolyzed for 10 minutes at a voltage of 1.5 V. The zinc-coated stent is washed 4 times with water in this way. In a cementing vessel (figure 2a), the previously described stent is mixed with an aqueous solution of citric acid (pH 5). Re-186 solution (initial activity 41.6 MBq) is added and stirred for 10 minutes at room temperature. The stent is washed 4 times with a physiological solution of sodium chloride. The stent can be used directly for the implant. The stent shows a quantity of radioactivity of 1.31 MBq. Example 52 Marking of a Z-stent (304 stainless steel) with Re-186 A Z-stent is introduced into an electrolytic cell (Figure 1) and a solution of chlorous tin (II) chloride solution (50 mg / ml) is added., pH 5). After introducing a tin anode it is electrolyzed for 5 minutes at a voltage of 3 V. The stent tinned in this way is washed 4 times with water. In a cementing vessel (figure 2a), the previously described stent is mixed with an aqueous solution of citric acid (pH 5). Re-186 solution (initial activity 37.7 MBq) is added and stirred for 10 minutes at room temperature. The stent is washed 4 times with a physiological solution of sodium chloride. The stent can be used directly for the implant. The stent shows a quantity of radioactivity of 1.44 MBq. Example 53 Labeling of a nitinol stent with Cu-67 In a cementing vessel (Figure 2b), a nitinol stent (approximately 488 mg) is mixed with an aqueous solution of hydrochloric acid (pH 3). Cu-67 sulfate solution is added (initial activity: 24.6 MBq) and stirred for 10 minutes at room temperature. The stent is washed 4 times with a physiological solution of sodium chloride. The stent can be used directly for the implant. The stent shows a quantity of radioactivity of 1.55 MBq. Example 54 Marking of a Palmaz stent (316 stainless steel) with Cu-67 In a cementing vessel (Figure 2a) a Palmaz stent (approximately 977 mg) is mixed with an aqueous solution of hydrochloric acid (pH 3). Cu-67 sulfate solution is added (initial activity: 24.6 MBq) and stirred for 10 minutes at room temperature. The stent is washed 4 times with a physiological solution of sodium chloride. The stent can be used directly for the implant. The stent shows a radioactivity amount of 0.88 MBq. Example 55 Marking of a Palmaz stent (316 stainless steel) with Re-186 A Palmaz stent is introduced into an electrolytic cell (Figure 1) and a solution of chlorous tin (II) chloride solution (50 mg / ml, pH 5). After introducing a tin anode it is electrolyzed for 5 minutes at a voltage of 3 V. The stent tinned in this way is washed 4 times with water. In a cementing vessel (Figure 2b), the above-described stent is mixed with an aqueous solution of citric acid (pH 5). Re-186 solution (initial activity 34.5 MBq) is added and stirred for 10 minutes at room temperature. The stent is washed 4 times with a physiological solution of sodium chloride. The stent can be used directly for the implant. The stent shows a quantity of radioactivity of 1.98 MBq. Example 56 Marking of a Palmaz stent (stainless steel 316) with Ag-110 In a cementing vessel (figure 2a) a Palmaz stent (approximately 977 mg) is mixed with an aqueous solution of nitric acid (pH 4). Ag-110 sulfate solution is added (initial activity: 24.6 MBq) and stirred for 10 minutes at room temperature. The stent is washed 4 times with water and can be used directly for the implant. The stent shows a quantity of radioactivity of 1.12 MBq.

Example 57 A Palmaz stent (15 mm, 80.3 mg, Johnson &Johnson) is coated with 1.0 ml of marker solution composed of 173 μl of sodium perrhenate solution (164 MBq) and 827 μl of 1 N HCl. the reaction is placed for 60 minutes at 50 ° C in an ultrasound bath (80% of the US power). The stent is then removed, washed with distilled H20 and dried. The dry stent carries an activity of 36.2 MBq = 0.45 MBq / mg of stent. To detach the non-specific bound activity, the stent is incubated for 60 minutes at 37 ° C in 1 ml of a 0.9% NaCl solution. After drying, the stent still carries an activity of 9.7 MBq = 0.12 MBq / mg of stent.

Example 58 A Palmatz stent (stent 1/11 = 26.2 mg, Johnson &Johnson) is coated with 1.5 ml of labeling solution composed of 60 μl of perrhenate solution (60 MBq) and 1440 μl of 1 N HCl. The reaction is sealed and heated for 30 minutes at 100 ° C (boiling water bath). The stent is then removed, washed with distilled H20 and dried. The dry stent carries an activity of 25.9 MBq (0.98 MBq / mg stent). For detachment or fixation of the non-specific bound activity, the stent is incubated for 10 minutes under agitation in 2 ml of a solution of 0.1 M gentisic acid / 0.1 M SnCl2. After drying, the stent carries an activity of 16.1 MBq ( 0.61 MBq / mg stent). Example 59 A Palmatz stent (31.4 mg, Johnson &Johnson) is coated with 1.5 ml of marker solution composed of 60 μl of sodium perrhenate solution (81 MBq) and 1440 μl of 0.75 N HCl. The reaction vessel it is sealed and heated for 30 minutes at 100 ° C (boiling water bath). The stent is then removed, washed with distilled H20 and dried. An activity of 27.1 MBq (0.86 MBq / mg stent) is fixed on the dry stent. For the detachment of the bound non-specific activity, the stent is incubated for 10 minutes under agitation in 2 ml of an alcohol solution of 0.1 M tetrabutylammonium bromide. After drying on the stent, 17.0 MBq (0.54 MBq / mg stent). Example 60 The stent from example 59 is immersed several times in a solution of 16% acrylate-vinyl acetate polymer in ethyl acetate. After drying the stent is ready to be used.

List of reference symbols 1 Cover 2 Septum 3 Septum 4 Cell (Teflon or glass) 5 Stent 6 Solution 7 Pt anode (+) Annular anode 8 Magnetic stirring wand 9 Cathode (-) of Pt. 10 Shut-off valve 11 2-way valve 12 Magnetic stirrer 13 Washing liquid 14 Active solution Addition of the solutions: injection needle or dosing pump. In the case of adding with injection needle: place septa in the lid. If electrolyzed at an elevated temperature, the solution is preheated.

Claims

CLAIMS Process for the preparation of radioactive stents, characterized by the fact that a non-radioactive stent is immersed in a solution containing at least one radioactive isotope in ionic form, the isotope is then deposited chemically on the stent. Process for the preparation of radioactive stents according to claim 1, characterized in that the isotope is reductively deposited on the stent. Process for the preparation of radioactive stents according to claim 2, characterized in that SnCl 2, KBH 4, dimethyl borane, formaldehyde or sodium hypophosphite are used as reducing agents. Process for the preparation of radioactive stents according to claim 1, characterized in that the isotope is deposited on the stent by means of chemical precipitation. Process for the preparation of radioactive stents according to claim 4, characterized in that oxalic acid, oxalates, phosphoric acid, phosphates or Na 2 CO 3 are used as the precipitating agent. Process for the preparation of radioactive stents according to one of claims 1 to 5, characterized by the fact that the radioactive isotope is an isotope of the elements Ag, Au, Bi, Co, Cr, Cu, Fe, Gd, Hg , Ho, In, Go, Lu, Mn, Ni, P, Pb, Pd, Pm, Pt, Re, Rh, Ru, Se, Sm, Tb, Te or Y. Process for the development of radioactive stents by chemical precipitation of according to claim 4, characterized in that the metallic surface of the stent is oxidized anodically in a radioactive solution of phosphoric acid. Process for the production of radioactive stents according to one of claims 1 to 7, characterized in that several isotopes are deposited on the stent. Use of radioactive stents produced according to one of the processes according to one of claims 1 to 8 for the preparation of an implant for the prophylaxis of restenosis. Radioactive stents characterized by the fact that the radioactive isotope is fixed to the surface of the stent by at least one adhesive. Radioactive stents characterized by the fact that on the surface of the stent is fixed at least one radioactive isotope of the elements Ag, Au, Ba, Bi, C, Co, Cr, Cu, Fe, Gd, Hg, Ho, In, Go , Lu, Mn, Ni, P, Pb, Pd, Pm, Pt, Re, Rh, Ru, S, Sb, Se, Sm, Tb, Te or Y by at least one adhesive. Radioactive stents according to claim 10 or 11, characterized in that the adhesive consists of a peptide, a fat or gold in combination with a complex former that contains thiol groups. Radioactive stents according to claim 10 or 11, characterized in that the adhesive consists of a complexing peptide, a complexing fat or gold in combination with a complexing agent containing thiol groups. Radioactive stents according to claim 10, characterized by the fact that the radioactive isotope is an isotope of the elements Ag, Au, Ba, Bi, C, Co, Cr, Cu, Fe, Gd, Hg, Ho, In, Go, Lu, Mn, Ni, P, Pb, Pd, Pm, Pt, Re, Rh, Ru, S, Sb, Se, Sm, Tb, Te or Y. Process for the development of radioactive stents, caracerizado by the fact that a non-radioactive isotope is reacted at 0-100 ° C with an adhesive and then the stent is coated with the radioactively labeled adhesive at 0 ° -100 ° C. Process for the preparation of radioactive stents, characterized by the fact that a non-radioactive stent is coated with the adhesive at 0-100 ° C and then mixed with a solution of the radioactive isotope at 0-100 ° C. Process for the preparation of radioactive stents, characterized by the fact that a non-radioactive stent is coated with gold and then mixed at 0-100 ° C with a solution of a 35S labeled thiol compound. Use of stents constituted by the base body of the stent, adhesive and radioactive isotope to produce an implant for the prophylaxis of restenosis. Process for the preparation of radioactive stents, characterized by the fact that a non-radioactive stent is immersed in a solution containing the radioactive isotope in ionic form, and then the isotope is deposited electrochemically on the stent. Process for the preparation of radioactive stents according to claim 19, characterized in that the isotope is deposited galvanically on the stent. Process for the preparation of radioactive stents according to claim 19, characterized in that the isotope is deposited on the stent by cementation. Process according to at least one of claims 19-21, characterized in that the radioactive isotope is an isotope of the elements Ag, Au, Bi, Co, Cr, Cu, Fe, Gd, Hg, Ho, In , Ir, Lu, Mn, Ni, Pb, Pd, Pm, Pt, Re, Rh, Ru, Se, Sm, Tb, Te or Y. Process for the preparation of radioactive stents according to claim 1 or 19, caracerized by the fact that the solution containing the radioactive isotope in ionic form additionally contains hydrochloric acid. Process for the preparation of radioactive stents according to claim 1 or 19, characterized in that the stents in another step of the process are treated with a solution containing reducing agents and hydroxycarboxylic acids. Process for the preparation of radioactive stents according to claim 1 or 19, characterized in that the stents in another stage of the process are treated with a solution containing lipophilic alcohols and cations. Process for the preparation of radioactive stents according to claim 23, 24 or 25, characterized in that the stent is additionally sealed with a polymer. Use of radioactive stents superficially coated with radioactive isotopes with the aid of a process according to one of claims 19 to 26, for the preparation of an implant for the prophylaxis of restenosis.