Use of a sterilization agent for enhancing hemocompatibility

The invention concerns the use of a sterilization agent comprising H2O2 or a derivative thereof, capable of generating H2O2 as the sterilising component under sterilization conditions, for enhancing the hemocompatibility of objects.

BACKGROUND OF THE INVENTION

The invention relates to the use of a sterilization agent comprising H2O2(hydrogen peroxide) or a derivative thereof.

Sterilization in the context of the present invention means any process that eliminates or kills all forms of life, including transmissible agents, such as fungi, bacteria, viruses, spore forms, etc. present on a surface, contained in a fluid, in medication or in a compound such as biological culture media. Sterilization methods include applying the proper combinations of heat, chemical agents, irradiation (gamma rays, e-beam, etc.), high pressure and/or filtration.

Sterilization of objects, in particular object used in medicine, such as objects that have contact with blood during use is known since long. Commonly used sterilization procedures use ETO or other chemicals such as ozone or hydrogen peroxide, gamma radiation, steam, or combinations thereof. In this regard, reference is made to EP 1 175 230 and EP 1 455 843 and the prior art cited therein.

In many medicinal operations, e.g. surgeries and extracorporeal blood circulation applications, such as in hemodialysis, wherein wastes and water are removed by circulating blood outside the body through an external filter, called a dialyzer, that contains a semipermeable membrane, the sterility of the objects in contact with blood is extremely important.

This is because patients who have to undergo a treatment including extracorporeal blood circulation, especially hemodialysis patients with nearly daily treatment, suffer a strong risk of inflammation which can in the worst case end in a sepsis.

In extracorporeal blood circulation applications, it is furthermore important that the blood does not coagulate or the quality of the blood is deteriorated while the blood is outside of the body. Due to this, it would be advantageous to dispose over a sterilizer which eases the transport and the storage of blood in extracorporeal blood circulation applications.

Any of the above mentioned sterilization methods has an impact on the surface properties of the sterilized object. In the case of chemical agents, these can as well penetrate into the surface of the object and remain there, if the same has a porous structure.

Some of the sterilization methods have a reduced compatibility with certain materials. For example, gamma radiation has a degrading effect on the surface of polypropylene objects. Yet, for other materials, a certain sterilization method may have a positive or negative effect on the surface in view of certain applications.

Therefore, it is an object of the present invention to provide a sterilization agent, in particular for extracorporeal blood circulation applications that assures a safe and reliable sterilization and influences the surface of objects in a positive manner for the contact with blood while being easily and economically to implement in a sterilization process.

SUMMARY OF THE INVENTION

This object is achieved by the teaching according to claim1. Preferred embodiments are claimed in the dependent claims.

In one embodiment the invention relates to the use of a sterilization agent comprising H2O2or a derivative thereof, capable of generating H2O2as the sterilising component under sterilization conditions, for enhancing the hemocompatibility of objects.

In one embodiment the invention relates to the use of a sterilization agent, wherein the object is a medical object, in particular an object that may be in contact with blood during use.

In one embodiment the invention relates to the use of a sterilization agent, wherein the object is a medical object useful in hemodialysis.

In one embodiment the invention relates to the use of a sterilization agent, wherein the object is a tubing system.

In one embodiment the invention relates to the use of a sterilization agent, wherein the sterilzation agent comprising H2O2or a derivative thereof, capable of generating H2O2as the sterilising component under sterilization conditions is used in combination with other sterilization means or agents.

In one embodiment the invention relates to the use of a sterilization agent, wherein said sterilization means or agent is selected among one or more of heat, UV or gamma radiation, or chemical or biological sterilization components, in particular ozone.

In one embodiment the invention relates to the use of a sterilization agent, which comprises H2O2or a derivative thereof, capable of generating H2O2as the sterilising component under sterilization conditions, or a mixture of two or more thereof, as the only sterilising component.

In one embodiment the invention relates to the use of a sterilization agent, wherein H2O2under sterilization conditions has a concentration of 3% w/w to 90% w/w, preferably 10% w/w to 90% w/w, more preferably 30% w/w to 90% w/w, even more preferably 30% w/w to 60% w/w and most preferably 30% w/w to 40% w/w.

In one embodiment the invention relates to the use of a sterilzation agent, wherein said derivative is selected among peracids, carbamide peroxides, triphenyiphosphine oxide and acetone peroxide.

In one embodiment the invention relates to the use of a sterilization agent, wherein the enhanced hemocompatibility comprises at least one of the following characteristics: reduction of the level of coagulation activation, a reduction of the loss of platelets, a lower concentration of anaphylatoxin C5a, and a decrease in hemolysis during use of the object.

In one embodiment the invention relates to the use of a sterilization agent comprising H2O2or a derivative thereof, capable of generating H2O2as the sterilising component under sterilization conditions for achieving at least one of the following characteristics within an object: reduction of the level of coagulation activation, a reduction of the loss of platelets, a lower concentration of anaphylatoxin C5a, and a decrease in hemolysis, respectively during use of said object, e.g. during contact with blood of said object.

In one embodiment the invention relates to the use of a sterilization agent, wherein the enhancement of hemocompatibility, the reduction of the level of coagulation activation, the reduction of the loss of platelets, the lower concentration of anaphylatoxin C5a, and the decrease in hemolysis during use of said object, e.g. during contact with blood of said object, are respectively achieved compared to an object that has been sterilized with a sterilization agent not containing H2O2.

DETAILED DESCRIPTION OF THE INVENTION

According to the invention, a sterilization agent comprising H2O2or a derivative thereof, capable of generating H2O2under sterilization conditions, is used for enhancing the hemocompatibility of objects.

H2O2(hydrogen peroxide) is a chemical sterilization agent. It is a strong oxidant destroying a wide range of pathogens and it is used to sterilize heat or temperature sensitive objects such as rigid endoscopes. In medical sterilization H2O2is used at relatively high concentrations, ranging from around 0% w/w up to 90% w/w. The biggest advantage of H2O2as a sterilizer is the short cycle time. Whereas the cycle time for ethylene oxide (ETO), another chemical sterilization agent, may be 10 to 15 hours, the use of high concentrations of H2O2allows much shorter cycle times.

Depending on what kind of object is being sterilized, different concentrations of H2O2are advantageous, particularly to avoid degradation of the object to be sterilized.

In a further embodiment of the invention, H2O2under sterilization conditions has a concentration of 30% w/w to 90% w/w, preferably 10% w/w to 90% w/w, more preferably 30% w/w to 90% w/w, even more preferably 30% w/w to 60% w/w and most preferably 30% w/w to 40% w/w.

In a further preferred embodiment of the invention, instead of H2O2a derivative capable of generating H2O2as a sterilization agent during sterilization conditions is used. Examples of such derivatives are peracids, carbamide peroxides, triphenylphosphine oxide and acetone peroxide.

In a further embodiment of the invention, the sterilization agent comprises H2O2or a derivative thereof, capable of generating H2O2as the sterilising component under sterilization conditions, or a mixture of two or more thereof, as the only sterilising component.

In another embodiment the sterilzation agent comprising H2O2or a derivative thereof, capable of generating H2O2as the sterilising component under sterilization conditions is used in combination with other sterilization means or agents, e.g. one or more of heat, UV or gamma radiation, or chemical or biological sterilization components, in particular ozone.

Sterilization conditions in the sense of the invention is an environment with a defined pressure, humidity and temperature, in which sterilization takes place. The respective conditions are known in the art.

Objects in the sense of the invention are particularly medical objects. Especially with medical devices, it is important that a good hemocompatibility is assured, since they are likely to come into contact with the blood circulation of a patient.

In one embodiment, the objects are those that are used in hemodialysis, particularly blood piping elements, such as tubes, tubing systems or filters, or elements coming into contact with blood, such as apparatuses in slaughterhouses or in the blood processing industry. Nevertheless, the term objects is not limited to the above objects but comprises all objects that might come into contact with blood, such as surgical instruments in general or stents.

Medical objects according to the invention are particularly tubes and tubing systems for medical apparatuses, components of a cardiovascular systems, components of blood transfusion systems or components of chirurgical systems, such as artificial organs or means for blood embolization.

In a further preferred embodiment of the invention, the object is a medical object useful in hemodialysis.

Medical objects useful in hemodialysis according to the invention are particularly components of dialyzers, such as tubes, tubing systems, filters, deaerators, drip chambers, pump tubes for the peristalsis or centrifuges.

In hemodialysis, particularly in single-needle-systems where the blood stays a relatively long time outside of the body, it is vital that the blood does not coagulate in the components of the dialyzer. Nor should the blood-cells be destroyed since the blood is reinjected in the patient after having been cleaned.

In a further embodiment of the invention, the object is a tube system.

The preparation of the tubes for the contact with blood is particularly advantageous, since a major portion of the extracorporeal blood circulation consists of tubes. This means that transported blood is in contact with the tubes for a long time. Therefore, the hemocompatibility of the tubes has a significant impact on the hemocompatibility of a medical device including an extracorporeal blood circulation.

Hemocompatibility is the compatibility of objects with blood. The hemocompatibility of objects is given when these objects allow contact with flowing blood of a human or an animal without causing adverse reactions such as thrombosis, hemolysis, complement activation or inflammation, or at least when such reactions are minimized to a significant extent.

Enhancing the hemocompatibiliy in the sense of the invention means improving at least one parameter defined in the International Standard ISO 10993 Part 4 “Biological evaluation of medical devices—Selection of tests for interactions with blood”.

In one embodiment, the enhancement of hemocompatibility is determined compared to an object, which has not been sterilized with a H2O2containing sterilization agent, e.g. an object that was sterilized with e-beam, gamma radiation and/or ozone, respectively, i.e. without the use of a H2O2containing sterilization agent.

By the use of a H2O2containing sterilization agent, the activation of the coagulation is reduced, shown by a lower thrombin-antithrombin III-complex (TAT-complex), indicating the activation of thrombin, the central enzyme of the coagulation cascade, the loss of the number of platelets caused by adhesion at the object surface or by platelet aggregation is reduced, the activation of the complement system acting as a defence mechanism against immigrated micro-organisms is reduced and/or the haemoglobin release occurring during damage of red blood cells which is called hemolysis is reduced.

Thus, the use of a H2O2containing sterilization agent reduces the level of coagulation activation and/or reduces the loss of platelets and/or results in a lower concentration of anaphylatoxin C5a and/or reduces the hemolysis during the contact of the object with blood, e.g. during medicinal use of the object.

In a further embodiment of the invention, the object is a single-needle-system and the sterlization agent comprises H2O2as the only sterilizing component. In a further embodiment of the invention, the object is a single-needle-system and the sterlization agent comprises H2O2as the only sterilizing component and a reduction of the level of coagulation activation and/or a reduction of loss of platelets and/or a lowering in the concentration of anaphylatoxin C5a and/or a reduction of hemolysis during the contact of the object with blood, e.g. during medicinal use of the object is achieved.

In a further embodiment of the invention, the object is a tube or a tubing system and the sterlization agent comprises H2O2as the only sterilizing component.

In a further embodiment of the invention, the object is a tube or a tubing system and the sterlization agent comprises H2O2as the only sterilizing component and a reduction of the level of coagulation activation and/or a reduction of loss of platelets and/or a lowering in the concentration of anaphylatoxin C5a and/or a reduction of hemolysis during the contact of the object with blood, e.g. during medicinal use of the object is achieved.

Thus, the hemocompatibility of the objects sterilized by the use of H2O2according to the invention is significantly enhanced.

Further details and advantages will now be explained in more detail by way of examples and with reference to the figures.

EXAMPLES

The experimental procedure of the examples was as follows:

The experimental procedure was developed in compliance with the International Standard ISO 10993 Part 4 “Biological evaluation of medical devices—Selection of test for interactions with blood”.

The test items, PVC tubes of a dialyzer system, were fixed on a board. The test systems consisted of tubes as bloodlines forming, together with a blood pump, a recirculation system for blood. In each experiment of both examples, two test systems (test vs. reference item) were evaluated in parallel in a standard incubator (Memmert, Schwabach, Germany). The temperature was set to 37° C. in all experiments. This test was effectuated three times with the whole blood of three different donors representing the tests A, B and C with the test items and representing the tests R1, R2and R3with the respective reference items inFIGS. 1 to 8.

The test items were preconditioned for 3 hours up to 60° C. in an external heating cabinet. Then they were sterilized with vapor of a 36% w/w H2O2concentration in a full cycle sterilization (24 cycles in total). After that, the test items were stored in a clima cabinet at 15° C. and 65% r.h.

The reference items were sterilized by e-beam sterilization. These were also stored in a clima cabinet at 15° C. and 65% r.h.

The experimental procedure was conducted 11 to 18 days after the sterilization of the items.

For the experimental procedure, blood was drawn from healthy volunteers, denying any medication with known influence on the platelets or coagulation. 450 ml whole blood was collected using a 17 G (1.5 mm) fistula needle. In the blood bag 750 IU heparin diluted in 50 ml saline solution results in a concentration of 1.5 IU/ml in the final mixture of blood and saline (9:1). Within 30 minutes after blood collection, the hemocompatibility experiments started.

In the experimental procedure, the test systems were firstly prerinsed with a saline solution (0.9% NaCl) for approximately 30 min. To simulate dialysis treatment, the systems were filled with 190 ml whole blood and blood flow was adjusted to 250 ml/min. Sampling times were at 15, 30, 60, 120 and 180 minutes. Before filling samples were taken out of the blood bag as “pre”-values. As “post”-values, samples were taken out of a separately stored syringe.

The evaluation parameter chosen for the laboratory analysis, thrombin-antithrombin III-complex, blood cells, complement factor 5a, free hemoglobin) reflect blood response concerning coagulation activation, blood cell adhesion, immune response and damage of red blood cells. The used methods, test kits and standard operation procedures are as follows:

In order to be able to compare all single results of a test, special indices were defined. “Mean TAT increase per hour”, “Mean platelet loss”, “Mean C5a decrease per hour” and “Normalized index of hemolysis” were used to simplify evaluation of the test results.

In the first example, the reference and test items were tubing systems of a double-needle-dialyzing system “AV-Set Online plus 5008” of Fresenius Medical Care. The tubes of this system consist of PVC.

FIG. 1refers to the thrombin-antithrombin III-complex (TAT) of the sample blood of the test and the reference item after the experimental procedure of the first example. Thrombin, the central enzyme of the coagulation cascade, is inactivated by antithrombin III forming the TAT complex. Increase TAT concentrations indicate the activation of the blood coagulation.

As can be seen fromFIG. 1, coagulation activation was found at a lower level for the test item (A, B, C) with respect to the respective reference item (R=100%) (Mean M: 74±11%; VK (variation coefficient)=15%; test A: 71%; test B: 65%; test C: 86%).

FIG. 2refers to platelet loss of the sample blood of the test and the reference item after the experimental procedure of the first example. Platelet loss is caused by adhesion at the surface of the material or by platelet aggregation.

As can be seen fromFIG. 2, platelet loss was lower for the test items (A, B, C) with respect to the respective reference items (R=100%) (Mean M: 65±5%; VK=8%; test A: 59%; test B: 69%; test C: 67%).

FIG. 3refers to the complement factor 5a of the sample blood of the test and the reference item after the experimental procedure of the first example. The complement system acts as a defense mechanism against immigrated microorganisms. Its activation sets the anaphylatoxin C5a free and leads to increased concentrations of C5a.

As can be seen fromFIG. 3, complement activation showed a clear donor dependence. Nevertheless, the normalized values were lower for the test items (A, B, C) with respect to the respective reference items (R=100%) (Mean M: 66±4%; VK=7%; test A: 65%; test B: 62%; test C: 71%).

FIG. 4refers to the free hemoglobin of the test and the reference item after the experimental procedure of the first example. Hemoglobin release occurs during damage of red blood cells which is called hemolysis. An increased concentration of free hemoglobin indicates hemolysis.

As can be seen fromFIG. 4, wherein the normalized index of hemolysis is shown, hemolysis was the same for the test items (A, B, C) with respect to the respective reference items (R=100%) (Mean M: 99±16%; VK=16%; test A: 90%; test B: 117%; test C: 90%).

In the second example, the reference and test items were tubing systems of a single-needle-dialyzing system “SN-Set Online plus 5008” of Fresenius Medical Care. The tubes of this system consist of PVC.

FIG. 5refers to the thrombin-antithrombin III-complex (TAT) of the sample blood of the test and the reference item after the experimental procedure of the second example.

As can be seen fromFIG. 5, coagulation activation was found at a lower level for the test items (A, B, C) with respect to the respective reference items (R=100%) (Mean M: 78±6%; VK=7%; test A: 74%; test B: 76%; test C: 85%).

FIG. 6refers to platelet loss of the sample blood of the test and the reference item after the experimental procedure of the second example.

As can be seen fromFIG. 6, platelet loss was lower for the test items (A, B, C) with respect to the respective reference items (R=100%) (Mean M: 51±23%; VK=45%; test A: 43%; test B: 34%; test C: 77%).

FIG. 7refers to the complement factor 5a of the sample blood of the test and the reference item after the experimental procedure of the second example.

As can be seen fromFIG. 7, complement activation showed a clear donor dependence. Nevertheless, the normalized values were lower for the test items (A, B, C) with respect to the respective reference items (R=100%) (Mean M: 58±27%; VK=47%; test A: 70%; test B: 27%; test C: 77%).

FIG. 8refers to the free hemoglobin of the test and the reference item after the experimental procedure of the second example.

As can be seen fromFIG. 8, wherein the normalized index of hemolysis is shown, hemolysis was lower for the test items (A, B, C) with respect to the respective reference items (R=100%) (Mean M: 76±9%; VK=11%; test A: 85%; test B: 76%; test C: 68%).

To conclude, for the first and the second example, all parameters considered for hemocompatibility showed an amelioration or at least did not degrade for the test items sterilized with a H2O2concentration in comparison to the test items sterilized with e-beam. Therefore, the hemocompatibility of the test item was better for coagulation activation, platelet loss, complement activation and hemolysis.

The sterilization of the invention and in particular the experimental procedures of the above described examples can be implemented by the sterilization apparatus and/or method described in the following:

FIG. 9shows a block diagram for an embodiment of a sterilization apparatus in accordance with the present invention. A sterilization chamber is labeled by the reference numeral10which can, for example, have a volume of at least 1 m3and a door which serves both loading and unloading. The objects to be sterilized can be introduced into the sterilization chamber10, for example, on steel baskets on one or more levels. 150 to 200 products can be sterilized simultaneously depending an the product size. An aerospace container20or a vaporizer20is connected before the sterilization chamber10.

As can furthermore be seen fromFIG. 9, an oxygen generator40is connected before the ozone generator30and 95% oxygen can be acquired from the environmental air in it. A molecular screen or zeolite serves this purpose, for example. The oxygen is converted into ozone in the ozone generator30, which can take place, for example, by a dielectric barrier discharge.

If the method in accordance with the invention is only carried out with H2O2, the Figure shown inFIG. 9can be made correspondingly modified. For example, the ozone generator30can then be dispensed with. Instead, for example, a reservoir or a tank can be provided for the H2O2or generally a H2O2supply can be provided. The H2O2is preferably introduced into the sterilization chamber10in steam form, for instance as liquid vaporized by evacuation.

A catalytic converter is labelled by the reference numeral100inFIG. 9which is suitable to decompose the sterilization agent after its use, in particular to decompose H2O2and/or ozone or their reaction products. Only water and oxygen are then created as decomposition products. The catalyst100can, for example, be manganese dioxide.

To generate the desired vacuum in the sterilization chamber10, a vacuum pump50is connected after said sterilization chamber which results in an evacuation of the sterilization chamber10with an opened valve V6and with a vacuum pump50in operation. Sterile air is introduced as a support gas into the sterilization chamber10via the valve V7. Finally, a unit is indicated by the reference numeral110which serves the metering in of water and/or H2O2into the aerosol container20or to the vaporizer20.

The sterilization procedure has the following form in detail:

After the insertion of the object or objects into the sterilization chamber10, a vacuum is generated in the sterilization chamber10, for which purpose only the valve V6in accordance withFIG. 9is opened and all the further valves V1, V2, V3, V4, possibly V5, V7and V8, are closed. The generation of the vacuum results in a reduction of the chamber pressure.

The pressure in the chamber10preferably drops to a value <10 mbar in step200due to the evacuation of the sterilization chamber10by means of the vacuum pump200.

For the humidification, the valve V5in the line between the aerosol container20or the vaporizer20and the sterilization chamber10can e.g. be opened so that a vaporization of the liquid in the aerosol container20takes place, provided its vapor pressure is fallen below. If the vapor pressure of the liquid, i.e. for example of the mixture of water and H2O2, is fallen below in the aerosol container, it starts to vaporize and in this manner enters into the sterilization chamber10. The vacuum pump50is thus not used only for evacuating, but also for vaporizing the liquid in the aerosol container20.

A sterilization agent is actively introduced into the sterilization chamber10simultaneously with the step of humidifying. This method step is labeled by the reference numeral201inFIG. 10. H2O2is advantageously introduced as the sterilization agent into the sterilization chamber as vapor here, for example.

Alternatively, the creation of hydroxide radicals can take place due to the contact of the ozone with water and/or H2O2, said hydroxide radicals entering into the sterilization chamber10with the aerosol and there contributing to the sterilization process or representing the decisive sterilization agent.

The valves V3and V5or V4and V5are opened and all the further valves are closed during the method step201in accordance withFIG. 11. The aerosol containing ozone enters into the sterilization chamber10due to the pressure drop between the ozone generator30and the sterilization chamber10.

This applies correspondingly to the H2O2vapor when H2O2is used as the sterilization agent instead of ozone.

A pressure increase thereby occurs such as can be seen fromFIG. 10. This pressure increase is a measure for the quantity of the sterilization agent in the sterilization chamber10. In this respect, the concentration is set to a value ideal for the product to be sterilized.

After the introduction of the sterilization agent, the pressure in the sterilization chamber10is increased by means of a support gas via the valve V7, as is shown in step202in accordance withFIG. 10. In the embodiment shown there, the pressure is increased to a first support pressure of approximately 500 mbar abs. This support gas enters into the sterilization chamber10in that the valve7in accordance withFIG. 9is opened for a predetermined duration or until a specific pressure value is reached. All the further valves of the apparatus are closed during this method step. V5can alternatively also be open. The sterilization phase in which the first pressure gas is applied is called the first sterilization phase S1.

As can further be seen fromFIG. 10, the first support pressure is held in the sterilization chamber10for a specific duration. This method step is identified by the reference numeral203inFIG. 10and can be, for example, a minute or in the minute region.

After the holding of the support pressure for a specific duration in accordance with step203inFIG. 10, this process step comprising the steps200to203are carried out four times in total, i.e. it is evacuated, then humidified and the sterilization agent is introduced and then the first support pressure is again generated and held for a specific duration.

After the fourfold carrying out of the steps200to203, the first sterilization phase S1is terminated and the process continues with the second sterilization phase S2. In the sterilization phase S2, the second support pressure is applied which here amounts to 50 mbar abs and the steps200′,201′,202′ and203′ are carried out a total of six times. In this respect, steps200′ to203′ correspond to steps200to203from the sterilization phase S1, i.e. it is evacuated, then humidified and the sterilization agent is introduced and then the second support pressure is generated again, with the difference that the second support pressure in the sterilization phase S2amounts to 50 mbar abs.

Due to the fact that the filling of the sterilization chamber10with sterilizing agent in accordance with step201,201′,201″ is terminated when a substantial underpressure is present in the sterilization chamber10, it can generally be achieved that an underpressure is always present in the aerosol generator20. This makes it possible that liquid, i.e. water, H2O2and/or a mixture of both substances, can subsequently easily be drawn from a reservoir110by opening the valve V4.

As can furthermore be seen fromFIG. 9, the pump50is in communication at the outlet side with the catalyst100so that the medium arising at the pressure side of the pump can be decomposed in the catalyst100.

It is generally conceivable to repeat and/or to vary the sterilization phases S1and S2, for example, or to carry out further sterilization phases at different support pressures subsequently to the sterilization phases shown inFIG. 10.

This is followed in the embodiment shown here by the flushing and degassing of the sterilization chamber10by multiple evacuation and ventilation. This phase is not shown in any more detail inFIG. 10.

An evacuation and a ventilation of the sterilization chamber10takes place multiple times during the flushing and degassing phase. This phase can be followed by a drying phase in which there is preferably a vacuum in the sterilization chamber10.

FIG. 11shows a tube system300or a so-called tubing system300which was sterilized by means of the apparatus and method shown inFIGS. 9 and 10. It is a tubing system300for dialysis which can have a total tube length of up to 6 m in dependence o the treatment process.

The packing for the tubing system300in which the tubing system300is, however, preferably sterilized is not shown. It is conceivable that at least one support pressure above the atmospheric pressure is applied or is being applied in such a case.

The tubing system300in accordance withFIG. 11is a tubing system300for the extracorporeal blood circuit which in particular has a needle302for connection of the tubing system300, e.g. to the shunt of the patient, a connector304e.g. for connection to the dialyzer, not shown, inflows and outflows310,312,314,316closed by closure caps and pressure measurement connections320,322.

The regions labeled with B1are sterilized by the application of the first support pressure of approximately 500 mbar abs, that is, during the sterilization phase S1shown in more detail inFIG. 2. All the regions of the tubing system300in which the lumen of the tubing system300is closed at the end side are affected, that is, the inflows or outflows310,312,314,316closed by closure caps and the pressure measurement connections320,322. It is conceivable that with particularly long tubing systems300, the middle region of the tubing system300is likewise sterilized during the sterilization phase S1.

The regions labeled by B2are likewise sterilized by the application of the first support pressure of approximately 500 mbar abs. All the regions of the tubing system300which are in the inner region of the lumen of the tubing system300are affected so that the first support pressure300is necessary or sufficient to transport the sterilization agent in it.

The regions labeled with B3are sterilized by the application of the second support pressure or gassing pressure of approximately 50 mbar abs, that is, during the sterilization phase S2shown in more detail inFIG. 10. These regions inFIG. 3are here the start regions and end regions of the tubing system300, that is, the regions which follow the needle302and the connection304respectively.

The above described sterilization method and apparatus include the following embodiments: A method for sterilizing at least one object300, wherein the object300is exposed to a sterilization agent, wherein at least one first support pressure and at least one second support pressure are applied and wherein a sterilization of at least one first region B1of the object300takes place by the sterilization agent at the first support pressure and a sterilization of at least one second region B2of the object300takes place at the second support pressure. A method wherein the sterilization agent at least partly includes ozone and/or hydrogen peroxide or one or more of the reaction products of these substances. A method wherein the at least one first support pressure and/or the at least one second support pressure is/are generated by introducing a support gas into a sterilization chamber10. A method wherein the support gas includes at least partially an inert gas and/or air, preferably includes or is sterile air. A method wherein in a first step, the object300to be sterilized is inserted into a sterilization chamber10, in a second step200, the sterilization chamber10is evacuated; and, in a third step201, the sterilization chamber10is humidified and sterilization agent is introduced into the sterilization chamber10; in a fourth step202, the first support pressure is applied; in a fifth step203, the first support pressure is maintained for a point in time or for a duration; in a sixth step, steps two to five are repeated once or a multiple of times; and in a seventh step, the at least one second support pressure is applied. A method, wherein in the seventh step, steps two to five or two to six are carried out at the second support pressure. A method, wherein in at least one further step, one or more further support pressures are applied; and in that steps two to five or two to six are accordingly carried out at the further support pressures. A method wherein the humidification of the sterilization chamber10takes place in that a liquid, in particular a mixture containing water and hydrogen peroxide, is brought to vaporization by application of a vacuum, in particular by the evacuation, and the vaporized liquid is supplied to the sterilization chamber10. A method, wherein the first support pressure is at least approximately 500 mbar abs and/or the second support pressure is at least approximately 50 mbar abs. A method wherein a third support pressure is applied, wherein the third support pressure is preferably up to approximately 50 mbar abs and/or corresponds to the gassing pressure without additional introduction of a support gas, with the fourth step already being carried out by step three. A method, wherein the sterilization agent is introduced into the sterilization chamber10in the form of an aerosol. A method, wherein the aerosol is formed by vapor containing hydrogen peroxide; and/or in that the aerosol is created by introduction of ozone into a liquid which contains water and/or hydrogen peroxide. A method, wherein the introduction of a sterilization agent into the sterilization chamber10takes place at a pressure in the sterilization chamber10which is below the atmospheric pressure. A method, wherein the holding of the support pressure, preferably in accordance with the fifth step203takes place for a duration whose length is in the range <20 minutes, preferably <10 minutes and particularly preferably <5 minutes. A method, wherein the duration between two application steps taking place successively, preferably in accordance with the fourth step202is in the range <20 minutes, preferably <15 minutes, and particularly preferably <10 minutes. A method, wherein after the last method step, in particular after the seventh step or after termination of the sterilization, the flushing and degassing of the sterilization chamber10is carried out, with the flushing and degassing preferably being carried out a multiple of times. A method, wherein the sequence of the steps two to five lasts approximately 15 to 20 minutes, preferably approximately 18 minutes.

A sterilization apparatus having at least one sterilization chamber10for the reception of at least one object300to be sterilized, having at least one first means for the supply and/or removal of a sterilization agent, having at least one second means by means of which at least one first support pressure and at least one second support pressure can be applied, and wherein at the first support pressure of the sterilization agent a sterilization of a first region B1of the object300can be carried out and at a second support pressure a sterilization of a second region B2of the object300can be carried out. A sterilization apparatus, wherein the sterilization apparatus has at least one control and/or regulation means by means of which the sterilization procedure can be controlled and/or regulated and/or monitored, can preferably be semiautomatically and/or fully automatically controlled and/or regulated and/or monitored. A sterilization, wherein a method in accordance with one of the above described methods can be carried out using the sterilization apparatus.