EP3860662A1

EP3860662A1 - Method for inactivating biologically active components in a liquid

Info

Publication number: EP3860662A1
Application number: EP19778498.6A
Authority: EP
Inventors: Volker Kirchhoff; André Weidauer; Jessy Schönfelder; Gaby GOTZMANN; Christiane Wetzel; Jörg KUBUSCH
Original assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Current assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Priority date: 2018-10-05
Filing date: 2019-09-25
Publication date: 2021-08-11
Also published as: US20210379218A1; CN112789060B; DE102018124664A1; KR20210070353A; CN112789060A; WO2020069942A1

Abstract

The invention relates to a method for inactivating biologically active components in a liquid using low-energy electrons generated by an electron source (14; 24), said electrons having an acceleration voltage of 25 keV to 300 keV. Said method comprises the following steps: a) filling a vessel (11; 21) with a liquid volume (12; 22); b) applying low-energy electrons to a first partial volume (15; 25) of the liquid filled into the vessel (11; 21), wherein the first partial volume (15; 25) is a maximum of 10% of the liquid volume (12; 22) in the vessel (11; 21); c) mixing the first partial volume (15; 25) of the liquid, applied with the low-energy electrons, to the second partial liquid volume in the vessel (11; 21), which has not been applied with low-energy electrons; d) repeating steps b) and c) several times.

Description

Process for inactivating biologically active components within a

liquid

description

The invention relates to a method for inactivating biologically active components within a liquid.

Liquid waste, which contains biologically active components such as microorganisms or vegetable residues, falls primarily in the pharmaceutical and

biotechnology industry, in the course of animal experiments, in the disposal of carcasses, in waste and wastewater treatment and in animal production in the form of slurry, to name just a few examples.

Biologically contaminated liquid or solid waste is assigned to different biosafety classes. So far, such waste has mainly been chemically or thermally activated, which means that the microbiological contamination in the form of viruses, bacteria, micro-fungi and possibly prions has been eliminated.

The term “inactivating” is to be understood below to mean that the health-damaging effect of biologically active constituents of a liquid is eliminated. On the one hand, this can mean that the biologically active constituents of a liquid are sterilized and / or destroyed. On the other hand, it can already be sufficient if the biologically active constituents of the liquid are influenced in such a way that they are no longer capable of replication or that the number of reproducible biologically active constituents of the liquid is reduced by their

prevent harmful effects. The term "biologically active constituents" includes all those constituents which trigger a reaction in living organisms. Biologically active constituents of a liquid can thus be, for example, viruses, bacteria, fungi, yeasts, algae, prions, protozoa, plant constituents or hormones. This list is only exemplary and is not to be considered as comprehensive.

The type of microbiologically contaminated waste ranges from aqueous liquids to chicken eggs from vaccine production to animal bodies such as experimental mice. But the manure from animal husbandry is also often contaminated with bacteria such as Salmonella, which should be inactivated before being applied to fields.

Depending on the type of waste and the contamination (danger of viruses, bacteria, micro fungi or prions), known methods of inactivation are associated with risks and sometimes considerable disadvantages. In particular, for example, require thermal

Methods require a considerable amount of energy because temperatures above 70 ° C or even above 130 ° C and long exposure times are required.

Another method is inactivation in the course of incineration. In this case, however, the product is destroyed and is no longer available for use.

Chemical methods, such as the inactivation of waste from vaccine production (e.g. incubated chicken eggs), are often based on treatment with acids or bases. This is associated with the risk that the inactivation of larger volumes does not cover every volume element. In addition, this method is associated with considerable waiting times to ensure the required minimum exposure time of the acids or bases.

It is known that germs or microorganisms can be killed by means of accelerated electrons. In DE 199 42 142 A1, for example, seeds are subjected to accelerated electrons in free fall during multiple passes in order to kill germs on the seeds. The disadvantage of this method is that it is not for

Germ reduction is suitable on masses that have liquid components.

Proposals are known from the field of water treatment in which liquids for germ killing are subjected to accelerated electrons. EP 0 024 487 A1, for example, shows a solution in which a liquid is first conveyed onto a plateau from which it falls as a liquid curtain and during which time it is irradiated once from one side. The disadvantage here is that

Components of the liquid on the front of the liquid curtain are exposed to a higher radiation dose than components on the back of the liquid curtain. If all of the biologically active components on the back of the liquid curtain are to be deactivated during the one radiation process, the radiation must be so strongly adjusted that this can damage or destroy the biologically active components on the front of the liquid curtain.

In some applications, such as inactivating biologically active components within bioreactors for vaccine production, it may be necessary to inactivate biologically active components of a liquid, but the biologically active components must not be damaged or destroyed because these subsequently lead to Vaccine recovery will be needed.

A method for inactivating pathogens in biological media is known from DE 10 2016 21 6 573 A1, in which a roller set in rotation is partially immersed in a liquid on its underside, so that a liquid film is formed on the top of the roller as a result of the rotation of the roller trains which is exposed to ionizing radiation. After loading the liquid film with

ionizing radiation, the liquid film is stripped off the roller and

subsequent processes fed. Since the liquid of the liquid film in this known method is also exposed to ionizing radiation only once and only from one side, this solution is also dependent on the disadvantages described above.

The invention is therefore based on the technical problem of creating a method for inactivating a liquid containing biologically active constituents, by means of which the disadvantages of the prior art can be overcome. In particular, it should also be possible with the method according to the invention to inactivate biologically active constituents of a liquid without destroying or damaging the biologically active constituents of the liquid.

The technical problem is solved by objects with the features of patent claim 1. Further advantageous embodiments of the invention result from the dependent claims.

While prior art methods often attempt to completely treat a batch of material with accelerated electrons in one

The process according to the invention is based only on doing radiation passage, mostly using high-energy, accelerated electrons To apply partial volumes of a batch of material with accelerated electrons, but several times and with very small doses of accelerated electrons.

In the method according to the invention, the inactivation of biologically active takes place

Components within a liquid by means of low-energy electrons generated by an electron source. Low-energy electrons in the sense of the invention are electrons with an acceleration voltage of 25 keV to 300 keV. First, a liquid volume of the liquid containing biologically active components is filled into a vessel. Such a vessel can be, for example, a bioreactor or any other vessel that is suitable for holding a liquid. Subsequently, a first partial volume of the liquid filled into the vessel is included

low-energy electrons are applied, the first partial volume comprising a maximum of 10% of the liquid volume in the vessel. The method according to the invention is further characterized in that at least 90% of the energy of the low-energy electrons generated by the electron source is applied within the first partial volume. The second partial volume at that point in time is the partial volume in the vessel which is not subjected to accelerated electrons at this point in time or into which a maximum of 10% of the energy of the low-energy electrons is introduced. After the first partial volume has been charged, the first partial volume of the liquid charged with low-energy electrons is mixed with the second liquid partial volume in the vessel, which was not charged with low-energy electrons. Subsequently, a first partial volume of the liquid filled into the vessel is acted upon by low-energy electrons and then mixed with the second partial volume not acted on by low-energy electrons. The application of low-energy electrons to a first partial volume and the mixing of the first partial volume with the second partial volume is repeated several times and until all biologically active components of the liquid volume in the vessel are inactivated.

The fact that only a relatively small part of the volume in relation to the total volume in a vessel and the small part of the volume is only subjected to low-energy electrons means that gentle inactivation of biologically active components within a liquid can be implemented without the biologically active components in the liquid to damage or destroy. It is therefore particularly advantageous if the first partial volume, which is charged with low-energy electrons, only comprises a maximum of 5% of the liquid volume in the vessel.

It is also advantageous for a gentle inactivation of biologically active constituents in a liquid if the first partial volume of the liquid during a

Irradiation period is applied with a maximum of 1% of the total amount of low-energy electrons that is required to inactivate all biologically active components within the first partial volume of the liquid. The application of such a low dose of low-energy electrons to a relatively small partial volume to be irradiated makes it necessary to inactivate all biologically active ones

Components in the entire liquid volume in the vessel require multiple irradiation of the first partial volume and multiple mixing of a currently irradiated first partial volume with a second partial volume that is not currently irradiated, but this has the advantage that all particles of the liquid have the same average Total dose of low-energy electrons are applied.

In one embodiment of the method according to the invention, a partial region of a wall of the vessel is formed as an electron exit window of the electron source, through which low-energy electrons penetrate into the first partial volume of the liquid within the vessel, means for mixing the liquid in the vessel having the effect that the composition of the first Partial volume of the liquid in the vessel changed.

Alternatively, the first partial volume of the liquid volume can also be removed from the vessel, charged with low-energy electrons outside the vessel and then mixed with the second liquid volume remaining in the vessel.

The present invention is explained in more detail below on the basis of exemplary embodiments. The figures show:

1 shows a device suitable for carrying out the method according to the invention in a schematic sectional illustration;

2 shows an alternative which is suitable for carrying out the method according to the invention

Device in a schematic sectional view. In Fig. 1, a device is shown schematically in a section, which for

Execution of the method according to the invention is suitable. A volume 12 of a liquid containing biologically active constituents is initially filled into a vessel 11, in which the biologically active constituents are to be inactivated. One wall of the vessel 11 is formed in one area as an electron exit window 13 of an electron source 14. Low-energy electrons with an acceleration voltage of 25 keV to 300 keV enter a first partial volume 15 of the liquid volume 12 through the electron exit window 13. It is known that the depth of penetration of accelerated electrons and the distribution of the energy introduced into a medium also change Medium such as a liquid can be calculated so that a person skilled in the art can set the electrical parameters of the electron source 14 according to the invention such that the first partial volume 15 acted upon by the low-energy electrons of the electron source 14 makes up a maximum of 10% and preferably a maximum of 5% of the liquid volume 12 and that at least 90% of the energy of the low-energy electrons is entered into this first partial volume 1 5.

Preferably, the first partial volume 15 of the liquid during a

Irradiation time period with a maximum of 1% of the total amount of low-energy electrons, which is required to inactivate all biologically active components within the first partial volume 15 of the liquid. In laboratory tests, it is possible to determine which dose of low-energy electrons is required to inactivate all of the biologically active constituents of a partial volume 15. Depending on this, a person skilled in the art can also set the electrical parameters of the electron source 14 in such a way that during a radiation period a maximum of 1% of the total amount of low-energy electrons penetrate into the partial volume 15, which is required to inactivate all biologically active constituents within the partial volume 15 will.

Means 16 ensure that a first partial volume 15 charged with low-energy electrons is mixed with the second partial volume not charged with low-energy electrons, as a result of which the composition of the first partial volume 15 also changes, and thus a new first partial volume 15 is continuously formed.

The application of the first partial volume 1 5 with low-energy electrons and the mixing of the liquid in the vessel 1 1 continue until one of the A liquid sample taken from vessel 1 shows that the biologically active components in the liquid are sufficiently inactivated.

In one embodiment, electron source 14 is used throughout

Inactivation process of all biologically active components within the

Liquid volume 12 operated continuously and with constant performance. Alternatively, the electron source 14 can also be activated only periodically at time intervals, the periods of time when the electron source is activated being the same length or

can be of different lengths.

In a further embodiment, the liquid in the vessel 11 is continuously mixed with the agents 16 during the entire inactivation process of all biologically active constituents within the liquid volume 12 in the vessel 11.

Alternatively, the liquid in the vessel 11 can also be mixed only periodically at time intervals, it being possible for the time intervals to be of the same length or of different lengths.

An alternative device for carrying out the method according to the invention is shown schematically in a section in FIG. 2. In a vessel 21 is first a

Filled liquid volume 22 of a liquid containing biologically active components, in which the biologically active components are to be inactivated. A continuous flow of the liquid located in the vessel 21 is branched off by means of at least one pump device 27, conveyed through a pipeline 28 and then returned to the vessel 21.

One wall of the pipeline 28 is formed in one area as an electron exit window 23 of an electron source 24. Low-energy electrons with an acceleration voltage of 25 keV to 300 keV enter a first partial volume 25 of the liquid volume 22 through the electron exit window 23. The pipeline 28 and the electron source 24 are dimensioned such that the low-energy electrons generated by the electron source 24 each have only a first one Apply partial volume 25, which is a maximum of 10% and preferably a maximum of 5% from

Liquid volume 22 makes up, with at least 90% of the energy of

low-energy electrons is entered into the first partial volume 25. With this procedure, the flow velocity of the liquid in the pipeline 28 and the electrical parameters of the electron source 24 are set in such a way that in a first partial volume 25 during one pass (that is, when it is once

Electron exit window 25 flows past) a maximum of 1% of the total amount

penetrate low-energy electrons, which are required to inactivate all biologically active components within the first partial volume 25.

The charging of the first partial volume 25 with low-energy electrons and the mixing of the liquid in the vessel 21 continue until a liquid sample taken from the vessel 21 shows that the biologically active constituents in the liquid have been sufficiently inactivated.

If, as shown in FIG. 2, the continuous flow is branched off from the liquid in the vessel 21 in a lower region of the vessel 21 and reintroduced in an upper region of the vessel 21, then this process alone ensures constant mixing liquid in the vessel 21. In addition, the liquid in the vessel 21 can also be mixed continuously or at intervals by means of means 26.

The procedures according to the invention described for FIGS. 1 and 2 require a relatively long time in relation to the methods known from the prior art for inactivating biologically active constituents in a liquid, but are advantageous in applications in which all constituents of a liquid with a continuously homogeneous dose of accelerated electrons and / or in which the biologically active components are not to be destroyed. The

The method according to the invention can be used, for example, in bioreactors for producing vaccines or else in wastewater treatment.

In the exemplary embodiments described for FIGS. 1 and 2, at least one sensor can also be arranged within the regions of the first partial volumes 15 and 25, respectively, with which the intensity of the current of accelerated, low-energy electrons; their distribution in partial volume 15 or 25 and / or the dose of the low-energy electrons applied in partial volume 15 or 25 can be detected and controlled by means of an evaluation device.

Claims

Method for inactivating biologically active constituents within a liquid by means of low-energy electrons generated by an electron source (14; 24) with an acceleration voltage of 25 keV to 300 keV,

characterized by the following process steps:

a) filling a volume of liquid (12; 22) into a vessel (1 1; 21);

b) acting on a first partial volume (1 5; 25) of the liquid filled in the vessel (1 1; 21) with low-energy electrons, the first partial volume (1 5; 25) not exceeding 10% of the liquid volume (12; 22) in the vessel (1 1; 21) includes;

c) Mixing the first with low-energy electrons

Partial volume (1 5; 25) of the liquid with the second liquid partial volume in the vessel (1 1; 21), which was not subjected to low-energy electrons; d) repeating steps b) and c) several times.

2. The method according to claim 1, characterized in that the first partial volume (1 5; 25) of the liquid is acted upon by a maximum of 1% of the total amount of low-energy electrons which are used to inactivate all biologically active constituents within the first partial volume (1 5; 25 ) the liquid is needed.

3. The method according to claim 1 or 2, characterized in that a portion of a wall of the vessel (1 1) is formed as an electron exit window of the electron source (14) through which low-energy electrons into the first partial volume (1 5) of the liquid within the vessel (1 1) penetrate, taking funds

(16) for mixing the liquid in the vessel (1 1) cause the

Composition of the first partial volume (1 5) of the liquid in the vessel changed.

A method according to claim 3, characterized in that the electron source (14) is operated continuously during the entire inactivation process of all biologically active components within the liquid.

A method according to claim 3, characterized in that the electron source (14) is activated periodically.

6. The method according to any one of claims 1 to 5, characterized in that the liquid in the vessel (1 1) is continuously mixed throughout the inactivation process of all biologically active constituents within the liquid volume in the vessel (1 1).

7. The method according to any one of claims 1 to 5, characterized in that the liquid in the vessel (1 1) is mixed periodically.

8. The method according to claim 1 or 2, characterized in that the first

Partial volume (25) of the liquid volume is removed from the vessel (21), applied to the outside of the vessel (21) with low-energy electrons and then mixed with the second volume of liquid remaining in the vessel (21).

9. The method according to claim 8, characterized in that a continuous

flowing liquid stream is branched off from the vessel (21), guided past an electron exit window (23) of the electron source (24) outside the vessel, subjected to low-energy electrons there and then introduced back into the vessel (21).

10. The method according to claim 8 or 9, characterized in that the liquid is continuously mixed in the vessel.

1 1. Method according to one of the preceding claims, characterized in that the first partial volume (1 5; 25) comprises a maximum of 5% of the liquid volume (12; 22) in the vessel (1 1; 21).

12. The method according to any one of the preceding claims, characterized in that at least 90% of the energy of the low-energy electrons generated by the electron source (14; 24) is applied within the first partial volume (1 5; 25);

13. The method according to any one of the preceding claims, characterized in that it is used for inactivating biologically active components of a liquid within a bioreactor.