Method for preparing an anthropogenic target substance

Abstract

The invention relates to a method for preparing an anthropogenic target substance, said method comprising: - producing an emulsion or suspension of the target substance, the emulsion or suspension containing particles and / or particulates of the target substance with an average particle size or particulate size in the nanometre range, and - concentrating the emulsion or suspension by: a) adding a superabsorber (2) to an initial first liquid volume (1) of the emulsion or suspension or adding the first liquid volume (1) to the superabsorber (2), b) incubating the mixture formed from the superabsorber (2) and the first liquid volume (1) for a first period of time (t1), and removing a second liquid volume (4) from the liquid portion (3) of the mixture present after incubation.

Description

[0001] Process for producing an anthropogenic target substance

[0002] The invention relates to a process for producing an anthropogenic target substance.

[0003] Nanoparticles and nanoparticles are playing an increasingly important role in our lives. This applies, for example, to the use and, in this context, also the production of these particles and particles for a wide variety of applications in the pharmaceutical industry (for example, in connection with encapsulated mRNA active ingredients), food technology, and the electrical engineering and electronics industries (for example, in connection with quantum dots).

[0004] Due to their small size and the associated changes in their physical characteristics, nanoparticles can be used to transport drugs to desired organs, as they can penetrate the blood-brain barrier (e.g., suitable for pharmaceutical applications) and the skin (e.g., suitable for the cosmetics industry). Nanoparticles are also used for diagnostic applications, such as color detection in rapid tests based on colloidal gold. They also stabilize food, thus ensuring longer shelf lives.

[0005] Nanoparticles are almost exclusively anthropogenic substances. This means that they were produced by humans through industrial, commercial, and municipal processes, rather than by biological organisms. Possible components include natural polymers such as albumin, biocompatible synthetic polymers such as polymethyl methacrylate, polyalkyl cyanoacrylate, and copolymers, as well as various inorganic or organic particles.

[0006] Most nanoparticle manufacturing processes are based on sol-gel processes, emulsion polymerization, interfacial polymerization, and similar techniques. At the end of the process, a nanoparticle emulsion is obtained in a suitable solvent.

[0007] The concentration of the desired nanoparticles in the solvent naturally fluctuates during the production process and is often too low. The produced nanoparticles or nanoparticles therefore need to be concentrated. However, due to their small size, this presents a problem. Concentration is usually carried out using ultracentrifugation. This process is complex and can often only be carried out with a relatively small volume for large-scale industry. Some nanoparticles or nanoparticles could also be destroyed during centrifugation. Filtration is not an option due to the small size of the nanoparticles or nanoparticles. The object of the invention is to present a production process for an anthropogenic target substance containing nanoparticles or nanoparticles, which process includes a simple, rapid, and universally applicable process for concentrating the nanoparticles or nanoparticles.

[0008] This object is achieved in a surprisingly simple and universally applicable manner by means of the method defined in claim 1. Advantageous embodiments are specified in the dependent claims.

[0009] The solution is based on the use of so-called superabsorbents, with which any aqueous liquid, for example an emulsion or suspension, can be processed in order to concentrate the nanoparticles contained in the liquid.

[0010] Superabsorbent polymers (SAPs) are plastics capable of absorbing many times their own weight in polar liquids. These are primarily water or aqueous solutions. When absorbing the liquid, the superabsorbent swells and forms a hydrogel. Hydrogels can be formed from any cross-linked polar polymer (e.g., polyacrylamide, polyvinylpyrrolidone, amylopectin, gelatin, cellulose). However, a copolymer of acrylic acid (propenoic acid, H2C=CH-COOH) or sodium acrylate (sodium salt of acrylic acid, H2C=CH-COONa) and acrylamide is most commonly used, although the ratio of the two monomers can vary. Additionally, a core cross-linker (CXL) is added to the monomer solution, which connects the formed long-chain polymer molecules to one another through chemical bridges, also known as cross-linking. These bridges make the polymer insoluble in water.This so-called base polymer may be subjected to a process called surface cross-linking (SXL). This involves applying another chemical to the surface of the particles, which, when heated, creates a second network only on the outer layer of the grain. This shell supports the swollen gel, ensuring it stays together even under external stress (movement, pressure).

[0011] The product is conventionally used as white granules with particle sizes ranging from 100 to 1000 μm. It is mainly used in baby diapers, sanitary pads, incontinence care, in bandages, and in small quantities in cable sheathing for deep-sea cables. Other applications include so-called gel beds, gel-forming extinguishing agents in firefighting, as a mechanical stabilizer for cut flowers in vases, or as an additive for potting soil to permanently store water. However, in these cases, potassium hydroxide-neutralized acrylic acid is used due to its better environmental compatibility. In the form of spherical particles, the use of superabsorbents is known as toys under names such as "water beads," "aqua beads," or "water beads." These are superabsorbents that are commercially available in the form of spheres of variable size (submillimeters to centimeters).The invention was based on the following unexpected observation: A water sample was mixed with fluorescent nanoparticles with an average particle size of 30 nm. After adding commercially available water beads and an incubation period during which the beads swelled to several times their original volume, it was found that the nanoparticles were not absorbed by the superabsorbents but were concentrated in the remaining liquid.

[0012] This observation demonstrates that by using superabsorbents, especially superabsorbents commercially available in the form of so-called water beads, a wide variety of nanoparticles can be easily and quickly concentrated in a liquid sample. In industrial nanoparticle manufacturing processes, this simple method of concentration (e.g., no complex and inefficient ultracentrifugation or ultrafiltration is necessary) allows them to be provided in higher concentrations.

[0013] On the basis of this observation, the problem underlying the invention could be solved.

[0014] The process according to the invention for producing an anthropogenic target substance comprises:

[0015] - Creating an emulsion or suspension of the target substance, wherein the emulsion or suspension contains particles and / or particles of the target substance with an average particle size in the nanometer range, and

[0016] - Concentrating the emulsion or suspension by: a) adding a superabsorbent to an initial first liquid volume of the emulsion or suspension or adding the first liquid volume to the superabsorbent, b) incubating the mixture formed from the superabsorbent and the liquid volume for a first period of time, and c) removing a second liquid volume from the liquid portion of the mixture present after incubation.

[0017] "Anthropogenic substances" are defined as substances that are not created by nature but by humans, for example, through industrial, commercial, or municipal processes. These include, for example, plastics, but also pesticides, pharmaceuticals, personal care products, and industrial chemicals, as well as their degradation products and metabolites. Biomolecules produced by microorganisms (e.g., enzymes, DNA / RNA fragments, etc.) and having similar sizes in the nanometer range are not considered to be particles or anthropogenic substances mentioned in this application.

[0018] In the above-described method according to the invention, the second liquid volume removed from the liquid portion of the mixture of liquid and superabsorbent present after incubation can be the entire remaining liquid portion. However, it is also possible to remove only a partial volume of the existing liquid portion as the second liquid volume.

[0019] The nanoparticles are present in a high concentration in the second liquid volume. The concentration, or the presence of the correct substance, can be investigated in a subsequent analysis, e.g. by means of a spectroscopic examination. The second liquid volume can also be further concentrated in a cascading process in one or more additional steps, e.g. by adding a superabsorbent again or adding it to a superabsorbent and incubating it again, or by using a conventional method for concentrating target substances, e.g. by one of the methods mentioned in the introduction. If only a portion of the liquid portion is removed as the second liquid volume, the target substance can be further concentrated in the liquid portion of the mixture remaining after removal by incubating it again for a second period.Both variants of the process can be repeated several times, so that a higher concentration of the target substance is obtained at each stage of the cascaded concentration.

[0020] In an advantageous embodiment of the process, the emulsion or suspension is produced by a sol-gel process, an emulsion polymerization process, or an interfacial polymerization process. Alternatively, the emulsion or suspension is produced by crystallization or complex formation. These are established processes for producing nanoparticles, which are present in an emulsion or suspension after completion of the processes.

[0021] It is advantageous to reduce the initial sample volume in a first step by means of the method according to the invention using a superabsorbent, and to carry out a further concentration of the target substance in a subsequent second step using a conventional concentration technique, e.g., filtration, ultrafiltration, precipitation reaction, ultracentrifugation, or enrichment using the method described in EP 2283026 B1. These known techniques can be used significantly more efficiently in already reduced liquid volumes than in more diluted solutions. Thus, the method according to the invention is suitable for significantly simplifying known methods for concentrating nanoparticles, or nanoparticles for large-volume sample liquids and / or those containing the target substance only in low concentrations.As mentioned, in an advantageous embodiment, the method may comprise a further concentration of the target substance in the first sample taken after taking the first sample.

[0022] The further concentration of the target substance in the withdrawn second liquid volume can be carried out using a filtration, ultrafiltration, or precipitation reaction technique. Alternatively, the further concentration of the target substance in the withdrawn second liquid volume can also be carried out again—and optionally repeated in a cascading manner one or more times—by performing the following process steps:

[0023] - adding a superabsorbent to the first sample or adding the first sample to the superabsorbent,

[0024] - incubating the mixture formed from the superabsorbent and the second volume of liquid for a second period of time, and

[0025] - Taking a concentrated third volume of the liquid portion of the mixture present after incubation.

[0026] Similar to the process described above for the first stage of the cascade, the concentrated third liquid volume, the concentrated third liquid volume taken from the liquid portion remaining after incubation, can comprise the entire volume of the liquid portion. Alternatively, the concentrated third liquid volume can be a partial volume of the remaining liquid portion.

[0027] The target substance can be further concentrated in the concentrated third liquid volume or in a further concentrated second liquid volume obtained by further concentration, in particular by means of a superabsorbent, by means of a filtration, ultrafiltration, or precipitation reaction. This is advantageous if the volume of the concentrated first sample corresponds to only a few milliliters, e.g., 1 to 10 ml.

[0028] In the process according to the invention, the initially used first liquid volume, i.e., the emulsion or suspension, can contain a polar liquid, in particular as the main component. In an advantageous embodiment of the process according to the invention, the liquid volume can contain a polar solvent, in particular as the main component. For example, the liquid volume can consist of a polar solvent to a mass fraction of at least 50%. The polar liquid or solvent can be water, for example.

[0029] The target substance is a nanoparticle. Such a nanoparticle consists of an anthropogenic substance, in particular of at least one natural polymer, at least one biocompatible synthetic polymer, an inorganic material, or an organic material.

[0030] As mentioned, in an advantageous embodiment, the superabsorbent can be a plastic or comprise a plastic that absorbs a portion of the first liquid volume, e.g., a polar solvent such as water contained in the first liquid volume, to form a gel or hydrogel. Advantageously, the plastic is selected such that it absorbs essentially no nanoparticles. This is the case, for example, with the aforementioned superabsorbents made from the aforementioned polymer or copolymer materials, e.g., with commercially available water beads, water pearls, etc.

[0031] The superabsorbent can be used in the form of particles, e.g., as a powder, as granules, or in the form of geometric bodies, especially spheres (spherical particles). It can thus be added to the liquid volume or the first sample in the form of such particles, or the liquid volume or the first sample can be added to the superabsorbent in this form. The particles or spheres can have a diameter between 100 and 5000 pm.

[0032] Advantageously, the superabsorbent is in the form of commercially available superabsorbent beads, for example superabsorbent beads available under the names “Aquabeads”, “Water Beads”, “Water Pearls”, “Aqua Pearls”, “Hydro Beads”, “Gel Beads”.

[0033] In an advantageous embodiment of the method, the volume of the liquid portion remaining after the incubation step, and thus the concentration of the target substance in the remaining liquid portion, can be controlled by the length of the incubation period or periods, by the size and number of superabsorbent particles or superabsorbent spheres added to the initially used first liquid volume of the sample liquid or the first sample, and / or by the temperature prevailing during the incubation.

[0034] Subsequent physical detection methods for the qualitative and / or quantitative detection of nanoparticles or nanoparticles in the sampled liquid volumes are also possible, for example, to determine whether certain nanoparticles or nanoparticles are present in the corresponding concentrated liquid volume, or to determine their concentration. In the emulsion or suspension, these would not be detectable using the physical detection method because their concentration is too low. A microscope is used for qualitative and / or quantitative determination. Here, for example, the nanoparticles or nanoparticles are counted in a section of a defined size. Alternatively, a fluorescence measurement method or a spectroscopic measurement method is used. For this purpose, the nanoparticles or nanoparticles must contain a fluorescent dye, which is added, in particular, before concentration.

[0035] The invention is explained in more detail below with reference to the figures and some exemplary embodiments. These examples do not represent a limitation of the means and methods according to the invention.

[0036] Fig. 1 shows a schematic representation of the cascading concentration of a target substance in a liquid: a) Liquid before adding a superabsorbent; b) Liquid after adding a superabsorbent and incubating the mixture; c) Second liquid volume removed from the mixture after adding another superabsorbent and incubating the mixture; d) Remaining mixture of liquid and superabsorbent, if applicable, after removing the second liquid volume and after renewed incubation.

[0037] Fig. 2 shows a representation of samples and blank samples, some of which were obtained by the concentration according to the invention and exposed to UV light; and

[0038] Fig. 3 Evaluation of the measured data: a) a graphical representation of the mean values ​​of the measured values ​​in a bar chart; b) a correlation between the degree of concentration and the increase in fluorescence of the samples.

[0039] The use of superabsorbents to concentrate a target substance, especially nanoparticles, in a polar liquid as a solvent, such as water, is very simple and universally applicable. A suitable method is briefly described as follows using Fig. 1 a and b:

[0040] 1. Addition of a superabsorbent 2 to a volume of a, in particular aqueous, liquid 1, or alternatively: addition of the liquid 1 to a superabsorbent 2 provided;

[0041] 2. Incubation of the mixture of the liquid 1 and the superabsorbent 2 over a first period t1 to reduce the volume of the liquid portion 3 of the mixture; and subsequently

[0042] 3. Transferring at least a second liquid volume 4 of the liquid portion 3 of the mixture into a new vessel for further processing.

[0043] Further processing may, for example, involve quantitative and / or qualitative detection of the target substance present in the liquid. Detection is carried out using, for example, a spectroscopic or microscopic method.

[0044] The degree of concentration and the speed of this process can be controlled very precisely by the type of superabsorbent used, by its amount used, or by the incubation time and / or the incubation temperature.

[0045] This method provides a simple solution to the problem of concentration during the production of nanoparticles. The method shown in Fig. 1 a and b does not require equipment such as ultracentrifuges, expensive ultrafiltration membranes, complex processes such as PEG precipitation or general precipitation reactions for concentrating nucleic acids, etc. Furthermore, the method is universally applicable with regard to the type of nanoparticles. A further advantage is that the superabsorbents are non-toxic and harmless and often biodegradable. The method according to the invention can therefore greatly simplify the investigation of low-concentration nanoparticles.

[0046] In the case of large-volume and / or highly diluted liquids which contain the nanoparticles or nanoparticles in a very low concentration, a cascading concentration of the target substance is an option. For example, in a first stage, the described process with the above-mentioned steps 1-3 can be used to concentrate the target substance. In a second stage, the second liquid volume 4 can be reduced in volume to further concentrate the target substance. This can be done either by means of a conventional filtration or precipitation process or other conventional methods. Alternatively, the further concentration of the target substance in the second liquid volume 4 can also be achieved, as shown in Fig. 1 c, by adding fresh superabsorbent 5 to the second liquid portion 4 orTransfer of the first sample 4 to a new superabsorbent 5 and renewed incubation for a second period t2. Additionally or alternatively, the liquid portion 6 remaining in the mixture with the superabsorbent 2 after removal of the second liquid volume 4 can be further reduced by incubating the mixture for a third period t3, as shown in Fig. 1d. This leads to further swelling and volume expansion of the spheres consisting of the superabsorbent 2 and to a further volume reduction of the liquid portion 6, which is accompanied by an increase in the concentration of the target substance in the liquid portion 6.

[0047] In both alternative process paths, further concentration stages can follow in cascading fashion.

[0048] An embodiment of the invention is described in more detail below.

[0049] Example: Concentration of Rhodamine B-filled latex nanoparticles (0 25.8 nm) in a water sample

[0050] The latex nanoparticles were provided by the Fraunhofer Institute for Applied Polymer Research. The concentration of the latex particles in the stock solution was 2.02 M%. The particles were added to a 500 ml water sample, creating a 1:10,000 dilution.

[0051] Subsequently, a superabsorbent in the form of commercially available "water beads" was added to the water sample. During the concentration process by absorbing water into the water beads, samples PO, P1, and P2 were taken at different times, each corresponding to a different concentration. The samples are divided into blank samples LO, L1, and L2 for control (without latex nanoparticles) and samples PO, P1, and P2 containing the latex nanoparticles. Specifically, the samples are as follows: Blank sample LO: Ultrapure water without latex particles (500 ml)

[0052] Blank sample L1: Concentration of 500 ml ultrapure water to 40 ml ultrapure water

[0053] Leeprobe L2: further concentration of L 1 to 1 ml ultrapure water

[0054] Sample PO: 1 :10,000 dilution of the latex particle stock solution in 500 ml ultrapure water Sample P1: Concentration of the 500 ml ultrapure water to 40 ml ultrapure water Sample P2: further concentration of P 1 to 1 ml ultrapure water

[0055] The particles in the respective samples were detected by measuring the fluorescence of the dye contained in the latex nanoparticles.

[0056] Fig. 1 shows a qualitative detection of latex nanoparticles. For this purpose, the respective samples PO, P1, P2 and the blank samples L0, L1, L2 were transferred in triplicate to a UV-transparent measuring plate. The measuring plate with the samples was then exposed to UV light. Exposure to UV light excites fluorescence in the samples containing latex particles. No fluorescence is visible in the blank samples L0, L1, L2, and the fluorescence of the samples PO, P1, P2, which contain the latex nanoparticles, increases with increasing concentration.

[0057] Table 1 shows a quantitative measurement of the respective samples using a fluorescence measuring device. The measurements were performed by exciting the samples PO, P1, P2 and the blank samples L0, L1, L2 (each in triplicate) at an emission of 559 nm. While the values ​​of the blank samples L0, L1, L2 remain stable and low with increasing concentration, the values ​​of the samples PO, P1, P2 containing the nanoparticles increase proportionally to the degree of concentration.

[0058] Table 1 :

[0059] Fig. 2 shows a graphic representation of the measured values ​​listed in Table 1, and their evaluation thereof. Fig. 2a shows the mean values ​​of the respective measured values ​​for a sample as a bar chart. Fig. 2b shows a correlation between the degree of concentration and the increase in fluorescence of samples PO ("1"), P1 ("2"), and P2 ("3"), which contained nanoparticles. The experimental data clearly show that the fluorescent latex nanoparticles in the sample do not diffuse into the superabsorbent ("water beads") used, but rather remain in the external solution, thus allowing the concentration of the latex nanoparticles to rise continuously in line with the degree of concentration. This allows for the optimal concentration of nanoparticles, or nanoparticles produced in an industrial process.The industrial process includes, for example, a sol-gel process, an emulsion polymerization process, or an interfacial polymerization process. This creates an emulsion or suspension consisting of a liquid component and the nanoparticles. The nanoparticles have an average size of less than one micrometer. Alternatively, the suspension can also be created by crystallization or complex formation. Adding the emulsion or suspension to the superabsorbent results in the superabsorbent absorbing the liquid of the emulsion or suspension, so that the nanoparticles are present in a high concentration in the remaining residue.

[0060] List of reference symbols

[0061] 1 initial first liquid volume 2.5 superabsorbent

[0062] 3, 6 liquid part of the mixture

[0063] 4 second liquid volume t1 , t2, t3 periods

[0064] L0, L1, L2 blank samples P0. P1. P2 samples

Claims

Patent claims 1. A process for producing an anthropogenic target substance, comprising: - Creating an emulsion or suspension of the target substance, wherein the emulsion or suspension contains particles and / or particles of the target substance with an average particle size in the nanometer range, and - Concentrating the emulsion or suspension by: a) adding a superabsorbent (2) to an initial first liquid volume (1) of the emulsion or suspension or adding the first liquid volume (1) to the superabsorbent (2), b) incubating the mixture formed from the superabsorbent (2) and the first liquid volume (1) over a first period of time (t1), and c) removing a second liquid volume (4) from the liquid portion (3) of the mixture present after incubation.

2. The method according to claim 1, wherein the emulsion or suspension is produced by a sol-gel process, an emulsion polymerization process, or an interfacial polymerization process.

3. The method according to claim 1, wherein the emulsion or suspension is produced by crystallization or complex formation.

4. Method according to one of the preceding claims, further comprising a further concentration of the anthropogenic target substance in the withdrawn second liquid volume (4).

5. The method according to claim 4, wherein the further concentration of the target substance in the withdrawn second liquid volume (4) is carried out by means of a filtration, ultrafiltration or precipitation reaction technique.

6. The method according to claim 4, wherein the further concentration of the target substance in the extracted second target substance (4) is carried out again by: - adding a superabsorbent (5) to the second liquid volume (4) or adding the second liquid volume (4) to the superabsorbent (5), - incubating the mixture formed from the superabsorbent (5) and the second liquid volume (4) for a second period of time (t2), and - Taking a concentrated third volume of liquid from the liquid portion of the mixture remaining after incubation.

7. The method according to claim 6, wherein the target substance is further concentrated in the third liquid volume, in particular by means of a superabsorbent.

8. Method according to one of the preceding claims, wherein the first liquid volume (1) contains a polar liquid, for example water.

9. The method according to claim 8, wherein the particles of the anthropogenic target substance consist of at least one natural polymer, of at least one biocompatible synthetic polymer, of an inorganic material or of an organic material.

10. The method according to any one of claims 1 to 9, wherein the superabsorbent (2, 5) comprises a plastic which absorbs a portion of the liquid volume, water, to form a hydrogel.

11. The method according to claim 9 and 10, wherein the plastic absorbs substantially no particles contained in the anthropogenic target substance.

12. Method according to one of claims 1 to 11, wherein the superabsorbent (2, 5) is used in the form of particles, e.g. as a powder, as granules or in the form of geometric bodies, in particular spheres.

13. Method according to one of claims 1 to 12, wherein the superabsorbent (2, 5) is used in the form of, in particular commercially available, water beads, hydrospheres, aqua pearls, aquabeads, waterbeads, or gel beads.

14. The method according to any one of claims 1 to 13, wherein the volume of the liquid portion remaining after incubation is controlled by the length of the period or periods (t1, t2) of incubation and / or by the type and / or amount of superabsorbent 2, 5) and / or by the temperature of the mixture prevailing during incubation.

15. The method according to claim 14, wherein the superabsorbent (2, 5) is used in the form of particles, e.g. as a powder, as granules or in the form of geometric bodies, in particular spheres, and wherein the volume of the liquid portion remaining after incubation is controlled by the size and / or number of the particles.

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