EP3721216A1

EP3721216A1 - Masking and subsquently visualising esr signals using the combination of two materials

Info

Publication number: EP3721216A1
Application number: EP18815955.2A
Authority: EP
Inventors: Norbert Windhab; Andreas Karau; Peter Hölig; Benedikt Hartwig; Julia Lyubina
Original assignee: Evonik Operations GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2017-12-04
Filing date: 2018-11-23
Publication date: 2020-10-14
Also published as: KR102573045B1; CA3084087A1; JP2021505866A; IL275036A; US11666668B2; MX2020005764A; US20210164927A1; KR20200093023A; CN111566474A; WO2019110321A1; BR112020011294A2

Abstract

The invention relates to a body comprising a plurality of phases that have different electron spin resonance spectra not resulting simply from combining the ESR spectra of each phase individually.

Description

Masking and subsequent visualization of ESR signals using the combination of two materials

The invention relates to a body having a plurality of phases which have different electron spin resonance spectra.

In the prior art systems with itinerant magnetism are known in detail, with band electrons showing a spontaneous magnetic order, and they are well distinguished from systems whose magnetic ordering is caused by localized electron spins. The latter are important in chemically complexed atoms, especially almost all colored minerals, often as technical fillers and pigments or rare earths. Other important paramagnetic centers are insulators such as synthetic and natural polymers and organic dyes such as chinoids, antocyanins and polyphenols. The magnetic moment of localized electron spins is also in main and

Subgroups with increasing atomic number of the chemical element, which is the core atom associated with the localized electron spin, are increasingly influenced by spin-orbit coupling effects. The material scientist is therefore also familiar with micro- and macroscopic spin-lattice systems up to metallic conductor bodies.

If the above-mentioned systems, ionic-atomic, chemical complexes, isolator-radical polymers, minerally inertized or naturally mineral, semi-metallic or metallic irradiated with microwaves, thus obtained in the most general different stationary or dynamic electron spin resonance spectra, in the context of Invention, the term "electron spin resonance" is abbreviated to "ESR".

ESR spectroscopy is basically only accessible to systems with unpaired electrons, such as radical systems, paramagnetic transition metals, band magnets, and semiconductors. In the article by Angelika Brückner in Chem. Ing. Tech. 2014, 86, 11, pp. 1871-1882, it is stated that, depending on the system, the resonant electron spin may be subject to complex interactions, for example between electron and nuclear spin, and / or influenced by spatial symmetry. When measuring on systems consisting of several superimposed components, this causes complex, often difficult to interpret, ESR spectra. Although this demonstrates the high potential of the spectroscopic method for the study of unpaired electron systems, it does show that a combination of different systems can not simply be assigned to a linear or easy-to-calculate combination of ESR spectra. If one now sets the task of a given substance in its course through the

To pursue human or animal organism, one expects the challenge, location, identity and the temporal change of the ESR spectrum must be accurately recorded in order to draw conclusions about the physical and / or chemical transformation of the aggregate or substance can, for example during their dissolution in the digestive process or in other processes of their metabolism.

Dorfman, J. Exp. Theor. Phys. 48 (1965), 715, estimates as with such systems

In principle, macroscopic magnetic observables depend on the grain size. Overall, therefore, can be in relevant materials here, especially the medical technical

Formulations predict the behavior of spin system, the moment giving "probe", the aggregate aggregate as well as the legalistic-regular applicability hard.

The intensity of the ESR signal, which is equivalent to the integral of the absorption signal, is directly proportional to the spontaneous magnetization M _{s of} the sample, as the article by B. Heinrich and JF Cochran in Advances in Physics 42 (1993), 523, sets forth. The linewidth of the ESR signal follows a dependence in the form of

DH ~ Ki / Ms,

where Ki is the magnetocrystalline anisotropy constant, cf. Ya.G. Dorfman, J. Exp. Theor. Phys. 48 (1965), 715.

The magnetic shape anisotropy also has a significant influence on the shape and position of the ESR signal. Since the magneto-crystalline anisotropy of the known ferro- or ferrimagnetic materials in the range of 10 ^{3 to} 10 ^® J / m are ^3, is accordingly an ESR linewidth

DH ~ (10 ² ... 10 ⁴ ) Oe

observed. VK Sharma and F. Waldner in J. Appl. Phys. 48 (1977), 4298, observed the linewidth DH in ferrimagnetic Fe 3+ ₄ powder of ~ 1000 Oe at room temperature. It should be noted that the magnetocrystalline anisotropy constant of magnetite is about 3 × 10 ⁴ J / m ³ .

It is also known that in particles with or below a critical size, thermal fluctuations above the magnetocrystalline anisotropy above a critical temperature, also called blocking temperature, dominate, and thus such particles exhibit a superparamagnetic behavior. By contrast, below the blocking temperature, the particles have a ferromagnetic or ferrimagnetic behavior. The critical size of the particles is determined by magnetocrystalline anisotropy. In magnetite, the critical particle size is about 14 nm, cf. G. Vallejo-Fernandez et al., J. Phys. D: Appl. Phys. 46 (2013), 312001. Magnetite nanoparticles with particle sizes of and below 14 nm may have relatively narrow ESR lines characteristic of paramagnetic and superparamagnetic particles. discussed in the article by J. Salado et al., J. Non-Crystalline Solids 354 (2008), 5207, and R. Berger, J. Magn. Magn. Mater. 234 (2001), 535.

A special form of such measurements is the detection of paramagnetic influences on magnetic resonance imaging, but their measurement is based on much weaker nuclear spin interactions.

The inventors have surprisingly encountered another, entirely different context.

If, in the current state of knowledge, one has to understand an ESR spectrum as typical for the irradiated substance, then the task has to be solved, such as systematically controlled and desired

Conversion processes of the substance, in particular by successfully used here

Combinations of different systems, such as in the form of mixtures, compounds or compositions generally from different macroscopic or microscopic phases for the respective composition characteristic ESR spectra provide.

Compositions of at least two materials have been found in which at least one material outside the composition in its pure form would provide a characteristic ESR spectrum. However, in the composition with at least one other material, this same ESR spectrum is surprisingly greatly attenuated or completely gone.

The subject of the invention is therefore a body which has several phases and is absorbed by the human or animal organism or is located within the organism, which is characterized in that the body has at least two phases with a different electron spin resonance spectrum. The article has the advantage of being limited in non-physiological or questionable toxicological in its vital function by radiation or toxicity of the material.

At least one of the phases advantageously has itinerant or localized magnetism. ESR spectra of rare earths are found to be less well suppressed, whereby, depending on the combination, the body according to the invention shows a weakening of the ESR spectrum or a superposition of different ESR spectra.

It may be advantageous if at least one phase of the inventive body has purely paramagnetic centers, preferably S radicals, preferably selected from

Ultramarine. It may be particularly advantageous to select superparamagnetic particles instead of the ultramarine, preferably containing or consisting of magnetite or maghemite or pyrite or iron-containing compounds such as amethyst. For such particles, a similar ESR signal is found. Preferably, at least one phase of the body according to the invention has at least one collective ordering state, which may be ferro-, ferri-, and / or antiferromagnetic. Most preferably, these iron-oxygen compounds. At least one phase of magnetite or a phase of the Fe-0 system is very particularly preferred. The mentioned phases are harmless substances especially for the human or animal organism. In addition, such selected phases may be expressed as tablets formulation.

Surprising are the orders of magnitude of the ESR spectrum weakening or

suppressive effect.

The phases can also be readjusted in particle dispersions. Again, it is surprising that a pharmaceutical formulation can thus be provided in a simple manner, since it is precisely magnetite or a material having Fe-O phases which is very well tolerated by the human organism and would also be useful in human medicine

extremely safe to use. The body according to the invention could therefore also be used safely in the gastrointestinal area, because the body has neither highly toxic substances nor harmful radicals.

Therefore, the invention also relates to the use of the body according to the invention, wherein the ESR spectra stored in a data storage device, and the stored data preferably on the receipt of a request signal out

a receiving device to be transmitted. Thus, the use is still in one

Data management network advantageous.

Particularly advantageous is the use in fingerprint spectroscopy, in

Copyright protection, and / or in the diet.

In any spectroscopy, the better the signal-to-noise ratio of the system under consideration, the better the measurement results, the better the signal-to-noise ratio of the system under consideration, the system in this case being the organism of the invention with the ESR spectrum detection instrumentation. Human and animal organisms by far show predominantly diamagnetic behavior in magnetic fields, and diamagnetic background hardly disturbs even the much more sensitive magnetic resonance imaging. So when using the

inventive body for the measurement of ESR spectra only very small

Magnetic field strengths required.

Furthermore, it may be advantageous that in the body according to the invention at least one phase is enveloped by at least one further phase. Particularly preferably, one phase envelops a further phase as a thin film. Preferably, the thickness of the film and the phases may be selected such that the ESR spectrum of the inner, enveloped phase is completely masked by the ESR spectrum of the outer, enveloping phase.

If the passage of the body according to the invention through the human or animal organism is accompanied by the decomposition of the body, then the decomposition of the enveloping phase causes the ESR signal of the coated phase to become more pronounced as a function of time. This simple time dependence is another beneficial property of the body.

If one chooses magnetite particles in at least one phase of the body, the inventors believe, without being bound to any particular theory, that the ESR spectrum is caused not only by intrinsic magnetic properties but also by dipole interactions between magnetite particles could be. The interactions are preferably influenced by the shape of the particles, for example ball, needle, cube, in general the spatial distribution of the magnetite, for example film. These forms show

different demagnetization fields.

The more ferromagnetic or ferromagnetic components of the body according to the invention, the stronger the ESR signal is weakened. In this case, an absorption of the radiated during spectroscopy microwaves is suspected.

Furthermore, bodies are conceivable in which a ferromagnetic and a free-radical phase, for example an ultramarine phase, are spatially separated, preferably in the form of spatially separated agglomerations. This corresponds to a clear ESR spectrum. If the body is now decomposed, a transient mixing of both phases happens, and with a suitable quantitative ratio of one phase to the other phase, the ESR spectrum of one phase, preferably that of the ultramarine, temporarily disappears completely. Thus, the decomposition of the body in the organism can be specifically attributed to the decomposition process.

It may furthermore be advantageous if the body according to the invention has at least three phases, one phase preferably being paramagnetic, preferably selected from (phen) CuCl 2.

In this case, the ESR line shape is more complex, and one obtains a time-resolved behavior in decomposing the mixture of phases, for example, in the decomposition of the body during the metabolic process in the organism, which is detected with a time-dependence of the ESR spectrum. It is a progressive decomposition documentable.

Accordingly, preferably magnetic, paramagnetic and radical phases can be combined. If such a composite body decomposes in the organism, appears with the decomposition-induced disappearance of the magnetic phase or its detachment from the Body another, so-called "final" ESR line shape, which differs significantly from the ESR line shape of the undecomposed body according to the invention.

Such decomposition processes are beneficial in non-therapeutic processes, such as in the context of personal, non-medically motivated nutrition issues or dietary habits.

However, the decomposition processes are also the goal of, for example, medical implants, in their functional coatings and especially oral dosage forms of

nutraceutical, dietetic or therapeutic formulations such as e.g. Capsules, tablets, films and granules and multiparticulate dosage forms of

Food technologies and, independently, pharmaceutical technologists. You can very targeted by the choice of excipients used, for. designed capsule shells, particle coatings and the materials used in medical technology and thus by the

Formulation process to be controlled. Solubility, particularly preferably pH- and time-dependent solubility of such auxiliaries and excipients are preferred. In the case of medical-technical implants, it is particularly the hydrolysis that leads to the desired absorption of matrices and coatings. Examples include the permissible materials and polymers Eudragit® methacrylates and Resomer® polyester, modified starches such as HMPC, HMPC-AS or polylactites and co-glycolites or co-caprolactone for surgical material, as well as resorbable medical coatings or implants. In doing so, such

Isolatorpolymere, especially medico-technical polymers themselves carry paramagnetic centers, such as e.g. arising during sterilization irradiation by means of e-beam or g-irradiation. Thus, it is further preferred that the inventive body has at least one phase with at least one medico-technical polymer having a paramagnetic center, preferably isolated radicals.

Thus, the appearance of the final ESR line shape can be interpreted as a fingerprint of the body during decomposition in the organism. This will be explained in more detail in Example 2 and Figure 3.

Thus, since mixed phases of pure phases are distinguishable or the elimination of at least one phase of the body according to the invention can be detected, it is now also possible to detect dosages, equivalent to mixtures of differently structured bodies in the organism. Thus, the invention also relates to the use of the body according to the invention, which has at least three phases, for the monitoring of decomposition processes in

human or animal organism.

The invention will be explained in more detail below with reference to examples. The term "room temperature" is understood in the context of the invention, an ambient temperature of 20 ° C.

Example 1. Inventive body containing ultramarine blue and magnetite.

Magnetite FesC powder, abbreviated to "MAG" in the context of the invention, trade name "Cathay pure Black B2310", available from Cathay Industries, and Ultramarine Blue Powder, abbreviated to "UB" or "Ultramarine", trade name "Kremer Pigment, Product No. 45000 ", using mortar with the aid of a plunger in the weight ratios MAG: UB = 1: 30, 3: 30 or

Mixed 4:30.

On the mixture thus obtained, ESR spectra were recorded in the X-band (9.5 GHz) at room temperature and a microwave energy of 6.3 mW, at a modulation frequency of 100 kHz and an amplitude up to 5 Gauss.

In addition, thin films containing MAG, wherein the concentration of the MAG was additionally diluted with methyl cellulose, or UB were applied to different adhesive strips, whereby each of these components had previously been provided in the form of a suspension in ethanol.

ESR spectra were recorded on the layers thus obtained.

In order to ensure that UB and MAG were received intimate contact, so that a sufficient interaction with the S ^- existed radical, the ESR spectra were first added to separate thin layers. Subsequently, the ESR spectrum was recorded on the glued-on adhesive strips.

FIG. 1a shows ESR spectra on various mixtures of MAG and UB.

At a weight-related mixing ratio of UB: MAG = 30: 1, the ESR signal of the S radical at g = 2.026 is still clearly visible. This suggests that not all S3 radicals of the UB have undergone strong magnetic dipole interactions with MAG. But already with an increased content of MAG, corresponding to one

Weight mixing ratio UB: MAG = 30: 3, gave a clear, broad ESR signal at g = 2.307 due to the ferrimagnetic MAG particles. In contrast, the S ^- radical signal was barely recognizable because of the strong magnetic interaction between MAG and S ^- radicals. With a weight fraction of MAG increased to a ratio of UB: MAG = 30: 4, this effect was further increased.

The second derivative of these line shapes after the external magnetic field H _{appi used} for the spectroscopy provided the diagram in FIG. 1b. The doubly differentiated line shapes showed even more clearly the radical signal, especially at the ratio UB: MAG = 30: 4. The increasing influence of the magnetic interactions between MAG and UB with the MAG fraction made itself in the respective peak-to-peak distance in the twofold after the

Magnetic field derived line shape noticeable.

FIG. 2 shows ESR spectra obtained on thin layers of UB and MAG on adhesive strips.

As expected, the ESR signals of the layers coincide with MAG or UB with the ESR signals of the pure components MAG and UB.

However, when intimate bonding was provided by gluing the adhesive strips together, other ESR signals were obtained.

The intensity of the S ^- radical induced ESR signal found it weakened, whereas the ESR signal of MAG hardly lost its intensity but for a slight shift from a value of g = 2.766 to 2.897 g = experience had.

It is believed that this effect was attributed to the magnetic dipole interaction between MAG and UB, which presumably means that even the mechanical

Has simultaneously influenced radical and the ferromagnetic ESR signal ^- contacting the thin layers on the adhesive strip, the ESR signal of the S.

The newly demonstrated ESR spectra show that was sufficient, a proportion of MAG already about 10 wt .-% in mixtures of UB and MAG to the ESR signal of the S ^- to press radical below the detection limit. Even contacting thin layers containing both components attenuated this signal to about half the value.

In contrast, when only a paramagnetic component was mixed with UB, the S radical ESR signal was obtained almost unchanged, even if the proportion of the paramagnetic component was much higher than that of MAG.

Without being bound by any particular theory, the inventors presume the cause of the shift in the ESR signal in FIG. 2 in the magnetic state of the particle which causes self-demagnetization. The resulting internal field Hint can be approximated with a simple relationship:

Hint ^- Happl-NM, where M is the magnetization, N is a demagnetization _factor and H _{appi is} the external magnetic field used for spectroscopy. The demagnetization is dependent on the geometry of the M-containing particles or substance as well as the global shape of the body, which consists of such particles or substance dependent. In the form of a layer, for example, which has led to the spectrum in Fig. 2, one finds a much stronger demagnetizing field when the external magnetic field is applied perpendicular to the layer surface, as is caused by spherical or cubic particles or body. N may be suspected close to 1.

For spherical or cubic particles or bodies, which are not arranged in particular as a layer, N «1/3 can be applied. It is also suspected that the

demagnetizing field causes the shift of the ESR spectra due to a change of magnetostatic interaction when the layers containing magnetite and ultramarine are stacked on each other, as the above-mentioned dipole interactions in the case that magnetite and ultramarine are mixed together.

Example 2. Body containing phen (CuCl2) and ultramarine blue.

As in Example 1, however, the mixture was provided in place of MAG with paramagnetic dichloro (1, 10-phenanthroline) Cu ^M (phen (CuCl 2)) complex and ultramarine blue in the weight ratio 1: 1.

Was observed, a significant attenuation effect in Example 1, in the strong magnetic interaction between MAG and S3 ^- is based radical anion of the ultramarine blue, this interaction was between the paramagnetic component with Cu ^M ions (d ^9, spin = Ά), namely the phen (CuCl2) complex, not present.

The ESR spectrum of the paramagnetic phen (CuCl2) complex showed the typical signals of Cu ^M at g = 2.246 and g = 2.061, shown in Fig. 3, line form b). From the mixture with UB to give the ESR spectrum as superposition of ^M Cu and S3 ^- radical (Figure 3, line shape c.)). Apparently, the line shape c) agreed in a very good approximation with the direct sum of the line forms a) and b), see Fig. 3, line shape a) + b). This proves a vanishing magnetic interaction between Cu ^M and S3 ^- the

Ultramarine blue.

Example 3. Inventive body suspended as a tablet in water.

A mixture of 10 mg Fe3Ü _4, 10 mg and 130 mg of Ultramarine Blue

Methylcellulose pressed into a tablet by the mixture was exposed during 2 min to a pressure of 10 bar.

The tablet thus obtained was crushed and suspended in water in a beaker. For the ESR measurements, samples of the suspension were filled into a glass capillary after different times. Various ESR spectra were obtained as a function of time, shown in Figure 6, with the line shape (a) the not yet suspended tablet and the line shape (b) the signal of the advanced suspension tablet. The apparent total intensity of the ESR signal demonstrates the altered content of suspended solid over time. The monitoring of decomposition processes according to the invention is therefore also possible for a simple dissolution of the body according to the invention. The line shape (c) in FIG. 6 shows the magnetite-free ESR signal for comparison.

Comparative example: ESR measurements on pure magnetite or ultramarine.

On each of a solid sample of magnetite, trade name "Cathey Pure Black B2310 (40969)", and a sample of ultramarine, trade name "Kremer Pigment (45000)", ESR spectra were recorded in X-band at different temperatures.

The pure magnetite showed the typical broad asymmetric singlet for

ferromagnetic behavior, the line shape of which reversibly changed with increasing temperature, shown in Fig. 4. Such behavior is probably due to an overlay

ferromagnetic domains of different structure and / or orientation due.

The ESR spectrum of ultramarine contained a narrow isotropic signal S3 ^- was attributable radical, see Figure 5. It was typical for purely paramagnetic centers.

Observed temperature behavior, d. h., the intensity increased with decreasing temperature.

Claims

claims:

1. Body with multiple phases, by the human or animal organism

is absorbed or is within the organism,

characterized,

the body has at least two phases with a different electron spin resonance spectrum.

2. Body according to claim 1, wherein

at least one phase has purely paramagnetic centers, preferably S radicals, preferably selected from ultramarine.

3. Body according to claim 1 or 2, wherein

at least one phase has at least one collective ordering state,

selected from ferro-, ferri-, and / or antiferromagnetic,

preferably selected from iron-oxygen compounds,

particularly preferably magnetite or a material with Fe-0 phases.

4. Body according to at least one of the preceding claims, wherein at least one phase is enveloped by at least one further phase.

5. Body according to at least one of the preceding claims, wherein

at least two phases are present mixed.

6. body according to claim 1, wherein

the body has at least three phases, one phase is preferably paramagnetic, preferably selected from (phen) CuCl2.

7. Body according to one of the preceding claims, wherein at least one phase comprises at least one medical-technical polymer having a paramagnetic center, preferably isolated radicals.

8. Use of the body according to one of claims 1-7, wherein the obtained ESR spectra stored in a data storage device, and

the stored data are preferably transmitted to a receiving device upon receipt of a request signal.

9. Use according to claim 8 in a data management network.

10. Use according to one of claims 8 or 9

in fingerprint spectroscopy, copyright protection, and / or nutrition.

11. Use of the body according to the invention according to claim 1, which has at least three phases for the monitoring of decomposition processes in the human or animal organism.