DE102010034256A1 - Luminescent substance exhibiting a host lattice doped with a luminescent activator, useful in a diagnostic or therapeutic method or a tissue labeling method in vivo or in vitro, where the diagnostic method is graphical angiographic method - Google Patents

Abstract

Luminescent substance exhibiting a host lattice that is doped with at least one luminescent activator, is claimed, where: at least a part of the luminescent substance absorbs a wavelength of 400-1500 nm and is activated for luminescence; the luminescent substance exhibits one or more luminescence emissions in a wavelength of 400-2500 nm; and the luminescent substance contains luminescent particles with a particle size of greater than 100 nm. Independent claims are included for: (1) a luminescent agent comprises the luminescent substance and a carrier, preferably sodium chloride solution; and (2) producing a luminescent agent, comprising either (a) providing the luminescent substance, (b) purifying the luminescent substance for applications in vivo, (c) preparing a stable suspension by obtaining the luminescent substance in a carrier and dispersing the luminescent substance in the carrier, and (d) filtering the suspension through a membrane filter having a pore size of 5 mu m or 2 mu m to obtain a suspension without sedimentable residue, or (a), (b) and preparing a paste by obtaining the luminescent substance in a carrier to produce a paste.

Description

The present invention relates to luminescent substances and luminescent agents for use in a diagnostic or therapeutic method or a tissue marking method, in vivo or in vitro, the use of the luminescent substances and the luminescent agents in a diagnostic or a therapeutic method as well as for the temporary or permanent marking of biological tissues, and methods of making the luminescent agents.

It is known to use electromagnetic radiation in medicine for diagnostic and therapeutic applications. For example, it is known to use infrared radiation in therapy. Infrared heat is used, for example, for complaints of acne, intervertebral discs, eczema, bronchitis, arthritis, head and limb pain, and many other conditions.

Examples of diagnostic applications are studies on the lymphatic system and the blood vessel system such as lymphography and phlebography, and eye examinations such as fluorescein angiography. In this case, a contrast agent is injected and imaged with the contrast agent filled vessel interior, for example by means of X-ray or magnetic resonance tomography. Diagnostic applications of electromagnetic radiation usually require the use of a contrast medium.

Blood vessel system examinations that do not rely on contrast media include sonography, which uses ultrasound, pulse oximetry, which determines the oxygen saturation of the blood by absorption measurements of 660 nm and 940 nm radiation in transmission, and thermal imaging techniques the heat radiation, d. H. the infrared radiation of a body (eg a skin surface) is visualized by means of suitable detectors which convert the infrared radiation into electrical signals.

Contrast agent-free in vivo examinations are less burdensome for the examinee, but in some cases only suitable for very special applications, such as pulse oximetry, and sometimes quite imprecise.

A precise image requires a marking of the object to be imaged. In in vitro methods, a suitable label is relatively unproblematic since the sensitivity of "dead" tissue to radioactive and other labels is not comparable to the sensitivity of living organisms. For example, the coupling of reactive dyes such as fluorescein isothiocyanate to various antibodies (immunoglobulins) and their use for fluorescence microscopy or flow cytometry is known. Thus, specific surface properties (antigens), for example of pathogens, can be detected in liquids, cells or tissues.

For use in vivo higher requirements must be met than when used only in vitro. Labeling agents used in vivo must be hemocompatible and cytocompatible, and must be readily broken down by the body or excreted unchanged through the gastrointestinal tract. The resulting degradation products, like the markers themselves, must not be toxic and cause no immune reactions or other irritant reactions. In addition, the marking agents must be able to be provided in a form suitable for the application. Of course, it is also desirable that the marking agents can be detected as far as possible without the application of potentially damaging radiation such as X-rays. Where possible, the labeling agents should also allow visualization of cohesive biological systems and their visual assessment, such as visualization and assessment of the circulatory system or at least significant portions of the circulatory system.

From the state of the art inorganic luminescent substances are known which can be used in diagnostics, therapy and as contrast agents. The luminescent substances have a particle diameter of at most 100 nm and can diffuse from lymphatic vessels and blood vessels into the surrounding tissue, partly through pores in the vessels and sometimes even through the endothelial layer itself. They are not capable of providing sharp images of the vessels.

It would be desirable to have substances that can be used as labeling agents both in vitro and in vivo. These substances should meet the requirements for in vivo use mentioned above. They should preferably also be inexpensive, and their application should be associated with the least possible expenditure on equipment. The marking agents should be particularly suitable for angiographic examinations, ie neither tend to block the vessels, nor to tend to diffuse out of the vessels. Also desirable would be markers that are suitable for long-term or permanent incorporation into biological tissues to allow for diagnostic or therapeutic applications over an extended period of time, or to allow for permanent labeling of organisms.

The object of the present invention is therefore to provide substances or compositions, and processes for the preparation of the substances or compositions which meet the above-mentioned requirements.

The objects are achieved by the luminescent substance having the features of independent claim 1, the luminescent agent having the features of independent claim 11, the use of the luminescent substance or luminescent medium according to independent claim 13 and the preparation of the luminescent agent having the steps according to independent claims 14 and 15.

Embodiments of the invention are set forth in the respective dependent claims.

The luminescent substance according to the invention for use in a diagnostic or therapeutic method and / or in a tissue marking method is characterized in that it has a host lattice doped with at least one luminescence activator, absorbed in at least part of the wavelength range from 400 to 1500 nm and excitable for luminescence, in the wavelength range of 400 to 2500 nm has one or more luminescence emissions, and that this luminescent substance consists essentially of luminescent particles having a particle size of more than 100 nm. The luminescent substances according to the invention show, even at high excitation intensity, no fluorescence quenching, as can occur with other luminescent substances by supersaturation. Therefore, the luminescent substances according to the invention emit their high-intensity luminescence light even at high excitation intensity.

The luminescent substances to be used according to the invention are inorganic, as a rule crystalline substances based on host lattices which are doped with at least one luminescence activator. The lattice host lattice may be selected from the group consisting of apatites, spodiosites, palmierites, forsterites, brushites, dahlites, ellastadites, francolites, monetites, morinites, whitlockites, willows, voelkites, pyromorphites, garnets, perovskites, silicates, titanates, Vanadates, phosphates, olivines, sulfates, aluminates and zirconates. Oxides, but also ion lattices with halide ions (fluorides, chlorides, bromides, iodides) and / or hydroxide ions as anions, are particularly suitable as host lattices. Often these are mixed grids with oxide ions and / or halide ions and / or hydroxide ions as anions. In contrast, host lattices with sulfide ions are not suitable for in vivo applications because sulfides are a potential source of hydrogen sulfide and hydrogen sulfide is to be avoided because of its toxicity. Hydrogen sulphide acts as an intracellular respiratory poison at certain concentrations. The host lattice of the luminescent substance according to the invention therefore has no sulfide ions. Most preferred are oxides and oxides with hydroxide moieties in the crystal lattice.

Luminescence activators may be different transition metals, depending on the host lattice. Preferably, the luminescence activators are a rare earth element (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and yttrium and / or scandium) or more rare earth elements. Further preferred luminescence activators are transition metals of the electron configuration 3d ² , ie titanium in the oxidation state ²⁺ , vanadium in the oxidation state ³⁺ , chromium in the oxidation state ⁴⁺ , manganese in the oxidation state ⁵⁺ or iron in the oxidation state ⁶⁺ . Codotings with a rare earth element and a luminescence activator of the electron configuration 3d ² are also advantageous.

Particularly preferred are luminescent substances, as disclosed in the documents EP 1 370 424 B1 . EP 0 977 670 B1 . EP 975 469 B1 . EP 0 991 522 B1 and WO 2006/005498 A1 , The disclosure of these references regarding the nature and properties of the luminescent materials is hereby incorporated by reference into the disclosure of the present invention. The luminescent substances are partly Stokes emitters and partly Antistokes emitters.

A preferred class of luminescent substances are substances based on a host lattice doped with at least one rare earth element, which absorbs substantially in the entire visible spectral range, excitable in significant parts of the visible spectral range and at least partially in the wavelength range between 0.8 μm and 1.1 μm is transparent, wherein the rare earth element emits in the wavelength range between 0.8 .mu.m and 1.1 .mu.m, and wherein the host lattice preferably a garnet or Having perovskite structure. The host lattice may have, in particular, chromium or another luminescence-enhancing element as the absorbing component. Preferred rare earth elements are ytterbium, praseodymium and neodymium, which can be used alone or in the form of a codoping.

According to a preferred embodiment, the host lattice has a garnet structure which can be described by the general formula A ₃ B _5-x Al _x O ₁₂ , where A is an element from the group scandium, yttrium, lanthanides, actinides, B is Cr ^{3 +} , Fe ³⁺ , Ga ³⁺ or an ion of one of the other elements of group IIIA of the periodic table and the index x satisfies the condition 0 <x <4.99.

In particular, the luminescent substance has the formula A _3-z B _z C _5-x Al _x O ₁₂ where A is an element from the group scandium, yttrium, lanthanides, C for Cr ³⁺ , Fe ³⁺ , Ga ³⁺ or an ion one of the other elements of group IIIA of the periodic table and B is an element from the group neodymium, praseodymium, erbium, holmium, thulium or ytterbium and the index z satisfies the condition 0 <z <1.

According to a further preferred embodiment, the host lattice has a perovskite structure which can be described by the general formula ABO ₃ , where A is an element from the group of yttrium, scandium or lanthanides and B is boron, aluminum, gallium or indium or other elements of the group Group IIIA of the Periodic Table. More preferably, the luminescent substance has the formula A _1-z C _z BO ₃ , wherein A is an element from the group scandium, yttrium, lanthanides, B is chosen as just mentioned, and C is an element from the group neodymium, praseodymium, erbium , Holmium, thulium or ytterbium and the index z satisfies the condition 0 <z <1.

Some of the abovementioned luminescent substances have emissions in the wavelength range from 800 nm to 1100 nm, others have emissions in the longer wavelength range, in particular at wavelengths just below 2000 nm. These are substances based on a host lattice with garnets doped with at least one rare earth element. or perovskite structure which is substantially absorbed and excitable in the visible spectral region and is transparent at least in partial regions of the IR spectral region, wherein the at least one rare earth element is neodymium, terbium, erbium, holmium, thulium or ytterbium, and wherein the optically transparent region of the At least one rare earth element doped host lattice in the range between 1 .mu.m and 10 .mu.m. As absorbent elements, the host lattice preferably contains iron and / or chromium.

Another preferred class of luminescent substances has the general formula XZO ₄ , where X is Sc _a Y _b La _c Ce _d Pr _e Nd _f Sm _g Eu _h Gd _i Tb _{k D} y _l HO _m Er _n Tm _o Yb _p Lu _q Sb ( III) _r Bi _s Cr _t Mn (III) _u Fe (III) _v [Ba _w Mn (II) _x Fe (II) _y Ca _z Sn (II) _α Sr _β Co _γ Ni _δ Cu _ε ] _3/2 Na _η K _λ ] ₃ [U (IV) _μ Pb _π Th _σ ] _3/4 U (VI) _{φ / 2}
and Z is Nb _za Ta _zb V _zc P _zd [Ti _ze Zr _zf Sn (IV) _zg ] _5/4 W _{zh5 / 6} Fe (III) _{zi5 / 3} and
a + b + c + d + e + f + g + h + i + k + l + m + n + o + p + q + r + s + t + u + v + 3/2 (w + x + y + z + α + β + γ + δ + ε) + 3 (η + λ) + 3/4 (μ + π + σ) + φ / 2 = 1 and
a, b, c, d, e, f, g, h, i, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z α, β, η, δ, ε, η, λ, μ, p, σ and φ respectively
range from 0 to 1 and
za + zb + zc + zd + 5/4 (ze + zf + zg) + 5 / 6zh + 5 / 3zi = 1 and
za, zb, zc, zd, ze, zf, zg, zh and zi range from 0 to 1, respectively.

With regard to preferred embodiments of the luminescent substance is on the WO2006 / 005498 directed.

Another preferred class of luminescent substances has host lattices selected from the group consisting of apatites, spodiosites, palmierites, forsterites, brushites, dahllites, ellestadites, Francolites, monetites, morinites, whitlockites, Wilkeites, voelckerites, pyromorphites, garnets, perovskites, olivines , Silicates, titanates, vanadates, phosphates, sulfates, aluminates and zirconates. These host lattices are preferably doped with Ti ²⁺ , V ³⁺ , Cr ⁴⁺ , Mn ⁵⁺ and / or Fe ⁶⁺ . Codotations with at least one member from the group of rare earth cations are particularly preferred, wherein the rare earth cation is in particular selected from neodymium, holmium, erbium, thulium and ytterbium.

Preferred host lattices are compounds of the following formulas (I) to (XVIII). [Ba _a Ca _b Sr _c Pb _d Cd _e (P _f V _g As _h Si _j S _k Cr _l O ₄ ) ₃ F _m Cl _n Br _p (OH) _q ] _x (I) in which
a + b + c + d + e = 5;
f + g + h + j + k + l = 1;
m + n + p + q = 1;
x = 1 or 2; and
a, b, c, d, e are each from 0 to 5;
f, g, h, j, k, 1, m, n, p, q each range from 0 to 1. [Mg _a Ba _b Ca _c Sr _d Pb _e Cd _f ] [P _g V _h As _j Si _k S _l Cr _m ] O ₄ [F _n Cl _p Br _q (OH) _r ] (II) in which
a + b + c + d + e + f = 2;
g + h + j + k + l + m = 1;
n + p + q + r = 1; and
a, b, c, d, e are each from 0 to 2;
g, h, j, k, 1, m, n, p, q, r each range from 0 to 1. [Mg _a Ba _b Ca _c Sr _d Pb _e Cd _f ] [Si _g Ti _h Ge _j ] O ₄ (III) in which
a + b + c + d + e + f = 2;
g + h + j = 1; and
a, b, c, d, e, f are each from 0 to 2 and
g, h, j range from 0 to 1, respectively. [Li _a Na _b K _c Rb _d ] [P _e AS _f V _g ] O ₄ (IV) in which
a + b + c + d = 3;
e + f + g = 1; and
a, b, c, d each from 0 to 3 and
e, f, g each range from 0 to 1. [Y _a La _b ] [Si _c Ti _d ] O ₅ (V) in which
a + b = 2;
c + d = 1; and
a, b are each from 0 to 2 and
c, d range from 0 to 1, respectively. [Ba _a Ca _b Sr _c Pb _d Cd _e ] (P _f V _g AS _h Si _j S _k Cr _l O ₄ ) ₂ (VI) in which
a + b + c + d + e = 3;
f + g + h + j + k + l = 1;
a, b, c, d, e are each from 0 to 3 and
f, g, h, j, k, l each range from 0 to 1. [Ba _a Ca _b Sr _c Pb _d Cd _e ] (P _f V _g AS _h Si _j S _k Cr _l O ₄ ) ₃ Cl (VII) in which
a + b + c + d + e = 5;
f + g + h + j + l = 1;
a, b, c, d, e are each from 0 to 5 and
f, g, h, j, k, l each range from 0 to 1. [Na _a K _b Cs _c Rb _d] [S Se _{e f g} Cr Mo _h] O ₄ (VIII) in which
a + b + c + d = 2;
e + f + g + h = 1;
a, b, c, d are each from 0 to 2 and
e, f, g, h range from 0 to 1, respectively. [Mg _a Ca _b Sr _c Ba _d ] [S _e Se _f Cr _g Mo _h W _i ] O ₄ (IX) in which
a + b + c + d = 1;
e + f + g + h + i = 1 and
a, b, c, d are each from 0 to 1 and
e, f, g, h, i each range from 0 to 1. [SC _a Y _b La _c Ce _d Pr _e Nd _f Pm _g Sm _h Eu _j Gd _k Tb _l Dy _m HO _n Er _p Tm _q Yb _r Ln _s ] [Al _u Fe _v Cr _x ] O (X) in which
a + b + c + d + e + f + g + h + j + k + l + m + n + p + q + r + s = 1;
u + v + x = 1;
a, b, c, d, e, f, g, h, j, k, l, m, n, p, q, r, s, u, v, x each range from 0 to 1. [Y _a Gd _b Sc _c La _d Ln _e ] [Al _f Fe _g Cr _h ] O ₁₂ (XI) in which
a + b + c + d + e = 3;
f + g + h = 5;
a, b, c, d, e are each from 0 to 3 and
f, g, h range from 0 to 5, respectively. [Mg _a Ca _b Sr _c Ba _d ] [Al _e Cr _f Fe _g Ga _h ] O ₄ (XII) in which
a + b + c + d = 1;
e + f + g + h = 2;
a, b, c, d are each from 0 to 1 and
e, f, g, h each range from 0 to 2. [Mg _a Ca _b Sr _c Ba _d ] [Al _e Cr _f Fe _g Ga _h ] O ₇ (XIII) in which
a + b + c + d = 1;
e + f + g + h = 4;
a, b, c, d are each from 0 to 1 and
e, f, g, h range from 0 to 4, respectively. Y ₂ [Si _a Ti _b Zr _c ] O ₇ or MgCa ₂ [Si _a Ti _b Zr _c ] O ₇ (XIV) or (XV) in which
a + b + c = 2 and
a, b and c each range from 0 to 2. [Ba _a Ca _b Sr _c ] [Si _d Ti _e Zr _f ] O ₅ (XVI) in which
a + b + c = 3;
d + e + f = 1; and
a, b, c are each from 0 to 3 and
d, e, f each range from 0 to 1. [Y _a La _b Zr _c ] [P _d Si _e ] O ₄ (XVII) in which
a + b + c = 1;
d + e = 1; and
a, b, c are each from 0 to 1 and
d, e range from 0 to 1, respectively. K [Ti _2a Zr _2b ] (PO ₄ ) ₃ (XVIII) in which
a + b = 1; and
a, b range from 0 to 1, respectively.

Particularly preferred luminescent substances are YTaO ₄ : Yb such as Y _0.1 TaO ₄ : Yb _0.9 , YNbO ₄ : (Yb, Er) such as Y _0.65 NbO ₄ : Yb _0.18 Er _0.17 and YNbO ₄ :( Yb, Nd) such as Y _0.4 NbO ₄ : Yb _0.5 Nd _0.1 , (La _0.9 Yb _0.1 ) ₂ O ₃ doped with rare earth cations; Ca ₅ (PO ₄ ) ₃ (OH / halogen) doped with rare earth cations or other activators; BaSO ₄ doped with rare earth cations or other activators; and rare earth cation-doped fergusonite: (Yb, Er) such as Y (Nb, Ta) O ₄ : (Yb, Er).

The luminescent substances can be brought into a suitable application form immediately before they are used, but they are preferably prepared and provided as ready-to-use luminescent agent formulations. The formulations of the luminescent agent formulations vary depending on the intended use.

The luminescent substances or the ready-to-use luminescent agent formulations are suitable for use on organisms of any kind, in particular mammals including humans, but also other animals and plants or samples of animal and vegetable material. The application can be in vivo or in vitro. Particularly suitable are the luminescent agent formulations for diagnostic and therapeutic applications in close-up, d. H. near the body surface, such as for diagnostic and therapeutic applications on the blood and lymphatic system, for example for monitoring blood circulation in vivo. The representation of vessels by means of diagnostic imaging methods is referred to in medicine as angiography.

The use in near-surface regions is preferred because of the transmission or absorption behavior of infrared radiation (IR radiation) in biological tissue. IR-A rays with a wavelength between 780 and 1400 nm have a penetration of about 6 mm. When irradiated from the outside, they penetrate into the very lowest layers of the skin. IR-B rays with a wavelength between 1400 and 3000 nm have a penetration depth of about 2 mm. When irradiated from outside, they penetrate into the middle layers of the skin. The value quoted above can be found in therapeutic offers for IR heat treatment: they relate to a comparison of UV, visible and infrared radiation, were thus determined on a concrete, but not exactly specified system and describe only the finding that one finds in the near infrared a penetration depth optimum for the heat treatment.

Systems suitable for medical application consist of an excitation and a detection system which are suitable for excitation of the respective luminescent substance and for detection of the light emitted by it. The excitation light source, the luminescent substance and the detector are spectrally matched to one another. In the selected spectral region of the luminescence, the luminescent substance has a high luminescence efficiency and the detector has a high detection efficiency. As a result, the luminescent light can be optimally detected. The luminescent substances are chosen so that their luminescent light reaches the desired penetration depth of the respective tissue. In order to be able to examine the tissue even at greater depths, wavelengths are chosen for both the excitation and for the detection, which allow a large penetration depth of the excitation and luminescent light. In addition, for medical applications, a high luminescence contrast of the observed tissue structures is advantageous. For this purpose, ambient light disturbances should be eliminated in the medical system used.

The luminescent agent formulations of the present invention are also suitable for eye imaging, which formulations can be used as a conventional contrast agent in fluorescence angiography.

In addition to incorporation into vessels for angiographic applications is also an introduction into tissue for their visualization, therapeutic treatment or marking, and an introduction into organs, for example in the gastrointestinal tract, for their visualization or therapeutic Treatment possible. The luminescent agents of the present invention are formulated as a suspension, as a paste or as a solid.

The introduction into a vascular system is preferably carried out in liquid form, d. H. as a suspension in a suitable carrier medium. The carrier medium is generally the known physiologically acceptable carrier media, in particular aqueous carrier media, in question. The preferred carrier medium is a buffered physiological saline solution. The luminescent agent formulations may also contain conventional auxiliaries, for example pH adjusters, buffer substances, preservatives, and other excipients known to a person skilled in the art. For applications in the blood vessel system, anticoagulants such as EDTA, citrate, ammonium heparinate, lithium heparinate, fluoride or Acid Citrate Dextrose (ACD) are added. The suspension is preferably sterile and injected intravenously.

For incorporation into tissues and organs, a liquid formulation may also be used, i. H. a suspension as in a vascular system, or a pasty formulation or a solid or aerosol formulation. Liquid formulations may be injected, for example, subcutaneously, aerosols for imaging or treatment of airway organs may be inhaled, and pasty formulations are preferably employed in the gastrointestinal tract and may be swallowed. Solid formulations are preferably implanted. The luminescent agents can be introduced only for a short period of time, for example, for a period in the range of minutes, or for a longer period, if necessary permanently.

The luminescent agents of the present invention can be used not only for medical applications but generally used for marking purposes. For example, living animals may be permanently implanted with a particular luminescent agent, similar to a chip implant, or implanted surgically. By combining a plurality of luminescent substances, optionally in different concentrations, or barcode-related applications, a coding can be formed, by means of which the animals can be unequivocally identified. A possible field of application of the luminescent agent is also the monitoring, access control etc. of persons or animals which are marked by the luminescent agent.

Of course, the luminescent agents can be used not only in vivo but also in vitro. These include, for example, tissue examinations and blood analysis in vitro. In particular, pathogens can be identified by detecting the corresponding antigens by means of antibodies which are coupled to luminescent substances of the luminescent agents according to the invention. Thus, recognizing or preventing disease, or monitoring a disease process, is achieved.

The luminescent agents according to the invention are used primarily in diagnostics and analytics, but are also suitable for therapeutic applications. While for diagnostic and analytical applications usually a temporary introduction of the luminescent agent is preferred, d. H. for a period of time ranging from minutes to days, a permanent incorporation is often preferred for therapeutic applications; H. a contribution for a period of a few weeks to a few years and beyond. For therapeutic applications, the fact is used that the infrared radiation emitted by the luminescent substances of the luminescent agents according to the invention can heat biological tissue and possibly burn it. Thus, by specific introduction of the luminescent certain narrow areas can be damaged or destroyed. For example, targeted tumors can be destroyed by a luminescent agent is specifically injected into the tumor to be destroyed and stimulated to luminescence. For targeted destruction of tumors, cysts or other abnormalities, the luminescent agent is introduced directly into the area to be destroyed, for example injected. In the case of a longer-term or permanent introduction of the luminescent agent, the treatment can be repeated as often as required, if necessary.

The luminescent agents according to the invention contain at least one luminescent substance. They may also contain several luminescent substances, for example luminescent substances which have emissions in different wavelength ranges. The type of luminescent substance, d. H. its selection from the viewpoint of suitable emission wavelength ranges, suitable particle sizes, and optionally suitable particle size distributions, depends on the intended use of the luminescent agents.

A particularly preferred use is the use of the luminescent agents for angiography. The angiography allows the display of a larger image of arterial and venous (venography) blood vessels and the identification of circulatory areas, and the representation of lymphatic vessels (Lymphography). In addition, non-anatomical vessels such as vascular prostheses or dialysis shunts can be displayed. Angiographies are mainly used to diagnose vascular diseases, such as atherosclerosis and its sequelae, vasoconstriction, acute vascular occlusions, vessel oozing, vascular injuries, vascular malformations, thrombosis and varicose veins. The luminescent agents according to the invention can thus be used, for example, for the diagnosis and therapy of diabetic angiopathy. A major advantage of angiography is that during the examination, interventions in the vessel shown can be made.

The use of solid particles, as they are the luminescent substances of the luminescent agents according to the invention, in vascular systems has a fundamental problem. On the one hand, blood and lymph capillaries have only small diameters of about 5 to 10 μm and can easily be blocked, in particular when agglomerating the solid particles. On the other hand, some capillaries have pores (fenestrated capillaries), the pores having diameters of about 60 to 80 nm. It must now be ensured that the luminescent particles are transported unhindered through the capillaries, d. H. the capillaries can not clog, and on the other hand can not escape through the pores.

According to the invention, it has been found that the abovementioned luminescent substances based on host lattices doped with at least one luminescence activator are outstandingly suitable for this purpose when they are brought to particle sizes of more than 100 nm. The particle size refers to the diameter of the approximately spherical particles. Preferably, the luminescent particles have diameters greater than 120 nm, more preferably greater than 150 nm. For some applications, the luminescent particles should have a particle size of less than 500 nm, preferably less than 400 nm. For other applications, a particle size of greater than 1000 nm more suitable. The specified particle sizes each denote the maximum value of the diameter distribution.

In addition, the size distribution of the luminescent substance particles should preferably be as narrow as possible. The grain distribution index K _{i of} the luminescent substance particles is preferably at least 2, more preferably at least 3. The grain distribution index K _i is defined as K _i = d ₅₀ / (d ₅₀ -d ₁₀ ). The d ₅₀ value corresponds to the median value of a class distribution, and the d ₁₀ value is analogous to the diameter value, which falls below 10% of the particles divided into classes.

For the observation of larger vessels, coarser particle fractions are also suitable. Arteries and veins can have diameters up to several millimeters and be probed with luminescent particles as small as several microns.

Luminescent agents to be used for imaging in tissues or organs are less subject to particle size and particle size distribution. In principle, luminescent substance particles in the range from 100 nm to 2.5 μm are suitable. The luminescent particles should have a diameter of more than 100 nm, otherwise their detection becomes increasingly difficult. The luminescence of particle fractions with diameters between 100 and 500 nm is better perceptible with the IR microscope. It should also be noted that the luminescent particles are degraded faster the smaller they are. Very small particles in the tissue are mobilized by the vascular system, for example taken up in lymphatic capillaries and transferred to the lymphatic system. For longer-term markings over weeks or months, or even for years, for example, for diagnostic examinations, which are to be repeated several times at specific time intervals, or for therapeutic applications that are repeated several times at intervals, coarse grain distributions are selected to the hydrolytic To slow down degradation of the luminescent substance or to aggravate or avoid mobilization of the luminescent particles by the vascular system. Preferred luminescent substance particles for longer-term or permanent markings have a distribution maximum of the particle sizes at more than 1200 nm, preferably at more than about 1500 nm. Even with longer-term markings, the preferred grain distribution index K _{i is} preferably at least 2, more preferably at least 3.

The particles emitting in the IR region can be detected with a night-vision device (after blocking of the excitation radiation), and if luminescent substance particles emitting in the visible range have been selected, they can be recognized by the naked eye. Otherwise, suitable detectors are available for each IR wavelength range, for example Si detectors, GaAs detectors, GaInAs detectors, Ge detectors and PbS detectors.

The emission wavelengths of the luminescent substances are in the range between 400 and 2500 nm, the emission wavelengths preferably being greater than 600 nm, particularly preferably greater than 750 nm, but preferably less than 2100 nm, particularly preferably less than 1500 nm. The most preferred emission wavelength range is the range of 780 to 1400 nm. The advantage of the near infrared wavelength range of 750 nm to 1500 nm, and more particularly from 780 nm to 1400 nm, is the relatively large penetration depth into biological tissue compared to visible light. As a result, not only directly below the surface emitted luminescent light, but also such luminescent light can be observed, which is emitted from areas of several millimeters depth in the biological tissue. Thus, for example, bloodstreams, parts of the lymphatic system and the nervous system present at these depths can be visualized.

The luminescent agents contain at least one luminescent substance, but may also contain a plurality of luminescent substances, it being possible for the various luminescent substances to be excited to luminescence in similar or different wavelength ranges, and to be able to emit in similar or different wavelength ranges.

To produce the luminescent agents according to the invention, first of all a luminescent substance, or several luminescent substances, are prepared as in the publications EP 1 370 424 B1 . EP 0 977 670 B1 . EP 0 975 469 B1 . EP 0 991 522 B1 or WO 2006/005498 A1 described. Of course, if commercially available, the luminescent substances can also be purchased commercially.

The at least one luminescent substance is then, if it does not have the desired particle size and the desired particle size distribution, brought to this particle size and particle size distribution, for example by grinding and subsequent sieving.

At least for in vivo applications, the at least one luminescent substance is then brought to a biocompatible state by purification, ie substances potentially harmful to a living organism are removed. For purification, the at least one luminescent substance is, for example, washed with distilled water until a dried sample no longer contains any impurity, ie according to standardized analytical methods ( ISO 17025 ) free of pyrogenic and process-related impurities such as heavy metals (Ni, Pb, Cd, Hg, Cr <0.01 ppm), isothiazolines (<0.1 ppm), nonylphenol (<5 ppm), amines (<0.1 ppm) , Aldehydes (<20 ppm) and soluble inorganic salts (<1 ppm).

The luminescent substance obtained in this way can be used as a powder, for example implanted pressed into tablets. In most cases, however, a luminescent agent is produced in the form of a suspension or a paste.

To prepare a suspension, the constant weight dried at least one luminescent substance in sterile, d. H. pathogen-free, physiological saline solution and dispersed, for example by means of a fast-running toothed disc in a closed vessel. The concentration of the at least one luminescent substance in the suspension is about 15 to 25 mg / l, preferably about 20 mg / l, for application of the luminescent agent in the tissue, and about 0.01 to 10 mg / l for use in the vascular system.

Finally, the suspension is filtered through membrane filters with a suitable pore size. Suitable pore sizes are in the range of about 2 μm for use in the vascular system, and in the range of about 2 μm to 5 μm for tissue application. The filtered suspension must have no sedimenting residue.

To prepare a paste, the at least one luminescent substance dried to constant weight is taken up in a quantity of sterile physiological saline solution sufficient to form a paste of the desired consistency and mixed homogeneously, for example by means of a plowshare mixer. Then the paste is ready to use.

The suspension and the paste may contain conventional, physiologically acceptable excipients.

The pH of the suspension or paste is usually adjusted within tolerable limits for optimum compatibility (+ -0.1) and adjusted to the pH value of the field of application. One reason is the better tissue compatibility. A pH close to the isoelectric point reduces the number of reactive Surface charge carriers and the probability of unwanted accompanying reactions. In particular, the pH is in the range 7.0 to 8.5.

After application of the luminescence agent, the luminescence agent in a suitable wavelength range is excited to luminesce to generate an image of the vessel, tissue, organ, etc., with a suitable radiation source, for example a laser, and the luminescence is detected with a commercially available detector. The wavelength range suitable for the excitation and the detector to be used depend on the type of luminescent substance used in the luminescence agent. If larger areas are to be imaged, the surface of the excitation source is scanned in the area in question in a grid pattern. The excitation source is then preceded by an xy scanner, which forwards its excitation signal function components time (t _i ) and location (x _i , y _i ) to an image output unit which (x _i , y _i , t _i ) synchronously the remitted emission corresponding to represents grid-shaped scanned surface.

In terms of a more flexible diagnostic technique, the excitation source or the entire optical unit can be guided around the body, as is known from tomography.

Subsequently, some exemplary formulations and their application are explained.

1. Formulation for the labeling of biological tissue:

A rare earth cation doped oxide (La _0.9 Yb _0.1 ) ₂ O ₃ is ground to a grain size greater than 100 nm, for example, to a grain size having a distribution maximum of 1.5 μm and a grain distribution index K _i of 2 -3, with K _i = d ₅₀ / (d ₅₀ -d ₁₀ ). The d ₅₀ value corresponds to the median value of a class distribution as described in textbooks of statistics, for d _{10 the} analogous "small 10% share" of the distribution of classes divided into classes applies.

The material is washed with distilled water until a dried sample contains no impurities, ie according to standardized analytical procedures ( ISO 17025 ) is free of pyrogenic and process-related impurities such as heavy metals (Ni, Pb, Cd, Hg, Cr), isothiazolines, nonylphenol, amines, aldehydes and (soluble) inorganic salts.

The pH of a 1% suspension is 8.1 +/- 0.1.

The material dried to constant weight is taken up in sterile, (pathogen-free) physiological saline solution at 20 mg / l and dispersed in a closed vessel with a high-speed toothed disc at 6000 rpm.

It is then filtered through membrane filters with a pore size of 5 μm. On the filter surface, no infrared luminescence must be detectable.

This sterile dispersion, which has no sedimenting residue and is allowed to be administered as a 1 ml dose intramuscularly. At the (later unrecognizable) injection sites, infrared luminescence with a conventional infrared sensor (excitation 900 nm, 1-10 mW / cm ² (pulsed) + interference filter 980 to 1100 nm + silicon detector with amplifier electronics + optical is even after years Signal detection + numerical or semi-quantitative output).

2. Formulation for angiography in vascular systems:

A calcium phosphate Ca ₅ (PO ₄ ) ₃ OH doped with rare earth cations or transition metal ions of the electron configuration 3d ² is ground to particle sizes in the range from 100 nm to 500 nm. The grain distribution index K _i is in the range 2-3, with K _i = d ₅₀ / (d ₅₀ - d ₁₀ ).

The material is washed with distilled water until a dried sample contains no impurities, ie according to standardized analytical procedures ( ISO 17025 ) is free from pyrogenic and process-related impurities such as heavy metals (Ni, Pb, Cd, Hg, Cr), nonylphenol, amines, aldehydes and inorganic salts.

The pH of the (later) used dispersion is 7.2 +/- 0.1 and is adjusted in this process step with a suitable phosphate buffer.

The material dried to constant weight is taken up to 0.01-10 mg / l in sterile (pathogen-free) physiological saline solution and dispersed in a closed vessel with a high-speed toothed disc at 6000 rpm.

It is then filtered through membrane filters with a pore size of 2 μm. On the filter surface, no infrared luminescence must be detectable.

After injection of the sterile dispersion, the distribution of infrared fluorescence is examined with a construction as described in the first example; only the excitation wavelength is preceded by an xy-scanner, which forwards its excitation signal function components time (t _i ) and location (x _i , y _i ) to an image output unit which (x _i , y _i , t _i ) synchronously the remitted emission according to represents grid-shaped scanned surface.

In contrast to a conventional angiography with X-ray contrast agents can be dispensed in the case of the present angiography example with the non-toxic luminescent agent Apatit on loading radiation doses of an X-ray source despite comparable information quality.

Another aspect of the substance selection is the complete absorption in the body's metabolism with a suitable half-life of the degradation process.

In terms of a more flexible diagnostic technique, the infrared source or the entire infrared optical unit can be guided around the body as is known from the tomography method.

3. Formulation for the luminescence agent investigation in the gastrointestinal tract:

A baryte (BaSO ₄ ) doped with rare earth cations or a transition metal of electron configuration 3d ² is used in the appropriate grain size between 100 nm to 2500 nm, preferably in grain sizes greater than 1000 nm. The undoped barite is commercially available.

The material is washed with distilled water until a dried sample contains no impurities, ie according to standardized analytical procedures ( ISO 17025 ) is free of process-related pyrogens and impurities such as heavy metals (Ni, Pb, Cd, Hg, Cr), nonylphenol, amines, aldehydes and (soluble) inorganic salts.

The pH of the aqueous (distilled, pathogen-free water) paste used is 7-8. The paste is mixed homogeneously in a ploughshare mixer. In order to eliminate all agglomerates, a so-called mixing accelerator with the construction principle of a pin mill grinding ring is switched on.

After instillation of the luminescent agent into the organism, the distribution of infrared fluorescence is examined with a structure as described in the first example; only the excitation source is preceded by an xy scanner, which forwards its excitation signal function components time (t _i ) and location (x _i , y _i ) to an image output unit which (x _i , y _i , t _i ) synchronously detects the transmitted emission ( to be examined body part between the excitation source and the detector) and on an image output unit passes.

Due to its similarity to X-ray barite, the material is excreted from the body with a typical half-life for contrast agents.

The conventional radiographic devices need only be changed so far that the X-ray source is replaced by an infrared source and the X-ray detector is replaced by a Si photodiode. Thus, the more damaging the body X-ray radiation can be bypassed.

4. Formulation variant for the "coded" labeling of biological tissue (upconversion luminescent substance with Stokes and anti-Stokes luminescence):

A doped with two rare earth fergusonite: (Yb, Er) (Y (Nb, Ta) O _4: Yb, Er) is ground to a grain size which is at least 100 nm, for example. B. a grain size with a distribution maximum of 1.5 microns and a grain distribution index K _i of 2-3 with K _i = d ₅₀ / (d ₅₀ - d ₁₀ ).

The material is washed with distilled water until a dried sample contains no impurities, ie according to standardized analytical procedures ( ISO 17025 ) free of pyrogens and process-related impurities such as heavy metals (Ni, Pb, Cd, Hg, Cr), nonylphenol, amines, aldehydes and (soluble) inorganic salts.

The pH of a 1% suspension is 8.1-8.2.

The material dried to constant weight is mixed with the luminescent substance of Example 1 in a variable ratio at discrete steps between 20 + 80 to 80 + 20 and added to 20 mg / l in sterile (pathogen-free) saline and with a high speed toothed disc at 6000 RPM dispersed in a closed vessel.

Then we filter through membrane filter with 2 micron pore size. On the filter surface, no infrared luminescence must be detectable.

This sterile dispersion, which does not possess any sedimenting residue, is administered intramuscularly as a 1 ml dose. Infrared luminescence with a conventional infrared sensor (excitation 900 nm + 1st channel with interference filter 480 to 580 nm + 2nd channel with interference filter 980 to 1100 nm + silicon detector with amplifier electronics (and signal separation) + optical signal detection + numerical or semi-quantitative output) in different intensity ratios of the two emission wavelengths detectable.

The greatest advantages of the luminescent agents according to the invention and the diagnostic methods and treatment methods carried out with these luminescent agents are that the luminescent agents are considerably better tolerated compared to conventional contrast agents, visualizing coherent biological systems and allowing their visual assessment, the use of potentially hazardous radiation such as X-rays dispensable, and overall represent a cost-effective alternative to previous diagnostic and therapeutic procedures.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1370424 B1 [0016, 0048]
• EP 0977670 B1 [0016, 0048]
• EP 975469 B1 [0016]
• EP 0991522 B1 [0016, 0048]
• WO 2006/005498 A1 [0016, 0048]
• WO 2006/005498 [0023]
• EP 0975469 B1 [0048]

Cited non-patent literature

• ISO 17025 [0050]
• ISO 17025 [0061]
• ISO 17025 [0067]
• ISO 17025 [0076]
• ISO 17025 [0082]

Claims (15)

A luminescent substance for use in a diagnostic or therapeutic method or a tissue marking method, characterized in that the luminescent substance - has a host lattice doped with at least one luminescence activator, - absorbed in at least part of the wavelength range from 400 to 1500 nm and can be excited to luminescence, - im Wavelength range of 400 to 2500 nm has one or more luminescence emissions, and - consists essentially of Lumineszenzstoffpartikeln with a particle size of more than 100 nm. Luminescent substance according to claim 1, characterized in that the host lattice is an oxide or an ion lattice with halide ions and / or hydroxide ions as anions or a mixed lattice with oxide ions and / or halide ions and / or hydroxide ions as anions. Luminescent substance according to claim 1 or 2, characterized in that the luminescence activator is at least one transition metal having the electron configuration 3d ² and / or at least one rare earth element. Luminescent substance according to one of claims 1 to 3, characterized in that the host lattice has a garnet structure or a perovskite structure, which preferably contains one or more of the elements chromium, vanadium, manganese, cobalt or iron as the absorbing element, and that the luminescence activator at least one rare earth element is preferably a rare earth element with one of the elements, ytterbium, praseodymium, erbium and / or neodymium. Luminescent substance according to one of claims 1 to 4, characterized in that the luminescent substance is selected from the group consisting of YNbO ₄ ; Y _b Nd _f NbO ₄ with b + f = 1 and 0 <b <1 and 0 <f <1; Y _b Yb _p NbO ₄ with b + p = 1 and 0 <b <1 and 0 <p <1; Y _b Yb _p Nd _f NbO ₄ with b + p + f = 1 and 0 <b <1 and 0 <p <1 and 0 <f <1; Y _b Yb _p Nd _f NbO ₄ : (Mg, Al) with 0 <b <1 and 0 <p <1 and 0 <f <1, with an additional doping with magnesium and aluminum; Y _b Nd _f NbO ₄ : (Cr, Al) with 0 <b <1 and 0 <f <1, with an additional doping with chromium and aluminum; Y _b Yb _p Pr _e NbO ₄ with b + e + p = 1 and 0 <b <1 and 0 <e <1 and 0 <p <1; Y _b Nd _f Fe _v NbO ₄ with b + f + v = 1 and 0 <b <1 and 0 <f <1 and 0 <v <1; Y _b Er _n NbO ₄ with b + n = 1 and 0 <b <1 and 0 <n <1; Y _b Nd _{f n} It NbO ₄ with b + f + n = 1 and 0 <b <1 and 0 <f <1 and 0 <n <0; Luminescent substance according to one of claims 1 to 5, characterized in that it has one or more luminescence emissions in the wavelength range of 600 to 2100 nm, preferably in the wavelength range of 750 to 1500 nm, more preferably in the wavelength range of 780 to 1400 nm. Luminescent substance according to one of claims 1 to 6, characterized in that the particle size of the luminescent substance particles is up to 2500 nm, wherein it is preferably in the range 120 nm to 2500 nm. Luminescent substance according to one of claims 1 to 7, characterized in that the particle size of the luminescent substance particles in the range 100 nm to 500 nm, preferably in the range 120 nm to 500 nm. Luminescent substance according to one of claims 1 to 7, characterized in that the particle size of the luminescent substance particles is more than 1000 nm, wherein it is preferably in the range 1000 nm to 2500 nm. Luminescent substance according to one of claims 1 to 9, characterized in that the luminescent particles have a particle size distribution index K _i of at least 2, preferably of at least 3. A luminescent agent for use in a diagnostic or therapeutic method or in a tissue marking method, characterized in that it comprises at least one luminescent substance according to any one of claims 1 to 10 and a physiologically acceptable carrier, preferably a physiological saline solution. Luminescent agent according to claim 11, characterized in that the luminescent agent is a suspension or a paste, wherein the concentration of the at least one luminescent substance in the luminescent agent suspension is 15 to 25 mg / l or 0.01 to 10 mg / l, and wherein the pH of the suspension or paste is preferably in the range of 7.0 to 8.5. Use of the luminescent substance according to any one of claims 1 to 10 or the luminescent agent according to claim 11 or 12 in a diagnostic or a therapeutic method or a tissue marking method in vivo or in vitro, the diagnostic method being in particular an angiographic method or a method for marking and examining biological tissue in vivo or in vitro. Process for the preparation of a luminescent agent according to Claim 11 or 12, characterized by the following steps: Providing at least one luminescent substance according to one of claims 1 to 10, Purifying the at least one luminescent substance to bring it into a physiologically acceptable condition, at least for in vivo applications, Preparing a stable suspension by taking up the luminescent substance in a physiologically acceptable carrier and dispersing the luminescent substance in the carrier, and - Filter the suspension through membrane filter a pore size of preferably 5 microns or 2 microns to obtain a suspension without sedementierbaren residue. Process for the preparation of a luminescent agent according to Claim 11 or 12, characterized by the following steps: Providing at least one luminescent substance according to one of claims 1 to 10, Purifying the at least one luminescent substance to bring it into a physiologically acceptable condition, at least for in vivo applications, and Preparing a paste by receiving the at least one luminescent substance in an amount of a physiologically acceptable carrier suitable for producing a paste.