• 专利附录
  • 专利说明
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  • 类似技术
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    • 专利摘要:
    System for addressing cells towards target internal regions of a human or animal body, and computer program. The system comprises: - an electromagnet (e) mounted on a first support (s1), - an electronic control system of the electromagnet (e) that calculate the magnitude in three dimensions of a magnetic field to be generated by it (e) so that it attracts and retains in some internal regions target cells paramagnetically marked and injected intravenously ; y - a permanent magnet (ie) mounted on a second support (s2) spaced from the electromagnet (e), to focus the magnetic field generated by the electromagnet (e) to precisely direct, in three dimensions, the marked cells towards the internal regions objective. The computer program is adapted to perform the calculation of the magnetic field to be generated by the electromagnet (e) of the system of the invention. (Machine-translation by Google Translate, not legally binding)
    公开号:ES2635311A1
    申请号:ES201630386
    申请日:2016-03-31
    公开日:2017-10-03
    发明作者:Sara María GARCÍA GIL-PEROTÍN；Paula GARCÍA BELDA；Helena PRIMA GARCÍA；José Manuel GARCÍA VERDUGO；Eugenio Coronado Miralles；Ángel LÓPEZ MUÑOZ；Luis MARTÍ BONMATÍ；Juan SAHUQUILLO BARRIS
    申请人:Instituto De Investigacion Sanitaria - Fundacion Para La Investigacion Hospital La Fe；Fund Hospital Univ Vall D'hebron- Inst De Recerca；Inst De Investig Sanitaria - Fundacion Para La Investigacion Hospital La Fe；Universitat de Valencia；Fundacio Hospital Universitari Vall dHebron Institut de Recerca FIR VHIR；
    IPC主号:
    专利说明:

    SYSTEM FOR THE DIRECTION OF CELLS TOWARDS INTERNAL REGIONSOBJECTIVE OF A HUMAN OR ANIMAL BODY, AND COMPUTER PROGRAM
    5Technical sector
    The present invention generally concerns, in a first aspect, a system for the direction of cells towards target internal regions of a human or animal body,
    10 adapted to magnetically attract cells labeled with superparamagnetic nanoparticles and injected intravenously, and more particularly to a system that precisely attracts, retains and directs the labeled cells towards target internal regions.
    A second aspect of the present invention concerns a computer program, which includes code instructions that when executed in a computer perform the calculation of the magnetic field to be generated by the electromagnet of the system of the invention.
    Prior art
    20 There are several studies related to the mobilization of cells marked with SPIOs (from the English terms "superparamagnetic iron oxide nanoparticles": superparamagnetic iron oxide nanoparticles) by applying a magnetic field. In general, these works have managed to address marked cells to areas
    25 of the organism such as the tail, retina, cartilage, liver, even at the level of the central nervous system in the spinal cord and brain tissue, but all of them using only the application of a stationary magnet, generally with a high field magnitude. In spite of this, in no case is there histological evidence of the specific location of the cells within the same organ.
    30 One such study, focusing in particular on targeting SPIO-labeled cells in brain tissue, is that described in the patent application with publication number US2011 / 0070202 A1 (Yarowsky et al.). In this case the administration of neural progenitor cells (NSCs) labeled with SPIOs is carried out, both
    35 intraventricularly as intraarterially. The magnetic field is generated by a stationary magnet that applies a magnitude between 0.3-0.6 T on one of the hemispheres


    cerebral, and the target tissue in question is the cortical region. The main problem of using NSCs lies in the invasiveness to obtain them, since for this it is necessary to access the walls of the lateral ventricles of the brain and therefore the need for a delicate surgery.
    On the other hand, both the use of the intra-arterial route and that of the intraventricular route have many drawbacks.
    In particular, as regards the intraarterial route, although pulmonary circulation is avoided with it and thus it is easier for the cells to reach the brain tissue directly, it presents a high risk of the occurrence of formation of thromboembolism and that micro-infarcts can be generated at the brain level. It is also a bloody route that requires open cervical surgery, which implies a greater peri-and postoperative risk for the animal. In the case of an alleged transfer to humans, the intra-arterial route would entail an increased risk of bleeding, and an increase in the cost of the intervention in case of endovascular catheterization, and the case of open carotid surgery is not even an option that can be considered by its morbidity On the other hand, a highly invasive surgical intervention is required for intraventricular administration, and therefore it is not very viable at the time of transfer to clinical practice.
    Another such study is that described in the following article: "In vitro angiogenic performance and in vivo brain targeting of magnetized endothelial progenitor cells for neurorepair therapies", Carenza E., et al; Nanomedicine: NBM 2013; January 2014, 10 (1), pages 225–
    234. This describes a system to mobilize endothelial progenitor cells (EPCs) labeled with SPIOs to cortical regions of one of the hemispheres in a cerebral infarction model. In this case, unlike the previous study, the cells are administered intravenously, so they must go a much longer way until they reach their goal. The cells are mobilized by the attraction exerted by a magnetic field generated by two permanent external magnets of 0.3 T glued to the animal's skull for 24 hours.
    The system described in the aforementioned article by Carenza E. et al. it meets the characteristics of the preamble of claim 1 of the present invention.
    The magnetic field generated by the aforementioned two permanent magnets is clearly excessive and causes the cells to be attracted abruptly and unspecifically,


    accessing only superficial layers of the cortical regions, practically at the level of the meninges almost in contact with the skull (as the images of the mentioned article show). Since the final destination of the cells administered for therapy should be the focus of ischemic injury, it should be noted that this is not found in such superficial layers of the cortex, but in deeper areas surrounding the middle cerebral artery. On the other hand, having to apply the magnetic field for such a long time (24h), as well as having to stick the permanent magnets to the animal's skull, make the proposal made in that article really disadvantageous, and hardly transferable to humans.
    There is, therefore, the need to offer an alternative to the state of the art that covers the gaps found therein, by providing a system that allows to direct with more precision the magnetically labeled cells and injected intravenously towards target regions that the system described in the article by Carenza et al., and that it does not have the disadvantages associated with it.
    Explanation of the invention.
    To this end, the present invention concerns a system for the directing of cells towards target internal regions of a human or animal body, which comprises, in a known manner, magnetic field generating means configured to be disposed externally adjacent to a target area of said human or animal body to magnetically attract target internal regions of said target zone to cells marked with superparamagnetic nanoparticles that are injected intravenously, distally, into said human or animal body.
    Unlike the system proposed in the previously described article by Carenza et al., Where the means for generating magnetic field include only stationary magnets, attached to the skull of the animal, and that exert a magnetic attraction on the cells that can be described as abrupt and not very precisely, in the system proposed by the present invention, said magnetic field generation means typically comprise:
    - an electromagnet and a first support on which at least part of said electromagnet is mounted;


    - an electronic control system of said electromagnet comprising a processing system configured to calculate at least the magnitude in three dimensions of a magnetic field to be generated by the electromagnet and of an electrical control signal to be applied to the electromagnet to generate it, from some input variables related at least to the magnetic and physicochemical properties of the labeled cells, to the distance between the injection point of the same and the target internal regions and to the time of application of the magnetic field, in order to that the application of the electrical signal for a certain time causes the electromagnet to generate a magnetic field with said calculated magnitude that attracts and retains the marked cells in said target internal regions; Y
    - at least one permanent magnet and a second support on which said permanent magnet is mounted distanced from the electromagnet, said permanent magnet being configured so that when, by means of said second support, it is disposed adjacent to said target area of the human body or animal, focus the magnetic field generated by the electromagnet to accurately direct, in three dimensions, the marked cells towards the target internal regions.
    Through the use of an electromagnet, the magnetic force of extraction of the bloodstream cells and therefore the addressing is modulated, and through the joint use with the electromagnet of one or more permanent magnets (separated from the electromagnet), the accuracy is improved. in the aforementioned addressing, once the cells are already closer to their final objective, that is to the internal target regions.
    According to an exemplary embodiment, the electromagnet comprises two coils and two respective poles aligned with each other and configured to arrange the human or animal body between them, the poles being left side by side of said target area thereof.
    Depending on the exemplary embodiment, the two coils and two poles are all mounted on said first support or, alternatively, one of the coils and their corresponding pole are mounted on the first support, and the other coil and pole are mounted in a third support, the second support being configured to arrange the permanent magnet or magnets distanced from both poles and coils of the electromagnet.


    Advantageously, the system of the invention comprises a platform or height adjustable stretcher configured to support the human or animal body on it and conveniently position it between the two poles of the electromagnet.
    5 According to an embodiment, the target internal regions belong to the central nervous system.
    According to a preferred embodiment, said second support is mobile.
    According to a variant of said preferred embodiment, the second support is configured to engage a part of the human or animal body by positioning the permanent magnet or magnets that it supports adjacent to said target area.
    15 For an implementation of said variant, the second support is a helmet or sterotomic cap configured to engage the head of the human or animal body, three-dimensionally positioning the magnet or permanent magnets adjacent to it, to focus the magnetic field generated by the electromagnet in target internal regions within the brain tissue of said head.
    20 The use of a support for the magnet or permanent magnets provides a large number of advantages, among which are those related to greater ease and flexibility when positioning the magnet or magnets with respect to the target area, being able to be integrated or coupled, fixed or preferably removable, with respect to the support,
    25 in fixed or adjustable positions, as well as those associated with being able to dispense with the need to have to apply some type of glue or adhesive on the skull of the animal. This aspect is very important to take into account when using the system of the present invention in clinical practice with patients.
    30 It is also proposed the provision, according to some examples of embodiment, of different types of support (helmets, bands, belts, corsets, etc.), each of them adapted to fit a specific part of the animal or human, to Different animals and humans.
    As regards the aforementioned variables associated with physicochemical properties of the 35 labeled cells, these refer, according to one embodiment, at least to the average diameter of


    they, having this, for some cases of particular interest, a value that is between 10 and 20 microns, preferably substantially 15 microns.
    According to an exemplary embodiment, the processing system of the system of the present invention has certain restrictions defined for carrying out said calculation of the magnitude of the magnetic field so that it is above the saturation magnetization of the labeled cells, and that have a value preferably between 180 and 270 mT, and more preferably between 200 and 250 mT.
    As regards the permanent magnet or magnets, this or each of them has a magnetic power of preferably up to 150 mT at zero distance.
    As for the aforementioned determined time, advantageously this has a value of between 1 and 60 minutes, preferably between 20 and 50 minutes and more preferably substantially 45 minutes.
    Both the magnitude values of the magnetic field and the values of its application time constitute substantial differences with the proposals of the state of the art where the magnitude values are larger and, even so, the application times are considerably long, for 24-hour example in the proposal described in the article by Carenza et al.
    Preferably, said cells are mesenchymal stem cells (MSCs) of the "Mesenchymal Stem Cells" in English and superparamagnetic nanoparticles are ultra-small iron oxide superparamagnetic particles (SPIOs), whereby the system of the present invention It is particularly adapted to work with such a class of cells and such a class of labeling.
    In relation to such an application, it is known that cell therapy is a booming field. Numerous trials are underway demonstrating the role of infusion and grafting of mesenchymal stem cells (MSCs) in the repair, after injury, of multiple organs and systems, including the central nervous system (CNS). Despite hopeful results, the main drawback is the poor performance of the techniques known in the state of the art, since only 5-10% of the cells access the CNS, and in particular the threatened areas. This is due to the pulmonary and hepatic filters, among others, that successively in each cardiac cycle are sequestering a percentage of the


    MSCs, which do not reach the target organ. The system proposed by the present invention, by applying magnetic fields in the three dimensions of space, of varying magnitude and obtained by mathematical calculations, allows graft yield to be increased by up to ten times, reaching damaged regions with great precision, which allows to enhance the therapeutic effect that MSCs have been shown to possess.
    Thus, by using the system proposed by the present invention, it is achieved that the labeled cells are finally distributed within the brain parenchyma, usually near large blood vessels, but in deep areas of the cortex that would correspond to the infarction zone in a stroke model, which has been achieved thanks to the theoretical calculation of the resulting magnetic field.
    For another example of embodiment, the system of the present invention further comprises a detection system configured and arranged to detect the concentration of marked cells in at least the target internal regions, said detection system being connected to the electronic control system for provide detection information relative to said detection, and the electronic control system being configured to adjust the electromagnet control based on the detection information received, varying the magnitude of the generated magnetic field and / or increasing or decreasing the application time and / or stopping or starting the application of it. It is thus possible to provide a closed loop control that optimizes the precise targeting of the labeled cells towards the target internal regions.
    Said detection system is, according to a variant of said embodiment, a magnetic resonance neuroimaging based system, although the inclusion of any other kind of detection system is also contemplated.
    As regards the aforementioned calculation of at least the magnitude of the magnetic field to be generated by the electromagnet, advantageously this is also performed from other additional input variables, such as those related to density and / or viscosity of the medium. , to a topographic map and / or connections (veins, organs, etc.), etc.
    In order to carry out the said calculation of the magnetic field, it should be understood that it must be large enough to tear out the marked cells from the blood flow in order to direct them towards the target internal regions, so that in general


    it is necessary to know the density and / or viscosity of the medium, in particular of the cerebral environment when the target internal regions are within the brain tissue.
    Therefore, according to an embodiment of the system of the present invention, said calculation of the magnetic field is carried out taking into account that the magnetic force of attraction experienced by cells marked with superparamagnetic nanoparticles in the direction of application of the magnetic field it is proportional to FM = k0 · M · V, where FM is the magnetic force, M the magnetic field, V the volume of the fluid and ko the coefficient of vacuum permeability, and using, on the other hand, to calculate the hydrodynamic drag force of the cells by blood flow Stokes approximation (drag approximation in a sphere in an applied field), Fa = 6 · π · η · R · vr, where η is the viscosity of the medium, R is the radius of the cell, and vr indicates the speed of the cells in a certain direction. The magnetic force FM (calculated according to the previous expression) to equal or exceed the drag force must be equal to or greater than said force Fa.
    The calculation of the magnetic field is carried out, in general, by an algorithm implemented in the processing system of the electronic control system.
    A second aspect of the present invention concerns a computer program, which includes code instructions that when executed on a computer perform the calculation of at least the magnitude in three dimensions of the magnetic field to be generated by the electromagnet and an electrical signal of control to be applied to the electromagnet to generate it, in accordance with the system of the present invention, according to any one of the embodiments described in relation thereto. Advantageously, said computer program implements said algorithm.
    A further aspect of the present invention concerns a method for targeting cells to target internal regions of a human or animal body, comprising:
    - inject intravenously, in said human or animal body, distally with respect to said target internal regions, cells marked with superparamagnetic nanoparticles; Y
    - accurately direct, in three dimensions, the labeled cells towards the target internal regions, using the system proposed by the present invention.


    Serve the description of the functions of the system elements proposed by the present invention made in the various embodiments described above, as valid to describe corresponding steps or actions of the method of the present invention.
    Brief description of the drawings
    The foregoing and other advantages and features will be more fully understood from 10 of the following detailed description of some embodiments with reference to the attached drawings, which should be taken by way of illustration and not limitation, in which:
    Figure 1 illustrates part of the system proposed by the present invention, for an exemplary embodiment.
    Figures 2a, 2b and 2c are views in respectively perspective, plan and front elevation of the second support of the system of the present invention and of a permanent magnet mounted therein, for an exemplary embodiment for which the second Support takes the form of a helmet for a rat.
    Figure 3 illustrates the system proposed by the present invention, with a rat disposed on the stretcher thereof carrying the second helmet-shaped support of Figure 2.
    Figure 4 shows two images obtained by means of a high-resolution transmission electron microscope.
    or HRTEM) of the magnetic USPs used in an experiment by the present inventors to test the system proposed by the present invention. In the left view a general image is shown and in the right view a detail of a smaller area.
    30 Figure 5 is a graph showing the measurement of USPIO magnetization as a function of temperature by applying a magnetic field of 1 Oe. The measurement was made with a ZC / ZFC protocol, where a blocking temperature of about 70 can be observed
    K. Below the blocking temperature the USPIO have a behavior
    ferromagnetic and for higher temperatures the USPIO will be superparamagnetic. 35


    Figure 6a is a graph in which the hysteresis cycles of the USPIO can be seen at two temperatures, at 300 K and at 2K, where it can be seen that at 2 K the USPIOs present a hysteresis cycle typical of ferromagnetic nanoparticles. At high temperatures and specifically at room temperature the nanoparticles exhibit a superparamagnetic behavior, which means that the particles are magnetic only in the presence of a magnetic field.
    Figure 6b is a graph showing an extension of the hysteresis cycle to 2 K of the graph of Figure 6a.
    Figures 7a and 7b are graphical paths that illustrate, for an experiment carried out by the present inventors, the measurement of the magnetization of the cells marked with USPIO of iron as a function of temperature by applying a magnetic field of 50 Oe and the temperature of blockage over 70 K. Figure 7b shows the hysteresis cycles of the USPIO at two temperatures of 300 K and 2 K, showing a superparagnetic behavior from 70 K. It can be concluded that the cells marked with the USPIO preserve the same magnetic behavior.
    Figure 8 is a comparative table showing the gradient of the magnetic field generated by the electromagnet of the system of the invention at different distances along the Z axis (see Fig. 1), with and without permanent magnet. An important fact that is extracted from this comparison is that the use of the permanent magnet grants a considerable increase in the magnetic force in a very small area, focusing the magnetic force in a given area.
    Figure 9 shows the magnetic field gradient in the ZX direction (see Fig. 1) on the rat's head, where the effect of the presence of the stationary magnet is clearly seen because the magnetic field flux locally increases in the area of interest.
    Detailed description of some embodiments
    An experimental scheme of the system proposed by the present invention is shown in Figure 1 where part of the components thereof are shown, for an exemplary embodiment. In particular, an electromagnet E is shown in Figure 1 which includes two coils B and their corresponding poles D, which are aligned with each other along the Z axis, according to the illustrated X, Y, Z axis nomenclature, the which will be followed during


    The entire process of the experiment will be described below. The coil B is mounted on a support S1 (stationary or mobile). Also illustrated in Figure 1 is a stretcher C, preferably adjustable at least in height, included in the system of the invention and whose purpose is to support the animal thereon.
    5With respect to the axes indicated in Figure 1, it should be indicated that the Z axis runs throughof the head of the rat or other animal, when it is arranged on the stretcher C, that the axisY is the height and X is the depth.
    10 Figures 2a, 2b and 2c show the design of the helmet that constitutes the second support S2, and which will take the animal to add the permanent magnet or magnets IE that are arranged in each experiment or application of the system of the invention.
    In particular in Figure 2a the helmet S2 is illustrated in perspective, in the 2b in plan from
    15 above and in front elevation 2c from the right (according to the position illustrated in Figure 2a). It can be seen how the shape of the helmet has been optimized to adapt it to the rat's head. Holes for the eyes, ears and snout have been opened. Although only one permanent magnet IE has been arranged, several other arrangements are available for other embodiments.
    In Figure 3 the system of the invention is shown again, once a rat has been arranged on the stretcher C carrying the second support, that is to say the hull S2, with the permanent magnet IE, in order to subject it to the experiment that will be described below for migration and targeting of USPIO-labeled cells to the internal regions of your brain.
    25 Description of the experiment:
    In order to carry out said experiment, the present inventors considered increasing the yield of stem cells that reached regions of the brain that had been
    30 damaged (for example, in a stroke). It was hypothesized that iron-labeled cells could be moved or directed by the action of magnetic fields.
    First, the cell type and the type of iron marking had to be determined. At
    The laboratory of the present inventors is conducting cell therapy studies, and lately they are developing the field of mesenchymal stem cells (MSCs) for their


    peculiar biological properties, among them, a very low rejection rate, versatility in terms of its potential for differentiation, immunomodulatory capacity (against inflammation) and reparative power (through in situ secretion of growth factors). The second point, that is to say that of marking, was resolved by going to Nanomedicine, since there are in the market (in various compositions and sizes) iron particles with superparamagnetic properties, of very small size, and of low toxicity, the so-called USPIO . The USPIOs have enormous utility in Biomedicine as contrast agents in magnetic resonance imaging or as drug transport systems, among other applications.
    The next step was to combine both, for which several experiments with polycationic particles were performed, since without them the labeling of MSCs with USPIO was completely absent. It was decided to use low toxicity poly-l-lysine and this allowed an optimal labeling with the nanoparticles. It was followed by the morphological and magnetic study of the USPIOs (both individual and associated with cells), of vital importance to determine their quantity and stability within the cells in vitro and their behavior in vivo, their physicochemical properties being especially important, specifically the size, in order to know the essential parameters to achieve the migration and addressing of the MSCs-USPIO at any point in the brain of a rat.
    Morphological characterization of the USPIO:
    For the morphological characterization of the USPIO, a high-resolution electron microscope HR-TEM was used. The USPIOs used are very small iron oxide particles (γFe2O3), very small, with an average size of 24.36 nm in hydrodynamic diameter (range 5-25 nm), and the representation of the size distribution of the Sample can be considered homogeneous. Figure 4 shows images of them taken in the microscope. The USPIOs have a size that varies from 5 nm to 25 nm, demonstrating that these USPIOs are in the superparamagnetic range.
    Magnetic characterization of the USPIO:
    Iron USPIO (γFe2O3) has a superparamagnetic behavior, and this was empirically confirmed, as well as its main magnetic properties, by means of a magnetometer (SQUID).


    The protocol that was followed was the following (Figure 5):
    • “Zero Field Cool” (ZFC) protocol: USPIOs were cooled to 2K without field
    5 magnetic. Immediately after, under an external magnetic field of 1 Oe, the ZFC was measured from 2 K to 298 K.
    • “Field Cool” protocol, consists of heating the system up to 298 K in the presence of a magnetic field H, FC is measured while lowering the temperature T.
    10 The results showed that magnetization (MFC) always increased when the temperature decreased, following a typical SSG behavior (“Super Spin glass” behavior). The blocking temperature was TB = 69 K. Above this temperature the magnetization decreases as the temperature increases. Further,
    15 above the blocking temperature, the majority of Fe2O3 USPs are superparamagnetic (SPM) and below this temperature are ferromagnetic. That is, nanoparticles that are only magnetic are needed when there is an external magnetic field, and in that respect, these nanoparticles are optimal for working at temperatures above the blocking temperature in their superparamagnetic phase. Without
    However, when they are in their ferromagnetic phase the nanoparticles have a magnetization even when there is no external magnetic field applied.
    Figure 6a shows the magnetization curves of the USPIOs below the 2K blocking temperature, showing a hysteresis cycle of the ferromagnetic phase
    25 with an Hc coercive field of 208 Oe. An extension of said hysteresis cycle is illustrated in Figure 6b.
    The magnetization curves of the USPIO at 300 K are also shown in Figure 6, showing an Hc coercive field of 4 Oe. At temperatures above the temperature
    30 block at 300 K, the coercivity is zero showing a superparamagnetic behavior, indicating that the USPIOs are demagnetized in the absence of an external field. The magnetic field to saturate the USPIO is 100 mT, indicating that the USPIOs are saturated for external magnetic fields greater than 100 mT and can start moving, from this value, in the direction of the magnetic field.


    Magnetic characterization of stem cells labeled with USPIO and calculation of the amount of iron that exists by USPIO:
    The cells marked with USPIO iron were also analyzed with a magnetometer (SQUID). This characterization showed that the cells with USPIO remain magnetic and allowed to reliably quantify the amount of USPIO of iron per cell.
    Figure 7a shows the measurement of magnetization as a function of the temperature measured with the ZFC / FC protocols, where the blocking temperature was TB = 70 K. The cells marked with the USPIO are supermagnetic for temperatures greater than 70 K Figure 7b shows the hysteresis cycles for the cells at two temperatures in the ferromagnetic phase at 2 K and in the superparamagnetic phase at a temperature of 300 K. To calculate the amount of iron in each cell, the data is taken of the remanence magnetization of the labeled cells and is divided by the number of cells in the sample, thus obtaining the magnetization per cell. Since within each cell the only thing that is magnetic is iron, to obtain the weight of iron per cell, the magnetization of the cells is divided by the magnetization of the USPIO. The amount of iron per cell is 3.69 · 10-7 g · Fe / cells.
    Therefore, both nanoparticles and MSCs labeled with USPIO have a similar magnetic behavior.
    Subsequently, in vitro migration experiments of MSC-USPIO were carried out in liquid and semi-solid medium (brain density) that showed indisputably that the cells loaded with iron moved according to applied magnetic fields, and that, in addition, their properties and viability they were not altered by iron or magnets. These experiments were performed with stationary magnets and with electromagnet (7 Amps), creating a magnetic field above the saturation magnetization (see graphs of the variation of the magnetic field with the distance to the stationary magnet IA and the electromagnet E in Figure 8 ).
    Finally, the in vivo test was performed in a control rat model. For this, the system of the invention consisting of: a) An electromagnet E (Figure 1) consisting of: two coils (B) and two poles (D) connected to a power supply was used. The role of the electromagnet E, with a


    7 Ampere electric current intensity is to maintain a magnetic field between 200-250 mT in the region of the animal's head to retain the greatest number of cells.
    b) An S2 hull of polylactic acid, biocompatible polymer, designed to measure the
    5 rat head (Figure 2) and on one side of which a stationary magnet IE with a magnetic power of up to 150 mT at zero distance was placed. That stationary magnet IE would be responsible for focusing the magnetic field, as demonstrated in the magnetic field maps (Figure 8). The magnetic field of the coils was measured with a digital teslmeter equipped with a Hall probe of
    10 standard sensitivity, mounted on an XYZ linear manipulator. The probe has a better accuracy of 99.997%. Magnetic field measurements were made at different distances from the coils of the coils as shown in Figure 8. The measurements correspond to sections in the XY plane, with dimensions 27x26 mm. The distances on the Z axis are referenced to the surface of the D pole of the
    15 electromagnet E. c) A support or stretcher C where the animal is placed in the prone position with the head next to pole D of the electromagnet E (Figure 3). This rat holder allows height adjustment and positioning in the proper position within the magnetic field generated by the electromagnet E.
    20 After placing the previously anesthetized control rat, 1-2 million iron-labeled cells were administered intravenously into the tail vein, and then the 0 A magnetic field (control group without magnet) was activated, -7 A (experimental group) (so that the pole D arranged to the left of the rat would be the south and the one arranged to the
    25 to the north), achieving the magnetic field strengths mentioned (see Figure 8 for the magnetic field gradient).
    A histological analysis of iron-labeled cells in the different regions of the brains of some rats was also performed, after using the same system of
    The present invention for the application of the combined magnetic field (electromagnet + stationary magnet), which showed a clear increase in the number of cells with respect to the controls performed on a control rat.
    Histological analysis of the brains showed a significant increase in concentration of 35 cells in the region where the permanent magnet was located, which was placed on the skin of the rat at the height of the middle region. A magnetic field was applied


    combined, in one case applying a current of -7A in coils B, and in another applying + 7A.
    In the two cases in which the magnetic field was applied, although of greater importance in the case
    5 of the application of a + 7A field, a greater number of cells was observed in the quadrants corresponding to middle and posterior regions. However, in the controls, although cells were observed (as described in cases of intravenous infusion of spontaneous graft MSCs), less than 3 cells were found per quadrant.
    10 Figure 8 shows, in grayscale, the magnetic field gradient generated by the electromagnet E when a current intensity of -7 A is adjusted in the coils
    B. One point was measured experimentally per millimeter with a field meter. Each graph shows the magnetic field gradient on the XY axis (see Figure 1) for
    15 different distances along the Z axis. The measurements were made without and with the permanent magnet IE, in order to provide the comparison of the magnetic field gradient without and with permanent magnet illustrated in the Figure. This shows a slight increase in the magnetic field gradient when the permanent magnet is used, and, above all, a great focus on it even in deep areas.
    20 Also, Figure 9 shows, also in grayscale, the magnetic field gradient in the ZX direction (see Fig. 1) on the rat's head, where the effect of the presence of the stationary magnet is clearly seen IE because it increases the magnetic field flow locally in the area of interest.
    A person skilled in the art could introduce changes and modifications in the described embodiments without departing from the scope of the invention as defined in the appended claims.

    权利要求:
    Claims (15)
    [1]
    1.-System for addressing cells to target internal regions of a human or animal body, which comprises means for generating magnetic field configured to be disposed externally adjacent to a target area of said human or animal body to magnetically attract internal regions objective of said target area to cells marked with superparamagnetic nanoparticles that are injected intravenously, distally, into said human or animal body, the system being characterized in that said means for generating magnetic field comprise:
    - an electromagnet (E) and a first support (S1) on which at least part of said electromagnet (E) is mounted;
    - an electronic control system of said electromagnet (E) comprising a processing system configured to calculate at least the magnitude in three dimensions of a magnetic field to be generated by the electromagnet (E) and of an electrical control signal to be applied to the electromagnet (E) to generate it, based on input variables related to at least the magnetic and physicochemical properties of the marked cells, the distance between the injection point of the same and the target internal regions and the application time of the magnetic field, so that the application of the electrical signal for a certain time causes the electromagnet (E) to generate a magnetic field with said calculated magnitude that attracts and retains the cells marked in said target internal regions; Y
    - at least one permanent magnet (IE) and a second support (S2) on which said permanent magnet (IE) is mounted distanced from the electromagnet (E), said permanent magnet (IE) being configured so that when, by means of said second support (S2), is disposed adjacent to said target area of the human or animal body, focus the magnetic field generated by the electromagnet (E) to accurately direct, in three dimensions, the marked cells towards the target internal regions.
    [2]
    2. System according to claim 1, wherein said electromagnet (E) comprises two coils (B) and two respective poles (D) aligned with each other and configured to arrange the human or animal body between them, leaving the poles (D) on the side and side of said target area thereof.

    [3]
    3. System according to claim 2, wherein one of said coils (B) and its corresponding pole (D) are mounted on said first support (S1), and the other coil (B) and pole (D ) are mounted on a third stand, the second being
    5 support (S2) configured to provide the permanent magnet (IE), which is at least one, distanced from both poles (D) and coils (B) of the electromagnet (E).
    [4]
    4. System according to claim 2 or 3, comprising a platform or stretcher
    (C) height adjustable configured to support the human or animal body on it 10 and position it between the two poles (D) of the electromagnet (E).
    [5]
    5. System according to any one of the preceding claims, wherein said second support (S2) is mobile.
    6. System according to claim 5, wherein the second support (S2) is configured to engage a part of the human or animal body positioning the permanent magnet (IE) that supports, which is at least one, adjacent to said target zone.
    [7]
    7. System according to claim 6, wherein the internal target regions 20 belong to the central nervous system.
    [8]
    8.-System according to claim 7, wherein the second support (S2) is a sterotomic helmet or cap configured to engage the head of the human or animal body, three-dimensionally positioning the permanent magnet (IE), which is at minus one,
    25 adjacent to it, to focus the magnetic field generated by the electromagnet (E) in internal target regions within the brain tissue of said head.
    [9]
    9. System according to claim 8, wherein said variables associated with physicochemical properties of the labeled cells refer to at least the mean diameter 30 thereof.
    [10]
    10. System according to claim 9, wherein the average diameter of the labeled cells has a value that is between 10 and 20 microns, preferably substantially 15 microns.

    [11]
    11. System according to claim 10, wherein the processing system has defined restrictions to carry out said calculation of the magnitude of the magnetic field so that it is above the saturation magnetization of the labeled cells, and having a value preferably between 180 and 270 mT, and with more
    5 preference between 200 and 250 mT.
    [12]
    12. System according to any one of claims 8 to 11, wherein said permanent magnet (IE), which is at least one, has a magnetic power of up to 150 mT at zero distance.
    13. System according to claim 11 or 12, wherein said determined time has a value of between 1 and 60 minutes, preferably between 20 and 50 minutes and more preferably substantially 45 minutes.
    14. System according to any one of the preceding claims, wherein said cells are mesenchymal stem cells and said superparamagnetic nanoparticles are ultra-small superparamagnetic particles of iron oxide.
    [15]
    15. System according to any one of the preceding claims, which
    20 further comprises a detection system configured and arranged to detect the concentration of labeled cells in at least the target internal regions, said detection system being connected to the electronic control system to provide detection information relative to said detection, and the electronic control system configured to adjust the electromagnet control (E) according to the
    25 detection information received, varying the magnitude of the magnetic field generated and / or increasing or decreasing the application time and / or stopping or starting the application thereof.
    [16]
    16. System according to claim 15, wherein said detection system is a system based on magnetic resonance neuroimaging.
    [17]
    17. System according to any one of the preceding claims, wherein said input variables are also related to at least density and / or viscosity of the medium.
    18. System according to claim 17, wherein the processing system is adapted to carry out said calculation of at least the magnitude of the magnetic field

    first calculating the drag hydrodynamic force (FA) of the labeled cells by the blood flow, and establishing as a condition for the calculation of the magnitude of the magnetic field that the magnetic force (FM) of attraction experienced by the cells marked with superparamagnetic nanoparticles in the direction of application of the same
    5 must have a value equal to or greater than that of the calculated drag hydrodynamic force (Fa).
    [19]
    19. System according to claim 18, wherein the processing system is adapted to perform said calculation of the drag hydrodynamic force (Fa) of the
    10 cells per blood flow using Stokes approximation or drag approximation in a sphere in an applied field, according to the following expression: Fa = 6 · π · η · R · vr, where η is the viscosity of the medium, R is the radius of the cell, and vr indicates the speed of the cells in a certain direction.
    15 20.-Computer program, which includes code instructions that when executed on a computer perform the calculation of at least the magnitude in three dimensions of the magnetic field to be generated by the electromagnet (E) and, in order to generate, from an electrical control signal to be applied to the electromagnet (E) of the system according to any one of the preceding claims.

    DRAWINGS
    Fig. 1
    IE

    IE
    Fig. 2b Fig. 2c
    AND
    S1
    Fig. 3

    Fig. 4
    Temperature / K
    Fig. 5

    Fig. 6a
    Fig. 6b

    Fig. 7a
    Fig. 7b

    No permanent magnet With permanent magnet



    Fig. 8

    Fig. 9
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    同族专利:
    公开号 | 公开日
    ES2635311B1|2018-07-19|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US20090287036A1|2008-05-19|2009-11-19|University Of Maryland|Methods And Systems For Using Therapeutic, Diagnostic or Prophylactic Magnetic Agents|
    US20110070202A1|2009-09-18|2011-03-24|Paul Yarowsky|Targeted delivery to the brain of magnetically labeled stem cells|
    US20110301452A1|2010-06-07|2011-12-08|Michael Maschke|Microcapsule for local treatment of a tumor and method for positioning a magnetic gradient field guiding magnetic nanoparticles to a target location as well as apparatus for positioning a magnetic gradient field|
    WO2015023980A2|2013-08-15|2015-02-19|The Methodist Hospital|Method and apparatus for ppoviding transcranial magnetic stimulation to an individual|
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