Device for distributing and receiving a heterogeneous population of pancreatic cells, method and bioreactor

Abstract

The invention relates to a device for distributing and receiving a population of pancreatic islets heterogeneous in size, the device comprising a matrix having a first face opposite a second face, characterized in that the matrix comprises concentric channels centered on a center O, the channels have an opening for receiving the pancreatic cells, the opening leading out onto the first face, the opening extending over the entire length (L) of the channel, the opening having a width (I) taken along the section Si, the device being configured such that the widths of the opening of two adjacent channels have an equal or increasing value moving away from the center O and such that the widths of the opening of a channel closest to the center O and of a channel furthest from the center O have an increasing value moving away from the center O. The invention relates to the field of implantable devices, in particular artificial pancreas devices.

Description

[0001] "Device for distributing and receiving a heterogeneous population of pancreatic cells, process and bioreactor"

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates to the field of implantable devices, in particular artificial pancreas. Its application is particularly advantageous in the production of insulin for the treatment of diabetes, and especially type 1 diabetes.

[0004] STATE OF THE ART

[0005] Diabetes is a global disease that affects both children and adults and requires intensive lifelong therapeutic monitoring. It is estimated that there are 300,000 patients with type 1 diabetes in France and 8 million worldwide.

[0006] Diabetics must constantly monitor their blood glucose levels (commonly abbreviated as GGT, which can also be referred to as blood sugar) in order to receive treatment in case of hypoglycemia (abnormally low GGT) or hyperglycemia (abnormally high GGT).

[0007] Many complications can be avoided by anticipating these critical glucose levels. Indeed, diabetes can cause problems with the heart, kidneys, retina, or nervous system if blood sugar levels rise or fall sharply. Furthermore, it should be noted that the costs of treating these complications represent the majority of expenses related to diabetes therapy.

[0008] It is therefore essential, from both a health and economic perspective, to find a way to maintain blood glucose levels within a normal range in individuals with diabetes. Currently, there are methods for patients to monitor their blood glucose. Among them, glucose tolerance testing (GTT) can be performed on an as-needed basis using an electrochemical device with enzyme electrodes printed on test strips, quantifying blood glucose from a single drop of blood. These devices, commonly called point-of-care devices, allow diabetics to independently monitor their blood glucose. However, patients are required to prick their fingers several times a day to monitor their blood glucose and thus avoid any complications of diabetes. This monitoring is burdensome for the patient and often leads to loss of sensation in the areas of the body where the needles are frequently inserted.

[0009] As an alternative, pancreatic islet transplantation is a proposed treatment for type 1 diabetes, particularly for so-called unstable diabetic patients for whom blood glucose control and monitoring are difficult to implement and cause complications.

[0010] To perform this pancreatic islet transplant, also called islet allotransplantation, doctors typically harvest islets containing healthy beta cells from the pancreas of a deceased organ donor. Doctors then inject these healthy islet cells into the patient through a vein that carries blood to the liver. Once attached to the patient's liver, these islets begin producing and releasing insulin into the patient's body. Several injections of transplanted islet cells are often necessary to stop the use of insulin.

[0011] However, after explantation, vascularization around the transplanted islets takes time, during which many islets degrade due to lack of oxygen and nutrients. Islet mortality is estimated to be between 0% and 40% of the transplanted islets. Furthermore, systemic immunosuppression must be administered to the patient to prevent rejection of the transplanted islets.

[0012] Several approaches have been proposed to limit problems related to inflammation. Some approaches include molecular and pharmacological treatments to protect pancreatic islets from immune reactions. However, these treatments remain burdensome for the patient and of limited effectiveness. Other solutions involve encapsulating the islets in polymer matrices, isolating them from the body's internal environment. The islets are thus protected from attacks by the immune system. Microencapsulation approaches for islets exist. Due to their size, however, microcapsules remain difficult to produce and retrieve for islet replenishment, thus hindering long-term insulin delivery.

[0013] There are also approaches to macroencapsulating islets. One of these generally involves mixing the islets with a polymer that is then solidified. However, due to their size, the diffusion of nutrients and oxygen within the macrocapsules is limited, particularly at the core. Furthermore, surface biofouling leads to isolation of the macrocapsule, further limiting nutrient and oxygen diffusion. Islet mortality remains too high to allow for effective insulin delivery.

[0014] A second type of macroencapsulation involves bioreactor-type devices, which confine islets within a closed system to form, for example, an artificial pancreas. This bioreactor offers patients the prospect of eliminating insulin therapy, thus improving their quality of life. However, the effectiveness of these devices hinges on developing strategies to ensure the islets can meet their oxygen needs. Currently, two solutions are being developed in parallel worldwide: an oxygen synthesis process within the bioreactor. This solution is notably being developed by the team of Anderson et al. [Krishnan SR, Liu C, Bochenek MA, Bose S, Khatib N, Walters B, O'Keeffe L, Facklam A, Langer R, Anderson DG (2023) A wireless, battery-free device enables oxygen generation and immune protection of therapeutic xenotransplants in vivo.]Proc Natl Acad Sci 120:e2311707120] which included a stack to hydrolyze water to extract oxygen or improvement of islet distribution in the bioreactor to avoid islet aggregates which are the source of anoxic nuclei leading to significant cell death.

[0015] US patent 5,425,764 A1 describes an implantable artificial pancreas comprising a chamber containing the islets of Langerhans, equipped with inlet and outlet channels to supply the islets, an open vascular chamber filled with foam, and a semi-permeable membrane separating the chambers. This patent attempts to address the problem of improving the lifespan of the islets by protecting them, within a chamber, from inflammatory agents, for example. However, the vascularization near the chamber, while intended to supply oxygen, also delivers molecules involved in inflammatory reactions and the development of biofouling. US patent 2018 / 0263238 also describes a device for encapsulating insulin-producing cells comprising layers formed from a first membrane and a second membrane, bonded together to form channels.Some channels contain islets, while others are islet-free, forming fluid transport channels that deliver nutrients to the islets. Although this system attempts to address the issue of nutrient delivery to the islets, it is not highly efficient because the nutrients are delivered to channels adjacent to those containing the islets, but also diffuse into the surrounding environment, which is intentionally open to vascularization. Thus, the supply of nutrients to the islets first passes through this external environment, which depletes the amount of nutrients available for further diffusion to the islets contained in other channels.

[0016] We also know of document WO2023275134A1, which describes a pancreatic cell receiving matrix comprising: a semi-permeable wall delimiting at least part of an internal volume, and a porous body, preferably based on at least one polymer, arranged within the internal volume, comprising: a first set of cavities containing pancreatic cells, and a second set of cavities free of pancreatic cells, the first and second sets of cavities not being fluidly connected to each other. The arrangement of the pancreatic cells in the cavity or cavities of the porous body allows control over the distribution of the cells within the porous body, unlike macroencapsulation solutions where the cells are fixed in a polymer matrix that has been solidified.

[0017] Another system for distributing islets within a microstructured matrix of alveoli, in which the islets are trapped, is described by Wang LH, Marfil-Garza BA, Ernst AU, et al (2023) Inflammation-induced subcutaneous neovascularization for the long-term survival of encapsulated islets without immunosuppression. Nat Biomed Eng 1-19.

[0018] However, for populations of varying sizes, such as islets ranging from 20 to 600 µm in diameter, their homogeneous distribution within these structures, which are composed of cells or cavities of a single size, is complicated. This can lead to the formation of islet aggregates in each cell and consequently create oxygen-depleted zones.

[0019] One object of the present invention is therefore to propose a solution to increase the lifespan of pancreatic cells.

[0020] The other objects, features, and advantages of the present invention will become apparent from an examination of the following description and accompanying drawings. It is understood that other advantages may be incorporated.

[0021] SUMMARY OF THE INVENTION

[0022] To achieve this objective, according to one embodiment, a distribution and reception device for a heterogeneous population of pancreatic islets is provided, comprising a matrix having a first face opposite, preferably parallel, to a second face, at least one of the first and second faces extending mainly in an XY plane, characterized in that the matrix comprises concentric channels centered on a center O, the channels having, at each point, a section S, taken along a plane perpendicular to the XY plane and perpendicular to a principal extension direction Dep of the channel at that point, the section S having at least two lateral walls and a bottom wall connecting the two lateral walls, the two lateral walls defining between them an opening for receiving pancreatic cells, opening onto the first face, the bottom wall being opposite the cell reception opening,the receiving opening extending over the entire length L of the channel, taken parallel to the main extension direction Dep, the receiving opening having a width I taken according to section S.,

[0023] The device is configured so that the widths of the receiving aperture of two adjacent channels, taken at points located on the same radial direction, preferably centrifugal passing through the center O and parallel to the XY plane, have an equal or increasing value when moving away from the center O and that the widths of the receiving aperture of a channel closest to the center O and of a channel furthest from the center O, taken at points located on the same radial direction, preferably centrifugal passing through the center O and parallel to the XY plane, have an increasing value when moving away from the center O.

[0024] More specifically, when the matrix comprises two channels, more precisely only two channels, one channel is closest to the center O, another channel is furthest from the center O, the two adjacent channels have receive aperture widths, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, of increasing value as they move away from the center O;when the matrix includes more than two channels, the device is configured so that the widths of the receiving aperture of two adjacent channels, taken at points located on the same radial direction, preferably centrifugal passing through the center O and parallel to the XY plane, have an equal or increasing value when moving away from the center O and that the widths of the receiving aperture of a channel closest to the center O and of a channel furthest from the center O, taken at points located on the same radial direction, preferably centrifugal passing through the center O and parallel to the XY plane, have an increasing value when moving away from the center O.;

[0025] This device allows the pancreatic islets to be distributed according to their size, limiting the formation of aggregates which present a significant mortality risk.

[0026] A second aspect of the invention relates to a pancreatic bioreactor intended to be implanted in the human or animal body comprising the distribution and reception device as described above and a heterogeneous population in size of pancreatic islets arranged in the channels.

[0027] A third aspect of the invention relates to a method for distributing a heterogeneous population of pancreatic islets according to their size, comprising: a. providing a distribution and receiving device as described above, b. depositing pancreatic islets at the center of said device, c. agitating the device so that the pancreatic islets are distributed into the channels according to their size.

[0028] A fourth aspect of the invention relates to a method of insulin delivery comprising the implantation of the bioreactor according to the second aspect, in a human or animal body.

[0029] BRIEF DESCRIPTION OF THE FIGURES

[0030] The aims, objects, features and advantages of the invention will become clearer from the detailed description of an embodiment thereof, which is illustrated by the following accompanying drawings in which:

[0031] Figure 1 represents a cross-sectional view in the XY plane of the device according to the invention.

[0032] Figure 2 represents a top view along the XY plane of the device according to the invention.

[0033] Figure 3 shows a detail of a device according to Figure 1.

[0034] Figure 4 shows a detail of the channels of a device according to Figure 1 in cross-sectional view in the XY plane.

[0035] Figure 5 shows a detail of a device in cross-sectional view in the XY plane according to an alternative embodiment in which the channels have a U shape.

[0036] Figure 6 shows a detail of a device in cross-sectional view in the XY plane according to another alternative embodiment in which the channels have a U-shaped form that narrows at the receiving opening. Figure 7 shows a graph illustrating the quantification of the total surface area of ​​the islands in the different channels of the device according to the invention.

[0037] Figure 8 represents a graph illustrating the average size of the islands in the different channels of the device according to the invention.

[0038] Figure 9 represents a top view along the XY plane of the device according to an embodiment of the spiral channels in the circular matrix.

[0039] The drawings are provided by way of example and are not limiting to the invention. They are schematic representations of principle intended to facilitate understanding of the invention and are not necessarily to scale with practical applications. In particular, the dimensions are not representative of reality.

[0040] DETAILED DESCRIPTION OF THE INVENTION

[0041] Before proceeding with a detailed review of embodiments of the invention, optional features that may be used in combination or alternatively are listed below:

[0042] For example, the receive aperture widths I17 of all the channels 10, measured at points on the same radial direction passing through the center O and parallel to the XY plane, increase in value as they move away from the center O. That is to say, no channel 10 has the same receive aperture width I17 as its adjacent channel. Thus, the receive aperture width I17 of each given channel 10 is less than the receive aperture width I17 of the channel 10 that is immediately adjacent to it and that at least partially surrounds that given channel 10.

[0043] As an example, the reception aperture width I of 17 different channels 10, taken at points located on the same radial direction passing through the center O and parallel to the XY plane, exhibits a maximum variation of 1000%.

[0044] As an example, the reception aperture width I of 17 different channels 10, taken at points located on the same radial direction passing through the center O and parallel to the XY plane, shows a minimum variation of 30%.

[0045] As an example, the bottom wall 16 forms an angle 19 with the two side walls 15. The section S thus has the shape of a rectangle or polygon.

[0046] For example, the bottom wall 16 and the two side walls 15 form a curve. The bottom wall 16 does not form an angle with the two side walls 15, so the section S has a "U" shape or a portion of a circle or ellipse.

[0047] For example, the width I of the receiving aperture 17 of the channels 10 varies between 50 and 800 micrometers. It can be equal to or less than the maximum distance D between the side walls 15, defined as the largest dimension taken transversely between the side walls 15.

[0048] For example, the depth P of channels 10 measures between 100 and 1000 micrometers. The depth P is defined as the largest dimension of the channel taken perpendicular to the XY plane.

[0049] As an example, the channels 10 have a closed contour when projected into the XY plane. The channels are not fluidically connected to each other except by the diffusion of a liquid through the matrix.

[0050] As an example, the device includes a semi-permeable cover 3 suitable for placement on the first face 6 of the matrix so as to seal the receiving openings 17 of the channels 10, and a membrane 5 having a cutoff threshold of less than 15 nm and preferably greater than or equal to 8 nm. This arrangement allows for selective permeability to block the host's immune system without altering the exchange of insulin, gases, and nutrients.

[0051] As an example, matrix 2 is based on methacrylate gelatin, the lid is based on collagen, and the membrane is based on polyvinyl alcohol.

[0052] As an example, the size of pancreatic islets ranges from 20 to 600 micrometers.

[0053] In the following description, the terms "on" or "in contact" do not necessarily mean "directly on" or "directly in contact." Thus, when it is stated that a part or component A1 is supported "on" a part or component B1, this does not mean that parts or components A1 and B1 are necessarily in direct contact with each other. These parts or components A1 and B1 may be either in direct contact or supported by one or more other parts.

[0054] In the detailed description that follows, terms such as "longitudinal," "transverse," "superior," "inferior," "internal," and "external" may be used. These terms should be interpreted relatively in relation to the normal operating position of the device and / or bioreactor, such as an artificial pancreas. For example, "internal" refers to the faces or elements facing inward of the device and / or bioreactor. "External" refers to the faces or elements facing outward of the device and / or bioreactor. For example, for channels extending along a principal direction, "longitudinal" means parallel to this direction, and "transverse" means perpendicular to it.

[0055] The expression "A fluidically connected to B" or "A fluidically connected to B" is synonymous with "A is in fluidic connection with B" and does not necessarily mean that there is no component between A and B. Thus, these expressions refer to a fluidic connection between two elements, which may or may not be direct. This means that it is possible for a fluid to flow between a first element and a second element that are fluidically connected, through one or more conduits, cavities, or channels, possibly including an additional component. This flow is distinct from the simple diffusion of the fluid through the matrix material and may or may not include other components.

[0056] Conversely, the term "fluidically connected directly" refers to a direct fluidic connection between two elements. This means that between a first element and a second element that are fluidically connected directly, no other element is present, other than a conduit / cavity / channel or several conduits / cavities / channels.

[0057] A parameter that is "approximately equal to / greater than / less than" a given value means that this parameter is equal to / greater than / less than the given value, to within 10% or even 5% of that value.

[0058] An element "made of" a material is defined as an element comprising that material and possibly other materials. "Made of" a material means that the said material is the predominant component relative to any other materials.

[0059] The porosity of an element or material is defined as the volume not occupied by the material composing it, relative to the apparent volume of the element or material. This volumetric proportion may be occupied by the surrounding medium of the element or material, a vacuum, a gas, or a liquid, such as water. In the context of the present invention, the porosity of the material is understood to refer specifically to the channels.

[0060] By "cut-off threshold" of a membrane, body or organ is meant the threshold molar mass or threshold dimension for which at least 90%, preferably at least 95%, preferably at least 99%, more preferably still 100%, of species of molar mass or dimension greater than or equal to the threshold molar mass or threshold dimension are blocked by the membrane, body or organ.

[0061] An islet is defined as a group of several cells, preferably of the same type, ranging from a few cells, such as ten, to approximately 5,000 cells. An islet is typically between 20 and 600 micrometers in size. Pancreatic cells may be isolated or grouped together to form pancreatic islets. A pancreatic islet comprises at least one pancreatic cell, and preferably a plurality of pancreatic cells. The cells or islets are advantageously living. In the following description, the terms cell and islet are used interchangeably.

[0062] Device 1 and the bioreactor comprising the device are now described according to several embodiment examples.

[0063] Device 1 according to the invention is intended to distribute and receive cells or islets according to their size.

[0064] Device 1 is applicable to any type of cell, organoid, or microorganism, advantageously living, forming a population or sample heterogeneous in size. More specifically, the device is applicable to the distribution and reception of pancreatic cells. Pancreatic cells may be isolated or grouped into pancreatic islets. A pancreatic islet comprises at least one pancreatic cell, and preferably a plurality of pancreatic cells. In the following, Matrix 2 is considered, for non-limiting purposes, to receive pancreatic islets, also referred to as islets. Examples of pancreatic cells include beta cells of Langerhans. Pancreatic cells may be stem cells destined to become pancreatic cells or pancreatic cells derived from stem cells.

[0065] The bioreactor, comprising device 1 and cells, is intended for implantation in the human or animal body. For example, the bioreactor is designed to receive pancreatic cells, particularly islets of Langerhans; such a bioreactor forms an artificial pancreas intended for implantation in the human or animal body to deliver insulin.

[0066] To receive pancreatic cells, the device includes a matrix 2 comprising channels 10 to accommodate cells.

[0067] According to a preferred embodiment, the device includes a membrane 5 delimiting at least in part an internal volume in which the matrix 2 is disposed and advantageously a lid 3. The membrane 5 is advantageously semi-permeable.

[0068] Matrix 2 comprises a first face 6 opposite a second face 7. The first face 6 is advantageously parallel to the second face 7. The first face 6 and the second face 7 are advantageously connected by an external face 8. The external face 8 defines the thickness of matrix 2. The external face 8 may be curved, for example in the case of a matrix 2 with a circular, oval, etc., cross-section, or it may comprise several straight sections connected successively by angles when the matrix has a polygonal cross-section. Optionally, the external face 8 may be a combination of both. The external face 8 is advantageously transverse, preferably perpendicular to the first face 6 and the second face 7.

[0069] The first face 6 and / or the second face 7 extend(s) mainly along an XY plane.

[0070] The channels 10 formed in matrix 2 to receive the cells are advantageously concentric centered on a center O. This means that the channels develop around the same point, a first channel enveloping a second, or vice versa.

[0071] The channels 10 define, in matrix 2, a receiving volume 18 for the cells. The channels 10 are hollow and elongated.

[0072] The channels extend in a main extension direction Dep. The channels can be of various shapes, for example curved such as circular, oval, rounded, arc of a circle or straight for example polygonal as illustrated in figure 2.

[0073] In one embodiment, the channels 10 can be fluidically independent. Each channel 10 is, for example, closed on itself. The channels 10 do not have a longitudinal end. The channels 10 can have two closed longitudinal ends, that is, ends not fluidly connected to each other and not fluidly connected to other channels. The channels 10 are not fluidly connected to each other except by the diffusion of a liquid through the matrix 2.

[0074] According to another embodiment, the channels 10 are fluidically connected to one another, forming a spiral. The spiral formed by the channels 10 comprises two closed longitudinal ends. The channels 10 are formed of portions rotating around a fixed center O and away from it. Along the same radial direction passing through the center O, the portions form concentric channels.

[0075] In the case where the channels 10 are curved, their main extension direction Dep is tangent to the channel at each point of the channel.

[0076] In the case where the channels 10 are polygonal in shape, the main extension direction Dep is parallel to each side of the polygon.

[0077] The channels 10 present, at each point, a section S, taken along a plane perpendicular to the XY plane and perpendicular to the main extension direction Dep of the channel at that point.

[0078] An example of the embodiment of a device according to the invention is illustrated in Figures 1 and 2.

[0079] The device, according to one embodiment, is illustrated in Figure 2 in a top view. In Figure 2, there are nine channels 10. The channels 10 are concentric around point O. The channels 10 are fluidically independent of each other. The channels extend in a principal extension direction Dep and have a parallelepiped-shaped perimeter in the XY plane, in this case rectangular. If the channels 10 are circular, the perimeter is the circumference of the channel 10. The perimeter can also be called the contour. The channel has a perimeter in the XY plane, which means that the channel's contour is closed. The channel is delimited by its closed contour.

[0080] In the detailed view of Figure 2 in Figure 3, the first three concentric channels 10 from the center O are shown. Each channel 10 has a first channel portion 11,111 corresponding to the first side of the rectangle, a second channel portion 12,112 corresponding to the second side of the rectangle, a third channel portion 13,113 corresponding to the third side of the rectangle, and a fourth channel portion 14,114 corresponding to the fourth side of the rectangle. The first channel portion 11,111, the second channel portion 12,112, the third channel portion 13,113, and the fourth channel portion 14,114 are fluidically connected to form the channel.

[0081] Each part 11,111 12,112 13,113, 14,114 of each channel 10 has a section S and a main extension direction Dep, noted in figure 3 with the index corresponding to the part in question.

[0082] The channels 10 comprise at least two lateral walls 15 and advantageously at least one bottom wall 16. The two lateral walls 15 and optionally the bottom wall 16 define the receiving volume of the cells 18 and a receiving aperture 17. The lateral walls 15 form, for example, an angle 19 with the bottom wall 16; in this case, the cross-section S of the channel 10 is polygonal. For example, the bottom wall 16 has at least one straight portion, or even several straight portions. For example, the bottom wall 16 is parallel to the XY plane and preferably, the bottom wall is parallel to the second surface 7, as illustrated in Figure 1 and Figure 4. The bottom wall 16 defines the receiving surface of the channel. The lateral walls 15 may not form an angle with the bottom wall 16; In this case, section S of channel 10 is at least partially rounded, as illustrated in Figure 5 and Figure 6.For example, the bottom wall 16 is rounded.

[0083] The receiving opening 17 opens onto the first face 6. The receiving opening 17 is defined between the lateral walls 15 at the level of the first face, advantageously in the XY plane. The receiving opening 17 extends over the entire length (L) of the channel.

[0084] The channels 10 are open along their entire length (L). The channels 10 are said to be surface channels on the first face 6 of the matrix 2. The channels 10 are open on the first face 6.

[0085] The receiving opening 17 has an opening width I taken according to section S. The opening width I is also called the channel width.

[0086] According to the invention, the width of the opening I of a different, non-adjacent channel, taken on the same radial direction passing through the center O, has an increasing value as it moves away from the center O. The concentric channels of increasing size allow the cells to distribute themselves according to their size over the entire surface of the device.

[0087] Advantageously, the channel closest to the center O and the channel furthest from the center O have opening widths I, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, of increasing value with respect to the center O. The end channels are of different dimensions, the furthest channel having a larger opening width I than the channel closest to O.

[0088] Advantageously, two adjacent channels have opening widths I, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, and have an equal or increasing value as they move away from the center O. Thus, two adjacent channels can have an equal width I.

[0089] According to one embodiment, it is possible that two adjacent channels 10 can have the same width I, provided that the channel closest to the center O and the channel furthest from the center O have opening widths I, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, of increasing value as they move away from the center O. In this case, there are at least three channels, a channel closest to the center O, a channel furthest from the center O and at least one so-called intermediate channel.

[0090] According to one embodiment, the matrix comprises two channels 10. More precisely, the matrix comprises only two channels, the two channels being adjacent. In this configuration, one channel is closer to the center O, the other channel is further from the center O; they have opening widths I, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, with increasing values ​​as they move away from the center O.

[0091] According to one embodiment, the matrix comprises more than two channels 10.

[0092] In this configuration, one channel is closest to the center O and the other channel is furthest from the center O, they have opening widths I, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, with increasing values ​​as they move away from the center O.

[0093] In this embodiment, the matrix comprises, according to a first possibility, three channels 10. In this configuration, one channel is closest to the center O and the other channel is furthest from the center O; they have aperture widths I, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, of increasing value with respect to the center O. The device is configured such that the widths I of the receiving aperture 17 of two adjacent channels 10, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, have an equal or increasing value with respect to the center O.That is to say that the channel 10, called intermediate, arranged between the channel 10 closest to the center O and the channel furthest from the center O has a width I of the reception opening 17 of value equal to that of the channel 10 closest to the center O and the channel furthest from the center O has a width I of the reception opening 17 of value increasing to that of the channel 10, called intermediate, or the channel 10, called intermediate, has a width I of the reception opening 17 of value increasing to that of the channel 10 closest to the center O and of value equal to that of the channel furthest from the center O.

[0094] In this embodiment, the matrix comprises, according to a second possibility, more than three channels 10, i.e. for example 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or more. In this configuration, the device is configured such that the widths I of the receiving aperture 17 of two adjacent channels 10, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, have an equal or increasing value with respect to the center O, and the widths I of the receiving aperture 17 of a channel 10 closest to the center O and of a channel 10 furthest from the center O, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, have an increasing value with respect to the center O.

[0095] In particular, more medium-width channels and fewer small or large channels can be planned, as it typically has few small or large islets and many medium-sized ones. The number of channels of the same size is adapted to the distribution of islet sizes among the population.

[0096] For example, for two given adjacent channels, the width 11 of the first channel is equal to the width I2 of the second channel. On the other hand, there exists at least a third channel that at least partially surrounds the first and second channels and has a receive aperture width I17 greater than those of the first and second channels.

[0097] According to another embodiment, two adjacent channels 10 have different widths I which advantageously increase as they move away from the center O. The width 11 of a receiving aperture 17 of a first channel is less than the width I2 of the receiving aperture 17 of a second channel 10.

[0098] For example, the width of the ducts and the number of ducts of each width are defined based on the number and probability density of the diameter of the pancreatic islets, which is specific to each species (i.e., human, porcine, etc.). The width of the ducts is determined by the distribution of the islet population according to their diameter. The number of ducts of the same width is defined based on the distribution of the islet population according to the total area occupied by each diameter.

[0099] As an example, the width I of two adjacent channels varies between 30% and 100%. For instance, among two adjacent channels, the channel furthest from the center O has a width I 30% to 100% greater than the width I of the adjacent channel closest to the center O.

[0100] As an example, the width I of the receiving openings 17 varies between 50 and 800 micrometers.

[0101] The lateral walls 15 are, for example, parallel to each other. The lateral walls 15 extend transversely from the first face 6 of the matrix 2. According to one possibility, the lateral walls 15 are parallel to each other. According to an alternative possibility, the lateral walls 15 are rounded.

[0102] Each channel has a width I corresponding to the width of the receiving opening 17 extending parallel to the XY plane and advantageously at the level of the ends of the side walls 15.

[0103] Each channel has a depth P. The depth P is understood as the greatest dimension along a direction perpendicular to the XY plane between the bottom wall 16 of the channel and the receiving opening 17. Preferably, the depth of the channels measures between 100 and 1000 micrometers.

[0104] Each channel 10 has a maximum distance D between the side walls 15. The distance D extends as the largest dimension along a direction parallel to the XY plane between the side walls 15. In one possibility, the distance D is identical to the width I of the receiving opening 17. In another possibility, the distance D is greater than the width I of the receiving opening 17. Each channel has a length L. The length L is understood as the dimension taken parallel to the main extension direction Dep. The length L of a channel corresponds to the length of its perimeter.

[0105] Section S can be of various shapes. Preferably, the 10 channels are all of the same shape.

[0106] According to one embodiment, the channels 10 have a polygonal S-section, more preferably rectangular, or even square.

[0107] According to another embodiment, the channels 10 have a rounded or oval S-section.

[0108] The channels 10 are spaced from each other by a spacing E. The spacing E is understood as the dimension taken along the XY plane separating two adjacent channels, that is to say, the dimension between the nearest lateral walls 15 of two adjacent channels 10. As an example, the spacing is on the order of 200 pm.

[0109] According to one embodiment, the device according to the invention, more specifically the matrix 2, may include at least one conduit and preferably conduits free of cells and configured to ensure the circulation of nutrients and gases within the matrix 2. The at least one conduit is, for example, of identical configuration to the channels 10, that is to say, in particular opening onto the first face 6. According to another example, the at least one conduit does not open onto the first surface 6, the at least one conduit is closed around its entire perimeter and only opens from the matrix 2 at at least one end or both of its ends.

[0110] In one example, matrix 2 is based on a material suitable for 3D printing. In another example, the matrix is ​​based on a natural or synthetic polymer, preferably biocompatible and non-biodegradable.

[0111] According to one example, matrix 2 is a hydrogel, for example, made of methacrylate gelatin.

[0112] According to another, more advantageous possibility, matrix 2 can be based on or made of a material capable of allowing the passage of nutrients and gases, as well as insulin produced by the islets, and of blocking the islets. Thus, exchanges between the cells and the outside of the device occur through the openings 17 of the channels 10 and through matrix 2 itself.

[0113] To achieve this, the matrix 2 material may have a cutoff threshold preferably significantly greater than or equal to the molecular mass of insulin, i.e., greater than or equal to 8 nm. To block the islets, the matrix 2 material may have a cutoff threshold preferably significantly less than or equal to the minimum size of the islets. As an example, the matrix 2 material may have a cutoff threshold significantly less than or equal to 20 pm.

[0114] Advantageously, matrix 2 has a cutoff threshold configured to limit or even prevent the passage of inflammatory agents. Advantageously, matrix 2 has a cutoff threshold configured to limit or even prevent the vascularization of matrix 2.

[0115] According to one example, the device includes a cover 3 intended to seal the channels 10 more specifically the receiving openings 17. The cover 3 is intended to be applied to and to be in contact with the first face 6.

[0116] Lid 3 is preferably made of polymers / biomaterials such as collagen or chitosan. To make them non-biodegradable, they are cross-linked, for example, with glutaraldehyde or genipin.

[0117] The lid 3 has non-selective porosity. It is designed to keep the cells in the channels 10 without limiting the diffusion of nutrients and gases, as well as the insulin produced by the islets, and serves only to block the islets.

[0118] In one possibility, the material of the lid 3 may have a porosity suitable for allowing the passage of nutrients and gases, as well as insulin produced by the islets. The porosity may be configured to allow the passage of molecules with a size at least equal to that of insulin. In one example, the material of the matrix 2 may have a cutoff threshold greater than or equal to 8 nm. Since nutrients and gases have a molar or molecular mass less than 8 kDa, their passage through the material of the lid 3 is permitted. To block the islets, the material of the lid 3 may have a cutoff threshold preferably less than or equal to the minimum size of the islets. In one example, the material of the matrix 2 may have a cutoff threshold preferably less than or equal to 20 µm.

[0119] The device according to the invention is advantageously coated at least in part with a membrane 5.

[0120] According to one example, membrane 5 is a flexible membrane covering at least part of matrix 2.

[0121] The membrane 5 is arranged around the periphery of the matrix 2 and advantageously of the lid 3. The second face 7 and the external face 8 of the matrix are covered by the membrane 5.

[0122] The cover 3 is preferably coated on its external face, opposite to the first face 6 of the membrane device 5.

[0123] Membrane 3 is advantageously semi-permeable and can be based on or made of a material capable of allowing the passage of nutrients and gases, as well as insulin produced by the islets, and of blocking immune system molecules, such as cytokines. Advantageously, membrane 5 has a cutoff threshold configured to limit or even prevent the passage of inflammatory agents. Advantageously, membrane 5 has a cutoff threshold configured to limit or even prevent the vascularization of matrix 2.

[0124] To achieve this, membrane 5 can have a cutoff threshold greater than or equal to 8 nm and less than 15 nm. With a cutoff threshold greater than or equal to 8 nm, membrane 5 allows communication of bodily fluid between the internal environment and matrix 2, which contains the islets. This allows the islets to receive the nutrients they need from the internal environment, and the insulin produced by the islets can be released into this environment to regulate blood glucose levels. With a cutoff threshold less than 15 nm, membrane 5 blocks the passage of immune system molecules, particularly cytokines, into device 1. This protects the islets from immune system reactions. Systemic immunosuppression in the patient can then be limited, and preferably avoided.

[0125] Device 1 can be configured so that membrane 5 is in direct contact with the patient's body.

[0126] As an example, membrane 5 is based on a natural or synthetic polymer, preferably biocompatible and non-biodegradable. Preferably, membrane 5 is based on a polymer exhibiting anti-biofouling properties.

[0127] As an example, membrane 5 is based on or made of at least one polymer from among polyethylene glycol (PEG), polyvinyl alcohol (PVA), a copolymer (ethylene vinyl alcohol) (EVOH), hexadimethrine bromide (more commonly known by the trade name Polybrene), and carboxymethyl cellulose. The membrane thus exhibits good biocompatibility and limits biofouling.

[0128] According to one example, the reservoir includes at least one of a nutrient for pancreatic cells and an anti-inflammatory compound.

[0129] As an example, the fluidic module includes a pump configured to induce a flow of liquid from a liquid external to the device, for example a body fluid, into the matrix and for example into the conduits.

[0130] In one example, the fluidic module includes a controller configured to regulate at least one parameter of the flow formation by the fluidic module. In another example, the device further includes at least one anode and at least one cathode, and an electrical power source. The anode and cathode can be electrically connected to the power source so that, in the presence of body fluid, a closed electrical circuit is formed to produce hydrogen at the cathode and oxygen at the anode through electrolysis of the body fluid. Pancreatic cells are thus protected by the production of oxygen and hydrogen through electrolysis, thereby enhancing insulin release into the internal environment.

[0131] In one example, the device is configured to electrolyze bodily fluid only in liquid form. The electrolyzed bodily fluid then contains no gaseous fraction.

[0132] According to one example, at least one of the cathode and the anode is disposed in the internal volume delimited at least in part by the membrane 5 of the device.

[0133] In one example, at least one of the cathode and anode is arranged in matrix 2. In another example, the cathode and anode are arranged in matrix 2.

[0134] According to one example, at least one of the cathode and the anode is disposed on, preferably directly on matrix 2.

[0135] According to one example, the cathode and the anode are arranged in contact, preferably directly in contact, with the outer perimeter of the matrix 2. According to another aspect, the invention relates to a bioreactor intended to be implanted in the human or animal body comprising the distribution and reception device and a heterogeneous in size population of cells arranged in the channels.

[0136] Advantageously, the cells are pancreatic cells.

[0137] Preferably, the cells, and in particular the clusters of pancreatic cells called pancreatic islets, have a size between 20 and 600 µm.

[0138] According to another aspect, the invention relates to a method for distributing and receiving a heterogeneous population of pancreatic islets in size according to their size.

[0139] The process first involves providing a distribution and reception device as described above.

[0140] The process then involves depositing cells at the center O of the device. For this step, a pipette deposition method is chosen, for example.

[0141] The process then involves agitating the device so that the cells are distributed into the channels according to their size. Advantageously, the device is agitated only along the XY plane. For example, the agitation can be done manually.

[0142] According to one aspect, the invention relates to a method for manufacturing the bioreactor in which, after the steps of the process of distributing and receiving a heterogeneous population in size of cells or islands of cells according to their size, the method includes the positioning of a lid 3 on the first face 6 of the matrix 2. The method advantageously includes a step of coating the matrix 2 and the lid 3 with the membrane 5.

[0143] Examples

[0144] Example 1: Manufacturing a cell distribution and reception device

[0145] A device comprising a matrix 2 based on 100 mg / ml methacrylate gelatin derived from bovine skin (type B) combined with lithium phenyl-2,4,6-trimethylbenzoylphosphinate, which initiates photopolymerization upon exposure to ultraviolet light (λ=405 nm). For this purpose, an Anycubic Photon Mono X (6K) printer is used for Digital Light Processing (DLP), heated to 42.5°C to prevent resin polymerization. The 3D matrix is ​​first designed using Computer-Aided Design (CAD) software (FreeCAD), saved as STL files (stereolithography), and then transmitted to the DLP printer, which produces matrix 2 in successive 100 µm thick layers with 30-second UV exposures. The total surface area of ​​the channels 10 is 1 cm². 2 / 1000 Equivalent Islands (IEQ). The 10 channels are of increasing size from 150 to 400 pm wide.

[0146] Figures 7 and 8 illustrate the quantification of the total surface area (D) and average size (E) of the islands in the different channels of the bioreactor. It can be seen that the majority of the islands are distributed within the channels (91.02%). It is also observed that the size of the islands correlates with the sizes of the channels.

[0147] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention.

[0148] LIST OF REFERENCES

[0149] 1. Device

[0150] 2. Matrix

[0151] 3. Lid

[0152] 5. Membrane

[0153] 6. First side

[0154] 7. Second side

[0155] 8. Outer face of the matrix

[0156] 10. Canal

[0157] 11. First side of a canal

[0158] 12. Second side of a canal

[0159] 13. Third side of a canal

[0160] 14. Fourth side of a canal

[0161] 15. Side walls

[0162] 16. Back wall

[0163] 17. Reception opening

[0164] 18. Reception volume

[0165] 19. Angle side wall - back wall

[0166] 111. First side of an adjacent canal

[0167] 112. Second side of an adjacent canal

[0168] 113. Third side of an adjacent canal

[0169] 114. Fourth side of an adjacent canal

[0170] O. Center

[0171] S. Section

[0172] Dept. Main Extension Directorate

[0173] I. Width of the receiving opening

[0174] P. Canal depth

[0175] D. Maximum distance between side walls

[0176] E. Spacing between two adjacent channels

[0177] L. Canal length

Claims

22 DEMANDS 1. Device (1) for distributing and receiving a population of pancreatic islets of heterogeneous size, comprising a matrix (2) having a first face (6) opposite a second face (7), at least one of the first (6) and the second face (7) extending mainly in an XY plane, Characterized in that the matrix (2) comprises concentric channels (10) centered on a center O, the channels (10) have, at each point, a section S, taken along a plane perpendicular to the XY plane and perpendicular to a principal extension direction Dep of the channel (10) at that point, the section S having at least two lateral walls (15) and a bottom wall (16) connecting the two lateral walls (15), the two lateral walls (15) defining between them a receiving aperture (17) for pancreatic cells, opening onto the first face (6), the bottom wall (16) being opposite the receiving aperture (17) for cells, the receiving aperture (17) extending along the entire length (L) of the channel (10), taken parallel to the principal extension direction Dep, the receiving aperture (17) having a width (I) taken along the section S, when the matrix comprises two channels (10), one channel is the one closest to the center O,If another channel is furthest from the center O, the two adjacent channels have receiving aperture widths (17), taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, of increasing value with respect to the center O; when the matrix comprises more than two channels (10), the device being configured such that the receiving aperture widths (I) (17) of two adjacent channels (10), taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, have an equal or increasing value with respect to the center O, and the receiving aperture widths (I) (17) of a channel (10) closest to the center O and of a channel (10) furthest from the center O, taken at points located on the same radial direction, passing through the center O and parallel to the XY plane, have an increasing value with respect to the center O.

2. Device according to the preceding claim in which, for two given adjacent channels (10), the width (I) of a first channel (10) is equal to the width (I) of the second channel (10), at least a third channel (10) surrounds at least in part the first and second channels (10) and has a receiving aperture width (I) (17) greater than those of the first and second channels (10).

3. Device according to claim 1 in which the receiving aperture widths (I) (17) of all the channels (10), taken at points located on the same radial direction passing through the center O and parallel to the XY plane, have an increasing value as they move away from the center O.

4. Device according to any one of the preceding claims wherein the width (I) of receiving opening (17) of different channels (10), taken at points located on the same radial direction passing through the center O and parallel to the XY plane, have a maximum variation of 1000%.

5. Device according to any one of the preceding claims wherein the width (I) of receiving opening (17) of different channels (10), taken at points located on the same radial direction passing through the center O and parallel to the XY plane, have a minimum variation of 30%.

6. Device according to any one of the preceding claims in which the bottom wall (16) forms an angle (19) with the two side walls (15).

7. Device according to any one of claims 1 to 5 in which the bottom wall (16) and the two side walls (15) form a curve.

8. Device according to any one of the preceding claims wherein the width (I) of the receiving opening (17) of the channels (10) varies between 50 and 800 micrometers.

9. Device according to any one of the preceding claims wherein the depth (P) of the channels (10) measures between 100 and 1000 micrometers.

10. Device according to any one of the preceding claims in which the channels (10) have a closed contour in projection in the XY plane.

11. Device according to any one of the preceding claims comprising a cover (3) of semi-permeable material suitable for being placed on the first face (6) of the matrix (2) so as to seal the receiving openings (17) of the channels (10) and a membrane (5) having a cut-off threshold greater than or equal to 8 nm and less than 15 nm.

12. Device according to the preceding claim in which the matrix (2) is based on methacrylate gelatin, the lid (3) is based on collagen, and the membrane is based on Polyvinyl Alcohol.

13. A pancreatic bioreactor intended for implantation in the human or animal body, comprising the distribution and receiving device (1) according to any previous claims and a heterogeneous population in size of pancreatic islets arranged in the ducts (10).

14. A bioreactor according to the preceding claim, wherein the size of the pancreatic islets is from 20 to 600 micrometers.

15. A method for distributing a size-heterogeneous population of pancreatic islets according to their size, comprising: a. providing a distribution and receiving device (1) according to any one of claims 1 to 12; b. depositing pancreatic islets at the center O of said device (1); c. agitating the device (1) so that the pancreatic islets are distributed into the channels (10) according to their size.

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