WO2023215876A1 - Method for isolation of pancreatic islets - Google Patents

Abstract

The present disclosure provides a method for isolating a composition comprising pancreatic islets and acinar tissue from pancreatic tissue material.

Description

METHOD FOR ISOLATION OF PANCREATIC ISLETS

TECHNOLOGICAL FIELD

[0001] The presently disclosed subject matter is related to devices and methods for use in supporting various therapeutic procedures including cell therapies and tissue engineering.

BACKGROUND

[0002] Cell therapy and tissue engineering is developing toward clinical applications for the repair and restoration of damaged or diseased tissues and organs. In particular, pancreatic conditions may be treated by implanting healthy tissue from a donor pancreas, either in an autologous procedure or in an allogeneic procedure.

[0003] In such a procedure, pancreatic islet cells from the donor pancreas are isolated, and implanted into a portion of the patient’s liver. The islet cells lodge in blood vessels, where they become active and produce insulin.

[0004] The process of isolating pancreatic islet cells is labor intensive. Current attempts to automate the process have been unsuccessful in performing the isolation in a reasonable timeframe without damaging the islet cells.

SUMMARY

[0005] According to aspects of the presently disclosed subject matter, there is provided a method for isolating a composition comprising pancreatic islets and acinar tissue from pancreatic tissue material, the method comprising: introducing pieces of pancreatic tissue material into a reservoir of a cell separation system; mixing the pancreatic tissue material within the reservoir with one or more dissociation enzymes, thereby forming a mixture; allowing digestion of the pieces of pancreatic tissue material in the mixture by the one or more dissociation enzymes; assessing, during the digestion, progress of the digestion; and separating, when the digestion has been assessed to have sufficiently progressed, the pancreatic islets and acinar tissue from the mixture by centrifugation.

[0006] In one embodiment, the above mixture is maintained at a temperature between 30- 39°C.

[0007] In one embodiment, assessing the progress of the digestion may comprise removing, at predetermined intervals, a sample of the mixture from the reservoir of the cell separation system and visually inspecting it to assess the progress of the digestion.

[0008] In one embodiment, the cell separation system may be configured to autonomously remove the sample from the mixture for inspection.

[0009] In one embodiment, the sample may be removed from the mixture using a syringe pump.

[0010] In one embodiment, the sample may be of any volume up to about 1.5ml.

[0011] In one embodiment, the cell separation system may comprise an optical probe with an objective disposed within the reservoir, wherein assessing the progress of the digestion comprises observing, using the probe, the mixture within the reservoir.

[0012] In one embodiment, the optical probe may comprise a microscope objective.

[0013] In one embodiment, the observation of the mixture may comprise performing optical coherence tomography using the optical probe.

[0014] In one embodiment, observing the mixture comprises fluorescent dye and fluorescence microscopy as generally known in the art.

[0015] In one embodiment, introducing the pieces of pancreatic tissue material into the reservoir may comprise breaking them up into pieces as small as possible so as to maximize surface area for enzyme interaction.

[0016] In one embodiment, the pieces of pancreatic tissue material may be introduced into the reservoir via an entrance orifice having a diameter of between about 5 mm and about 5 cm.

[0017] In one embodiment, the entrance orifice may have a diameter larger than about 6.5 mm. In one embodiment, the entrance orifice may have a diameter smaller than about 2.5 cm.

[0018] In one embodiment, the pancreatic tissue material may be introduced via the entrance orifice using a syringe. [0019] In one embodiment, the dissociation enzymes may comprise one or both of a collagenase and a protease.

[0020] In one embodiment, the method may comprise pretreating the pancreatic tissue material to remove red blood cells and/or extraneous fluids prior to mixing the pancreatic tissue material with the dissociation enzyme.

[0021] In one embodiment, the pretreating may be performed with a buffered saline solution or a sodium lactate solution.

[0022] In one embodiment, the mixture may be agitated during the digestion.

[0023] In one embodiment, the reservoir may comprise internal baffles, the agitation comprising rotating the reservoir at a speed which is below that at which separation of the pancreatic islets by centrifugation will occur.

[0024] In one embodiment, the centrifugation may be continuous flow centrifugation.

[0025] In one embodiment, at least a portion of the mixture nay be removed from the reservoir during the digestion for agitation external thereof, and subsequently reintroduced into the reservoir.

[0026] In one embodiment, the method may further comprise separating exocrine microvessel fragments from the mixture by centrifugation.

[0027] In one embodiment, the method may further comprise separating acinar tissue from the mixture by centrifugation.

[0028] In one embodiment, the islets may be used in an autologous procedure or in an allogeneic procedure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

[0030] Fig. 1 is a perspective view of one embodiment of a cell separation apparatus according to the presently disclosed subject matter; [0031] Fig. 2A is a cross-sectional view of an example of centrifuge of the cell separation apparatus illustrated in Fig. 1;

[0032] Fig. 2B is a perspective view of a nozzle member of the centrifuge illustrated in Fig. 2A;

[0033] Fig. 3 is a cross-sectional view of another example of a centrifuge of the cell separation apparatus illustrated in Fig. 1; and

[0034] Fig. 4 illustrates a method according to the presently disclosed subject matter of separating pancreatic islet cells.

DETAILED DESCRIPTION

[0035] Embodiments of the presently disclosed subject matter are described herein in the context of methods and devices for use in supporting various cell therapies and tissue engineering methods. Those of ordinary skill in the art will realize that this is by way of illustration only, and is not to be construed as limiting. Other embodiments of the presently disclosed subject matter will readily suggest themselves to those of ordinary skill in the art having the benefit of this disclosure.

[0036] In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer’s specific goals, such as compliance with application-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.

[0037] In accordance with the present disclosure, the components and process steps described herein may be implemented using various types of operating systems, computing platforms, computer programs, and/or general-purpose machines. In addition, those of ordinary skill in the art will recognize that more specialized devices, such as hardwired devices, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), or the like, may also be used without departing from the scope of the presently disclosed subject matter, mutatis mutandis.

[0038] The presently disclosed subject matter relates to devices and methods for use in supporting various cell therapies. “Cell therapy,” “cellular therapy,” “cell-based therapy,” and other related terms are used herein to refer to the use of human or animal cells to replace or repair diseased or damaged tissue and/or cells, or to treat or prevent a disease or disorder.

[0039] According to the presently disclosed subject matter, a method for isolating pancreatic islets from pancreatic tissue material may be provided. The method may be performed on any suitable device, for example as or similar to the cell separation apparatus disclosed in any one or more of US Pat. 8,202,725, US Pat. 9,144,583, US Pat. 11,174,458, and US2020/0024568, the full contents of which are incorporated herein by reference.

[0040] In one embodiment, the cell separation apparatus comprises: a media reservoir; a cell processing device in fluid communication with the media reservoir, via at least one inlet and at least one outlet, the cell processing device having an interior chamber rotatable about a vertical axis that passes through the interior chamber, the interior chamber comprising: (i) a plurality of lobes forming part of the water-tight interior surface of the interior chamber, each extending perpendicularly to the vertical axis; and (ii) a spray nozzle within the interior chamber for spraying a pressurized jet of fluid in a direction perpendicular to the vertical axis, the spray nozzle in communication with a rotating coupling and aligned with a support structure to fix its location within the interior chamber, wherein the interior chamber may be rotated around the vertical axis to align each of the lobes with the spray nozzle; wherein the cell processing device is configured to force cells in the interior chamber to move radially outward toward each lobe, such that the lobe collects and maintains cells while the interior chamber is rotating about the vertical axis. In another embodiment, the cell separation apparatus comprises: a base; a cell processing device coupled to the base, the cell processing device having a vertically oriented interior chamber rotatable about a vertical axis that passes through the interior chamber, and a plurality of horizontally extending lobes in communication with the interior chamber and extending from the interior chamber body laterally outward from the vertical axis and gradually tapering to terminate at an end point, wherein each lobe collect cells at a respective end point while the interior chamber is rotating about the vertical axis; and a spray nozzle within the interior chamber for spraying a pressurized jet of fluid in a direction perpendicular to the vertical axis, the spray nozzle in communication with a rotating coupling and aligned with a support structure to fix its location within the interior chamber, wherein the interior chamber may be rotated around the vertical axis to align each of the lobes with the spray nozzle.

[0041] As illustrated in Fig. 1, the cell separation apparatus, generally indicated at 100, comprises, inter alia, a centrifuge 102, a replaceable tube cassette 104, syringe pumps 106, and a collection syringe 108. It will be appreciated that while the cell separation apparatus 100 typically comprises other elements, for example as described in the above-mentioned and incorporated publications, the presently disclosure will only describe in detail those elements which are pertinent to the method described below. For example, the cell separation apparatus 100 may further comprise pinch valves, motors, sensors, and/or other elements necessary for carrying out steps of the method.

[0042] As illustrated in Fig. 2A, the centrifuge 102 comprises a lower portion constituting a reservoir 120, and centrifuge lobes 122 thereabove. A nozzle member 124, for example as illustrated in Fig. 2B, may be provided, configured to produce a pressurized jet of fluid to flush separated pancreatic islets (as will be described below) from the centrifuge lobes 122. The nozzle member 124 may be mounted within a rotating coupling 126, thereby allowing the nozzle member to remain in place while the centrifuge 102 to which is it mounted rotates. [0043] An internal surface of the reservoir 120 may comprise one or more baffles 128, for example as illustrated in Fig. 2 A. It will be appreciated that while only one baffle 128 is illustrated, the reservoir may be provided of any suitable number, each being provided according to a suitable design.

[0044] According to some examples, the centrifuge 102 comprises an inspection system, configured to facilitate visual observation of the contents of the reservoir 120. As seen in Fig. 2B, the inspection system may comprise an optical probe 130 disposed within the reservoir 120, having an optical objective 132 at distal end. The optical objective 132 may be any suitable element or elements, for example comprising a microscope objective, i.e., a high- powered magnifying glass having a short focal length. The proximal end of the optical probe 130 may be connected to a viewing mechanism, for example an eyepiece configured to enable a user to directly view the interior of the reservoir 120, a digital sensor functionally coupled with a processing system for producing and/or analyzing digital images of the interior of the reservoir, etc. The optical probe 130 may be mounted within the nozzle member 124 and/or the rotating coupling 126, thereby allowing it to remain in place while the centrifuge 102 rotates.

[0045] According to some examples, for example as illustrated in Fig. 3, the centrifuge 102 comprises a sampling probe 134, configured to facilitate removal, e.g., by an autonomous system, of samples from the reservoir 120. Accordingly, a sample of the contents of the reservoir 120 may be directly inspected without interrupting the process therein. The sampling probe 134 may be mounted within the nozzle member 124 and/or the rotating coupling 126, thereby allowing it to remain in place while the centrifuge 102 rotates.

[0046] It will be appreciated that while the centrifuge 102 is typically provided either with an inspection system, for example as described above with reference to and as illustrated in Fig. 2B, or with a sampling probe, for example as described above with reference to and as illustrated in Fig. 3, according to some examples the centrifuge comprises both, allowing the contents of the reservoir 120 to be inspected in either or both of the ways described, mutatis mutandis.

[0047] The cell separation apparatus 100 may further comprise a screen filter (not illustrated), connected to the reservoir 120 such that contents therein may be selectively removed therefrom, and then returned after passing through the filter screen. According to some examples, the filter screen has a mesh size between about 500 pm and 1 mm.

[0048] According to some embodiments, for example as illustrated in Fig. 4, a method 200 of isolating predetermined types of pancreatic tissue may be performed using the cell separation apparatus 100 described above with reference to and as illustrated in Figs. 1-3, and/or with any other suitable device.

[0049] According to some examples, the method 200 is for isolating pancreatic islet cells, exocrine microvessel fragments, and/or acinar tissue. For the sake of simplicity of disclosure, the method 200 will be described with reference to isolation of pancreatic islet cells, but it will be appreciated that this is by way of example only, and is not to be construed as limiting. [0050] It will be appreciated that while the method 200 will be described with reference to the cell separation apparatus 100 and its components, this is by way of example only, and is not to be construed as limiting. The method may be performed autonomously, or it may be performed manually. [0051] In step 210 of the method 200, a pancreas is provided and prepared for processing. Optionally, one or more dissociation enzymes are infused into the ducts of the pancreas. The pancreas is trimmed, for example as is known in the art. Fat tissue may remain on the pancreas. The pancreas is cut into pieces of pancreatic tissue material, suitably sized for injection, as will be described below.

[0052] In step 212 of the method 200, the pancreatic tissue material previously obtained in injected into the reservoir 120 of the centrifuge 102. The injection may be performed using a syringe or similar suitable device. The orifice through which the pancreatic tissue material enters the centrifuge 102 may be configured to break the pancreatic tissue material into pieces which are not significantly larger than the typical size of pancreatic islets (between about 20 and about 650 pm, with a majority of islet being between about 50 pm and about 500 pm). According to some examples, the orifice is configured to facilitate breaking up of the pancreatic tissue material into pieces no bigger than about 2 cm. According to some examples, the orifice is configured to facilitate breaking up of the pancreatic tissue material into pieces no bigger than about 500 pm.

[0053] In step 214 of the method 200, the pancreatic tissue material is pretreated to remove red blood cells, unwanted fluids, etc. The pretreatment may comprise rinsing the pancreatic tissue material any suitable material, e.g., using a buffered saline solution or a sodium lactate solution, for example known as lactated Ringer’s solution.

[0054] In step 216 of the method 200, the pretreated pancreatic tissue material is mixed within the reservoir 120 with one or more dissociation enzymes, thereby forming a mixture. The dissociation enzymes may include a collagenase and/or a protease. The collagenase may comprise a class I collagenase, a class II collagenase, and/or a mixture of the two. According to some examples, the dissociation enzymes comprise a mixture of 60% class I collagenase and 40% class II collagenase mixed with a neutral protease, for example sold under the trade same CIzyme by VitaCyte, LLC.

[0055] In step 218 of the method 200, the mixture is allowed to digest in the dissociation enzymes within the reservoir 120. According to some examples, the mixture is agitated to promote digestion. The agitation may comprise rotating, either in the same direction or by oscillating several times per minute. In some embodiments, the speed of agitation or oscillation can be adjusted over time. For example, the speed of oscillation can be increased as the digestion progresses. The rotation speed should be low enough to prevent centrifugation and/or cavitation from occurring. According to some examples, the rotation speed is no greater than about 120 rpm.

[0056] According to some examples, at least a portion of the mixture is removed from the reservoir 120 during digestion to be agitated externally, and can be reintroduced during digestion.

[0057] In step 220 of method 200, the progress of the digestion is assessed. It will be appreciated that while this step occurs during the digestion step 218, it is being described as a separate step for clarity. The progress of the digestion may be assessed based on a visual inspection of the mixture during digestion.

[0058] According to some embodiments, inspecting the mixture comprises removing a portion of the mixture from the reservoir and inspecting it by a trained laboratory technician. For example, a small sample, e.g., about 2 ml, are removed via the sampling probe 134. A syringe pump may be used to provide suction for removing the sample via the sampling probe 134. A syringe pump is suited to draw a sample without damaging it, requires a relatively small amount of tubing, and results in a relatively low amount of heat exchange with the environment.

[0059] The sampling may be performed on a predetermined schedule, e.g., about every two minutes, for example autonomously. The technician inspects the sample to assess the progress of the digestion.

[0060] According to some embodiments, inspecting the mixture to assess the progress of the digestion within the reservoir 120 comprises visually observing the mixture in situ, via the optical probe 130. According to some examples, a trained laboratory technician may directly observe the mixture via the optical probe 130. According to some examples, an image of the mixture is captured by a digital sensor in optical communication with the optical probe 130. A processor may be configured to render an image of the mixture. According to some examples, the processor may be configured to perform optical coherence tomography in assessing the progress of the digestion. The digitally obtained/processed images may be assessed by a trained technician and/or by software configured for this purpose, for example trained using a machine learning algorithm to assess progress of digestion. [0061] The mixture may be filtered, e.g., by passing through the screen filter. This may be done at any point during digestion. According to some examples, the filtering is performed prior to centrifugation, as described below. In some embodiments, this filtering is done in certain autologous procedures in order to allow collection and prevent over digestion if extended digestion period is required.

[0062] In step 222 of method 200, once the digestion has completed, the centrifuge 102 is operated to isolate the pancreatic islet cells and acinar tissue. The centrifuge 102 is then spun at a predetermined speed, during which the pancreatic islet cells are separated from the digested mixture and are deposited in the centrifuge lobes 122. The cells and tissue will tend to pack into the centrifuge lobes 122 and remain therein until dislodged therefrom, as is well- known in the art. According to some examples, a pressurized jet produced by the nozzle member 124 may be used to dislodge the cells and tissue from the centrifuge lobes 122.

[0063] According to some examples, the centrifugation comprises continuous-flow centrifugation. The process allows addition of dissociation enzymes or any other suitable fluid to the mixture during centrifugation, thereby facilitating retrieval of pancreatic islets in a shorter time while maintaining the integrity of the islets by avoiding over digestion.

[0064] The pancreatic tissue which is isolated from the pancreatic tissue material may be used, e.g., in an autologous, allogeneic or a xenogeneic procedure.

[0065] It will be recognized that examples, embodiments, modifications, options, etc., described herein are to be construed as inclusive and non-limiting, i.e., two or more examples, etc., described separately herein are not to be construed as being mutually exclusive of one another or in any other way limiting, unless such is explicitly stated and/or is otherwise clear. Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations, and modifications can be made without departing from the scope of the presently disclosed subject matter, mutatis mutandis.

Claims

1. A method for isolating a composition comprising pancreatic islets and acinar tissue from pancreatic tissue material, the method comprising: introducing pieces of pancreatic tissue material into a reservoir of a cell separation system; mixing the pancreatic tissue material within the reservoir with one or more dissociation enzymes, thereby forming a mixture; allowing digestion of the pieces of pancreatic tissue material in the mixture by said one or more dissociation enzymes; assessing, during the digestion, progress of the digestion; separating, when the digestion has been assessed to have sufficiently progressed, said composition comprising pancreatic islets and acinar tissue from the mixture by centrifugation.

2. The method according to claim 1, wherein the mixture is maintained at a temperature between 30-39°C.

3. The method according to claim 1, wherein assessing the progress of the digestion comprises removing, at predetermined intervals, a sample of the mixture from the reservoir of the cell separation system and visually inspecting it to assess the progress of the digestion.

4. The method according to claim 1, wherein the cell separation system is configured to autonomously remove said sample from the mixture for inspection.

5. The method according to any one of claims 3 and 4, wherein the sample is removed from the mixture using a syringe pump.

6. The method according to any one of claims 3 through 5, wherein the sample is up to about 1.5ml.

7. The method according to any one of the preceding claims, said cell separation system comprising an optical probe with an objective disposed within the reservoir, wherein assessing the progress of the digestion comprises observing, using the probe, the mixture within the reservoir.

8. The method according to claim 7, wherein said optical probe comprises a microscope objective.

9. The method according to any one of claims 7 and 8, wherein observing the mixture comprises performing optical coherence tomography using said optical probe.

10. The method according to any one of claims 7 and 8, wherein observing the mixture comprises fluorescent dye and fluorescence microscopy.

11. The method according to any one of the preceding claims, wherein introducing the pieces of pancreatic tissue material into the reservoir comprises breaking them up into smaller pieces.

12. The method according to claim 11, wherein the pieces of pancreatic tissue material are introduced into the reservoir via an entrance orifice having a diameter of between about 5 mm and about 5 cm.

13. The method according to claim 12, wherein the entrance orifice has a diameter larger than about 6.5 mm.

14. The method according to any one of claims 12 and 13, wherein the entrance orifice has a diameter smaller than about 2.5 cm.

15. The method according to any one of claims 12 through 14, wherein the pancreatic tissue material is introduced via the entrance orifice using a syringe.

16. The method according to any one of the preceding claims, wherein the dissociation enzymes comprise one or both of a collagenase and a protease.

17. The method according to any one of the preceding claims, comprising, prior to mixing the pancreatic tissue material with the dissociation enzyme, pretreating the pancreatic tissue material to remove red blood cells and/or extraneous fluids.

18. The method according to claim 17, wherein the pretreating is performed with a buffered saline solution or a sodium lactate solution.

19. The method according to any one of the preceding claims, wherein the mixture is agitated during the digestion.

20. The method according to claim 19, wherein the reservoir comprises internal baffles, the agitation comprising rotating the reservoir at a speed which is below that at which separation of the pancreatic islets by centrifugation will occur.

21. The method according to any one of the preceding claims, wherein the centrifugation is continuous flow centrifugation.

22. The method according to any one of claims 19 through 21 , wherein at least a portion of the mixture is removed from the reservoir during the digestion for agitation external thereof, and can subsequently be reintroduced into the reservoir.

23. The method according to any one of the preceding claims, further comprising separating exocrine microvessel fragments from the mixture by centrifugation.

24. The method according to any one of the preceding claims, further comprising separating acinar tissue from the mixture by centrifugation.

25. The method according to any one of the preceding claims, wherein the islets are used in an autologous procedure.

26. The method according to any one of the claims 1 through 24, wherein the islets are used in an allogeneic procedure.

27. The method according to any one of the claims 1 through 24, wherein the islets are used in a xenogeneic procedure.