Kit for treating damaged nerves
Patent Information
- Application Number
- JP2023549983
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2021-02-23
- Filing Date
- 2022-02-22
- Publication Date
- 2025-02-26
- Estimated Expiration
- 2042-02-22
AI Technical Summary
Existing methods for treating damaged nerves, such as crushed or severed nerves, are inadequate in promoting effective regeneration and functional recovery.
A method and kit using whole blood drawn from a subject, coagulated in situ, to form a blood clot within a nerve sleeve or nerve graft, enhancing nerve repair by physically contacting the injured area and promoting nerve regeneration.
The method and kit facilitate partial or complete restoration of nerve function by inducing nerve growth and regeneration, as demonstrated by increased axon density and functional recovery in treated nerves.
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Abstract
Description
[Technical field]
[0001] TECHNICAL FIELD This disclosure is in the field of medical treatment of damaged nerves. [Background technology]
[0002] The following references are considered relevant background to the subject matter of this disclosure: -International Publication No. 2019 / 058373 Brochure -International Publication No. 2019 / 058375 Brochure -U.S. Patent No. 9,180,142
[0003] The identification of the above references in this specification should not be inferred as meaning that they are in any way relevant to the patentability of the disclosed subject matter. Summary of the Invention
[0004] The present disclosure provides a method and kit for inducing growth or regenerating a damaged nerve in a subject, or treatment thereof, by using whole blood drawn from the subject and coagulated in situ in a controlled manner. The nerve to be treated may be a crushed nerve, a nerve damaged by a certain disease process (e.g., inflammation), a partially severed nerve, or a nerve completely severed to leave two nerve stumps. According to some embodiments, blood drawn from the subject is introduced into the lumen of a nerve enveloping sleeve that encases the damaged portion of the nerve or two ends of opposing nerve stumps that are taken into the sleeve from opposite ends of the sleeve, and while controllably coagulating within the lumen, forms a blood clot or coagulated blood matrix between such damaged nerve portion and / or two severed nerve stumps. This blood clot, while in physical contact with the damaged portion of the nerve, may enhance the repair of the nerve and partially or completely restore its function. In other embodiments, a nerve graft is used to bridge the two stumps of a severed nerve.
[0005] The term "nerve treatment portion" or "treatment portion" is used herein to denote a portion of a nerve that is treated in accordance with the present disclosure to induce nerve regeneration across a damaged nerve portion between the two end portions of a severed nerve stump, or a portion that includes the two end portions of a severed nerve stump and a nerve graft therebetween.
[0006] As used in this disclosure, whole blood is typically blood drawn from an individual, but may also be blood obtained from a donor or blood bank. Thus, the terms "blood" or "whole blood" should be taken to mean whole blood regardless of its source, unless otherwise specified.
[0007] The term "coagulation inducer" is used herein to refer to one or more coagulants and / or anti-anti-coagulants. The term "mixture" is used herein to refer to a mixture comprising whole blood and a coagulation inducer.
[0008] The terms "clot," "blood clot," or "clotted blood" are used interchangeably to refer to the clotted whole blood matrix formed from the mixture.
[0009] In the following, when methods are described, the order of the steps in performing the method may or may not be the order in which they are written.
[0010] The subjects treatable in accordance with the present disclosure can be human or non-human animals.
[0011] Thus, one aspect of the present disclosure provides a method for regenerating nerves within or across a neurotherapy portion. The method includes attaching a sleeve having a lumen to encase the neurotherapy portion so as to be received within the lumen. The method also includes introducing a mixture of whole blood and the clot-inducing agent into the lumen (mixing occurs before or during introduction). The nerve-encasing sleeve can be manufactured or configured to encase the neurotherapy portion while maintaining a space between its inner surface and the neurotherapy portion, allowing introduction of coagulated blood into the space to form a clot on the injured nerve. The mixture of whole blood and the clot-inducing agent is typically introduced into the lumen before clotting of the mixture is complete.
[0012] It should be noted that in any aspect of the present disclosure, whole blood may be drawn from a subject and first mixed with an anticoagulant to prevent its natural clotting. At a desired time, the whole blood is mixed with a clotting inducer to controllably coagulate the whole blood in the area of the injured nerve to form a desired clot therein.
[0013] In some embodiments of the method, the attaching includes placing a film or sheet over the neural treatment portion and enveloping the portion with the sheet to form a nerve encircling sleeve. In other embodiments, the sleeve may be a pre-existing tubular element into which the treatment portion is introduced. The sleeve may be made of a plastic material or other suitable biocompatible material.
[0014] It should be noted that any combination of the embodiments described with respect to any aspect of the present disclosure is applicable, in other words, any aspect of the present disclosure may be defined by any combination of the embodiments described.
[0015] Yet another aspect of the present disclosure provides a method of inducing nerve fiber growth across an injured nerve segment, the method comprising: attaching a nerve encircling sleeve having a lumen, such as a nerve guidance conduit, to encase the nerve segment so as to reside within the lumen; and introducing the mixture into the lumen prior to complete solidification of the mixture.
[0016] In some embodiments of the method, the sleeve is a nerve guidance conduit.
[0017] In some embodiments of the method, the damaged nerve portion comprises a severed nerve fiber.
[0018] In some embodiments of the method, the nerve portion comprises two severed nerve stumps that are surgically joined or approximated within the sleeve.
[0019] In some embodiments of the method, the attaching comprises placing a film or sheet over the treatment area and encasing the area with the sheet to form the conduit.
[0020] In some embodiments of the method, the attaching includes introducing two nerve stumps into the sleeve, one from each end of the sleeve, and approximating the two stumps to each other within the nerve encircling sleeve. According to some embodiments, a mixture may be made to fill the space between the two stumps.
[0021] In some embodiments of the method, the approximating comprises securing the two stumps within the sleeve with sutures.
[0022] In some embodiments of the method, the introducing comprises filling a portion of a lumen of a conduit with the mixture so as to contact the nerve portion.
[0023] In some embodiments of the method, the nerve portion comprises two severed nerve stumps, and the introducing is performed such that the mixture contacts the stumps.
[0024] In some embodiments, the method further comprises saturating the blood with an oxygen-rich gas, such as oxygen-enriched air or pure oxygen, prior to said introducing (which may be before, during or after mixing the blood with the clotting agent).
[0025] In some embodiments, the method further comprises mixing the blood with one or more autologous cells prior to said introducing, hi some embodiments, said one or more autologous cells comprise Schwann cells.
[0026] Yet another aspect of the present disclosure provides a method of promoting nerve regeneration between first and second nerve stumps of a severed nerve. According to one embodiment, the method includes attaching and securing, e.g., by suturing, a first open end portion of a nerve guidance conduit onto the first nerve stump and attaching and securing a second open end portion of the nerve guidance conduit onto the second nerve stump. The nerve guidance conduit defines a lumen extending between the first and second open end portions. The method further includes mixing whole blood with a clot-inducing agent and introducing the mixture into the lumen before it is fully coagulated, i.e., while still in a flowable form, and allowing the blood to clot within the lumen.
[0027] In some embodiments of the method, the securing comprises suturing the first and second nerve stumps to the first and second open end portions, respectively.
[0028] In some embodiments of the method, the introducing includes filling a portion of the lumen with blood so as to contact both the first and second nerve stumps, i.e., filling the gap or space between the first and second nerve stumps with blood and forming a continuous matrix of nerve stumps and blood.
[0029] In some embodiments, the method further comprises saturating the blood with oxygen prior to said introducing.
[0030] In some embodiments of the method, the anticoagulant is one or more from the group consisting of: ACD-A (anticoagulant citrate dextrose, solution A), EDTA (ethylenediaminetetraacetic acid), EGTA (ethylene glycol tetraacetic acid), citrate, heparin, and oxalate ("first group").
[0031] In some embodiments of the method, the one or more coagulants or anti-anticoagulants are one or more of the group consisting of: kaolin, Ca 2+ , for example in the form of calcium salts such as calcium gluconate, Mg 2+ , negatively charged phospholipids (PL) and protamine sulfate ("second group"); or a mixture of one or more of the first group with one or more of the second group.
[0032] In some embodiments, the method further comprises adding or saturating the blood with keratin, stem cells (of any type), growth factors, collagen, bone marrow, or other gases or materials prior to said introducing.
[0033] In some embodiments of the method, the introducing comprises inserting a blood applicator into the lumen and injecting blood into the lumen with the blood applicator, e.g., a syringe.
[0034] In some embodiments, the method further comprises mixing the blood with one or more autologous cells prior to said introducing, hi some embodiments, said one or more autologous cells comprise Schwann cells.
[0035] In some embodiments of the method, the conduit is made from or comprises collagen, polyglycolic acid (PGA), polycaprolactone (PCL), polyvinyl alcohol (PVA), and porcine small intestinal submucosa (SIS).
[0036] Yet another aspect of the present disclosure provides a kit for treating, inducing growth, or regenerating a damaged nerve portion of a subject, which may be employed in the above method, comprising a nerve encircling sleeve having a lumen for encircling said damaged nerve portion such that said portion is within at least a portion of the lumen; one or more blood withdrawal devices for enabling the withdrawal of blood from the subject; optionally one or more blood collection receptacles for receiving blood withdrawn from the subject or means for receiving whole blood obtained from a blood bank; a clotting assembly configured to enable mixing of the withdrawn blood with a clotting inducer to initiate the clotting process of the blood; and an applicator for introducing incompletely coagulated blood into said lumen.
[0037] In some embodiments of the kit, the one or more collection receptacles are evacuated tubes.
[0038] In some embodiments of the kit, the clotting assembly comprises a container for receiving drawn blood, said container configured to contact the blood with said clotting inducer.
[0039] In some embodiments, the kit further comprises one or more clot-inducing agents for mixing with the drawn blood.
[0040] In some embodiments of the kit, one or more coagulation-inducing agents are contained within said one or more blood collection receptacles.
[0041] In some embodiments of the kit, the anticoagulant agent is selected from the group consisting of one or more of the first group, or one or more of the second group, or a combination of one or more of the first group and one or more of the second group.
[0042] In some embodiments, the kit further comprises a film or sheet for placement over the damaged nerve portion to form a nerve encircling sleeve.
[0043] In some embodiments of the kit, the sleeve is a nerve guidance conduit.
[0044] In some embodiments of the kit, the neurotherapeutic portion is a severed nerve having first and second nerve stumps.
[0045] In some embodiments, the kit further comprises a fixation or retention element for fixing the neurotherapy portion to the sleeve.
[0046] In some embodiments, the kit is intended for use in a method for treating, inducing growth of, or regenerating a damaged nerve segment, the method comprising: (i) encasing the damaged nerve segment with the sleeve having a lumen such that the damaged nerve segment resides within the lumen, (ii) withdrawing whole blood from a subject, (iii) mixing the subject's blood with one or more clotting inducers, (iv) introducing blood containing a clotting agent into the lumen before clotting of the blood is complete, and (v) allowing blood to clot within the lumen.
[0047] In some embodiments, the kit is intended for use in a method according to any one of the method embodiments described above.
[0048] According to other aspects of the present disclosure, a bridging nerve graft is employed to bridge two stumps of a severed nerve. These aspects include a method referred to as the "Nerve Graft Aspect Method" and a kit referred to as the "Nerve Graft Aspect Kit." According to the graft aspect, a method for inducing nerve fiber growth or regenerating a nerve between a first nerve stump and a second nerve stump includes: (i) Positioning a nerve graft between a first nerve stump and a second nerve stump. The nerve graft can be an autologous or non-autologous nerve graft, may be obtained from a donor or a cadaver, and may be allogeneic or xenogeneic. The nerve graft may be partially synthetic, an engineered human nerve allograft, or fully synthetic. The nerve graft may be fresh, e.g., maintained in a suitable medium, or may be frozen or otherwise preserved. The nerve graft may be processed to become acellular, e.g., by freezing, prior to use. The nerve graft may be placed without suturing within the lumen of a nerve encircling sleeve (e.g., tube) before or after it is attached over one of the stumps. The nerve graft includes an empty endoneurial tube, which is a microchannel / tunnel left by axons that previously passed therethrough, allowing nerve growth between the first and second nerve stumps. The microchannel extends between both ends of the nerve graft, i.e., between the first nerve stump and the second nerve stump, when the graft is connecting the stumps; (ii) introducing a mixture of whole blood and a clotting-inducing agent into the channel prior to complete clotting of the mixture, said introducing being performed before or after said positioning. This can be accomplished by forced introduction, by contacting one or both ends of the nerve graft with the mixture and allowing blood to enter the channel by capillary forces, or by any other suitable means. This introduction can be before or after said positioning; and (iii) allowing blood to clot within said channel;
[0049] It should be noted that at least a portion of the clotted whole blood may contact the first nerve stump and / or the second nerve stump. Thus, in some embodiments, the method further includes forming a continuous clotted whole blood matrix between the first nerve stump and the nerve graft and between the nerve graft and the second nerve stump, thereby connecting the first nerve stump and the second nerve stump through the nerve graft channel.
[0050] In some embodiments, the method of the nerve graft aspect further comprises fastening the graft to one or both of the first and second nerve stumps.
[0051] In some embodiments of this method, the securing comprises suturing the first and second nerve stumps to the nerve graft.
[0052] In some embodiments, the nerve graft aspect of the method further comprises saturating the blood with oxygen prior to said introducing.
[0053] In some embodiments, the method of the nerve graft aspect further comprises mixing the blood with one or more autologous cells prior to said introducing.
[0054] In some embodiments of the method of the nerve graft aspect, the one or more autologous cells comprise Schwann cells.
[0055] In some embodiments of the method of the nerve graft aspect, the one or more clotting inducers are in the form of a powder, and at least some of the particles of the powder are sized to fit into the channel, i.e., the particles are small enough that their diameter is smaller than the diameter of a cross-section of the channel.
[0056] In some embodiments, the method of the nerve graft aspect further comprises filtering the powder prior to mixing with blood to obtain a mixture in which at least a portion of the particles have a size less than 2.5 microns, less than 2 microns, less than 1.5 microns, or even less than 1 micron. In some embodiments, the powder comprises greater than 50% of particles of a size compatible with entering the channel.
[0057] In some embodiments of the method of the nerve graft aspect, the filtering comprises (i) introducing a powder into a liquid for a selected time, (ii) collecting the suspended particles, i.e., collecting the top of the liquid, and (iii) drying the particles to obtain the desired filtered particles.
[0058] In some embodiments of the nerve graft method, the coagulation inducer is one or more of the first group, or one or more of the second group, or a combination of one or more of the first group and one or more of the second group.
[0059] In some embodiments, the nerve graft aspect of the method further includes attaching the sleeve or nerve guidance conduit over at least one of a first nerve stump and a portion of a nerve graft, a second nerve stump and a portion of a nerve graft, or the first nerve stump, the nerve graft and the second nerve stump; and the introducing includes filling the lumen with the mixture.
[0060] A nerve graft embodiment of a kit for inducing or regenerating growth of a damaged nerve portion in a subject having a first nerve stump and a second nerve stump further includes, in addition to the kit elements described above, a nerve graft having microchannels that allow nerve growth therethrough, or a means for harvesting or creating such a nerve graft.
[0061] In some embodiments of the kit of nerve graft aspects, the one or more collection receptacles are vacuum tubes.
[0062] In some embodiments of the kit of nerve graft aspects, the clotting assembly comprises a container for introducing the drawn blood, said volume being contactable with one or more clotting agents or anti-anticoagulants.
[0063] In some embodiments, the nerve graft aspect of the kit further comprises one or more clot-inducing agents for mixing with the withdrawn blood.
[0064] In some embodiments of the nerve graft aspect of the kit, one or more anticoagulants are contained within the one or more blood collection receptacles.
[0065] In some embodiments of the nerve graft kit aspect, the coagulation inducer is one or more of the first group, or one or more of the second group, or a combination of one or more of the first group and one or more of the second group.
[0066] In some embodiments, the kit of nerve graft aspects further comprises the sleeve for placement over at least one of the first nerve stump and a portion of the nerve graft, the second nerve stump and a portion of the nerve graft, or the first nerve stump, the nerve graft, and the second nerve stump. By using an applicator, it is intended that the clotting whole blood is introduced into the lumen of the sleeve. In doing so, the whole blood forms a continuous clotted whole blood matrix between the first nerve stump and the second nerve stump through the channel of the nerve graft. The blood clot formed from the clotted whole blood enhances the nerve regeneration process.
[0067] In some embodiments of the kit, the sleeve is a nerve guidance conduit.
[0068] In some embodiments, the kits of the nerve graft aspects are intended for use in the methods of the nerve graft aspects.
[0069] In some embodiments, the kit of nerve graft aspects is intended for use in any one of the above-described embodiments of the method of using a nerve graft, or any combination thereof.
[0070] Embodiment The following are optional embodiments and combinations thereof according to aspects of the present disclosure. These embodiments are intended to add to, but not limit, the disclosure herein as generally described above. In these embodiments, the method steps may or may not be in the order written. 1. A method for regenerating nerves within or across a damaged nerve segment, comprising: attaching a sleeve over the nerve portion such that the nerve portion is received within an inner lumen of the sleeve; and introducing into said lumen a mixture of whole blood, typically drawn from the subject (but which may also be from a donor or a blood bank), and one or more coagulation-inducing agents, which may be coagulants and / or anti-anticoagulants, prior to complete clotting; The method includes: 2. The method of embodiment 1, wherein said attaching comprises placing a film or sheet over said part and encasing said part with said sheet to form said sleeve. 3. A method of inducing the growth of nerve fibers across a damaged nerve segment, comprising: attaching a sleeve to enclose the nerve portion; and introducing into said lumen a mixture of whole blood, typically drawn from a subject, and one or more coagulation-inducing agents prior to complete clotting; The method includes: 4. The method of any one of embodiments 1 to 3, wherein the damaged nerve portion comprises a severed nerve fiber. 5. The method of embodiment 4, wherein the nerve portion comprises two severed nerve stumps that are surgically joined or approximated. 6. The mounting of the 6. The method of claim 5, comprising placing a film or sheet over the portion and encasing the portion with the sheet to form the sleeve. 7. The mounting, introducing two nerve stumps into the sleeve, one from each end of the sleeve; and bringing the two stumps into close proximity to each other within the conduit. 6. The method of embodiment 5, comprising: 8. The method of embodiment 7, wherein said approximating comprises fixing the two stumps within the sleeve with sutures. 9. The method of any one of embodiments 3-8, wherein the introducing comprises filling a portion of the lumen of the sleeve with the mixture so as to contact the nerve portion. 10. The method of embodiment 9, wherein the nerve portion comprises two severed nerve stumps, and the introducing is performed such that the mixture contacts the stumps and forms a coagulated blood matrix between the stumps. 11. The method of any one of the preceding embodiments, comprising saturating the blood with an oxygen-rich gas prior to said introducing. 12. The method of any one of the preceding embodiments, comprising mixing the blood with one or more autologous cells prior to said introducing. 13. The method of embodiment 12, wherein the one or more autologous cells comprise Schwann cells. 14. A method for inducing nerve fiber growth between a first nerve stump and a second nerve stump of a severed nerve, comprising: attaching and securing a first open end portion of a sleeve over the first nerve stump and attaching and securing a second open end portion of a sleeve over the second nerve stump, the sleeve defining a lumen extending between the first and second open end portions; mixing whole blood drawn from a subject with one or more coagulation-inducing agents and introducing the blood into the lumen before clotting of the mixture is complete; allowing blood to clot within said lumen; The method includes: 15. The method of embodiment 14, wherein the fixing comprises suturing the first and second nerve stumps to the first and second end portions, respectively. 16. The method of embodiment 14 or 15, wherein the introducing comprises filling the lumen or a portion thereof with the mixture such that the mixture and a clotted blood matrix formed therefrom contacts both the first and second nerve stumps. 17. The method of any one of embodiments 14-16, comprising saturating the blood with oxygen prior to said introducing. 18. The method of any one of embodiments 14-17, wherein the introducing comprises inserting a blood applicator into the lumen and injecting blood into the lumen with the blood applicator. 19. The method of any one of embodiments 14 to 18, comprising mixing the blood with one or more autologous cells prior to said introducing. 20. The method of embodiment 19, wherein the one or more autologous cells comprise Schwann cells. 21. A kit for inducing or regenerating the growth of a damaged nerve part in a subject, comprising: a sleeve having an internal cavity for encasing the damaged nerve portion such that the damaged nerve portion resides in at least a portion of the internal cavity; Optionally, one or more blood withdrawal devices for withdrawing blood from the subject; one or more blood collection receptacles for receiving blood; a clotting assembly configured to allow mixing of one or more clotting inducers with the withdrawn blood to initiate the clotting process of the withdrawn blood; an applicator for introducing partially coagulated blood into said lumen; A kit comprising: 22. The kit of embodiment 21, wherein the one or more collection receptacles are vacuum tubes. 23. The kit of embodiment 21 or 22, wherein the clotting assembly comprises a container for receiving blood, the container being configured to contact the blood with the clotting inducer. 24. A kit according to any one of embodiments 21 to 23, comprising one or more coagulation-inducing agents. 25. The kit of embodiment 24, wherein the one or more coagulation-inducing agents are contained within the one or more blood collection receptacles. 26. The kit according to embodiment 24 or 25, wherein the coagulation inducer is an anti-anticoagulant selected from the group consisting of ACD-A (anticoagulant citrate dextrose, solution A), EDTA (ethylenediaminetetraacetic acid), EGTA (ethylene glycol tetraacetic acid), citrate, heparin and oxalate. 27. The one or more coagulation inducers are selected from the group consisting of kaolin, Ca 2+ , Mg 2+ 27. The kit according to any one of embodiments 21 to 26, wherein the lipid peroxide is selected from the group consisting of negatively charged phospholipids (PL) and protamine sulfate. 28. A kit described in any one of embodiments 21 to 27, comprising a film or sheet for placement over the damaged nerve portion to form the nerve encircling sleeve. 29. A kit according to any one of embodiments 21 to 27, wherein the nerve encircling sleeve is a nerve guidance conduit. 30. A kit described in any one of embodiments 21 to 29, comprising a fixation element for fixing the damaged nerve portion to the nerve surrounding sleeve. 31. A kit according to any one of embodiments 21 to 30, wherein the damaged nerve portion is a severed nerve having a first and second nerve stump. 32. A kit according to any one of embodiments 21 to 31 for use in a method for treating, inducing growth of, or regenerating a damaged nerve part, the method comprising: (i) encasing the damaged nerve portion with a sleeve having an internal lumen such that the damaged nerve portion is contained within the internal lumen; (ii) drawing whole blood from the subject; and (iii) mixing the subject's blood with one or more coagulation-inducing agents; (iv) introducing blood into the lumen together with a clotting-inducing agent before clotting of the blood is complete; (v) clotting blood within said lumen; Kit including: 33. A kit according to any one of embodiments 21 to 31, for use in a method according to any one of embodiments 1 to 20. 34. A method of inducing nerve fiber growth between a first nerve stump and a second nerve stump, comprising: placing and optionally attaching a nerve graft between the first nerve stump and the second nerve stump, optionally attaching each of the first nerve stump and the second nerve stump to a different end of the nerve graft, the nerve graft including microchannels that allow nerve growth between the first nerve stump and the second nerve stump; introducing a mixture of whole blood, typically blood drawn from a subject, and one or more coagulation-inducing agents into said channel prior to complete coagulation of the mixture, said introducing being performed before or after said placing; allowing blood to clot within said channel; and The method includes: 35. The method of embodiment 34, comprising fixing the graft to one or both of the first and second nerve stumps. 36. The method of embodiment 35, wherein the fixing comprises suturing the first and second nerve stumps to the nerve graft. 37. The method of any one of embodiments 34-36, comprising saturating the blood with oxygen prior to said introducing. 38. The method of any one of embodiments 34 to 37, comprising mixing the blood with one or more autologous cells prior to said introducing. 39. The method of embodiment 39, wherein the one or more autologous cells comprise Schwann cells. 40. The method of any one of embodiments 34-39, wherein the one or more coagulants and / or anti-anticoagulants are in the form of a powder, and at least a portion of the particles of the powder are of a size suitable for entering the channel. 41. The method of embodiment 40, comprising filtering the powder before mixing with blood to obtain a mixture in which at least a portion of the particles have a size of less than 2.5 microns. 42. The filtering step comprises: introducing a powder into a liquid for a selected period of time; Collecting airborne particles; and drying the collected particles to obtain the desired filtered particles; 42. The method of embodiment 41, comprising: 43. The method according to any one of embodiments 34 to 42, wherein the coagulation inducer is an anti-anticoagulant selected from the group consisting of ACD-A (anticoagulant citrate dextrose, solution A), EDTA (ethylenediaminetetraacetic acid), EGTA (ethylene glycol tetraacetic acid), citrate, heparin and oxalate. 44. The one or more coagulants are selected from the group consisting of kaolin, Ca 2+ , Mg 2+ 43. The method according to any one of embodiments 34 to 42, wherein the lipid is selected from the group consisting of negatively charged phospholipids (PL) and protamine sulfate. 45. The method includes attaching an encircling sleeve over at least one of the first nerve stump and a portion of the nerve graft, the second nerve stump and a portion of the nerve graft, or the first nerve stump, the nerve graft, and the second nerve stump; said introducing includes filling a lumen of said sleeve with said mixture; The method according to any one of embodiments 34 to 43. 46. A kit for inducing nerve fiber growth between a first nerve stump and a second nerve stump, comprising: a nerve graft having microchannels that allow for the growth of nerve fibers between the first nerve stump and the second nerve stump; Optionally, one or more blood withdrawal devices for withdrawing blood from the subject; one or more blood collection receptacles for receiving blood; a clotting assembly configured to mix the drawn blood with one or more clotting inducers to initiate a clotting process of the drawn blood; an applicator for introducing partially coagulated blood into said channel; A kit comprising: 47. The kit of embodiment 46, wherein the one or more collection receptacles are vacuum tubes. 48. The kit of embodiment 46 or 47, wherein the clotting assembly comprises a container for receiving blood, the container configured to contact the blood with the clotting inducer. 49. A kit according to any one of embodiments 46 to 48, comprising one or more coagulation-inducing agents. 50. The kit of embodiment 49, wherein the one or more coagulation-inducing agents are contained within the one or more blood collection receptacles. 51. The kit according to embodiment 49 or 50, wherein the coagulation inducer is an anti-anticoagulant selected from the group consisting of ACD-A (anticoagulant citrate dextrose, solution A), EDTA (ethylenediaminetetraacetic acid), EGTA (ethylene glycol tetraacetic acid), citrate, heparin and oxalate. 52. The one or more coagulation inducers are selected from the group consisting of kaolin, Ca 2+ , Mg 2+ 52. The kit according to any one of embodiments 46 to 51, wherein the lipid peroxide is selected from the group consisting of negatively charged phospholipids (PL) and protamine sulfate. 53. A kit described in any one of embodiments 46 to 52, comprising at least one tubular element for use as a sleeve to be placed over at least one of a first nerve stump and a portion of a nerve graft, a second nerve stump and a portion of a nerve graft, or the first nerve stump, the nerve graft, and the second nerve stump. 54. The kit according to embodiment 53, wherein the nerve-encircling hollow element is a nerve guidance conduit. 55. A kit according to any one of embodiments 46 to 54 for use in a method for inducing the growth of nerve fibers between a first nerve stump and a second nerve stump, the method comprising: (i) placing, placing, and optionally attaching a nerve graft including a microchannel extending therethrough between the first nerve stump and the second nerve stump, and optionally attaching a first end of the nerve graft to the first nerve stump and a second end of the nerve graft to the second nerve stump; (ii) obtaining blood, optionally whole blood drawn from the subject; (iii) mixing the blood with one or more coagulation-inducing agents; (iv) introducing the mixture into the microchannels of the graft before clotting of the blood is complete; (v) clotting blood within the microchannel; and Including the kit. 56. A kit according to any one of embodiments 46 to 54 for use in a method according to any one of embodiments 34 to 45.
[0071] In order to better understand the subject matter disclosed herein, and to illustrate how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]
[0072] [Figure 1A-1D] FIG. 1 is a schematic diagram illustrating different steps of a method for inducing growth or regenerating damaged or severed nerves according to an aspect of the present disclosure. [Figure 2A-2C] FIG. 1 is a schematic diagram illustrating different steps of a method for inducing growth or regenerating damaged nerves according to an aspect of the present disclosure. [Diagram 3] 1 is a schematic diagram illustrating an embodiment of a method according to an aspect of the present disclosure. [Figure 4] 1 is a schematic diagram illustrating an embodiment of a method according to an aspect of the present disclosure. [Figure 5A-5B] The results of the test of rabbit transected nerves treated with the method of the present disclosure are shown in comparison with transected rabbit nerves treated with standard conventional methods: Figure 5A shows a histogram of axon density in the midsection of the nerves of the two test groups, and Figure 5B shows a cross-section of the midsection of the nerves of the two test groups. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0073] Reference is made to Figures 1A-1D, which are schematic diagrams illustrating different stages of a method for inducing growth or regenerating a damaged or severed nerve according to an embodiment of the present disclosure. Figure 1A shows first and second stumps 102 and 104 of a severed nerve of a subject to be treated. A sleeve 106, e.g., a nerve guidance conduit, has an internal lumen 107 and extends between first and second open ends 108 and 110 and is configured to receive each of the stumps 102 / 104 through the respective open ends, whereby the sleeve 106 is mounted over the first and second stumps 102 and 104. It is noted that in Figures 1A-1D and 2A-2B, the sleeve is transparent to allow for the viewing of elements that would otherwise be hidden, but the sleeve can be made of a material with any degree of transparency between completely transparent and completely opaque.
[0074] In Figure 1A, nerve stumps 102 / 104 are introduced through first and second open ends 108 and 110, respectively, and secured, such as by sutures, to the portion of the sleeve encasing the stumps. Figure 1B shows stumps 102 and 104 in sleeve 106, with the end portions of stumps 103 and 105 in the lumen of sleeve 106 and secured in place by fixation elements 112 such that each stump extends beyond its respective opening.
[0075] As seen in FIG. 1C, a mixture 114 of whole blood, typically blood drawn from a subject, and one or more coagulation inducers, which are one or more coagulants and / or one or more anti-anticoagulants, is introduced into the lumen 107 before the mixture is fully coagulated, i.e., while the blood is still in a flowable state. The introduction of the mixture into the lumen can be done by a syringe 109 or any suitable means. The lumen 107 is filled with the mixture so that the mixture contacts at least a portion of each of the stumps. FIG. 1D shows that the mixture forms a continuous matrix connecting the two stumps 102 / 104. When the mixture is in the lumen 107, the clotting process of the mixture proceeds until a clot is formed that contacts or encases one or two of the stumps 102 / 104. The sleeve 106 may be made to fit snugly around the nerve stumps. However, if this is not the case, the first and second open ends 108 and 110 may be sealed, for example by a cloth, a dressing means, or any suitable sealing means, to retain the mixture within the lumen 107.
[0076] Reference is now made to Figures 2A-2C, which are schematic illustrations of non-limiting examples of embodiments according to aspects of the present disclosure. Figure 2A shows a sleeve 206 mounted over a damaged portion 211 of a nerve NE of a subject. The sleeve may be formed by a sheet wrapped around the nerve NE or may be formed from a flexible tubular element with an axially extending slit in its wall so that it can be opened for placement over the nerve. Once the sleeve 206 is in place, a mixture 214 of whole blood, typically blood drawn from the subject, and one or more coagulation inducers is introduced into the lumen 207 of the sleeve 206 before clotting of the mixture is complete, i.e., while the blood is still in a flowable form as seen in Figure 2B. The mixture 214 fills the lumen 207 so as to contact or encase the damaged portion 211 of the nerve NE and is maintained in the lumen to form a clot that contacts or encases the damaged portion 211 of the nerve NE, as seen in Figure 2C. In time, the clot induces regeneration or growth of the damaged nerve.
[0077] 3 is a schematic diagram of a non-limiting example of an embodiment of a method according to aspects of the present disclosure. In this example, the damaged nerve is a severed nerve having a first nerve stump 302 and a second nerve stump 304. The two stumps 302 and 304 are connected to each other via a nerve graft 320 having a channel 322 through which nerve growth is promoted. The channel 322 of the nerve graft 320 extends between a first end 324 and a second end 326 of the nerve graft 320. The first end 324 is joined to the first nerve stump 302, and the second end 326 is joined to the second nerve stump 304. Typically, whole blood drawn from the subject to be treated is mixed with one or more clot-inducing agents (i.e., coagulants and / or anti-anticoagulants) to obtain a whole blood and clot-inducing agent mixture 315, which is then introduced into the channel 322 by an applicator 309. This can also be done by placing one or both ends 324 / 326 in the mixture to allow capillary forces to drive the mixture into the microchannels. Optionally, the mixture 315 can also be applied to the interfaces between the nerve graft 320 and each nerve stump 302 and 304. The whole blood is then allowed to coagulate in the channels and optionally on the interfaces to form a clot that enhances the growth of nerve fibers between the two stumps through the microchannels.
[0078] 4 is a schematic diagram illustrating a non-limiting example of an embodiment of a method according to one aspect of the present disclosure. This example differs from that of FIG. 3 by surrounding the interface between each nerve stump and the nerve graft with a sleeve 406 and optionally fixing each of the stumps to the sleeve 406 and / or the nerve graft 420. The lumen 407 of the sleeve 406 is filled with whole blood that coagulates such that the channel 422 of the nerve graft 420 is completely or partially filled with a mixture of clotting initiator and whole blood 415, and the gap between the stumps 402 and 404 and the nerve graft 420 is also filled with whole blood that coagulates, resulting in a continuous clot between the two stumps.
[0079] Testing the method of the present invention in rabbits The disclosed method was tested in rabbits. A 2.5 cm section of the rabbit's tibial nerve was cut. A nerve guidance conduit was attached over the two edges of the nerve stump and the gap between them. Both edges were sutured and secured to the nerve guidance conduit. Autologous whole blood was drawn from the rabbit and mixed with a clotting initiator to initiate blood clotting. The lumen of the nerve guidance conduit was then filled with activated whole blood from the rabbit, forming a clot matrix in the lumen connecting the two edges. The status of the growth and regeneration of the rabbit's nerve was examined after 4 months. Figure 5A shows histograms of the percentage of axons in a given region of the nerve after 4 months. The left bar of each histogram shows the results in the proximal part of the nerve, and the right bar of each histogram shows the results in the middle part of the nerve. The group marked "with ActiGrft" represents the rabbits tested with the disclosed method. In both the proximal and middle parts, the group that used the whole blood clot in the conduit had more axons than the group that did not.
[0080] Figure 5B shows a cross-section of the midsection of a severed nerve after 4 months. The left cross-section is a control group where the method of the present disclosure was not used, the conduit was left unfilled, and the right cross-section is a test group where the method of the present disclosure was used, the conduit was filled with clotted whole rabbit blood. Myelin is labeled and visible, and the test group cross-section shows a much higher axon density than the control group.
Claims
1. A kit for inducing growth or regenerating a damaged nerve portion of a subject, comprising: a nerve enveloping hollow element having an internal cavity for enveloping the damaged nerve portion such that the damaged nerve portion is present in at least a portion of the internal cavity; one or more blood withdrawal devices to enable the withdrawal of blood from the subject; one or more blood collection receptacles for receiving blood drawn from the subject; a clotting assembly configured to allow mixing of one or more clotting inducers with the withdrawn blood to initiate the clotting process of the withdrawn blood; an applicator for introducing partially coagulated blood into said lumen; A kit comprising:
2. 10. The kit of claim 1, wherein the clotting assembly comprises a volume for receiving the withdrawn blood, the volume being contactable with one or more procoagulants or anti-anticoagulants.
3. 3. The kit of claim 1 or 2, further comprising one or more anticoagulants for mixing with the withdrawn blood.
4. A kit according to any one of claims 1 to 3, comprising a film or sheet for placement over the damaged nerve portion to form the nerve-encircling hollow element.
5. The kit according to any one of claims 1 to 4, wherein the nerve-encircling hollow element is a nerve guidance conduit.
6. The kit according to any one of claims 1 to 5, comprising a fixation element for fixing the damaged nerve portion in the nerve-enveloping hollow element.
7. A nerve graft having microchannels that allow for the growth of nerve fibers between a first nerve stump and a second nerve stump, the applicator is an applicator for introducing partially coagulated blood into the lumen; The kit of any one of claims 1 to 6, wherein the nerve-enveloping hollow element is for placement over at least one of the first nerve stump and a portion of the nerve graft, the second nerve stump and a portion of the nerve graft, or the first nerve stump, the nerve graft and the second nerve stump.
8. 1. One or more coagulation inducers for use in a method of inducing nerve fiber growth across a damaged nerve segment, the method comprising: attaching a nerve guidance conduit to encase the nerve portion; introducing a mixture of whole blood drawn from the subject and one or more coagulation-inducing agents into said lumen prior to complete clotting; One or more coagulation inducers comprising:
9. 9. The one or more coagulation inducing agents of claim 8, wherein the damaged nerve portion comprises a severed nerve fiber.
10. 10. The one or more coagulation inducing agents of claim 9, wherein the nerve portion comprises two severed nerve stumps that are surgically joined or approximated.
11. The attaching step comprises: placing a film or sheet over said portion and encasing said portion with said sheet to form said conduit; 11. The one or more coagulation inducing agents of claim 10, comprising:
12. The attaching step comprises: Introducing the two nerve stumps into the conduit, one from each end of the conduit; bringing the two stumps into close proximity to one another within the conduit; 11. The one or more coagulation inducing agents of claim 10, comprising:
13. 13. The one or more clot inducing agents of claim 12, wherein said approximating comprises fixing said two ends within said conduit with sutures.
14. said introducing includes filling a portion of a lumen of said conduit with said mixture such that said mixture contacts said nerve portion; 14. The one or more coagulation inducers of any one of claims 8-13, wherein the nerve portion comprises two severed nerve stumps, and the introducing is performed such that the mixture is in intimate contact with the stumps.
15. (i) saturating the blood with an oxygen-rich gas prior to said introducing; (ii) mixing the blood with one or more autologous cells prior to said introducing; The one or more coagulation inducing agents of any one of claims 8 to 14, wherein the one or more autologous cells comprise Schwann cells.