Patent Application
20150148901
The present invention relates generally to instrumentation, kits and methods for reconstruction or augmentation of soft tissue, including soft tissue such as fat, glands, and blood vessels, and particularly mammary tissue.
Breast cancer often requires women to undergo mastectomies to remove cancerous tissue and prevent metastasis. Removal of significant volumes of breast tissue can leave women physically scarred and emotionally distraught. Many women who have undergone mastectomies may feel insecure about their appearance or feel a loss of their femininity due to the loss of one or both breasts. Therefore many of these women choose to have breast reconstructive surgery.
Elective breast augmentation surgery has also become a prevalent procedure among women seeking to improve their appearance or self-confidence. Both breast reconstruction and augmentation involve surgical implantation of artificial implants which are typically saline or silicone filled polymeric bags. These procedures cause a foreign body reaction within the patient wherein the patients immune cells attempt to wall off the foreign material by encapsulating it in fibrous scare tissue. While these implants may physically replace lost tissue or increase the size of breasts, they do not promote healing or growth of natural tissue. Because they are made from foreign materials they cannot completely mimic the appearance or mechanical properties of natural breasts. Furthermore breast implants may lead to complications such as leakage or hardening that ultimately require additional medical interventions.
The present invention may generally comprise a system and method of soft tissue reconstruction and augmentation using a platelet-rich fibrin matrix. In most of the below embodiments, the present invention forms a platelet-rich fibrin matrix from components of the patients own blood which can then be implanted into the breast. A platelet-rich fibrin matrix is a blood clot with a decreased number of red blood cells. In certain embodiments the platelet-rich fibrin matrix may be essentially devoid of red blood cells. It comprises platelets within fibrin network and may contain other plasma components and/or white blood cells. Upon implantation this fibrin matrix provides a natural filler material to replace lost tissue or increase breast size. This natural filler has mechanical properties similar to native tissue allowing it to better mimic the look and feel of native breast tissue. Because it is formed from components of the patients own blood that are normally involved in tissue healing, it does not cause a foreign body reaction. After implantation the matrix will begin to degrade and be replaced by new tissue growth. The platelet-rich fibrin matrix provides a temporary scaffold for cells to populate and begin to generate new tissue. As it degrades the platelet-rich fibrin matrix releases growth factors such as platelet derived growth factor (PDGF), fibroblast growth factor (FGF), epithelial growth factor (EGF), vascular endothelial growth factor (VEGF), and transforming growth factor-beta (TGF-β). These growth factors recruit cells from surrounding tissue and cause them to divide ultimately leading to wound healing and the formation of new tissue and blood vessels. In some circumstances formation of significant new tissue may not occur, but the fibrin matrix would still provide a natural filler material to replace lost tissue or increase breast size on a temporary basis.
The present invention may generally, in a first embodiment, include instrumentation for creating a platelet-rich fibrin matrix from a patient's blood and implanting that matrix into the patient's breast. The instrumentation may include any of a blood collection and matrix preparation system, a centrifuge, and a matrix delivery device. The use of these instruments may create implants for increasing breast volume and promoting new tissue growth for breast reconstruction or augmentation surgery. The instrumentation may further include other elements such as sterile packaging (to maintain sterility of the matrix during processing) and centrifuge buckets (for holding the blood collection and matrix preparation system during centrifugation).
In one embodiment, the present invention may include an instrumentation system for breast reconstruction or augmentation; the instrumentation system may include a blood collection and matrix preparation system capable of removing and storing a patient's blood; a centrifuge capable of forming a platelet-rich fibrin matrix from blood; matrix delivery device for implanting the platelet-rich fibrin matrix. The blood collection and matrix preparation system may comprise a blood collection needle, flexible tubing, a blood collection bag, and a large needle-shaped conduit for injection of the platelet-rich fibrin matrix.
The blood collection and matrix preparation system may comprise a blood collection apparatus removably coupled to a matrix preparation container and may be packaged in sterile packaging. The blood collection apparatus may comprise a flexible blood collection tube with a proximal end and a distal end, and a blood collection needle mounted on the distal end. The blood collection needle may be a butterfly needle which may be capped for safety and sterility. The butterfly needle may further be a retractable needle. The matrix preparation container may comprise an ellipsoidal blood collection bag with a large needle-shaped conduit extending radially outward along a major axis of the ellipsoidal bag such that fluid may flow though the conduit and into the bag. The conduit may be elliptical or circular in cross section and may contain a beveled outer tip. The conduit may be rigid or flexible. Additionally, the matrix preparation container may have valves, ports, or the like for removal of red blood cells or platelet-poor plasma. Optionally, the matrix preparation container may also include a physical barrier for sequestering red blood cells to a separate compartment within the matrix preparation container. The barrier may be a valve, a float, a thixotropic gel, beads, a porous membrane, or the like. The proximal end of the blood collection apparatus may further contain an adaptor for removably coupling to and providing fluid communication with the matrix preparation container. Furthermore this adaptor may substantially surround the needle-shaped conduit of the matrix preparation container forming an airtight seal and protecting the sterility of the conduit while the blood collection apparatus is coupled to the matrix preparation container. Certain embodiments may require blood to come into contact with a substance that activates platelets or otherwise supports coagulation while within the matrix preparation container. Such substances may include glass, silica, collagen, or the like. For such embodiments components of the matrix preparation container may be made from, coated with, or otherwise contain such coagulation supporting substances.
The instrumentation system may further include a centrifuge and one or more centrifuge buckets which are configured to safely hold the blood collection and matrix preparation system during centrifugation. The centrifuge buckets may further be shaped to substantially surround the matrix preparation container and maintain its shape during centrifugation.
The instrumentation system may also include a matrix delivery device for implanting the platelet-rich fibrin matrix into a patient. The matrix delivery device may be configured to receive the matrix preparation container therein such that the needle-shaped conduit extends out of one end for insertion into the patient. In a preferred embodiment the matrix delivery device is configured like a gun with a handle and trigger wherein the needle-shaped conduit is substantially aligned with the barrel of the gun and extends outwardly from the distal end of the gun. The trigger may activate actuation means that move a plunger along the axis of the barrel driving the end of the blood collection bag furthest from the conduit toward the conduit thereby forcing the contents of the bag through the conduit and into the patient. The actuation means may be electronic, pneumatic, hydraulic, spring loaded, mechanical, or the like. Alternatively the surgeon may manually push the plunger for example by pushing on the proximal or back end of the gun. In addition to a plunger other means of compressing the blood collection bag may be used.
In an alternate embodiment, the present invention may be a method for creating a platelet-rich fibrin matrix from a patient's blood and implanting that matrix into the patient's breast. The method may include accessing a vein of the patient with a blood collection needle which is attached to a blood collection and matrix preparation system; allowing the blood to flow into and fill the matrix preparation container; centrifuging and coagulating the blood within the blood collection and matrix preparation system to separate red blood cells and form a platelet-rich fibrin matrix; and implanting the platelet-rich fibrin matrix into the patients breast.
The method may further include the step of simultaneously separating red blood cells and coagulating during a single centrifugation. Due to the differing densities of the various blood components it will separate into three layers such that red blood cells are furthest from the axis of rotation of the centrifuge, the platelet-rich fibrin matrix is in an intermediate position, and a platelet poor plasma layer is closest to the axis of rotation. Because this step precludes the use of anticoagulants it requires relatively rapid transfer of the blood collection bag to a centrifuge to prevent the blood from naturally coagulating before red blood cells can be separated from the clot via centrifugation. The blood collection and matrix preparation system may further be placed in a centrifuge bucket configured to receive the matrix preparation container and maintain its shape during centrifugation. The method may also include the step of removing red blood cells from the matrix preparation container via a valve, port or the like. Additionally the blood collection and matrix preparation system may then be placed within a matrix delivery device. In a preferred embodiment the matrix delivery device may take the form of a gun for injection of the platelet-rich fibrin matrix from which the needle-shaped conduit of the matrix preparation container extends outwardly. The gun may further include a plunger, a handle, and a trigger which actuates the plunger which forces the platelet-rich fibrin matrix out through the needle-shaped conduit. The method may further include the step of disconnecting the blood collection apparatus from the matrix preparation container thereby exposing the sterile needle-shaped conduit. In this method the needle-shaped conduit may also be introduced into the patient's breast through an incision in the skin. The platelet-rich fibrin matrix may further be compressed and forced through the conduit and into the patient's breast.
The method my further include the step of preparing the breast to receive the platelet-rich fibrin matrix implant by creating space within the breast for the matrix to reside. The step of preparing the breast may include sharp and/or blunt dissection of the soft tissue within the breast. Additionally the method may include the step of temporarily implanting a tissue expander to stretch and expand the breast. The step of implanting a tissue expander may occur immediately prior to implantation or several weeks beforehand.
An alternative embodiment of the method of the present invention may further include the step of adding an anticoagulant to the blood collection and matrix preparation system to prevent premature clotting of harvested blood. This method may further include the step of introducing a chemical or physical platelet activator or other procoagulant to later reverse the effects of the anticoagulant.
Yet another embodiment of the method of the present invention may further include the steps of adding an anticoagulant to the blood collection and matrix preparation system; separating the red blood cells from the blood to create platelet-rich plasma; and reversing the anticoagulant to form a platelet-rich fibrin matrix from the platelet-rich plasma. Separation of red blood cells from the blood may be performed by any method known in the art including centrifugation, aphaeresis, plasmapheresis, and platelet-rich plasmapheresis. Centrifugation techniques may include the use of a thixotropic separating medium with a density that is less than that of red blood cells but greater than platelets and plasma. Such thixotropic media behave like viscous fluids under the shear forces of centrifugation allowing them to separate along the density gradient and form a physical barrier between the red blood cells and the other blood components. Once removed from the shear forces of the centrifuge the thixotropic medium forms a solid barrier. The anticoagulant may be any anticoagulant known in the art including ethylenediaminetetraacetic acid (EDTA), citrate, oxalate, heparin, and the like. Reversal of the anticoagulant may be accomplished by any method known in the art including the use of proteins or other compounds that activate or catalyze the natural pathways of clotting (“coagulation activators”). These include, for example, thrombin, thromboplastin, calcium (e.g. calcium glucuronate), bismuth compounds (e.g. bismuth subgallate), collagen, desmopressin and analogs, denatured collagen (gelatin), and fibronectin. Vitamin K may contribute to activation of coagulation. This method may also include the step of centrifugation during platelet-rich fibrin matrix formation.
In an alternate embodiment, the present invention may be a method for creating a plurality of platelet-rich fibrin matrixes from a patient's blood and implanting these matrixes into the patient's breast. The method may include puncturing a vein of the patient with a blood collection needle which is attached to a blood collection and matrix preparation system; allowing the blood to flow into and fill the matrix preparation container; centrifuging and coagulation the blood within the blood collection and matrix preparation system to separate red blood cells and form a platelet-rich fibrin matrix; implanting the platelet-rich fibrin matrix into the patients breast; and repeating the previous steps. The repetition of the steps of this method may occur within one treatment such that multiple smaller matrixes are implanted into the patient's breast so that they are adjacent to one another. The handling of smaller volumes of blood may be useful in embodiments where no anticoagulant is used and the blood needs to be centrifuged quickly after collection to avoid premature coagulation. Furthermore the smaller matrix size may allow for smaller incisions and a less invasive procedure. Alternatively the method may be repeated in several treatments over the course of several months. This would allow for more volume to be created as more blood can be safely drawn. Furthermore it allows for the breast tissue to grow more gradually over time.
In an alternate embodiment, the present invention may be a method for creating a platelet-rich fibrin matrix, implanting that matrix into a patient's breast, and separately but concurrently implanting cells into the patient's breast. The implanted cells may add to the initial breast volume as well as increase the number of cells available for new tissue growth. The method may include puncturing a vein of the patient with a blood collection needle which is attached to a blood collection and matrix preparation system; allowing the blood to flow into and fill the matrix preparation container; centrifuging and coagulation the blood within the blood collection and matrix preparation system to form a platelet-rich fibrin matrix; implanting the platelet-rich fibrin matrix into the patient's breast; and injecting cells into the patient's breast. The method may further include the step of obtaining adipocytes, fibroblasts, blood vessel cells, adipose derived stem cells, and the like via liposuction. Additionally the method may include the step of isolating, enriching, or concentrating adipose derived stem cells from liposuction aspirate. Alternatively progenitor or stem cells may be isolated via any other means known in the art.
In an alternate embodiment, the present invention may be a method for creating a platelet-rich fibrin matrix embedded with cells and implanting that matrix into the patient's breast. The embedded cells may add to the initial implant volume as well as increase the number of cells available for new tissue growth. The method may include puncturing a vein of the patient with a blood collection needle which is attached to a blood collection and matrix preparation system; allowing the blood to flow into and fill the matrix preparation container; adding cells to the matrix preparation container; centrifuging and coagulating the blood and cell mixture; and implanting the platelet-rich fibrin matrix with embedded cells into the patient's breast. Alternatively the method may also include the steps of anticoagulating the blood, removing red blood cells, adding cells to the matrix preparation container and reversing the anti-coagulant without further centrifugation. The method may further include the step of obtaining adipocytes, fibroblasts, blood vessel cells, adipose derived stem cells, and the like via liposuction. Additionally the method may include the step of isolating, enriching, or concentrating adipose derived stem cells from liposuction aspirate. Alternatively progenitor or stem cells may be isolated via any other means known in the art.
While the following instrumentation and methods may be used to repair or augment any suitable type of soft tissue—such as adipose, dermis, epithelium, muscle, nerve, or connective tissue in any area of anatomy—reconstruction and augmentation of breast tissue will be the exemplary focus of the disclosure below. As used herein, “proximal” or “proximally” means closer to or towards an operator, e.g., surgeon, while “distal” or “distally” means further from or away from the operator.
In a first embodiment, the instrumentation system may include a blood collection and matrix preparation system such as those illustrated in
The blood collection apparatus may comprise a flexible blood collection tube 30 with a proximal end 31 and a distal end 32, and a blood collection needle 20 mounted on the distal end. The blood collection needle may be a butterfly needle which may be capped for safety and sterility. The butterfly needle may further be a retractable needle. The proximal end of the blood collection apparatus may further contain an adaptor 60 for removably coupling to and providing fluid communication with the matrix preparation container.
The instrumentation system may further include a centrifuge and one or more centrifuge buckets which are configured to safely hold the blood collection and matrix preparation system during centrifugation.
The instrumentation system may also include a matrix delivery device 70 for implanting the platelet-rich fibrin matrix into a patient. The matrix delivery device may be configured to receive the matrix preparation container 40 therein such that the needle-shaped conduit 42 extends out of one end for insertion into the patient.
The present invention also includes various methods using the above-discussed instrumentation system for repair, regeneration, or augmentation of soft tissue. As above, the exemplary surgical site will be for implants to increase breast volume and promote new tissue growth for breast reconstruction or augmentation surgery. In a first embodiment, the blood collection and matrix preparation system may be removed from its outer sterile packaging 10 and the blood collection needle 20 used to puncture the vein of a patient. Blood will then flow through the blood collection tube 30 and collect in the matrix preparation container 40. Once blood has filled the matrix preparation container the blood collection needle may be removed from the patient's vein and the blood collection and matrix preparation system may be transferred to a centrifuge. The blood collection and matrix preparation system may be placed into the centrifuge in any position relative to the centrifugal force applied by the centrifuge. In one example illustrated in
In another embodiment the blood collection tube 30 of the blood collection apparatus depicted in
The system may then be centrifuged to simultaneously separate red blood cells and coagulate the blood plasma. To allow for natural coagulation the blood should come into contact with a substance that activates platelets or otherwise supports coagulation while within the matrix preparation container. Such substances may include glass, silica, collagen, or the like. Components of the matrix preparation container 40 may be made from, coated with, or otherwise contain such coagulation supporting substances. The centrifuge may be spun at a slow speed, preferably between 2,000 and 4,000 RPM or between 200 to 1,000 g. Due to the differing densities of the various blood components it will separate into three layers as illustrated in
The blood collection and matrix preparation system may then be placed within a matrix delivery device 70. In one example illustrated in
In a second embodiment, an anticoagulant is included in the blood collection and matrix preparation system in an effective amount to prevent the blood from clotting. Various known anticoagulants may be used including for example ethylenediaminetetraacetic acid (EDTA), citrate, oxalate, heparin and the like. The anticoagulant prevents the blood from naturally coagulating before red blood cells can be separated from the clot via centrifugation thereby affording more time to collect and handle the patient's blood. The blood collection and matrix preparation system may be removed from its outer sterile packaging 10 and the blood collection needle 20 used to puncture the vein of a patient. Blood will then flow through the blood collection tube 30 and collect on the matrix preparation container 40. Once blood has filled the matrix preparation container the blood collection needle may be removed from the patient's vein and the blood collection and matrix preparation system may be transferred to the centrifuge 90. In a preferred embodiment of the blood collection and matrix preparation system 50 depicted in
The system may then be centrifuged to simultaneously separate red blood cells and coagulate the blood plasma. The centrifuge may be spun at a slow speed, preferably between 2,000 and 4,000 RPM or between 200 to 1,000 g. Due to the differing densities of the various blood components it will separate into three layers as illustrated in
The blood collection and matrix preparation system may then be placed within a matrix delivery device 70. In one example illustrated in
In another embodiment, the present invention may be a method for creating a plurality of platelet-rich fibrin matrixes from a patient's blood and implanting these matrixes into a single breast. The plurality of platelet-rich fibrin matrixes may be produced and implanted in a single treatment session. Alternatively, they may be produced and implanted in multiple treatments over the course of several months. A blood collection and matrix preparation system may be removed from its outer sterile packaging 10 and the blood collection needle 20 used to puncture the vein of a patient. Blood will then flow through the blood collection tube 30 and collect in the matrix preparation container 40. Once blood has filled the matrix preparation container the blood collection needle may be removed from the patient's vein and the blood collection and matrix preparation system may be transferred to a centrifuge. The blood collection and matrix preparation system may be placed into the centrifuge in any position relative to the centrifugal force applied by the centrifuge. In one example illustrated in
In another embodiment the blood collection apparatus depicted in
The system may then be centrifuged to simultaneously separate red blood cells and coagulate the blood plasma. The centrifuge may be spun at a slow speed, preferably between 2,000 and 4,000 RPM or between 200 to 1,000 g. Due to the differing densities of the various blood components it will separate into three layers as illustrated in
The blood collection and matrix preparation system may then be placed within a matrix delivery device 70. In one example illustrated in
In yet another embodiment, the present invention may be a method for creating a platelet-rich fibrin matrix and implanting that matrix into the patient's breast while separately but concurrently implanting regenerative cells. The implanted cells may add to the initial implant volume as well as increase the number of cells available for new tissue growth. Such cells may also secrete growth factors such as FGF, EGF, VEGF, TGF-β or other cell signaling molecules that promote tissue growth and regeneration. The cells may include connective tissue cells such as adipocytes, fibroblasts, blood vessel cells, adipose derived stem cells, or other progenitor cells. The cells may be autologous, allogenic, or zenogenic. Furthermore the cells may be genetically modified. The cells may be obtained via any technique known to those skilled in the art. For example liposuction may be performed on the patient to collect autologous adipocytes, fibroblasts, blood vessel cells, and adipose derived stem cells to be re-implanted. In another example liposuction aspirate may be processed to enrich the proportion of adipose derived stem cells or isolate adipose derived stem cells to create a substantially pure cell population. By way of nonlimiting example, the liposuction aspirate may be processed via the Icellator Cell Isolation System® (Tissue Genesis, Inc., Honolulu, Hi.) or any method known in the art such as that disclosed in U.S. Pat. No. 8,067,234, the entirety of which is incorporated by reference herein as if fully set forth herein. The blood collection and matrix preparation system may be removed from its outer sterile packaging 10 and the blood collection needle 20 used to puncture the vein of a patient. Blood will then flow through the blood collection tube 30 and collect in the matrix preparation container 40. Once blood has filled the matrix preparation container the blood collection needle may be removed from the patient's vein and the blood collection and matrix preparation system may be transferred to a centrifuge. The blood collection and matrix preparation system may be placed into the centrifuge in any position relative to the centrifugal force applied by the centrifuge. In one example illustrated in
In another embodiment the blood collection apparatus depicted in
The system may then be centrifuged to simultaneously separate red blood cells and coagulate the blood plasma. The centrifuge may be spun at a slow speed, preferably between 2,000 and 4,000 RPM or between 200 to 1,000 g. Due to the differing densities of the various blood components it will separate into three layers as illustrated in
The blood collection and matrix preparation system may then be placed within a matrix delivery device 70. In one example illustrated in
Although the above method of preparing and implanting a platelet-rich fibrin matrix has been provided as an example, any method described herein is compatible with concurrently implanting regenerative cells. The cells may be implanted via syringe injection into the pocket 106 through the skin incision 105 prior to or subsequent to implantation of the platelet-rich fibrin matrix, or directly through the skin after the incision has been closed. Either a single injection or multiple injections into various locations within the pocket 106 of breast 101 may be used. The cells may be injected as a single-cell suspension in sterile buffered saline or any other pharmaceutically suitable carrier. A single-cell suspension is a suspension of cells in a liquid or aqueous medium wherein substantially all the cells have been isolated so that they are not adhered to other cells. The cells also may be adhered to microcarriers or embedded within microcapsules. Alternatively, the cells may be aggregated into small clusters of cells ranging in diameter from 50 to 500 micrometers, preferably between 100 to 200 micrometers.
In yet another embodiment, the present invention may be a method for creating a platelet-rich fibrin matrix embedded with regenerative cells and implanting that matrix into the patient's breast. The embedded cells may be homogeneously dispersed throughout the platelet-rich fibrin matrix or localized on or near one surface of the platelet-rich fibrin matrix. The embedded cells may add to the initial implant volume as well as increase the number of cells available for new tissue growth. Such cells may also secrete growth factors such as FGF, EGF, VEGF, TGF-β or other cell signaling molecules that promote tissue growth and regeneration. The cells may include connective tissue cells such as adipocytes, fibroblasts, blood vessel cells, adipose derived stem cells, or other progenitor cells. The cells may be autologous, allogenic, or zenogenic. Furthermore the cells may be genetically modified. The cells may be obtained via any technique known to those skilled in the art. For example liposuction may be performed on the patient to collect autologous adipocytes, fibroblasts, blood vessel cells, and adipose derived stem cells to be re-implanted. In another example liposuction aspirate may be processed to enrich the proportion of adipose derived stem cells or isolate adipose derived stem cells to create a substantially pure cell population. By way of nonlimiting example, the liposuction aspirate may be processed via the Icellator Cell Isolation System® (Tissue Genesis, Inc., Honolulu, Hi.) or any method known in the art such as that described in the above-cited '234 patent, incorporated by reference herein.
In a preferred embodiment the embedded cells may be dispersed throughout the platelet-rich fibrin matrix. In this embodiment, the separation of red blood cells and coagulation of the plasma may occur in two subsequent steps. The patient's blood is anticoagulated during collection and separation of red blood cells to prevent the blood from clotting. Various known anticoagulants may be used including for example ethylenediaminetetraacetic acid (EDTA), citrate, oxalate, heparin and the like. The anticoagulant prevents the blood from naturally coagulating before red blood cells can be separated from the blood to create platelet-rich plasma (PRP). Any method known in the art to generate PRP may be used such as those described in U.S. Pat. Nos. 6,979,307, 7,745,106, 6,579,219, 7,553,413, 7,708,152, and 6,398,972, the entireties of which are incorporated by reference herein as if fully set forth herein. For example, a blood collection and matrix preparation system containing an effective amount of anticoagulant to prevent blood clotting may be removed from its outer sterile packaging 10 and the blood collection needle 20 used to puncture the vein of a patient. Blood will then flow through the blood collection tube 30 and collect in the matrix preparation container 40. Once blood has filled the matrix preparation container the blood collection needle may be removed from the patient's vein and the blood collection and matrix preparation system may be transferred to the centrifuge 90. In a preferred embodiment of the blood collection and matrix preparation system 50 depicted in
Cells may then be added to the matrix preparation container, for example via injection of a single-cell suspension into port 47 or membrane 61. A platelet activator or other procoagulant such as thrombin, collagen, calcium ions, or the like, is introduced, for example through port 47 or membrane 61, to reverse the effects of the anticoagulant. For example, if a calcium chelator such as sodium citrate or EDTA is used as an anticoagulant, it may be reversed with a source of calcium ions such a calcium chloride or calcium gluconate. Mixing means such as rocking, shaking, vibrating, inversion, oscillating, or rotating may be used to keep the cells dispersed throughout the matrix preparation container during coagulation of the platelet-rich fibrin matrix.
In another embodiment the matrix preparation container may be centrifuged after the addition of cells and procoagulant causing the cells to be embedded at an outer surface of the platelet-rich fibrin matrix. The blood collection and matrix preparation system may be placed into the centrifuge in any position relative to the centrifugal force applied by the centrifuge. In one example illustrated in
The centrifuge may be spun at a slow speed, preferably between 2,000 and 4,000 RPM or between 200 to 1,000 g. Most cells are denser than plasma and therefore will become embedded on the surface of the platelet-rich fibrin matrix which is furthest from the axis of rotation of the centrifuge. Cells that are less dense than plasma such as adipocytes will become embedded on the surface of the platelet-rich fibrin matrix which is closest to the axis of rotation.
The blood collection and matrix preparation system may then be placed within a matrix delivery device 70. In one example illustrated in
This application claims the benefit of the filing date under 35 U.S.C. §119 (e) of U.S. Provisional Application No. 61/780,959, filed Mar. 13, 2013, the contents of which are incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61780959 | Mar 2013 | US |
