Autologous tissue transfer devices and methods of use

Abstract

Embodiments disclosed herein relate to devices and methods for autologous tissue transfer for a subject. In some embodiments, a syringe may include a barrel and an outlet as well as a primary plunger and a secondary plunger disposed at least partially within the barrel. The primary plunger may be transitioned between a closed configuration and an open configuration to permit fluid communication between a primary chamber and a secondary chamber located within the internal volume of the barrel. The user may employ the embodiments of such a device to extract adipose, or other desired, tissue from a subject into the primary chamber. In some embodiments, extracted adipose tissue may be separated into density-based layers of fat graft and waste products. The waste products may be isolated in the secondary chamber while retaining the fat graft in the primary chamber such that the fat graft may be re-administered to the subject.

Description

AUTOLOGOUS TISSUE TRANSFER DEVICES AND METHODS OF USECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application 63 / 625,108, filed on January 25, 2024, the content of which is incorporated herein by reference in its entirety.FIELD

[0002] Disclosed embodiments are related to autologous fat tissue transfer devices and associated methods of use.BACKGROUND

[0003] Autologous fat transfer is a technique in which harvested adipose tissue is injected into a subject for reconstructive and augmentation surgeries. In particular, adipose tissue is harvested from a subject and is then processed using decantation and / or centrifugation to separate debris, excess fluid, dead cells, and / or other waste products from viable adipose fat cells to provide a fat graft that may then be reinjected into the subject from which the adipose tissue was harvested.SUMMARY

[0004] In some embodiments, a syringe including a barrel having an internal volume and an outlet in fluid communication with the internal volume may be provided. The syringe may also include a primary plunger and a secondary plunger each disposed within the internal volume. A primary chamber may be formed between the outlet of the syringe and the primary plunger while a secondary chamber may be formed between the primary plunger and the secondary plunger. In some embodiments, the primary plunger may be configured to be transitioned between a closed configuration and an open configuration. In the closed configuration, the primary chamber may be isolated from the secondary chamber while in the open configuration the primary chamber may be in fluid communication with the secondary chamber.

[0005] In some embodiments, a method of operating a syringe is provided. The method may include a first step of separating tissue into a tissue graft and one or more waste layerswithin a primary chamber of a syringe. The method may i primary chamber in fluid communication with a secondary chamber of the syringe through a portion of a primary plunger of the syringe. The method may include a third step of displacing the primary plunger of the syringe to flow the one or more waste layers from the primary chamber into the secondary chamber. The method may include a fourth step of isolating the primary chamber of the syringe from the secondary chamber.

[0006] It should be appreciated that the foregoing concepts, and additional concepts discussed below, may be arranged in any suitable combination, as the present disclosure is not limited in this respect. Further, other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments when considered in conjunction with the accompanying figures.BRIEF DESCRIPTION OF DRAWINGS

[0007] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:

[0008] FIG. 1 A is a schematic perspective view of a syringe including a primary plunger and a secondary plunger which are shown in a first arrangement, according to some embodiments;

[0009] FIG. IB is a schematic perspective view of the syringe of FIG. 1 A, where the primary plunger and the secondary plunger are shown in a second arrangement, according to some embodiments;

[0010] FIG. 2A is a perspective view of the plunger arrangement of FIG. IB, where the primary plunger includes a piston having openings and the openings are shown in a closed configuration, according to some embodiments;

[0011] FIG. 2B is a perspective view of the plunger arrangement of FIG. 2A, where the openings in the piston of the primary plunger are shown in an open configuration, according to some embodiments;

[0012] FIG. 3 is a perspective view of a shaft of the primary plunger of FIGs. 1A-B, where projections extending outwardly from a distal end of the shaft are shown, according to some embodiments;

[0013] FIG. 4 is a perspective view of the secondary plunger of FIGs. 1A-B, according to some embodiments;

[0014] FIG. 5A is a perspective view of a piston c according to some embodiments;

[0015] FIG. 5B is a cross-sectional perspective view of the piston of FIG. 5 A taken along lines 5B-5B where one or more openings in a bottom flange of the piston are shown, according to some embodiments;

[0016] FIG. 6A is a cross-sectional schematic view of a syringe including a primary plunger and a secondary plunger following extraction of adipose tissue into a primary chamber of the syringe, according to some embodiments;

[0017] FIG. 6B is a cross-sectional schematic view of the syringe of FIG. 6A, where the syringe is moved to an orientation with an outlet of the syringe oriented upwards relative to a biasing field applied to the syringe such as a direction of gravity and the primary plunger is rotated to an open configuration, according to some embodiments;

[0018] FIG. 6C is a cross-sectional schematic view of the syringe of FIG. 6B, where the primary plunger is displaced in a longitudinal direction relative to a barrel of the syringe, according to some embodiments;

[0019] FIG. 6D is a cross-sectional schematic view of the syringe of FIG. 6C, where the primary plunger is rotated to a closed configuration, according to some embodiments; and

[0020] FIG. 6E is a cross-sectional schematic view of the syringe of FIG. 6D, where the primary plunger is displaced in a longitudinal direction relative to the barrel of the syringe to expel isolated fat graft from an outlet of the syringe, according to some embodiments.DETAILED DESCRIPTION

[0021] Conventional autologous fat grafting procedures typically involve large machines which harvest large volumes of adipose tissue from a subject via suction. Such machines are often used to extract adipose tissue from the subject’s thighs, abdomen, or buttocks, among other locations, and then are used to isolate and transfer viable fat graft of the adipose tissue to another location of the subject (e.g., the subject’s breast, etc). However, while such arrangements may be effective for larger volume fat grafting procedures as described above, the inventors have recognized that it may be desirable to isolate and transfer smaller volumes of fat graft to locations of a subject where larger volumes of fat graft are not necessary (e.g., a subject’s face, hands, feet, and other small cosmetic locations). In such scenarios, it may be inefficient to use large suction machines to isolate fat graft for small scale procedures. While syringes may be used to extract adipose tissue from a subject in smaller volumes, the extracted tissue is typically then exposed to secondary processing systems typically used for larger fat grafts such ascentrifugation or other mechanical processing methods to waste products of the tissue, which can negatively affect the fat graft by damaging or destroying the healthy fat cells. Such secondary processes may also result in calcification of the fat graft, thus rendering the graft unsuitable for reinjection into the subject.

[0022] In view of the above, the inventors have appreciated benefits associated with an autologous fat transfer device that may be used for fat grafting procedures, where the device may extract adipose tissue, separate and isolate viable fat graft from one or more waste products of the tissue, and permit reinjection of the isolated fat graft into a target site of the subject using a single device. In particular, the inventors have found benefits with using density based separation methods to separate the viable fat graft from the waste products of the adipose tissue, where the separated fat graft is then isolated from the waste products via separate chambers of variable size. The inventors have recognized that such an arrangement may be configured for use in a syringe to allow for fat graft collection while permitting separation of the adipose tissue components in the same syringe. In some embodiments, the syringe may include two or more variably sized chambers which can be transitioned into and out of fluid communication with one another, thereby permitting the fat graft and the waste products to be separated from one another in the respective chambers. Specifically, the waste products may be moved into a secondary chamber of the syringe while the fat graft is retained within a primary chamber of the syringe that is in fluid communication with an outlet of the syringe, thus permitting the isolated fat graft to be re-administered into the subject as desired.

[0023] In some embodiments, a syringe according to the embodiments disclosed herein includes a barrel having a defined internal volume and an outlet in fluid communication with the internal volume. The syringe may also include two or more plungers, e.g., a primary plunger and a secondary plunger. The primary plunger and the secondary plunger may each be at least partially disposed within the internal volume of the barrel and configured to move within the internal volume of the barrel.

[0024] In some embodiments, at least one of the primary plunger and the secondary plunger may include a shaft and a piston disposed on a distal portion of the shaft. As disclosed herein, the shaft and / or the piston of any of the primary plunger and the secondary plunger may be hollow or solid as the disclosure is not so limited. For example, the piston of the primary plunger may include a cavity having a defined internal volume configured to receive the shaft of the primary plunger. In some embodiments, each of the primary plunger and the secondary plunger may be arranged within the syringe barrel to divide the internal volume of the barrel into a primary chamber and a secondary chamber, where the sizing of the primary and secondarychambers may vary depending on the relative position of within the internal volume of the barrel. For example, a primary chamber may be defined as the internal space between the outlet of the syringe and the piston of the primary plunger while a secondary chamber may be defined as the internal space between the piston of the primary plunger and the piston of the secondary plunger.

[0025] In some embodiments, at least one of the primary and secondary plungers may form a seal with an inner perimeter of a cross-section of the barrel perpendicular to a longitudinal axis of the barrel, e.g., through an interference fit between the pistons of the primary and secondary plungers and the inner perimeter of the syringe barrel. In some embodiments, the interface between the primary and secondary plungers and the inner perimeter of the barrel may include a gasket (e.g., a rubber gasket) to form the seal to prevent inadvertent fluid communication between the primary and secondary chambers. Accordingly, in some embodiments, the primary and secondary chambers may be initially isolated from one another. In some such embodiments, adipose tissue may be extracted from a target tissue site of a subject and flow into a primary chamber by moving at least one of the primary plunger and the secondary plunger longitudinally in first direction away from an outlet of the syringe, e.g., to generate a negative pressure within the barrel to promote suction of a volume of adipose tissue from the subject into the primary chamber.

[0026] Once a volume of adipose tissue is received within the primary chamber, the syringe may be oriented in a desired orientation in a biasing field to promote separation of the components of the adipose tissue into density-based layers. In particular, in some embodiments, the syringe may be inverted (i.e., with the outlet of the syringe oriented vertically upward relative to a direction of gravity or other biasing field) such that gravity promotes separation of the adipose tissue components within the primary chamber into a layer containing viable fat graft and a layer containing waste products. In such an example, the layer of waste products may be denser than the layer of fat graft, and thus the fat graft layer may be the “upper” layer while the waste products is the “lower” layer. While the syringe may be inverted to employ gravitybased separation, the inventors have recognized other means of separation may also be used as the disclosure is not so limited. For example, the syringe may be centrifuged to promote separation of the collected adipose tissue into a fat graft layer and a waste product layer. In another example, magnetic particles may be used to bind to target fat cells, and a magnetic field may be applied to separate the fat cells bound with magnetic particles from the waste products of the adipose tissue.

[0027] Following separation of the viable fat graft tissue into density -based layers, or other types of layers based on the separation mechanism (e.g., magnetic field based separation), the primary and secondary chambers formed in the internal volume of the syringe barrel may be placed in fluid communication with one another. As disclosed herein, the primary plunger may include a valve having one or more openings in a first portion of the valve and one or more openings in a second portion of the valve, and the valve may be configured to move between an open configuration and a closed configuration. In particular, the first portion may be a primary piston of the primary plunger and the second portion may be a distal portion of a shaft of the primary plunger. The shaft may rotate between a closed configuration where the shaft covers the openings in the primary piston and an open configuration where the openings of the distal portion of the shaft are aligned with the openings of the primary piston. For example, the openings in the first portion of the valve may be formed on a bottom flange of the primary piston and the distal portion of shaft may be received within an internal cavity of the primary piston. The distal portion of the shaft may include one or more projections that extending outwardly from the distal portion of the shaft such that openings are formed between the projections. In such an example, in the closed configuration, the projections of the shaft may cover the openings on the flange of the primary piston. Likewise, in the open configuration, the openings between the projections of the shaft may be aligned with the openings in the flange of the primary piston such that fluid communication is permitted into the internal cavity of the primary piston. The primary piston may also include a third portion (e.g., a top flange of the piston) having one or more openings and moving the valve to the open configuration as described above may additionally permit fluid to move through the openings of the third portion. That is, in the open configuration of the valve, the primary chamber (e.g., the region between the outlet of the syringe and the primary piston of the primary plunger) may be in fluid communication with the secondary chamber (e.g., the region between the primary piston of the primary plunger and the secondary piston of the secondary plunger) such that the waste products may flow through the openings of the primary piston and into the secondary chamber.

[0028] In some embodiments, to form the secondary chamber, the secondary plunger may be moved longitudinally in a first direction away from an outlet of the syringe. Subsequently, once the valve of the primary plunger is in the open configuration to permit fluid communication between the primary and secondary chambers, the primary plunger may be moved longitudinally in a second direction towards the outlet of the syringe while the secondary plunger remains stationary, which in turn moves debris, excess fluid, dead cells, and / or other waste products into the secondary chamber while retaining viable fat graft in the primarychamber. With the fat graft in the primary chamber and th chamber, the valve of the primary plunger may be moved to the closed configuration to prevent fluid communication between the chambers. As noted above, the shaft of the primary plunger may be rotated such that the shaft covers the openings in the primary piston in the closed configuration, thus isolating the viable fat graft in the primary chamber from the secondary chamber.

[0029] Once the viable fat graft has been isolated in the primary chamber, at least one of the primary plunger and the secondary plunger may be moved longitudinally in the second direction towards the outlet of the syringe such that the fat graft is dispensed to a target site of the patient (e.g., breast, buttocks, face, hands, feet, etc.). The syringe and plunger arrangement as well as the steps described above are one exemplary embodiment in which the syringe device may permit filtered fat cells to be re-administered to the subject while retaining the undesired, separated filtrate (i.e., waste products) within the syringe barrel. The waste products may then be disposed of as needed following administration of the fat graft to the subject.

[0030] In some embodiments, a portion of the primary plunger may be oriented distally relative to the secondary plunger. For example, each of the primary and secondary plungers may include a shaft and piston disposed at a distal portion of the shaft, and the primary piston of the primary plunger may be positioned distally relative to the secondary piston of the secondary plunger. In such an example, the portion of the barrel internal volume located between the outlet of the syringe and the primary piston of the primary plunger may be defined as the primary chamber while the portion of the barrel internal volume located between the piston of the primary plunger and the secondary piston of the secondary plunger may be defined as the secondary chamber, as noted above. As disclosed herein, these chambers may be initially isolated from one another, but may be selectively put into fluid communication with one another. For example, this may be accomplished by rotating a shaft of the primary plunger relative to the secondary plunger to expose one or more openings in the primary piston of the primary plunger. In some embodiments, the secondary plunger may remain stationary while the primary plunger rotates.

[0031] In some embodiments, the primary plunger may be at least partially received within an interior passageway of the secondary plunger. That is, the secondary plunger may at least partially surround a shaft of the primary plunger while permitting movement of the primary and secondary plungers in a longitudinal direction relative to the barrel of the syringe. While the primary and secondary plungers have been described above as including a shaft and a piston disposed at a distal portion of the shaft, at least one of the plungers may not include a piston. Forexample, the secondary plunger may be formed as a rigid of the primary plunger that is configured to remain stationary as the primary plunger moves.

[0032] In some embodiments, the primary and secondary plungers disclosed herein may be constructed out of any suitable material as the disclosure is not so limited. For example, the plungers, pistons, barrel, and / or other portion of the devices disclosed herein may be constructed out of plastics such as polypropylene and polyethylene, metals such as aluminum and stainless steel, glass, combinations of the foregoing, and / or any other suitable biocompatible materials as the disclosure is not so limited. In some embodiments, at least a portion of the plunger may be made out of an elastomeric material such as rubber. For example, the primary and secondary plungers may each contact an inner perimeter of the syringe barrel at an interface, and an elastomeric material may be provided at that interface to form a seal between the plungers and the inner perimeter of the barrel (e.g., to form primary and secondary chambers that are isolated from one another).

[0033] In some embodiments, the plungers may include a shaft and a piston disposed on a distal portion of the shaft, where the shaft includes one or more projections extending outwardly from the distal portion. These projections may be constructed and arranged in any suitable fashion as the disclosure is not so limited. For example, the projections may be arranged in a pinwheel shape with openings formed between each of the projections. Alternatively, the projections may be arranged in a “plus-sign” shape. In some embodiments, the projections may form a solid outer disk with openings that are spaced inwardly from a circumference of the disk. Without wishing to be bound by theory, the arrangement of the projections and / or corresponding openings formed in these structures may be of any suitable shape as the disclosure is not so limited.

[0034] Any suitable number of projections may be used as needed to cover the one or more corresponding openings in the piston as the disclosure is not so limited. In some embodiments, the number of projections may be greater than or equal to 1, 2, 3, 4, 5, 6, or more as the disclosure is not so limited. In some embodiments, the number of projections may be less than or equal to 10, 9, 8, 7, 6, 5, or less. In some embodiments, the number of projections may be between or equal to 4 and 6, or any other suitable range as the disclosure is not so limited. Likewise, the number of openings disposed on an upper or lower flange of a piston of the plunger may be greater than or equal to 1, 2, 3, 4, 5, 6, or more as the disclosure is not so limited. In some embodiments, the number of openings may be less than or equal to 10, 9, 8, 7, 6, 5, or less. In some embodiments, the number of openings may be between or equal to 4 and 6, or any other suitable range as the disclosure is not so limited. The openings and projections mayalso be of any suitable size to permit fluid communicatior the openings to be covered, respectively, as the disclosure is not so limited. In some embodiments, the piston of the plunger may also include one or more blocking surfaces that are configured to abut the projections of the shaft to limit movement (e.g., a rotational travel path) of the shaft of the plunger.

[0035] While the collection of adipose tissue is primarily described herein, any suitable types of cells may be collected and isolated using the device according to the embodiments disclosed herein as the disclosure is not so limited. In some embodiments, suitable types of cells may include, but are not limited to fat cells (e.g., adipocytes), bone cells, cartilage cells, blood cells, muscle cells, or any other suitable cell type as the disclosure is not so limited.

[0036] The inventors have appreciated that embodiments of autologous fat transfer devices disclosed herein may provide a variety of benefits. These benefits may include that the overall procedure time may be reduced as the separation, isolation, and re-administration of a subject’s fat graft from extracted adipose tissue may occur within a singular device. In addition, the device disclosed herein may permit two or more different types of materials to be collected and separated within the syringe barrel (e.g., viable fat graft cells and waste products such as dead cells and fluids). Moreover, the embodiments disclosed herein may employ decantation to separate the adipose tissue components into density-based layers, which reduces the likelihood of damaging the isolated fat graft cells in comparison to mechanical processing techniques such as centrifugation. That is, use of decantation may reduce shear stress exerted on the cells during separation, thus increasing the likelihood that the isolated fat graft is viable for re-administration to the subj ect.

[0037] The embodiments disclosed herein may also be used for a variety of applications. As noted above, conventional devices such as large-scale suction machines are typically employed for large volume fat graft collection, and while syringes may be used to collect smaller fat graft samples, these smaller samples typically undergo the same secondary processing techniques optimized for large volume fat grafts (e.g., mechanical processing such as centrifugation) which may damage the fat graft. Thus, the embodiments of an autologous tissue transfer device disclosed herein may be used for small-scale fat grafting procedures (e.g., a subject’s face, hands, feet, etc.) and may permit separation and isolation of the viable fat graft from the waste products of the adipose tissue within a singular device unlike conventional syringes. Of course, it should be understood that the disclosed devices may be used to facilitate the collection, separation, and reinjection of any desired volume of a target type of material as the disclosure is not so limited.

[0038] Turning to the figures, specific non-limitin detail. It should be understood that the various systems, components, features, and methods described relative to these embodiments may be used either individually and / or in any desired combination as the disclosure is not limited to only the specific embodiments described herein.

[0039] FIG. 1 A is a perspective view of a syringe 100 including a barrel 102. A primary plunger 210 and a secondary plunger 220 may be at least partially disposed within an internal volume of the barrel 102. A hub 104 may be disposed at a distal portion of the barrel 102 and include an outlet 106 extending therefrom. In some embodiments, the outlet is in fluid communication with an internal volume of the barrel. The outlet may be connected with a needle 108 as shown in FIG. 1 A to permit extraction of adipose tissue into the internal volume of the barrel 102. In some embodiments, the outlet may include a cap or be otherwise sealed to prevent leakage of the adipose tissue once the tissue has been extracted into the barrel 102. The primary plunger 210 and the secondary plunger 220 may each include a handle portion 212 and 222, respectively, extending in a proximal direction that a user may grasp to move the primary and secondary plungers in a longitudinal direction relative to the barrel 102. The primary plunger 210 may also include a shaft 214 and a primary piston 230 disposed at a distal portion of the shaft 214. Likewise, the secondary plunger 220 may include a shaft 224 and a secondary piston 226 disposed at a distal portion of the shaft 224. The adipose tissue of a subject may be extracted into the barrel of the syringe by moving the primary and secondary plungers in a first direction (e.g., proximally) away from the outlet 106 to generate a negative pressure in the internal volume of the barrel, thus causing the adipose tissue to be suctioned into a primary chamber 250 (i.e., the region of the barrel internal volume between the outlet 106 and the primary piston 230 of the primary plunger 210).

[0040] FIG. IB shows the arrangement of FIG. 1 A where the primary plunger 210 and the secondary plunger 220 have been moved relative to one another such that the secondary piston 226 is spaced proximally from the primary piston 230 to form a secondary chamber 260 disposed therebetween. In some embodiments, the secondary plunger 220 may be moved in a first longitudinal direction away from the outlet 106 to form the secondary chamber 260. In addition or alternatively, the primary plunger 210 may be moved in a second longitudinal direction towards the outlet 106 to form the secondary chamber 260. In some embodiments, the barrel 102 may have end stops (not shown) which may retain each of the pistons 230 and 226 of the primary and secondary plungers, respectively, within the internal volume of the barrel 102. That is, while portions of the plungers such as handle portions 212, 222 may be outside of thebarrel 102 so that they may be grasped by the user, the en plungers from the barrel.

[0041] FIG. 2A shows a perspective view of the plunger arrangement of FIG. IB including the primary plunger 210 and the secondary plunger 220 without the syringe barrel 102 shown for clarity. In FIG. 2A, a distal portion of the shaft 214 of the primary plunger covers a plurality of openings 232 formed in the primary piston 230 of the primary plunger 210 while the shaft is in a closed configuration. As described herein, the configuration of FIG. 2A is referred to as the “closed configuration” where the primary and secondary chambers are not in fluid communication with one another through the primary piston 230. In some embodiments, the primary plunger may be in the closed configuration during extraction of adipose tissue into a primary chamber of the barrel (not shown).

[0042] FIG. 2B shows the plunger arrangement of FIG. 2A where the distal portion of the shaft 214 of the primary plunger 210 has been rotated such that the distal portion no longer covers the openings 232 in the primary piston 230 such that the primary and secondary chambers are in fluid communication with one another through the primary piston, which is referred to as the “open configuration”. As disclosed herein, the distal portion of the plunger shaft may include one or more projections which cover the piston openings in a closed configuration and one or more openings between the projections which align with the piston openings in the open configuration. In some embodiments, the user may grasp the handle portion 212 of the primary plunger 210 and rotate the handle portion 212 clockwise, thus rotating the distal portion of the shaft 214 clockwise relative to the secondary plunger 220 and the primary piston 230 to align the openings between the projections with the openings 232 in the primary piston 230. In some such embodiments, the user may rotate the handle portion 212 counter-clockwise to return the primary plunger to the closed configuration. While such an example is disclosed, in some embodiments the user may rotate the shaft 214 counter-clockwise to move the primary plunger to the open configuration and then rotate the shaft 214 clockwise to return the primary plunger to the closed configuration as the disclosure is not so limited.

[0043] FIG. 3 shows a perspective view of the primary plunger 210 which may include a handle portion 212, a shaft 214, a plurality of projections 216 extending radially outward from a distal portion of the shaft 214 relative to a longitudinal axis of the shaft and barrel. The primary plunger also includes a plurality of openings 218 formed between the projections 216. As disclosed herein, the projections 216 may align with and cover the openings formed in the primary piston of the primary plunger in the closed configuration while the openings 218 may align with the openings in the primary piston of the primary plunger in the open configurationsuch that fluid communication is permitted through the pr plungers with projections used to cover openings in a valve are disclosed herein, any suitable arrangement may be employed for selectively allowing fluid communication through the valve as the disclosure is not so limited. For example, in some embodiments, instead of the projections of the shaft only covering the openings in the valve in a closed configuration, the projections may be inserted into the openings to prevent fluid communication through the valve. That is, the projections may instead function like a plug and plug the openings in the valve. In another example, a valve of a plunger may include one or more flexible portions (e.g., a cross-slit valve) and movement of the shaft of the primary plunger to abut the flexible portions may permit fluid communication through the valve (e.g., the abutment of the shaft with the flexible portions may flex the portions to the open configuration). In such an example, the flexible portions may be constructed and arranged to prevent fluid communication through the valve when the shaft is not abutting the flexible portions.

[0044] FIG. 4 shows a perspective view of the secondary plunger 220 which may include a handle portion 222 for the user to grasp, a shaft 224, and a secondary piston 226. The secondary plunger 220 may at least partially surround the shaft 214 of the primary plunger 210 (not shown). In particular, a passageway 228 of the secondary plunger may be formed as a channel that it sized and shaped to receive the shaft 214 of the primary plunger such that the primary plunger is permitted to move longitudinally within the passageway. In some embodiments, the secondary plunger may form a seal with the primary plunger in the passageway 228 using a slip fit, O-rings, gaskets, or other appropriate type of seal such that fluid communication is prevented through the passageway. This may be beneficial to prevent inadvertent leakage of contents (e.g., waste products) that are stored in the secondary chamber of the syringe described above.

[0045] FIG. 5A shows a perspective view of a primary piston 230 configured to be operatively coupled with a shaft 214 of a primary plunger 210. The primary piston 230 may receive the shaft 214 (not shown) through the aperture of conduit 235, and the piston may be coupled with the shaft 214 (not shown) in any suitable fashion as the disclosure is not so limited. In some embodiments, the primary piston 230 may be threadingly engaged with the corresponding shaft 214, e.g., the conduit 235 may have internal threads while a portion of the shaft has external threads, and the shaft may be threaded into and out of the conduit to move the shaft in a distal direction (i.e., toward the piston) and a proximal direction (i.e., away from the piston), respectively. In other embodiments, however, the primary piston 230 may be engaged with the corresponding shaft via an interference fit, adhesive, weld, fasteners, and / or any othersuitable type of connection as the disclosure is not so limi include a lower flange 236, an upper flange 238, and a circumferential portion 237 connecting the upper and lower flanges. The upper and lower flanges may be of any suitable shape such as circular, rectangular, triangular, or any other shape as the disclosure is not so limited. For example, the shape of the upper and lower flanges may substantially correspond to the shape of the inner perimeter of the barrel of the syringe (e.g., circular). The circumferential portion connecting and extending between the flanges may also be of any suitable shape as the disclosure is not so limited. In some embodiments, the circumferential portion may substantially correspond to the shape of the upper and lower flanges (e.g., the circumferential portion may be shaped as a hollow cylinder). The upper flange 238 may include a plurality of openings 233 extending from a first surface of the upper flange to an opposing surface of the upper flange as shown in FIG. 5A. The lower flange may also include a plurality of openings extending from a first surface of the lower flange to an opposing surface of the lower flange as described below and shown in FIG. 5B. In some embodiments, the primary piston 230 may enclose the distal portion of the shaft 214 such that the shaft is not able to be removed from the piston. For example, in some embodiments the upper flange 238, the lower flange 236, and / or the circumferential portion 237 may be coupled with one another after having enclosed the distal portion of the shaft. This may be accomplished by use of adhesive, ultrasonic welding, or other suitable means of engagement to form the piston.

[0046] FIG. 5B shows a cross-sectional perspective view of the primary piston 230 of FIG. 5A taken along lines 5B-5B. As shown in FIG. 5B, the lower flange 236 may include a plurality of openings 232. In some embodiments, the openings 232 in the lower flange 236 may align with the openings 233 in the upper flange 238. In other embodiments, however, the openings need not align as the disclosure is not so limited. The lower flange 236 may include a center region 231 from which the openings 232 are positioned radially outward. As noted above, an internal cavity of the primary piston 230 may receive a shaft 214 of the primary plunger, and the shaft 214 may include a distal portion with projections extending outwardly therefrom. In some such embodiments, the distal portion of the shaft may be configured to abut the lower flange 236, and the projections may be received within recessed portions 234. In particular, the shaft 214 may be rotated between an open configuration and a closed configuration. When in the open configuration, the projections may be at least partially out of alignment with the openings 232 and 233 of the upper and lower flanges such that there is fluid communication between the two sets of openings through the primary piston. For example, the projections may be positioned at the portion of the lower flange 236 adjacent the openings. When in the closedconfiguration, the projections may be at least partially in <233 of the upper and lower flanges such that there is limited or no fluid communication between the two sets of openings through the primary piston. The primary piston 230 may also include one or more blocking surfaces 239 extending inwardly towards the center region 231 from the circumferential portion 237. These blocking surfaces may be configured to limit movement (e.g., a rotational travel path) of the distal portion of the shaft 214 when moving the primary plunger between the open and closed configurations. That is, the projections may abut the blocking surfaces when the projections are at least partially out of alignment with the openings 232 and 233 of the upper and lower flanges.

[0047] FIGs. 6A-6E show a series of cross-sectional schematic views of a syringe 100 with a plunger arrangement according to embodiments disclosed herein. Each of FIGs. 6A-6E show a different stage of operation of the syringe.

[0048] In FIG. 6A, the user has extracted adipose tissue into the primary chamber 250 of the barrel 102 by moving the primary plunger and the secondary plunger longitudinally in a first direction (i.e., proximally) away from an outlet 106 of the syringe. By moving these plungers in this fashion, a negative pressure is created within the primary chamber 250, thus urging the adipose tissue to flow from a target tissue site of the subject into the primary chamber via outlet 106 in the direction of arrow 270. The adipose tissue comprises viable fat graft 240 and waste products 242 which are initially interspersed within the tissue sample as shown in FIG. 6A. As disclosed herein, the primary plunger comprises a handle portion 212, a shaft 214, a distal portion of the shaft including projections 216, and a primary piston 230. Likewise, the secondary plunger comprises a handle portion 222, a shaft 224, and a secondary piston 226, where the shaft 224 of the secondary plunger may at least partially surround the shaft 214 of the primary plunger. As shown in FIG. 6A, the primary plunger may initially be in a closed configuration such that the projections 216 cover the openings 232 in the secondary piston 230, thus preventing fluid communication through the secondary piston.

[0049] In FIG. 6B, the syringe 100 may be inverted, or otherwise oriented in a desired direction relative to a biasing field. For example, following extraction of the adipose tissue such that the outlet 106 of the syringe is oriented vertically upwards relative to a direction of gravity or centripetal force within a centrifuge. As disclosed herein, this may allow the adipose tissue to decant and separate into density -based layers of viable fat graft 240, or other types of layers of a desired graft material, and waste products 242. In some instances, the fat graft 240 may be the upper layer while the waste products 242 may be the lower layer while the syringe is inverted as shown in FIG. 6B. The user may then rotate the shaft 214 of the primary plunger in a clockwisedirection such that the projections no longer cover the ope secondary chambers 250, 260 in fluid communication with one another through the primary piston 230. In some embodiments, the shaft 214 of the primary plunger may instead be rotated in a counter-clockwise direction, translated in a desired direction, and / or otherwise manipulated to uncover the openings or open fluid communication through the piston in any other appropriate manner as the disclosure is not so limited.

[0050] In FIG. 6C, while the openings 232 and 233 in the primary piston 230 are uncovered, or the primary piston is otherwise in the open configuration, the primary plunger is moved longitudinally in a second direction (i.e., distally) toward the outlet 106 of the syringe. In some embodiments, the secondary plunger may remain stationary while the primary plunger is moved. By moving the primary plunger relative to the secondary plunger, a volume of a secondary chamber 260 is increased to receive waste products 242 that flow into the secondary chamber through the primary plunger while the viable fat graft 240 is retained in the primary chamber 250. In particular, the waste products 242 first flow through the openings 232 and into the internal cavity of the primary piston 230, and then through the openings 233 to enter the secondary chamber 260. The inventors have recognized that as a result of the density differences between the layers of fat graft and waste products, the displacement of the primary plunger may be controlled such that only the waste products 242 enter the secondary chamber 260. For example, the primary plunger may be displaced until a medical practitioner sees that the waste product has been fully displaced into the secondary chamber at which point displacement of the primary plunger may be stopped.

[0051] In FIG. 6D, once the fat graft 240 and the waste products 242 have been separated into the primary chamber 250 and the secondary chamber 260, respectively, the shaft of the primary plunger may be counter-rotated (e.g., in a counter-clockwise direction as shown by arrow 274 in FIG. 6D) such that the projections 216 cover the openings 232 or otherwise displaced to transition the primary piston from the open configuration to the closed configuration. With the primary plunger and associated piston in the closed configuration, the fat graft is then isolated in the primary chamber from the waste products disposed in the secondary chamber.

[0052] In FIG. 6E, the isolated fat graft 240 is then dispensed out of the outlet 106 of the syringe in the direction of arrow 276. This dispensing step may be accomplished by moving the primary plunger longitudinally in the direction of the outlet 106. In some embodiments, both the primary plunger and the secondary plunger may be moved in the direction of the outlet 106 to dispense the fat graft. For example, the waste products may be substantially incompressible insome embodiments such that when the secondary volume the primary and secondary plungers may be moved in sync with one another. In some embodiments, the outlet may be fluidly coupled to a needle of any suitable type to permit extraction of the adipose tissue and re-administration of the isolated fat graft to a target tissue site of a subject (e.g., face, hands, feet, etc.). The needle may be of any suitable gauge or shape (e.g., beveled), and the needle may be used for intramuscular, intradermal, or subcutaneous extraction and injection as the disclosure is not so limited.

[0053] The embodiments described herein may be embodied as a method. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0054] While the present teachings have been described in conjunction with various embodiments and examples, it is not intended that the present teachings be limited to such embodiments or examples. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art. Accordingly, the foregoing description and drawings are by way of example only.

Claims

CLAIMS1. A syringe comprising: a barrel including an internal volume and an outlet in fluid communication with the internal volume; a primary plunger disposed within the internal volume; a secondary plunger disposed within the internal volume, wherein a primary chamber is formed between the outlet and the primary plunger and a secondary chamber is formed between the primary plunger and the secondary plunger, and wherein the primary plunger is configured to be transitioned between a closed configuration and an open configuration, wherein in the closed configuration the primary chamber is isolated from the secondary chamber, and wherein in the open configuration the primary chamber is in fluid communication with the secondary chamber.

2. The syringe of claim 1, wherein the primary plunger comprises a valve configured to move between the open configuration and the closed configuration.

3. The syringe of claim 2, wherein the valve comprises one or more openings in a first portion of the valve and one or more openings in a second portion of the valve, wherein the first portion and the second portion are configured to be rotatable relative to each other such that the one or more openings of the first portion are aligned with the one or more openings of the second portion in the open configuration and the one or more openings of the first portion are not aligned with the one or more openings of the second portion in the closed configuration.

4. The syringe of claim 3, wherein the first portion of the valve is a bottom flange of a piston of the primary plunger, further comprising a third portion of the valve which is a top flange of the piston of the primary plunger, wherein the third portion of the valve comprises one or more openings, and wherein the one or more openings of each of the first portion and the third portion are configured to permit fluid communication through the piston of the primary plunger when the primary plunger is in the open configuration.

5. The syringe of claim 3, wherein the first portion is a first piston having the one or more openings extending through the first piston, wherein the first piston comprises a cavity having an internal volume, wherein the second portion is constructed and arranged to be received withinthe internal volume of the cavity, and wherein the second to the first piston such that one or more projections of the second portion are configured to align with the one or more openings of the first piston in the closed configuration and the one or more projections are configured to not align with the one or more openings of the first piston in the open configuration.

6. The syringe of claim 5, wherein the valve comprises one or more blocking surfaces configured to limit movement of the one or more projections of the second portion.

7. The syringe of claim 1, wherein the primary plunger and the secondary plunger are each configured to move in a longitudinal direction relative to the barrel.

8. The syringe of claim 1, wherein the secondary plunger is configured to remain stationary while the primary plunger moves relative to the secondary plunger.

9. The syringe of claim 1, wherein each of the primary plunger and the secondary plunger comprises a shaft and a piston disposed at a distal portion of the shaft.

10. The syringe of claim 9, wherein the piston of at least one of the primary plunger and the secondary plunger is configured to form a seal with an inner perimeter of the barrel.

11. The syringe of claim 1, wherein the primary chamber is configured to receive tissue in the primary chamber by translating both the primary plunger and the secondary plunger in a first direction relative to the barrel.

12. The syringe of claim 11, wherein the primary plunger is configured to translate relative to the secondary plunger within the barrel when the primary plunger is in the open configuration to change a volume of the secondary chamber.

13. The syringe of claim 12, wherein the primary plunger and the secondary plunger are configured to be translated in sync within the barrel when the primary plunger is in the closed configuration.

14. A method of operating a syringe, the method comprising:separating tissue into a tissue graft and one chamber of a syringe; placing the primary chamber in fluid communication with a secondary chamber of the syringe through a portion of a primary plunger of the syringe; displacing the primary plunger of the syringe to flow the one or more waste layers from the primary chamber into the secondary chamber; and isolating the primary chamber from the secondary chamber.

15. The method of claim 14, wherein the tissue is adipose tissue and the tissue graft is a fat graft.

16. The method of claim 14, further comprising flowing the tissue into the primary chamber of the syringe by translating both of the primary plunger and a secondary plunger of the syringe in a first direction relative to a barrel of the syringe.

17. The method of claim 16, further comprising transitioning the primary plunger between a closed configuration and an open configuration, wherein in the closed configuration the primary chamber is isolated from the secondary chamber, and wherein in the open configuration the primary chamber is in fluid communication with the secondary chamber.

18. The method of claim 17, wherein isolating the primary chamber from the secondary chamber separates the tissue graft of the tissue disposed in the primary chamber from one or more waste layers disposed in the secondary chamber.

19. The method of claim 18, further comprising ejecting the tissue graft from the syringe by translating of the primary plunger and the secondary plunger in sync within a barrel of the syringe in a second direction relative to the barrel when the primary plunger is in the closed configuration.

20. The method of claim 16, wherein separating the tissue into the tissue graft and the one or more waste layers includes moving the syringe to an orientation with an outlet of the syringe oriented upwards relative to a biasing field.

21. The method of claim 16, further comprising keepi: while moving the primary plunger relative to the secondary plunger.

22. The method of claim 16, wherein each of the primary plunger and the secondary plunger comprise the shaft and the piston disposed at the distal portion of the shaft, and further comprising forming a seal between the piston of at least one of the primary plunger and the secondary plunger with an inner perimeter of the barrel of the syringe.

23. The method of claim 17, wherein the portion of the primary plunger is a valve that is configured to move between the open configuration and the closed configuration.

24. The method of claim 23, wherein the primary plunger comprises a valve configured to move between the open configuration and the closed configuration, wherein the valve comprises one or more openings in a first portion of the valve and one or more openings in a second portion of the valve, further comprising rotating the second portion of the valve relative to the first portion of the valve such that the one or more openings of the first portion are aligned within the one or more openings of the second portion in the open configuration and the one or more openings of the first portion are not aligned with the one or more openings of the second portion in the closed configuration.

25. The method of claim 24, wherein the first portion is a first piston having the one or more openings extending through the first piston, wherein the first piston comprises a cavity having an internal volume, further comprising receiving the second portion within the internal volume of the cavity, and wherein rotating the second portion relative to the first piston includes rotating one or more projections of the second portion between the open configuration and the closed configuration.

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