Patent Publication Number: US-2021177906-A1

Title: Adipose tissue particle processing, transfer and storage system

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application claims the benefit of U.S. Provisional Application No. 62/946,701 filed on Dec. 11, 2020, which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     The present invention relates to systems and methods for processing, transferring and storing adipose tissue, such as fat aspirate obtained by liposuction. 
     Adipose tissue, or body fat, is loose connective tissue composed mostly of adipocytes, such as fat cells, along with a vast array of regenerative cell populations, including adipose-derived stem cells or mesenchymal stem cells, which have tremendous potential benefits for human tissue regeneration. 
     In order to harvest adipose tissue or fat aspirate containing regenerative call populations such as adipocyte-derived stem cells, a minimally-invasive treatment that uses tumescent liposuction techniques to harvest fat tissue as lipoaspirate can be used. Additional processing steps are routinely used following the initial harvesting procedure (i.e., tumescent liposuction), including fat aspirate particle sizing (micro-fragmenting or micronizing), filtering (removal of sinuate, connective tissue strands, and coarse debris), separating and concentrating (via gravity decanting or centrifugation to separate, isolate and remove water, blood, and oil from viable fat aspirate particles) in order to create an autologous fat graft that can be used for injection or deployment during an autologous fat grafting (fat transfer) treatment for the purpose of aesthetic (cosmetic) and/or regenerative purposes. Autologous fat grafting and/or autologous regenerative treatments containing autologous fat aspirate particles are used for cosmetic and/or therapeutic rejuvenation, restoration, and repair of aging or degenerative tissues such as the skin, hair, face, body, breasts, cleavage, dorsum of hands, soft tissue, wounds, scars, musculoskeletal tissues, vocal chords, and genitalia. 
     Currently, several procedures exist for processing (sizing, filtering, separating, and concentrating) fat aspirate particles. One such procedure involves placing the fat aspirate inside a chamber having many small steel balls immersed in saline. The chamber is then shaken whereby the steel balls micro-fragment the fat aspirate while the saline cleans it. This procedure can result in pulverization and indiscriminate sizing of the fat particles due to the high variability in shaking the chamber. Other procedures entail passing the fat aspirate back-and-forth many times across a mesh-like surface or screen with a square-shaped pattern to micronize the particles by using luer-to-luer syringe transfer. This processing can severely mechanically traumatize the fat aspirate particles and destroy the adipocyte cells, as well as be time consuming and physically straining. As a result, there is a need for systems and methods that result in precision processing (sizing, filtering, separating and concentrating) and single-pass outer dimensional sizing of fat aspirate obtained by liposuction harvesting for cosmetic and/or regenerative purposes. 
     SUMMARY 
     An adipose tissue particle processing system according to the present disclosure includes a container and a filter screen assembly at least partially extending into an interior of the container. The filter screen assembly has a first open end configured to receive adipose tissue from a syringe, and a second closed end opposite to the first open end located in the interior of the container. The filter screen assembly further includes a screen portion between the first open end and the second closed end, the screen portion including a plurality of apertures having diameters selected for processing the adipose tissue received through the first open end into controlled fat aspirate particle sizes that are output through the plurality of apertures into the interior of the container. 
     A method of processing adipose tissue particles according to the present disclosure includes coupling a syringe containing adipose tissue particle material to an adipose tissue particle processing system that extends at least partially into a container. The adipose tissue particle material is transferred from the syringe via a first open end of a filter screen assembly of the adipose tissue particle processing system into an interior of the filter screen assembly, with a second end of the filter screen opposite the first open end being closed. Fat aspirate particles in the adipose tissue material are forced to pass through apertures in a screen portion of the filter screen assembly into the interior of the container, with a size of the fat aspirate particles being based on a size of the apertures in the screen portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings are intended to illustrate embodiments of, but not to limit, the present invention. In the drawings, like reference characters denote corresponding features consistently throughout similar embodiments. 
         FIGS. 1A and 1B  illustrate an adipose tissue particle processing system according to an embodiment of the present invention. 
         FIGS. 2A and 2B  illustrate the assembly of the adipose tissue particle processing system shown in  FIGS. 1A and 1B . 
         FIG. 3  illustrates a filter screen assembly for use in an adipose tissue particle processing system according to an embodiment of the present invention. 
         FIGS. 4A and 4B  illustrate a cap/bushing for use in an adipose tissue particle processing system according to an embodiment of the present invention. 
         FIG. 5  illustrates a transfer cannula that may be used with an adipose tissue particle processing system according to an embodiment of the present invention. 
         FIG. 6  illustrates a cannula cleaner that may be used with an adipose tissue particle processing system according to an embodiment of the present invention 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure provides an adipose tissue particle processing system that allows a physician to micro-fragment and process adipose tissue into controlled fat aspirate particle sizes for use in autologous fat grafting and/or autologous regenerative treatments containing the autologous fat aspirate particles. 
       FIGS. 1A and 1B  illustrate adipose tissue particle processing system  10  that includes a filter screen assembly  12  (which is also shown in more detail in  FIG. 3 ) positioned to extend into plastic centrifuge tube  14  through cap/bushing  16 .  FIGS. 2A and 2B  illustrate the assembly of the filter screen assembly  12  extending through cap/bushing  16  into the interior of centrifuge tube  14  of adipose tissue particle processing system  10 . Filter screen assembly  12  includes screen portion  17  that is made up of a plurality of apertures  18  that have diameters selected for processing adipose tissue into controlled fat aspirate particle sizes. In the embodiment shown (see  FIG. 3  in particular), the distal end of filter screen assembly  12  has female luer fitting  19 , which allows male luer cap  20  to be attached to close the distal end of filter screen assembly  12  during use. Other methods or configurations for providing a closed distal end of filter screen assembly  12  during use may be used in alternative embodiments. 
     Also, in the embodiment shown (see  FIGS. 2A and 2B  in particular), filter screen assembly  12  includes male threads  22  near its proximal end, and cap/bushing  16  includes female threads  24  that are configured to receive male threads  22  of filter screen assembly  12 , to secure filter screen assembly  12  to cap/bushing  16  so that screen portion  17  is suspended in the interior of centrifuge tube  14  when cap/bushing  16  is positioned on the top of centrifuge tube  14 . In other embodiments, filter screen assembly  12  could alternatively be connected to a luer fitting or threaded fitting on cap/bushing  16 , or could be integrally formed (e.g., by welding or adhesive connection) with cap/bushing  16 . 
     In the embodiment shown, centrifuge tube  14  is made of clear plastic, and has a tapered configuration from its top (where cap/bushing  16  is provided) to its bottom (where a conical tapered end is provided). This is a common configuration for a plastic centrifuge tube, which is readily manufactured by injection molding, for example. In an alternative embodiment, a zero-draft, cylindrical plastic centrifuge tube may be constructed and used, which has no taper from the top to the bottom of the tube, and which has a flat bottom surface rather than a conical tapered end. With such a construction, the cylindrical plastic centrifuge tube could be used with the system described in U.S. patent application Ser. No. 16/295,695 entitled “Aspirating Separated Liquid Components From A Vessel” filed on Mar. 7, 2019, which is incorporated by reference herein in its entirety. In the system described in U.S. patent application Ser. No. 16/295,695, a diaphragm is slidably coupleable to the hollow inner portion of the centrifuge tube, and allows liquid contained in the centrifuge tube to be selectively and controllably aspirated out of the centrifuge tube through the diaphragm. 
     Centrifuge tube  14  shown in  FIGS. 1A-2B  is a 50 mL tube, but it should be understood that larger or smaller sizes and volumes of centrifuge tubes may be used in other embodiments. 
     In the embodiment shown (see  FIGS. 4A and 4B  in particular), cap/bushing  16  is made of plastic, and has a threaded central aperture (having female threads  24 ) that engages with male threads  22  of filter screen assembly  12 , so that screen portion  17  of filter screen assembly  12  is supported and suspended inside centrifuge tube  14 . In the embodiment shown, cap  16 /bushing is formed with a configuration that allows cap/bushing  16  to slip over male threads  26  at the top of centrifuge tube  14  (rather than threadedly engaging with male threads  26  at the top of centrifuge tube  14 , as a standard lid for centrifuge tube  14  would do). With cap/bushing  16  configured to slip over male threads  26  at the top of centrifuge tube  14 , venting is provided to allow depositing and aspirating of material to/from centrifuge tube  14 , due to the non-airtight fitting between cap/bushing  16  and centrifuge tube  14 . In alternative embodiments, cap/bushing  16  may have female threads which are threadedly engaged with male threads  26  at the top of centrifuge tube  14 , thereby providing an airtight coupling between them, and cap/bushing  16  may be further designed to include venting apertures in its disc-shaped face, with a suitable air-permeable membrane, such as a 0.2 micron filter in some examples, to prevent liquid material from escaping through cap/bushing  16 . In some alternative embodiments, cap/bushing  16  may be formed of stainless steel (with any of the variations of configurations described above), and may be a reusable component. 
     Exemplary dimensions for the various features of cap/bushing  16  are shown in  FIGS. 4A and 4B . It should be understood that these dimensions are provided to illustrate one example of cap/bushing, and that the configuration of the features of cap/bushing  16  may have other dimensions either larger or smaller than the dimensions listed in other embodiments. 
     Apertures  18  in screen portion  17  of filter screen assembly  12  may be formed in by laser drilling in some embodiments. Example sizes/diameters of apertures  18  may be as large as 4.0 millimeters, as small as 0.2 millimeters, any size/diameter in between, or sizes/diameters larger than 4.0 millimeters or smaller than 0.2 millimeters, depending on the application in which the adipose tissue particle processing system  10  is used. 
     In one example, screen portion  17  of filter screen assembly  12  may have an outer diameter of about 0.259 inches (about 6.58 millimeters). In other examples, screen portion  17  of filter screen assembly  12  may have larger or smaller radial dimensions. In some embodiments, filter screen assembly  12  is composed of stainless steel. 
     In various embodiments, some of the components of adipose tissue particle sizing system  10  are designed to be reusable components (typically made of stainless steel), while other components are designed to be single-use, disposable components (typically made of plastic). In this context, components described as reusable are capable of being cleaned and sterilized multiple times, such as be a sterilizing autoclave, by enzyme treatment, or by other methods, while single-use, disposable components are provided in sterile packaging for a single use. 
     In operation, as shown in  FIGS. 1A and 1B , female luer fitting  28  at the proximal end of filter screen assembly  12  is configured to allow coupling to the outlet of syringe  30 , which can contain tissue material to be processed by adipose tissue particle processing system  10 . Once syringe  30  is coupled to adipose tissue particle processing system  10 , tissue material may be transferred into adipose tissue particle processing system  10  by pressing plunger  32  of syringe  30 . This causes adipose tissue material to pass into the interior of screen portion  17  of filter screen assembly  12 , with the distal end of filter screen assembly  12  being closed by luer cap  20 , so that fat aspirate particles in the adipose tissue material are forced to pass from the interior of filter screen assembly  12  through apertures  18  of screen portion  17  into the interior of centrifuge tube  14 . The fat aspirate particles are effectively “filtered” and “sized” (micro-fragmented) by sieve filtering and shearing force by apertures  18  of screen portion  17  of filter screen assembly  12 , to a size that is determined by the size of apertures  18 , while undesired sinuate, connective tissue strands, and coarse debris are not able to pass through apertures  18 . 
     Once the micro-fragmented “sized” fat aspirate particles are transferred through screen portion  17  of filter screen assembly  12  into centrifuge tube  14 , then centrifuge tube  14  may be prepared for centrifugation, by removing components of adipose tissue particle processing system  10 , and replacing cap/bushing  16  with a conventional threaded lid. After the micro-fragmented fat aspirate particles are separated by either gravity decantation, or by centrifugation in a centrifuge system, various separated components may be aspirated from centrifuge tube  14 . In some embodiments, aspiration may be performed by inserting a transfer cannula into the interior of centrifuge tube  14  and aspirating material through the transfer cannula with a syringe coupled to the transfer cannula (as illustrated in  FIG. 5 ). The transfer cannula shown in  FIG. 5  may be a 6-inch or 12-inch length cannula with a female luer-lock connector on its proximal end and an approximately 0.146-inch (3.7 mm) outer diameter cylindrical tubular blunt tip on its distal end In other embodiments, where centrifuge tube  14  has a zero-draft, cylindrical configuration, the method described in U.S. patent application Ser. No. 16/295,695 may be used, where a diaphragm is slidably coupleable to the hollow inner portion of centrifuge tube  14 , and allows liquid contained in centrifuge tube  14  to be selectively and controllably aspirated out of centrifuge tube  14  through the diaphragm. 
     Filter screen assembly  12  may be cleaned after use by removing male luer cap  20  from the distal end, and inserting a cannula cleaner that is configured with projecting surfaces such as convex fins into the interior of filter screen assembly  12 . Cleaning is performed by scraping, dislodging, and removing debris and contaminants when making direct physical contact with the interior of a cannula device when moved back-and-forth following use of the cannula device, to be moved back and forth to cause frictional engagement with filter screen assembly  12  for cleaning. The cannula cleaner may be made of medical-grade nylon in some embodiments. In some embodiments, the cannula cleaner may be configured as shown and described in U.S. Provisional Application No. 62/855,167 entitled “Method and Apparatus for Cleaning the Interior Cannula of Suction Lipoplasty Cannula Devices and Adipose Tissue and/or Fluid Particle Sizing Devices,” filed on May 31, 2019, which is hereby incorporated by reference. 
     Adipose tissue particle processing system  10  described herein allows adipose tissue material to be micro-fragmented (“sized”) to a controllable fat aspirate particle size, with easy connections of components, in a system that minimizes contamination, spillage, and infection issues, while maintaining an essentially closed system during the processing of tissue and/or fluid. 
     While various components of adipose tissue particle processing system  10  are shown and/or described in the exemplary embodiments herein as integrated, connected, or separate components, it should be understood that in alternative embodiments, components may be integrally formed, connected, and/or separated in different ways than are shown and described herein, all within the scope and spirit of the present invention. Similarly, the sizes and dimensions of components, both in terms of absolute sizes and relative sizes with respect to other components, may be varied from what is shown and described herein, all within the scope of the present invention. 
     While certain example embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions disclosed herein. Thus, nothing in the foregoing description is intended to imply that any particular feature, characteristic, step, module, or block is necessary or indispensable. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions disclosed herein.