Patent Application
20210379247
The present invention generally relates to the field of devices for preparing cell compositions. It more particularly relates to a device for the mechanical fragmentation of tissues intended for the preparation of a composition of isolated cells, as well as a method using the device.
It is known to proceed, for various purposes, to injections of living cells into certain parts of the human or animal body. These cells have properties that allow an action on injured tissues or organs, by regeneration or symptomatic treatment, for example, of pain.
Methods for obtaining such cells have hence been developed, in particular for adipocytes. Generally, these methods for obtaining such adipocyte cells have a common step based on the enzymatic digestion of the extracellular matrix of the tissue by a cocktail of proteases (collagenases) in order to release the cells from the tissue.
Among the known methods, document WO 2007/034115 A1 may be mentioned, which describes both a method and tools for purifying certain cells contained in adipose tissue.
The methods described in documents WO 2015/035221 A1; US 2005/139704 A1 and WO 95/09051 A1 are also known.
Such cell release by this enzymatic method is efficient but this type of enzymatic method is subjected to regulatory constraints and is very expensive.
To avoid these constraints, purely mechanical methods may be used, which make it possible to purify the adipocyte cells without the use of enzyme. Most of the known mechanical methods use a mechanical action in order to release the cells from the matrix structure of the tissue. The devices allowing these operations are considered as Class II Medical Devices.
In the field of preparation of cells from tissue samples, it may be mentioned, in 2014, a StromaCell® system from MicroAire, which is described as a semi-automated method for mechanically isolating cells from the adipose tissue with 140 000 cells per millilitre of lipoaspirate. A publication from M. Rapisio's team, of the same year, describes a vibration isolation in a pot during 6 min, followed by a centrifugation to collect the cells with a yield of 125 000 cells per millilitre of lipoaspirate, hence 5% of progenitor cells (Aronowitz et al., SpringerPlus, 2015).
Thereafter, devices claiming the isolation of cells derived from the adipose tissue have arrived in mass. More than ten systems have been listed by Oberbauer in 2105 (Oberbauer et al., Cell Regeneration, 2015), the most known being PureGraft (Cytori), Fastem (Corios Soc Coop), Revolve/GID 700 (LifeCell Corporation/GID Group Inc), Lipogems (Lipogems International S.p.A.), StromaCell (MicroAire Surgical Instruments LLC) and MyStem (MyStem LLC). In 2016, Cicione's team has described cell isolation with the MyStem EVO technique (Cicione et al., PRS, 2016), and Domenis's team has made a comparative study of the Fastem technique with 2 enzymatic digestion protocols (Domenis et al., Stem Cell Research & Therapy, 2015).
The following year, the Lipogems technique is reported, which uses balls in a closed system to manually microfragment the adipose tissue. The publication from Tremolada's team (Tremolada et al., Curr Stem Cell Rep, 2016) already claims more than 7000 patients treated by this method all over the world, in plastic surgery, general surgery, orthopaedic surgery, but also maxillofacial surgery applications.
In 2016, Condé-Green's team has made a review about the mechanical extraction of cells from adipose tissue. The studies remain mainly in vitro and use at the same time centrifugation, stirring (manual or electrical) and vortex to isolate the cells (Condé-Green PRS 2016).
Finally, the emulsification technique described by Tonnard in 2013 (Tonnard et al., PRS, 2013) under the name of Nanofat, which consists in adipocyte lysis by inter-syringe shuffling, is also considered as a method for extracting cells from the stromal fraction, and in particular multipotent cells (Banyard et al., PRS, 2016). The Nanofat protocol has thereafter been marketed by Tulip Medical.
The literature of the field includes many articles, including:
In order to remedy the above-mentioned drawbacks of the state of the art and others that will appear upon reading of the present document, the present invention proposes a mixer with a particular structure operable to implement a mechanical method for preparing cells from sampled tissues, in particular by shearing of the tissues.
More particularly, it is proposed according to the invention a device for the mechanical fragmentation of tissues intended for the preparation of a composition of isolated cells, in particular adipocytes and/or cells contained in the adipose tissue, from a tissue sample, obtained in particular during a liposuction, said preparation including at least one step of mechanically fragmenting the tissues in the device, said device comprising a motorized support and a container, the motorized support comprising a motor having a rotor integral with a coupling member, the container internally including an axially rotatable rotary shaft and including radial arms capable of sweeping the inside of the container as the rotary shaft rotates, the motorized support and the container including complementary detachable fastening means for immobilizing the container on the motorized support, the coupling member and the rotary shaft being configured in such a way as to allow axial rotation of the rotary shaft as the motor rotor rotates.
According to the invention, the radial arms are of two types: vane-type arms and filamentary-type arms.
Other non-limitative and advantageous features of the device according to the invention, taken individually or according to all the technically possible combinations, are the following:
The invention also proposes a method for preparing a composition of isolated cells, in particular adipocytes and/or cells contained in the adipose tissue, from a tissue sample, obtained in particular during a liposuction, said preparation including at least one step of mechanical fragmentation of the tissues in a device, said device comprising a motorized support and a container, the motorized support comprising a motor having a rotor integral with a coupling member, the container internally including an axially rotatable rotary shaft and including radial arms capable of sweeping the inside of the container as the rotary shaft rotates, the motorized support and the container including complementary detachable fastening means for immobilizing the container on the motorized support, the coupling member and the rotary shaft being configured in such a way as to allow axial rotation of the rotary shaft as the motor rotor rotates.
According to said method, a device according to any one of the preceding claims is implemented for the fragmentation of the tissues, and the sampled tissue is introduced into the container, the motor is powered on, the container having previously been fastened to the motorized support so that the coupling member can rotate the rotary shaft then, after the motor has been stopped, at least one portion of the container content is collected.
In variants, possibly combined together, of said method:
The following description with respect to the appended drawings, given by way of non-limitative examples, will permit a good understanding of what the invention consists in and of how it can be implemented.
In the appended drawings:
Within the framework of the solution of mechanical processing of the sampled tissue implemented in the invention, the separation of the cells from the tissue is based on attrition and shearing forces undergone by the tissue in a mixer.
Preferentially, this mixer is intended for crushing the adipose tissue and for obtaining cells composing the adipose tissue, mainly the cells of the SVF (Stromal Vascular Fraction) but it may also be used to purify cells contained in other tissues or organs.
The mixer of the invention mainly includes two components: a support including an electric motor, called motorized support, and a container capable adaptable on the motorized support. The motorized support includes a motor making it possible, when the container is fastened to the motorized support, to rotate a rotary shaft internal to the container, said rotary shaft including radial arms. The container is detachably fastened to the motorized support and a coupling means, which is disengageable from the rotational driving, is installed between the motorized support and the rotary shaft of the container.
The speed of rotation of the rotary shaft is preferentially of about 4000 rpm (rotation per minute), which provides an optimum yield of cell purification in terms of number of cells and of viability. In variants, a speed of rotation comprised between 2000 and 8000 rpm is provided, and the mixer may include means for adjusting the speed of rotation of the motor rotor and hence of the rotary shaft.
The rotary shaft, which is central/coaxial to the container, herein substantially frustoconical in shape, is provided with radial vanes at the base thereof, for a convection of the adipose tissue. Higher, along the rotative shaft, nylon or metal wires are fastened perpendicularly/radially to the rotary shaft in order to ensure efficient cutting and splitting of the tissue. The diameter of the nylon or metal wires is comprised between 0.5 mm and 3 mm. The number of nylon or metal wires is comprised between 3 and 15.
In order to optimize the cutting of the tissue by the nylon or metal wires, serrations may be inserted on the inner face of the container. The number thereof may be comprised between 2 and 12 and the thickness thereof may be comprised between 1 mm and 6 mm. The presence of the serrations makes it possible to create a turbulent flow of tissues allowing an optimal mixture. These serrations are nevertheless optional in the sense that it is possible to obtain cells without them, but their presence significantly increases the cell preparation yield.
The container has, in its upper part, a lid that includes two devices making it possible to reduce the contamination of the tissue during the implementation of the invention. The first device is a vent through the lid, provided with a filter of 0.22 μm, allowing exchanges of air devoid of infectious or inert particles. The second device is a valve or a septum allowing the passage of a cannula without passage of external air concomitantly with the passage of the cannula. Preferably, this valve or this septum let a 3-mm cannula, typically a liposuction cannula, pass through. This usable cannula diameter may however be from 1 mm to 5 mm. This valve or this septum allows the adipose tissue coming from the liposuction to enter directly the container for being crushed and makes it possible to sample the homogenate after mixing in the mixer.
Hence, preferably, the container is closed by a septum that is a silicone valve, accepting the passage of a hollow cannula, of diameter 1 to 5 mm, and that closes automatically upon removal of said cannula. This silicone valve may be completed by an external/top plug, to avoid a prolonged direct contact of the valve with the external air. This non-pierced silicone valve is impermeable, in particular in the outward direction from the container, to liquids, particles and cells. The silicone valve and the plug are impermeable to gas+liquid+particles+cells in the two directions.
In
The motorized support 3 (see
The frustoconical bowl with a narrow lower base and a wide top is closed at its top by an upper wall 5 forming a lid. This lid 5 is in this example clipped and is not intended to be removed. It may even be welded. In a variant embodiment, this lid is removable. The lid 5 includes two through-openings. The first opening 17 is closed by a filter of 0.22 μm and a grating 18. The second opening 20 is closed by a self-closing valve 16 of 3-mm diameter and that ensures a total sealing when closed. This flap 16 gives way when a cannula is introduced into the second opening 20. In the case of a self-sealing septum of the silicone valve type, the latter closes after removal of the cannula. The second opening 20 is externally covered by a removable cap.
The rotary shaft 9 includes radial arms 10, 12 of two types. Towards the bottom of the rotary shaft are arranged rigid vane-type arms 10 and, above these latter, flexible or soft filamentary-type arm 12 made of nylon or metal. The vane-type arms 10 may include ridges 6 extending in a vertical plane substantially perpendicular to the radial extension of the arm 10. The radial arms, in particular the filamentary arms 12, are staggered over the height of the rotary shaft 9 and angularly distributed all over the latter.
The steps of obtaining the desired cell composition are schematized in
Beforehand, at step A, a sampling of adipose tissue has been performed on a patient 21 by a suction syringe 22 or an automatic vacuum-sucking device. At step B, the adipose tissue is introduced into the container 1 by passage of the cannula of the syringe 22 through the second opening 20. During the injection of the tissue into the container, the air that is over-pressurized inside the container 1 exhausts through the first opening 17 by passing through the filter 15. At step C, the syringe 22 is removed from the container 1. At step D, the container 1 is fastened to the motorized support 3 and the motor of the latter is activated to rotate the rotary shaft 9 of the container 1, which destructs the tissue and releases the cells. The operating parameters are adjusted by the adjustment means 13, 14 of the motorized support. At step E, the cells and other elements of the tissue that has been broken up are collected into a syringe cannula 23 introduced through the second opening 20. At step F, during the sucking by means of the syringe 23, external air may enter the container through the first opening 17 by passing through the filter 15. At step G, a centrifugation is performed in order to select the desired cells for a reinjection at step H.
Based on a sampled adipose tissue, the mixer of the present invention allows obtaining a cellular composition called SVF (Stromal Vascular Fraction) close to that obtained by the protocol using collagenase.
Typically, from the quantitative point of view, based on 25 ml of adipose tissue, about 200 000 of viable cells are obtained. From the qualitative point of view, the use of the mixer of the invention makes it possible to obtain about 17% of cells having a phenotype CD34+, CD31−, CD45− with respect to the total number of purified cells gathering the cells considered as progenitor cells (Mesenchymal Stem Cells) as well as the pericytes. Such a ratio is very close of that obtained with the purification protocol based on the use of the collagenase (19%).
| Number | Date | Country | Kind |
|---|---|---|---|
| 1756643 | Jul 2017 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2018/051763 | 7/12/2018 | WO | 00 |
