Bioreactor for biological constructs

Abstract

A bioreactor (1) for a biological construct is provided comprising: a support (2) defining a support surface (2a) of the biological construct; a frame (3) to which the support (2) is bound; and a stimulation device (4) of the biological construct comprising at least one piston (41) movable with respect to the support (2) along or parallel to a stimulation axis (4a) and a mechanism (42) configured to control the movement of the piston (41) along or parallel to said stimulation axis (4a) so as to bring the piston (41) against the support surface (2a) deforming it so as to define a peristaltic stimulation of the biological construct.

Description

[0001] DESCRIPTION

[0002] BIOREACTOR FOR BIOLOGICAL CONSTRUCTS

[0003] The object of the present invention is a bioreactor for the culture of cellular constructs, natural / artificial tissue constructs, monolayers or tissues (hereinafter uniquely identified for simplicity by the term "cellular construct(s)" or "construct(s)") of the type specified in the preamble to the first claim.

[0004] In particular, the invention relates to an innovative device by means of which to subject biological constructs, the same or different, to mechanical stimuli, thus simulating the physiological or pathological conditions present within an organism. The applications of this bioreactor are in the field of Tissue Engineering, with the aim of promoting the proliferation, differentiation and in vitro reproduction of functions / structures of organs or parts thereof.

[0005] Every tissue or biological system during its evolution and its normal activity is subjected to physical and chemical stimuli that determine its pathophysiological state and affect its normal function.

[0006] In particular, an organism is constantly subjected to external mechanical loads, such as gravity and motion, and to internal forces, such as contractile and haemodynamic forces. Each cell, due to its own cytoskeleton, is able to develop and feel external forces that influence its morphology, cytoskeletal organization, survival, cell differentiation and gene expression.

[0007] To try to reproduce the chemical-physical stimuli in biological constructs or on tissue explants, bioreactors have been developed that can simulate the mechano- biological environment present in an organism.

[0008] A first example of a bioreactor is described in the patent US20020106625 developed to generate a functional cartilage construct and which simultaneously applies a hydrostatic pressure and a deformation through a loading plate, while the device described in patent US20060068492, in addition to applying a compressive deformation through a loading plate, subjects the entire specimen to shear stresses through a rotary motion of the cell in which the biological construct is placed.

[0009] Particular cases are the bioreactors that allow the intestinal environment to be replicated to study the HIM and its fermentative pathways under pathophysiological conditions and in the presence of specific foods and drugs. Such devices are composed of one or more reactors that shape different gastrointestinal tracts.

[0010] The technique described comprises some important drawbacks.

[0011] In particular, the bioreactors on the market and / or described in the literature develop a hydrodynamic pressure (i.e. by moving fluids incident to the biological construct itself); some systems are limited to stimulating the biological constructs with a hydrostatic pressure, generated through hydraulic mechanisms and regulated by special regulators. Therefore, they do not make it possible to correctly simulate the mechano-biological environment present within an organism such as, for example, the intestinal environment.

[0012] Another drawback is the fact that the known bioreactors have large volumes of the culture chambers (working volume), similar to the physiological volumes, which however implies high space and cost requirements and a non-optimal control of fluid-dynamic parameters and, in particular, of the pressure acting on the biological construct.

[0013] A not insignificant drawback is the fact that in the known bioreactors there are no suitable media to promote adhesion, viability and proliferation, thus complicating the setting / changing of the hydrodynamic pressure, which can lead to culture problems. It should be noted that these drawbacks are accentuated by the fact that the known bioreactors lead to the formation near the biological construct of dangerous hydrodynamic shear stresses that could damage the construct.

[0014] In this situation, the technical task underlying the present invention is to devise a bioreactor for biological constructs capable of substantially overcoming at least part of the aforementioned drawbacks.

[0015] Within said technical task it is an important aim of the invention to obtain a bioreactor capable of correctly, and therefore realistically, simulating the mechano-biological environment present within an organism and in particular the intestinal environment. Another important object of the invention is to have a bioreactor capable of stimulating biological constructs without creating problems for the culture and therefore damaging the biological construct. In particular, one aim is to have a bioreactor free of dangerous fluid currents parallel to the support surface of the construct.

[0016] The technical task and the specified aims are achieved by a bioreactor for biological constructs as claimed in the attached Claim 1. Examples of preferred implementation are described in the dependent claims.

[0017] The features and advantages of the invention are clarified below by the detailed description of preferred embodiments of the invention, with reference to the attached drawings, in which:

[0018] Fig. 1 shows, to scale, a perspective view of the bioreactor for biological constructs according to the invention;

[0019] Fig. 2 illustrates, to scale, an exploded view of the bioreactor for biological constructs according to the invention;

[0020] Fig. 3a presents, to scale, a section of the bioreactor;

[0021] Fig. 3b exhibits, to scale, a section of the bioreactor at a different time of use; and

[0022] Fig. 3c exhibits, to scale, a section of the bioreactor at a further different time of use.

[0023] In this document, when measurements, values, shapes, and geometric references (such as perpendicularity and parallelism) are associated with words like "approximately" or other similar terms, such as "almost" or "substantially", they are to be understood as excluding measurement errors or inaccuracies due to production and / or manufacturing errors and, above all, as having less than a slight deviation from the associated value, measurement, shape, or geometric reference. For example, if associated with a value, such terms preferably indicate a divergence of no more than 10% of the value itself.

[0024] Moreover, when used, terms such as "first", "second", "upper", "lower", "main" and "secondary" do not necessarily identify an order, a priority of relationship or a relative position, but can simply be used to clearly distinguish between their different components.

[0025] Unless otherwise indicated, "perpendicular”, "transverse”, "parallel”, or "normal”, or other terms of geometric positioning between geometric elements (e.g., axes, directions, and straight lines) are to be understood with reference to their mutual geometric position between corresponding projections. Said projections are defined on a single plane parallel to the lying plane(s) of said geometric elements.

[0026] Unless otherwise stated, the measurements and data reported in this text shall be considered as provided in International Standard Atmosphere ICAO (ISO 2533:1975).

[0027] Unless otherwise specified, as reflected in the following discussions, terms such as "processing", "computing", "determination", "calculation", or the like are considered to refer to the action and / or processes of a computer or similar electronic computing device that manipulates and / or transforms data represented as physical, such as electronic quantities of records of a computer plant and / or memories, into other data similarly represented as physical quantities within computer plants, records, or other information storage, transmission, or display devices.

[0028] With reference to the figures, the bioreactor for biological constructs according to the invention is globally indicated with the number 1 .

[0029] The bioreactor makes it possible to perform a culture, suitably dynamic and continuous, of one or more biological constructs simulating the internal mechano- biological environment of an organism. Preferably, the bioreactor 1 is configured to perform a suitably dynamic and continuous in vitro culture of the human intestinal microbiota (HIM) in order to, for example, make it possible to contribute to the study of the HIM and the metabolic modes and pathways with which it interacts with the organism. The biological construct may then be a human intestinal microbiota.

[0030] The bioreactor 1 comprises a support 2 defining a support surface 2a at which the biological construct is placed; a frame 3 to which the support 2 is bound, suitably in an integral manner; and a stimulation device 4 of the biological construct on the support surface 2a configured to press against said support 2 along a stimulation axis 4a transverse to said support surface 2a.

[0031] The support surface 2a indicates the area occupied by the biological construct when arranged on the support 2, suitably calculated by projecting the construct onto the same surface 2a. It is noted that the construct, if inoculated for example, can occupy a section volume substantially equal to said surface 2a.

[0032] In particular, the support 2 comprises a scaffold 21 defining the support surface 2a of the biological construct, for example, placed thereon for inoculation; and a container 22 defining a culture chamber, i.e. a housing for the scaffold 21 and thus the biological construct. Preferably, support 2 defines only one support surface 2a and appropriately includes only one scaffold 21 and one container 22. The scaffold 21 is a plate-shaped element, i.e. it develops mainly along a development surface, preferably flat, so as to have dominant dimensions with respect to the third dimension (called thickness). Said development surface is identified by said support surface 2a and, in this document, the term "thickness" identifies a measure calculated perpendicularly to said support surface 2a.

[0033] The scaffold 21 may identify a usually artificial structure for example in biological material. For example, it may have nanometric morphological characteristics such as to emulate the extracellular matrix (ECM) in order to house and support one or more biological constructs and promote their growth / development; alternatively, the scaffold 21 may have nanometric morphological characteristics such as to emulate the microbiological environmental niche.

[0034] In detail, it can have a crosslinked structure and in detail be an electrophilate. The scaffold 21 may thus be produced by an electrospinning process.

[0035] The scaffold 21 may be deformable, suitably elastically, if subject to stimulation pressures, i.e. pressures / forces acting at least along a normal to the support surface 2a. In particular, the scaffold 21 is suitably elastically deformable. It may have an elastic modulus suitably ranging from 103 to 106 Pa.

[0036] The scaffold 21 may have a thickness of less than 1 mm and for example 0.5 mm.

[0037] The scaffold 21 can be made of elastic material with elastic modulus suitably between 103 and 106 Pa such as for example of natural origin (gelatin, chitosan, alginate, pectin agarose) or synthetic (PCL (polycaprolactone), PLLA (poly-L-lactic acid, acid), PLGA (poly(lactic-co-glycolic acid))). Preferably it is in electrospun gelatin.

[0038] The container 22 may comprise a bottom wall 221 on which the scaffold 21 rests; and at least one side wall 222 configured to surround the scaffold 21 . The container 22 thus defines a cup-shaped element.

[0039] It is noted that, in some cases, the bottom wall 221 may not be present and thus the scaffold 21 may identify the bottom of the container 22.

[0040] The bottom wall 221 also has a plate-shaped structure. It may develop along a development surface preferably parallel to the surface 2a. It may have a greater thickness than the scaffold 21 .

[0041] As well as the scaffold 21 , the bottom wall 221 can also be deformable, suitably elastically, if subjected to said stimulation pressures. To be precise, the bottom wall 221 is deformable if subjected to stimulation pressures preferably similar to that of the scaffold 21 .

[0042] In detail, it may have an elastic modulus suitably comprised between 103 and 106 Pa.

[0043] The bottom wall 221 may have a thickness substantially between 5 mm and 1 mm and for example between 3 mm and 1 .5 mm.

[0044] It should be noted that the side wall 222 has a thickness and therefore a greater rigidity than the bottom wall 221 .

[0045] The container 22 and in particular the walls 221 and 222 can be made of silicone such as polydimethylsiloxane (PDMS). (It can be in silicone-based elastomeric material that is a two-component system with a polymer base and a curing agent that bonds with the polymer matrix; the resulting compound can then be a polydimethylsiloxane (PDMS) with tensile strength (UTS) of ~5.2 MPa and shore hardness of ~44 at room temperature.) As a result, the container 22 (i.e., the culture chamber) is soft and flexible allowing both a deformation of the bottom wall 221 consistent with that which occurs physiologically as a result of intestinal peristalsis, but ensures the hydraulic seal of the culture chamber without the need for seals.

[0046] The container 22 can be in a single piece.

[0047] In some cases the support 2 also comprises a holder 23, for clarity not shown in Figs 3a-3c, configured to define a sub-chamber of the chamber in which the scaffold 21 and therefore the biological construct is arranged and enclosed.

[0048] The holder 23 is therefore configured to be inserted into the defined culture chamber by tightening the scaffold 21 against the possible bottom 221. If the bottom 221 is absent, the holder 23 may be absent.

[0049] The holder 23 can be placed in contact with the scaffold 21 on the side opposite to the bottom wall 221 .

[0050] It comprises a central body 231 configured to overlap, suitably at least partially, the scaffold 21 at least along a normal to the support surface 2a and suitably come into contact with said scaffold 21 ; and a perimeter body 232 integral and surrounding the central body 23 at least in part and in detail in full and configured to be bound to the container 22 making the holder 23 integral with the container 22.

[0051] The central body 231 may be plate-shaped. It can develop along a development surface preferably parallel to the scaffold 21 .

[0052] The body 231 may comprise an opening 231a configured to overlap at least part, in detail only part, of the support surface 2a so as to allow any nutrients to access the biological construct through said opening 231 a.

[0053] The perimeter body 232 is configured to bind to the container 22 in a resolvable manner. It may be attached to the side wall 222 in an interlocking manner.

[0054] The holder 23 can be made of silicone such as polydimethylsiloxane (PDMS). The holder 23 can be made in one piece and of the same material as the container 22. Accordingly, for the material of holder 23, reference is made to what is described for container 22.

[0055] The frame 3 is bound, suitably integrally, to the support 2 in such a way as to define along the stimulation axis 4a an accessible portion of the support surface 2a, i.e. a portion of the surface 2a in which the frame 3 does not interpose itself between the support surface 2a and the stimulation device 4. The accessible portion thus represents at least a part (in some cases the whole) of the support surface 2a accessible to the stimulation device 4 through the frame 3 and therefore can be stimulated thereby as described below.

[0056] Preferably the frame 3 is bound, suitably integrally, to the support 2 not at the support surface 2a. It is preferably bound to the support 2 at the only side wall 222 so as not to overlap the chamber along the axis 4a.

[0057] The frame 3 therefore comprises a bracket 31 to which the support 2 is bound.

[0058] The bracket 31 may comprise a hole 31a superimposed on at least the accessible portion of the surface 2a and, to be precise, on the entire support surface 2a along said stimulation axis 4a. Preferably the only side wall 222 is in contact with the support 31 and in particular the frame 3.

[0059] The extent of the section of the hole 31 a is therefore at least equal to the extent of the accessible portion. Said extensions are calculated perpendicularly to the stimulation axis 4a.

[0060] Conveniently, the support 31 may comprise one or more anchoring detents (not shown in the figure for representative clarity) of the support 2 to the bracket 31 ; and a recess 31 b configured to house at least part of the support 2, for example the side wall 222, and in detail surrounding said hole 31 a. The support 31 may comprise a plate 311 on which the hole 31 a and the recess 31 b are obtained; and preferably a receptacle 312 couplable to said plate 311 so as to define a culture space in which the support 2 and therefore the biological construct isolated from the external environment is placed. For simplicity, the receptacle 312 is depicted with a dashed line only in Fig. 1 .

[0061] The frame 3 may also comprise a base 32 defining a housing compartment in which the stimulation device 4 is arranged.

[0062] The base 32 may comprise a box-like body 321 defining said housing compartment and an access section to said compartment; and an at least partial closing body 322 of the access section and therefore of said box-like body 321 .

[0063] In a preferred embodiment, the closing body 322 is interposed between the support 31 and the box-like body 321 .

[0064] Base 32 and support 31 can be in two separate elements. The support 31 can rest (in particular be appropriately integrally constrained) on the base 32, and to be precise on the closing body 322.

[0065] The stimulation device 4 is configured to stimulate the support surface 2a (thus the biological construct), suitably in a dynamic and continuous manner, simulating mechanical stimuli internal to an organism. In detail, it is configured to recreate on the support 1 , suitably at the support surface 2a, and in particular to apply the mechanical stimuli of the gastrointestinal tract to the biological construct.

[0066] Preferably, the device 4 is configured to perform a peristaltic stimulation, i.e. deform (appropriately elastically) at least the scaffold 21 generating a controlled wave motion of the scaffold 21 and therefore of the construct that suitably develops substantially along the support surface 2a.

[0067] The stimulation device 4 comprises at least one piston 41 movable with respect to the support 2 and in particular to the scaffold 21 along the stimulation axis 4a transverse, i.e. not parallel, to the support surface 2a; a mechanism 42 configured to move one or more pistons 41 along the stimulation axis 4a; and for each piston 41 a sliding guide 43 of the piston 41 along or parallel to the stimulation axis 4a.

[0068] The stimulation axis 4a may be straight.

[0069] Preferably the stimulation axis 4a is perpendicular to the surface 2a.

[0070] It should be noted that the contact between support 2 and pistons 41 is direct.

[0071] In a preferred embodiment, the stimulation device 4 comprises several pistons 41 ; and the mechanism 42 is configured to selectively control the movement of the one or more pistons 41 along or parallel to the axis 4a so as to - preferably sequentially - press the pistons 41 against the support 2 at the accessible portion of the support surface 2a deforming - appropriately elastically - the scaffold 21 and, if present, the bottom wall 221 and therefore defining a peristaltic stimulation of the biological construct.

[0072] Each piston 41 defines a contact surface 4b with the support 2. The total contact surface 4b of the one or more pistons 41 may be substantially less than the extent of the accessible portion and therefore of the support surface 2a. Preferably, said entire contact surface 4b is spaced apart and not superimposed, along the axis 4a, with respect to the side wall 222 so as to define a perimeter portion of the bottom wall 221 and / or of the scaffold 21 never in contact with the pistons 41 .

[0073] The entire opening 231 a is suitably totally superimposed on the contact surfaces 4b of the one or more pistons 41 along the stimulation axis 4a.

[0074] The pistons 41 can have, in particular in an inactive condition in which none of the pistons 41 is moved with respect to the frame 3, contact surfaces 4b aligned defining an axis of propagation 4c of the stimulation. Preferably the axis of propagation 4c is barycentric to the contact surface 4b. Preferably the axis of propagation 4c is barycentric to the support surface 2a. The axis of propagation 4c may be parallel to the support surface 2a.

[0075] Each piston 41 is movable with respect to the frame 4 and in particular to the base 42. To be precise, it is configured to protrude from the base 32 and in particular from the closing body 322. Consequently, each guide 43 can be identified in a through duct obtained in the base 32 and in particular in the closing body 322.

[0076] The one or more guides 43 overlap, i.e. face, the portion accessible along the stimulation axis 4a and therefore the hole 31 a.

[0077] Finally, it should be noted that each piston 41 defines an active position in which it presses against the support 2 and an inactive position in which it does not press against the support 2 and suitably is in contact with the support 2.

[0078] The pistons 41 in the active position preferably have the contact surfaces 4b coplanar with each other.

[0079] The mechanism 42 is configured to push the pistons 41 against the support 2. It may comprise a shaft 421 configured to be moved with respect to a movement axis 4d suitably transversely and in detail normal to the stimulation axis 4a; pushing means 422 configured to transform the movement of the shaft 421 into a movement of the pistons 41 along the stimulation axis 4a; and suitably a control block of at least said rotation of said shaft 421 .

[0080] Therefore, in the active position, the piston 41 has the maximum distance from the movement axis 4d, while in the inactive position the piston 41 has the minimum distance from the movement axis 4d.

[0081] The pushing means 422 can be magnetic so as to press the pistons 41 against the support 2 for magnetic repulsion. They may comprise at least a first magnet integral with the shaft 421 and, for each piston 41 , a second magnet integral with the pistons 41 . Preferably they comprise a first magnet for each piston 41 . The magnets can then have same polarity so as to define said magnetic repulsion.

[0082] In a preferred non-limiting embodiment the control block may be configured to control at least rotation of the shaft 421 about the movement axis 4d.

[0083] Preferably the block controls a roto-translation and in particular a helical motion of the shaft 421 along the movement axis 4d. It may comprise a sliding channel 423 of the shaft 421 ; a helical track 424 obtained in a first element chosen from frame 3 and shaft 421 ; at least one pin 425 integral with a second element chosen from frame 3 and shaft 421 and configured to slide in the track 424; and an actuator 426 configured to move the shaft 421 along the movement axis 4d and therefore, due to the pin 425 and the track 424, said rototranslation of the shaft 421 .

[0084] In a first embodiment, the track 424 is obtained on the shaft 421 and the pin 425 is integral with the frame 3.

[0085] The actuator 426 is preferably pneumatic and suitably double-acting. It may comprise a plunger 426a; a base 426b defining a plunger sliding duct 426a; and a pump / compressor, 426c, shown for convenience only in figure 2, in fluid passage connection with the base 426b and configured to control the translation of the plunger 426a as a function of a pressure variation in said duct.

[0086] The plunger 426a is bound to the shaft 421 so as to prevent their reciprocal translation along the axis of movement and suitably allow their reciprocal rotation around said axis of movement 4d.

[0087] The base 426b is integral with the frame 3.

[0088] Conveniently, the stimulation device 4 is almost entirely housed in the base 32 and in detail in the box-like body 321 . Preferably, only the pistons 41 can protrude from the base 32 when they press against the support 2.

[0089] The control block may also include a control card for the operation of the block itself and therefore for the movement of the one or more pistons 41 .

[0090] Preferably the pump / compressor and board are external to the frame 4.

[0091] The operation of the above described bioreactor 1 for biological constructs in structural terms is as follows. This operation introduces a novel method for culturing biological constructs that can be carried out by said bioreactor 1 .

[0092] The culturing process comprises a step of depositing a biological sample on / in the scaffold 21 and to be precise at the support surface 2a obtaining the cell construct. Preferably exploiting the crosslinked (in detail electrospun) structure of the scaffold 21 , the deposition step is performed by inoculating a biological sample into the scaffold 21 making the biological construct. Consequently, at the end of the deposition step the construct is substantially integrated into the scaffold 21 at the surface 2a.

[0093] The culturing process comprises a step of stimulating the biological construct placed at the surface 2a.

[0094] The stimulation step is after the deposition step.

[0095] In the stimulation step, the mechanism 42 controls the movement of one or more pistons 41 along the stimulation axis 4a. In particular, the stimulation device 4 defines a peristaltic stimulation of the biological construct due to the mechanism 42 that pushes one or more pistons 41 , preferably sequentially, against the accessible portion deforming the support 2 and in particular at least the scaffold 21 (preferably the bottom wall 221 ). To be precise, the mechanism 42 actuates and then pushes the pistons 41 against the support 2 according to an activation sequence in such a way as to bring them to press against the accessible portion according to a predefined order. More precisely still, appropriately due to said magnetic pushing means 422, the mechanism 42 actuates and then pushes the pistons 41 against the support 2 by magnetic repulsion.

[0096] It is to be noted that pistons 41 go to press / stimulate distinct portions of surface 2a and appropriately distinct portions of the same surface 2a.

[0097] Said activation sequence may, for example, provide for an actuation of the pistons 41 according to an order defined according to a direction of the axis of propagation 4c as shown in Figs. 3a-3c. For example, the activation sequence can provide that the pistons 41 are controlled and then pressed against the support 1 starting from the piston next to a first end of the surface 2a to the piston distal from the first end, that is, closer to a second end of the support surface 2a opposite to the first along the axis of propagation 4c.

[0098] This (suitably elastic) deformation of the scaffold 21 is accentuated by the presence of the holder 23 which, by tightening the scaffold 21 against the bottom wall 221 , maximises the action of the pistons 41 against the scaffold 21 .

[0099] Other advantages are provided by the presence of multiple pistons 41 , which makes bioreactor 1 a more controllable system with more versatile and localized possibilities for modulating mechanical stimulation and more accurate and realistic reproduction of peristaltic movements typical of different anatomical districts under both physiological and pathological conditions. In fact, a multiple piston 41 design enables the generation of peristaltic waves that vary not only in time but also in space. Greater space-time control of mechanical stimulation implies the possibility of generating complex peristaltic strain profiles.

[0100] Furthermore, by stimulating different parts of the culture sample in a differentiated manner, different effects can be induced in the biological metabolism within the same culture.

[0101] It is also noted that in some cases several pistons 41 , even if not adjacent, can be pressed simultaneously against the support 2.

[0102] It is also stressed that the removal of each piston 41 from the support 2 can be controlled by exploiting the elastic response of the bottom wall 221 and / or the holder 23 to their deformation caused by the pistons 41 under pressure on the support 2. Alternatively or additionally the spacing of each piston 41 may be determined by the weight of the piston 41 itself and / or the pushing means 422.

[0103] The bioreactor 1 for biological constructs and therefore the new culture method according to the invention achieve important advantages.

[0104] In fact, the bioreactor 1 and said culture process allow a dynamic and continuous culture to be carried out in an extremely simple manner. In particular, they make it possible to simulate, in an almost perfect way, the intestinal peristalsis inside the culture chamber and therefore act on the biological construct. In fact, the innovative stimulation device 4 reproduces the mechanical stresses of deformation of the wall and, due to a possible flow of fluid, shear stress due to the intestinal content to which, for example, the HIM is subjected in vivo.

[0105] This aspect is accentuated by the fact that the pistons 41 , being pushed transversely and in detail normally to the surface 2a, tap the support 2 without sliding on the support 2, limiting the risk of damaging the support 2 itself.

[0106] Another advantage is represented by the fact that the device 4, by generating a peristaltic pressure, does not create fluid movements that could damage the biological construct. This aspect is also accentuated by the possibility of inoculating the construct into the scaffold due to the particular structure of the latter. In fact, the crosslinked structure (even more so if electrospun) of the scaffold 21 favours the construction of a biofilm and therefore of a construct even in dynamic environments such as those of the bioreactor 1 .

[0107] Another aspect is substantially represented by the fact that the bioreactor, exploiting a pneumatic actuator 426, is devoid of electrical components that can therefore alter the biological construct, distorting the study and making it easier to place the bioreactor in environments that could damage any electrical components such as an incubator.

[0108] Another advantage is represented by the fact that the bioreactor has particularly small dimensions. In addition, it is relatively cheap and simple both to implement and maintain.

[0109] A further advantage is represented by the opening 231 a which allows a fluid flow to lap the cell construct and thus determine a shear stress functional to the in vitro reproduction of physiological stresses and thus to the optimal development of the construct itself.

[0110] Important advantages are obtained by exploiting the magnetic repulsion to move one or more pistons 41 . In fact, this particular actuation of pistons 41 , being achieved by magnetic repulsion and thus without direct mechanical contact between piston 41 and mechanism 42 (or any of its other components), results in a longer life of bioreactor 1 due to significantly reduced deterioration, virtually no material degradation and wear and tear (i.e., less maintenance) resulting in increased life of bioreactor 1 components; the establishment of a more suitable environment for biological cultures due to the fact that the special magnetic actuation of bioreactor 1 reduces the generation and accumulation of debris due to mechanical friction between bioreactor 1 components making the environment cleaner and more suitable for biological cultures; a higher quality of stimulation due to the absence of direct contact between the actuation elements and the pistons 42 given by a reduction in mechanical resistance, need for lubrication and vibration and thus allowing smoother, more precise and controllable actuation; an increased reliability of the bioreactor 1 given to said non-wearing and said non-degradation of the materials; increased repeatability of stimulation by improving the reliability of the system, even in the long term; increased versatility due to the fact that magnetic actuation provides greater flexibility in terms of design, mechanics underlying actuation, positioning, and material of the pistons, and thus a generation of different support 2 strain waves that can model peristalsis under different conditions, both physiological and pathological.

[0111] The invention can be modified to create different versions falling within the scope of the inventive concept defined by the claims.

[0112] In a non-limiting embodiment, the control block can be configured to control a translation of the shaft 421 and therefore of the pushing means 422 (to be precise the at least one first magnet) along the axis of movement 4d. Consequently, the actuator 426 is configured to translate the shaft 421 along the axis of movement 4d and the possible track 424 is straight and parallel to the axis 4d.

[0113] In this context all the details can be substituted by equivalent elements and materials; the shapes and dimensions can be any.

Claims

CLAIMS1. Bioreactor (1 ) for biological construct comprising:- a support (2) defining a support surface (2a) of said biological construct;- a frame (3) to which said support (2) is bound; and- a stimulation device (4) of said biological construct on said support surface (2a); characterized in that- said frame (3) is constrained to said support surface (2) so as to define, along a stimulation axis (4a) transverse to said support surface (2a), an accessible portion of said support surface (2a) in which said frame (3) does not interpose itself between said support surface (2a) and said stimulation device (4) along said stimulation axis (4a); and- said stimulation device (4) comprises o at least one piston (41 ) movable relative to said support surface (2) along or parallel to said stimulation axis (4a); and o a mechanism (42) configured to command the movement of said piston (41 ) along or parallel to said axis of stimulation (4a) so as to press said piston (41 ) against said accessible portion by deforming said support (2) in correspondence of least said accessible portion and thereby defining a peristaltic stimulation of said support (2) and then of said biological construct.

2. Bioreactor (1 ) according to claim 1 , wherein support (2) defines a single support surface (2a) of said biological construct; wherein said support (2) includes a scaffold (21 ) defining said single support surface (2a); wherein said stimulation device (4) comprises a plurality of said pistons (41 ); wherein each of said pistons(41 ) defines a contact surface (4b) with said scaffold (21 ); and wherein said mechanism (42) is configured to command a sequential movement of said pistons (41 ) so that said pistons (41 ) press sequentially against said scaffold (21 ) at the level of said portion deforming said scaffold (21 ) and thereby defining said peristaltic stimulation of said biological construct.

3. Bioreactor (1 ) according to the previous claim, wherein the totality of said contact surfaces (4b) of said pistons (41 ) is less than the extent of said accessible portion of said support surface (2a).

4. A bioreactor (1 ) according to at least one of claims 2-3, wherein said scaffold (21 ) is elastically deformable.

5. Bioreactor (1 ) according to claim 4, wherein said scaffold (21 ) is a slab element.

6. Bioreactor (1 ) according to at least one of claims 4-5, wherein said scaffold (21 ) is made by electrospinning process.

7. Bioreactor (1 ) according to the preceding claim, wherein said scaffold (21 ) is electrospun gelatin.

8. Bioreactor (1 ) according to at least one preceding claim, wherein said mechanism (42) comprises a shaft (421 ) configured to at least rotate about a movement axis (4d) normal to said axis of stimulation (4a); pushing means (422) configured to transform the rotation of said shaft (421 ) into a motion of said pistons (41 ) along said axis of stimulation (4a); and a control block of at least the rotation of said shaft (421 ).

9. Bioreactor (1 ) according to the preceding claim, wherein said pushing means (422) are magnetic and configured to push said pistons (41 ) against said support (2) by magnetic repulsion; and wherein said pushing means (422) compriseat least a first magnet integral with said shaft (421 ) and, for each said piston (41 ), a second magnet integral with said piston (41 ) configured to interact with said first magnet defining said magnetic repulsion.

10. Bioreactor (1 ) according to at least one claim 6-7, wherein said control block is configured to control a helical motion of said shaft (421 ) along said axis of movement (4d) and includes a channel (423) of sliding said shaft (421 ), a helical raceway (424) formed in a first element chosen between said frame (3) and said shaft (421 ) and at least one pin (425) integral with a second element chosen between said frame (3) and said shaft (421 ) and configured to slide in said raceway (424), and an actuator (426) configured to move said shaft (421 ) along said axis of movement (4d); and wherein said actuator (426) is pneumatic and double-acting and includes a plunger (426a), a base (426b) defining a plunger sliding duct (426a) and a pump in fluid passage connection with said base (426b) and configured to control the translation of said plunger (426a) as a function of a change in pressure in said duct.

11. A process for culturing a biological construct configured to be carried out by said bioreactor (1 ) according to at least one preceding claim; wherein said process comprises a stimulation step in which said mechanism (42) moves and presses said at least one piston (41 ) along said stimulation axis (4a) against said accessible portion by deforming said support (2) in correspondence of least said accessible portion and thereby defining a peristaltic stimulation of said support (2) and then of said biological construct.

12. Process according to the preceding claim, wherein said support (2) defines a single support surface (2a) of said biological construct; wherein said support (2) comprises a scaffold (21 ) defining said single support surface (2a);wherein said stimulation device (4) comprises a plurality of said pistons (41 ); wherein each of said pistons (41 ) defines a contact surface (4b) with said scaffold (21 ); and wherein in said stimulation step said mechanism (42) commands a sequential movement of said plungers (41 ) so that by said pistons (41 ) sequentially pressing against said scaffold (21 ) at said portion deforming said scaffold (21 ) and thereby defining said peristaltic stimulation of said biological construct13. Process according to the preceding claim, wherein during said stimulation phase to which said mechanism (42) moves said pistons (41 ) according to a sequence of activation starting from said piston (41 ) proximal to a first end of said surface (2a) to said piston (41 ) distal from said first end along said axis of propagation (4c).

14. Process according to at least one preceding claim, in which in said stimulation phase said mechanism (42) moves said pistons (41 ) by magnetic repulsion.

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