Bioreactors and methods for processing biological material

Abstract

A bioreactor including a housing, a first fluid dispenser and a second fluid dispenser. The bioreactor is configured to receive a scaffold mounted within the housing with the first and second fluid dispensers being positioned to apply respective first and second fluids to at least two different regions of a mounted scaffold.

Claims

1. A bioreactor comprising a housing, a first fluid dispenser and a second fluid dispenser spaced apart from the first fluid dispenser; the bioreactor being configured to receive a scaffold mounted within the housing with the first and second fluid dispensers being positioned to apply respective first and second fluids to at least two different regions of a mounted scaffold, wherein the bioreactor is configured such that, in use, the first fluid dispenser is provided along the axis of rotation of a mounted scaffold, said mounted scaffold being coaxial with and surrounding the first fluid dispenser, and the second fluid dispenser is positioned directly above the position of the mounted scaffold.

2. A bioreactor of claim 1 comprising a fluid outlet for removing fluid from within the housing.

3. A bioreactor of claim 1 wherein the first and second fluid dispensers are positioned to apply fluid to different surfaces of a mounted scaffold.

4. A bioreactor of claim 3 wherein the first fluid dispenser is positioned to apply the first fluid to an interior surface of a mounted scaffold.

5. A bioreactor of claim 3 wherein the second fluid dispenser is positioned to apply the second fluid to an exterior surface of a mounted scaffold.

6. A bioreactor of claim 2 operable to recycle the fluid removed through the fluid outlet.

7. A bioreactor of claim 6 comprising means for connecting the bioreactor to, one or more pipelines to direct the removed fluid to the first and/or second fluid dispensers for reapplying the fluid to one or more surfaces of a mounted scaffold.

8. A bioreactor of claim 1 comprising means for connecting the bioreactor to one or more oxygenators.

9. A bioreactor of claim 8 comprising means for connecting the bioreactor to one or more oxygenators operable in use to re-oxygenate fluid removed through the fluid outlet.

10. A bioreactor of claim 2 configured such that the second fluid is supplied to the second fluid dispenser from the fluid outlet, only.

11. A bioreactor of claim 1 wherein the first and/or second fluid dispenser comprises a perforated shaft or conduit having one or more holes therein.

12. A bioreactor of claim 11 wherein the first and/or second shafts or conduits are operable to apply the first or second fluid onto one or more surfaces of a mounted scaffold through said one or more holes within the shaft or conduit.

13. A bioreactor of claim 1 comprising a support structure onto which a scaffold may be mounted, in use.

14. A bioreactor of claim 13 wherein the support structure is configured such that a scaffold may be rotatably mounted thereon.

15. A bioreactor of claim 1 configured to receive a tubular scaffold which, when mounted, is rotatable about an axis running through the centre of the tubular scaffold.

16. A bioreactor of claim 15 wherein the first fluid dispenser of the bioreactor is provided along the axis of rotation of a mounted scaffold such that a mounted scaffold is coaxial with and surrounds the first fluid dispenser.

17. A bioreactor of claim 1 wherein the second fluid dispenser is positioned directly above the position of a scaffold when mounted within the housing of the bioreactor.

18. A bioreactor of claim 1 comprising a scaffold mounted within the housing.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

(2) FIG. 1 is a side cross-sectional view of a section of a bioreactor in accordance with the invention;

(3) FIG. 2 is a further side cross-sectional view of the section of the bioreactor shown in FIG. 1;

(4) FIG. 3 is a schematic diagram of an operational setup including an embodiment of a bioreactor in accordance with the invention; and

(5) FIG. 4 is a schematic diagram of a further operational setup including an embodiment of a bioreactor in accordance with the invention.

(6) FIGS. 1 and 2 illustrate an exemplary embodiment of a bioreactor 10 in accordance with the invention. The bioreactor 10 includes a housing 12 which is substantially cylindrical and has a cylindrical cavity 14 therein. Within the cavity 14 is located a first fluid dispenser in the form of a first shaft 16 and a second fluid dispenser in the form of a shaft 18. The first shaft 16 is located substantially centrally within the cavity 14 of the housing 12, whereas the second shaft 18 is located near an upper edge of the housing 12 (in the orientation shown in the Figures). As will be described hereinbelow, the shafts 16, 18 are operable in use to apply a fluid onto surfaces of a scaffold 38 mounted within the cavity 14. The bioreactor 10 additionally includes a fluid outlet 20 which may be used to remove fluid from within the cavity 14 of the housing 12, in use, as will be described in detail below.

(7) The bioreactor 10 also comprises a support structure in the form of cylindrical blocks 22. The cylindrical blocks 22 are mounted on the first shaft 16 and are positioned apart along the length of the first shaft 16 towards opposing ends thereof. The blocks 22 are used in the illustrated embodiment to mount a scaffold 38, which will specifically be a tubular scaffold which is substantially cylindrical, within the cavity 14 of the housing 12. Preferably, the blocks 22 are rotatable about an axis defined by the length of the first shaft 16. In this way, a tubular scaffold 38 when mounted on the blocks 22 may also be rotatable about this axis. The position of a tubular scaffold 38 when mounted within the cavity 14 of the housing 12 is shown in FIG. 2.

(8) The tubular scaffold 38 is a biological tissue scaffold that has been decellularised to remove substantially all cellular material. The type of biological tissue is not limited and may be, for example, trachea, oesophagus, bowel or blood vessel, for example.

(9) The first shaft 16 is located mostly within the cavity 14 of the housing 12. However, a portion of the first shaft 16 protrudes out of the housing 12 through an opening in a first end surface 24 of the housing 12. The end of the first shaft 16 protruding from within the housing 12 comprises a fluid connector 28 which acts as both an inlet and outlet for fluid to be introduced or removed from within the first shaft 16. To ensure a fluid-tight seal about the first shaft 16 and at the first end surface 24 of the housing 12, O ring seals 36a, 36b are provided. This prevents unwanted leaks of fluid from within the cavity 14 of the housing 12.

(10) Similarly, the second shaft 18 is located mostly within the cavity 14 of the housing 12. However, a portion of the second shaft 18 protrudes out of the housing 12 through an opening in a second end surface 26 of the housing 12. The end of the second shaft 18 protruding from within the housing 12 comprises a fluid connector 30 which acts as an inlet for fluid to be introduced to the second shaft 18. To ensure a fluid-tight seal about the second shaft 18 and at the second end surface 26 of the housing 12, O ring seals 36c, 36d are provided. Again, this prevents unwanted leaks of fluid from within the cavity 14 of the housing 12.

(11) Each of the first and second shafts 16, 18 are hollow and perforated and comprise a series of holes 32, 34 along their length. As is described below in detail, the holes 32, 34 allow fluid within the shaft 16, 18 to be dispensed from within the shaft 16, 18 onto a surface of a scaffold 38 mounted within the cavity 14 of the housing 12. The holes 32 within the first shaft 16 are provided along the length of the shaft 16 between the blocks 22. Similarly, the holes 34 within the second shaft 18 are provided along the length of the shaft 18, but only along an equivalent length of the shaft 18 as the holes 32 within the first shaft 16. In the orientation shown in the Figures, the holes 34 within the second shaft 18 are provided along the length of the second shaft which is directly above the length of the first shaft 16 which contains holes 32.

(12) As shown in FIG. 2, with the scaffold 38 mounted within the cavity 14 of the housing, the first shaft 16 is positioned centrally through the tubular scaffold 38 such that fluid may be applied to an interior surface 37 of the scaffold 38 through the holes 32 in the shaft 16. In the illustrated embodiment, a first fluid 33 is applied to the interior surface 37 of the scaffold 38 through the holes 32 in the first shaft 16. The second shaft 18 is positioned directly above the tubular scaffold 38 (in the orientation shown in the Figures) such that fluid may be applied to an exterior surface 39 of the scaffold through the holes 34 in the shaft 18. In the illustrated embodiment, a second fluid 35 is applied to the exterior surface 39 of the scaffold 38 through the holes 34 in the second shaft 18.

(13) The first and second fluids 33, 35 may comprise growth media and cells, for example epithelial cells and stem cells respectively in appropriate growth media.

(14) FIGS. 3 and 4 illustrate operational setups which incorporate an embodiment of a bioreactor 10 in accordance with the present invention. In particular, these Figures illustrate how first and second fluids 33, 35 are provided in the respective shafts 16, 18 for application to surfaces of a mounted scaffold 38.

(15) As shown in FIG. 3, the bioreactor 10 is connected to a first pump 41 at the fluid connector 28 at the end of the first shaft 16 via pipelines 50 and 52. Specifically, pipeline 50 is operable to supply fluid from the pump 41 to the fluid connector 28 whereas pipeline 52 is operable to transport fluid from the fluid connector 28 back to the pump 41. The setup shown additionally comprises a first fluid reservoir 42 which is fluidly connected to the pump 41 via pipeline 48.

(16) Similarly, there is also provided a second pump 46 for supplying the second fluid 35 to the second shaft 18 under pressure through fluid connector 30. The second pump 46 is fluidly connected to the fluid connector 30 of the bioreactor 10 through pipelines 66 and 68. Specifically, pipeline 66 is operable to supply fluid from the pump 46 to the fluid connector 30 whereas pipeline 68 is operable to transport fluid from the fluid connector 30 back to the pump 46. The setup shown additionally comprises a second fluid reservoir 62 which is fluidly connected to the pump 46 via pipeline 64.

(17) A waste pipe 70 is provided fluidly connected to the fluid outlet 20 to drain excess fluid from within the housing 12 of the bioreactor 10.

(18) The setup shown in FIG. 4 differs from that shown in FIG. 3 in that the second pump 46 is not supplied with fluid from a reservoir. Rather, the second pump 46 is supplied with fluid obtained through removal of fluid from within the cavity 14 of the housing 12 through fluid outlet 20. In the illustrated embodiment, the bioreactor 10 additionally comprises an oxygenator 44 provided between the second pump 46 and the fluid outlet 20. Specifically, the oxygenator 44 is fluidly connected to the outlet 20 via pipeline 54 and to the second pump 46 via pipeline 56. As will be described below, in such a setup, the oxygenator 44 is operable in use to re-oxygenate fluid removed from within the cavity 14 of the housing 12 such that it can be reused as a second fluid 35 for application to a further surface of a mounted scaffold 38.

(19) The operational use of the bioreactor 10 will now be described with reference to FIGS. 1 to 4.

(20) The bioreactor 10 is used to grow biological material on the surfaces of a scaffold 38 mounted within its housing 12. To achieve this, first and second fluids 33, 35 are applied onto the interior and exterior surfaces 37, 39, respectively. The fluids 33, 35 are applied via respective shafts 16, 18 which protrude into the housing 12. The fluids 33, 35 typically comprise a biological medium containing a plurality of cells which may all be of the same cell type, or may be of two or more different cell types. Preferably, the first and second fluids 33, 35 comprise different biological media. It is, however, to be understood that the first and second fluids 33, 35 could comprise the same media.

(21) In the illustrated bioreactor 10, the first fluid 33 is applied to an interior surface 37 of a mounted scaffold 38 via the first shaft 16. As shown, the scaffold 38 is mounted coaxially about the first shaft 16 within the housing 12 as is positioned such that first fluid 33 contained within the first shaft 16 drips through holes 32 within the first shaft 16 onto the interior surface 37 of the scaffold 38. Whilst the first fluid 33 drips through holes 32 in the first shaft 16, the scaffold 38 is rotated about an axis defined by the first shaft 16 through rotation of the blocks 22 (and in some instances the shaft 16 also). This rotation of the scaffold 38 enables the first fluid 33 to be applied to the entire interior surface 37 of the scaffold 38 upon a full 360° rotation of the scaffold 38 about this axis as the portion of the interior surface 37 located directly below the holes 32 in the first shaft 16 continually changes upon rotation of the scaffold 38.

(22) Similarly, at the same time, the second fluid 35 is applied to an exterior surface 39 of the mounted scaffold 38. To achieve this, the scaffold 38 is mounted directly below the second shaft 18 (in the orientation shown in the Figures) such that second fluid 35 contained within the second shaft 18 drips through holes 34 within the second shaft 18 onto the exterior surface 39 of the scaffold 38. As discussed above, the scaffold 38 is rotated about an axis defined by the first shaft 16 through rotation of the blocks 22 (and in some instances the shaft 16 also). This rotation of the scaffold 38 also enables the second fluid 35 to be applied to the entire exterior surface 39 of the mounted scaffold 38 upon a full 360° rotation of the scaffold 38 about this axis as the portion of the exterior surface 39 located directly below the holes 34 in the second shaft 18 continually changes upon rotation of the scaffold 38.

(23) Excess fluid 40 (which may originate from either the first and/or second shafts 16, 18) will collect underneath the scaffold 38 at the bottom of the cavity 14. This excess fluid 40 is removed from within the cavity 14 through the fluid outlet 20.

(24) In the setup shown in FIG. 3, the removed excess fluid 40 is drained through waste pipe 70 and is not reused. However, in the alternative setup shown in FIG. 4, the removed excess fluid 40 is recycled for use as the second fluid 35 for application to the exterior surface 39 of the mounted scaffold. Specifically, the excess fluid 40 is directed towards an oxygenator 44 subsequent to removal of the fluid 40 through the fluid outlet 20. The oxygenator 44 is operable to re-oxygenate the fluid which is then passed through the second pump 46 to supply the fluid to the second shaft 18 under pressure. This fluid is then applied to the exterior surface 39 of the scaffold 38 as is described above.

(25) In FIG. 4, the fluid 40 removed from within the housing 12 through the fluid outlet 20 is directed back to the second shaft 18. However, it should be understood that the invention is not limited in this sense. Rather, the removed fluid 40 may alternatively be directed to the first shaft 16 for application to the interior surface 37 of the scaffold 38. In further embodiments the removed fluid 40 may be directed to both the first and second shafts 16, 18 for application to both the interior and exterior surfaces 37, 39 of the scaffold 38. In yet further embodiments, such as those using the setup illustrated in FIG. 3, the removed fluid 40 may simply be drained from within the housing 12 and not be reused, as discussed above.

(26) In some embodiments the bioreactor 10 may be connected to a second fluid reservoir as a source of second fluid for application to the scaffold 38, as shown in FIG. 3. In such embodiments, the recovered fluid 40 from within the housing 12 may be used to supplement the first and/or second fluids 33, 35.

(27) In some embodiments the bioreactor 10 may comprise one or more additional oxygenators. For example, in some embodiments the bioreactor 10 may be provided with an oxygenator between the fluid connector 28 and the first pump 41 along pipeline 52. In doing so, fluid which is removed from within the first shaft 16 along pipeline 52 may be re-oxygenated before being pumped back to the first shaft 16 for application to a surface of the mounted scaffold 38.

(28) The above embodiment is described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.