CELL-CULTURE SYSTEM

Abstract: A cell-culture system comprising a vessel and a wound dressing system is disclosed wherein the cell culturing substrate material of the wound dressing system is releasably secured by e.g. peelable adhesive or heat sealing means, to a part of the interior surface of the vessel. The culturing substrate may optionally comprise a detachable handle portion and/or a support layer. In various embodiments, the vessel is formed into two interlocking or mutually fitting parts for example a base and lid, one of which may be peelably attached to the other. The system may also comprise a support which supports the dressing system and resiliently engages the vessel.

Description: CELL-CULTURE SYSTEM The present invention relates to substrates and vessels used for cell-culture techniques. In particular it relates to substrates on which ceils may be grown for subsequent transfer to a patient requiring a layer of cells. WO91/13638 describes a wound dressing which comprises a layer of a polymeric material having a layer of cultured mammalian cells anchored to one surface. Such a dressing is suitable for use in the treatment of partial-thickness wounds such as burns and skin donor sites. The cells are preferably epithelial cells which may be cultured from autologous skin cells taken by biopsy or may be from other sources. The cells are cultured and grown in the presence of the polymer substrate to which they attach. When the substrate is applied to a prepared site on the patient the ceils transfer from the substrate to the patient and continue to multiply to form a layer of epidermal cells. The dressings described are made by culturing the cells in contact with the surface of the polymeric dressing substrate, removing the substrate form the culture medium, and then placing the dressing on the patient such that the cells contact the wound- bed on the patient. An object of the present invention is to provide an improved form of substrate system and/or culture vessel to facilitate culture and anchorage of cells to the substrate and transfer of cells to the patient. According to the invention, a cell culture system comprises; (a) a vessel having interior and exterior surfaces suitable for containing a liquid medium in which mammalian cells may be cultured and (b) a wound dressing system which comprises a culture substrate materiai which is not cytotoxic and having a first surface to which cultured mammalian cells may attach and a second, opposed surface; said wound dressing system being releasably secured to at least a part of the interior surface of said vessel such that said first surface of said substrate material is exposed to the interior of said vessel. The vessel may conveniently have the appearance of a known type of culture flask generally having a rectangular or polygonal, e.g. hexagonal, shape and two opposed flat walls and a side wall or walls extending there between with a closable access port located in one of the sidewalls. Alternatively the vessel may have any other suitable shape e.g. a dish, such as a petri dish or a cylinder optionally having a closable access port or lid. The vessel may have a peelable lid to allow access to the interior of the vessel. The vessel is formed from a material which is not toxic to cells, not porous to liquid, and preferably capable of being sterilised. The material from which the vessel is formed may be advantageously transparent but this is not essential for the working of the invention. The vessel may be partly transparent or translucent and partly opaque. Suitable materials for the vessel include synthetic polymers such as polystyrene, polyesters (e.g. polyethylene terephthalate, polyethylene naphthalate) copolymers of either or both materials e.g. polyethylene terephthalate-co-isophthalate, polycarbonate, acrylic materials, polyetherimides and polyolefins, ethylene ethylacrylate copolymer, ethylene methyl acrylate copolymer, ethylenevinyl acetate copolymer and others. The vessel may comprise two or more parts which fit together to form a substantially water-tight vessel. Those parts may form a base and a lid. The parts may be moulded to form an interference fit. For example one form of vessel comprises a shallow base and a deep lid. The base has a moulded lip formed around the periphery of the base or near the edges of the base or a raised central portion having edges which may form an interference fit with a portion of the lid. The deep lid has a flat top wall and depending side walls shaped to form an interference fit with the moulded lip or raised portion of the base. The culture substrate is attached to the flat part of the base, optionally by means of a support layer. The base and lid may be sealed together by e.g. shrink wrapping or heat sealing to prevent leakage. The lid preferably has an access port by which culture medium and cells may be introduced into the vessel. The vessel may be similarly formed from a deep base which has upwardly extending sidewalls and a shallow or flat lid. This configuration may be beneficial to the water-tightness of the vessel. A lip may, optionally be present on the side walls or two cooperating lips may be present, one on each part of the vessel. The vessel may include one or more walls which are peelable from the remainder of the vessel. The peelable walls may be sealed to the remainder of the vessel by heat sealing or by peelable adhesive; the seal should be waterproof and should not introduce cytotoxic materiai into the vessel. The culture substrate is preferably disposed on the interior of the peelable wall or walls. In a preferred form, the peelable wall may, when peeled from the vessel form a support layer for the culture substrate. Alternatively a support layer has one surface attached to the second surface of the culture substrate and the other surface attached to the interior surface of the peelable wall. The vessel may alternatively be formed as a single piece which may be cut to form a removable portion when required. In this form the vessel may be provided with a guide line for assisting with the cutting operation or a line of weakness. The wound dressing system which is releasably secured to the interior of the vessel comprises a cell culture substrate material. Suitable cell culture substrate materials include those mentioned in WO91/13638, i.e. polyesters, polypropylene, blends or copolymers of vinyl acetate, e.g. ethylene - vinyl acetate copolymer, polyvinylidene chloride, polystyrene, polybutadienes, polyethylene, ionomers, e.g. SURLYN (trade mark), or copolymers and blends containing these compounds. Alternatively hydrophilic polymers such as hydrophilic polyurethanes may form the culture substrate. The culture substrate has a first surface to which cultured mammalian cells may attach. This surface may be treated to modify its properties such as by coating with another material such as a collagen-based material, or by other means, e.g. corona-discharge or plasma treatment. The substrate material is preferably a film of polymeric material. Preferably the substrate material is relatively conformable to body contours. The substrate may be continuous or may be apertured. The wound dressing system may comprise a dressing portion which has one or more surfaces formed of a cell culture substrate material. Thus the dressing system may comprise a dressing comprising more than one layer of material. At least one surface of one layer of such a dressing would then form the first surface of the culture substrate surface to which cultured mammalian cells would attach. The wound dressing system may further comprise a support layer which is releasably attached to the culture substrate material, preferably to the second surface of the substrate material, at least in a region or regions along or adjacent to the edges of said culture substrate. The support layer may have the form of a frame such as to support the culture substrate around at least a part of the edge regions of the substrate material or it may be a continuous sheet or film of material which is attached to the second surface of the substrate materiai over at least a major part of said second surface. The support layer may extend beyond the edges of said substrate material at one or more edges. The support layer may form at least a part of a wall of the vessel or it may be releasably attached to an interior surface of the vessel. In a preferred form of the invention, the wound dressing system comprises a layer of cell culture substrate material which has a first surface to which cultured mammalian cells may attach and a second opposed surface which is releasably attached over at least the greater part of its second surface to the first surface of a continuous polymeric film which forms a support layer for the culture substrate. The second, opposed surface of the support layer is releasably attached to the interior surface of a cell culture vessel, e.g. a culture flask. The culture substrate may be attached to the interior surface of the culture vessel by any suitable means which enables the substrate to be removed from that surface without undue difficulty. Such means may include an adhesive material provided that the adhesive materiai is either not toxic to the cells to be grown or not exposed to those cells. Non-adhesive methods of attachment may be used and may be preferable so as to avoid introducing potentially cytotoxic materials into the vessel. Such non-adhesive means may include heat sealing, co-extrusion techniques, or lamination of the substrate to the vessel. The method selected must be chosen to suit the particular material being used. The culture substrate should preferably be attached to the interior surface of the vessel or support layer in such a way that at least a substantial part of it remains flat when cell culture liquid is introduced into the vessel. By this we mean that the surface of the culture substrate should not wrinkle or deform to allow bubbles of culture medium to form between the substrate and the vessel. This is because any undulations in the surface of the substrate may encourage cells to pool in regions of the substrate which are lower than others. In most cases this is undesirable although some cell culture techniques may favour or tolerate an uneven culture substrate. When the vessel is shaped as a cylinder, the culture substrate is attached around the cylindrical inner surface of the vessel so that it is not flat but curved. The above methods may also be suitable for bonding the culture substrate material to a support layer or bonding a support layer to the interior surface of a culture vessel. In an alternative form of cell culture system the wound dressing system comprises a support which comprises an engaging surface which may resiliently engage a corresponding surface disposed within the vessel. The engaging surface of either the support or the vessel may be a surface of a protrusion which extends away from the respective support or vessel. The other one of the engaging surfaces may form part of a groove. The support preferably comprises a layer of polymeric material formed to include a dressing support portion which, in use, contacts the wound dressing system and an engagement portion which includes the engaging surface. The support may further comprise handle means for gripping during disengagement of the support from the engaging surface of the vessel. The support may or may not be adhered to the wound dressing system. The support may serve to hold the wound dressing system in a flat configuration, e.g. against the base of the vessel. Alternatively the support may be adhered to at least a part of the wound dressing system, preferably in the region of the edges of the dressing system. The support may have the appearance of a frame or framework or may be otherwise configured to allow access to the culture substrate by a culture medium contained within the vessel. In one example of this form of system the vessel comprises a polygonal base having upwardly extending sidewalls, and, optionally, a lid. A support is formed from a semi-rigid layer of polymeric film which may have a similar polygonal shape and size as the base of the vessel. The support has a peripheral edge or flange which is raised, one part of which is extended to form a handle. A wound dressing system system which comprises a cell- culture substrate is removably secured to a surface of the support. The vessel comprises a lip or retaining rib which extends inwardly from the sidewalls around at least a part of the sidewalls. The support may be placed in the vessel such that its raised peripheral edge or flange locates beneath the retaining rib and thereby brings the engaging surface of the support into engagement with the engaging surface of the vessel. The dressing system may include markings to indicate the correct orientation of the culture substrate for placement on a patient. For example, the second, opposed surface of the culture substrate, or the support layer may be so marked e.g. by printing, embossing or by other means. Alternatively the support layer or the substrate material may be coloured. The dressing system may include a handle or tab on the culture substrate, support layer or both. More than one handle or tab may be present. The handle or tab may be located so as to enable the support layer or culture substrate to be removed from the vessel and/or to enable the support layer to be removed from the substrate. The tab or handle is preferably located at or near one or more edges of the support layer and/or culture substrate and is preferably designed to be gripped and pulled by the user. If the culture substrate is provided with a handle or tab then the handle or tab may be detachable. The handle or tab may be perforated in the region where it attaches to the culture substrate to enable the handle to be torn away, or alternatively the handle or tab may be reversibly adhered to the substrate or attached by mechanical means such as a clip. The handle or tab may be formed as an integral part of the support layer or substrate layer or may be formed separately and subsequently attached to the relevant part of the dressing system. The handle or tab may be coloured or otherwise marked to assist identification. The invention further provides a method of manufacturing a cell culture system comprising a vessel having a first part and a second part and a wound dressing system comprising a cell culture substrate material which is releasably secured to at least one of said first and second parts of said vessel, the method comprising the steps of: (a) forming said first part of said vessel, (b) forming said second part of said vessel, (c) forming said wound dressing system, (d) securing, by releasable means, said wound dressing system to said first part of said vessel and, (e) securing said first and second parts of said vessel together to form a liquid-tight vessel having said wound dressing system secured to an interior surface thereof. The first and second parts may be secured together by welding, adhesive, or by interference fit. Additional securing means may also be provided, such as clips, shrink-wrap, tape etc. Preferably the first and second parts are easily detachable from one another. The first and/or second parts may be formed by injection moulding, blow moulding, vacuum forming, pressure forming or other means such as extrusion, or a combination of any of these methods. The wound dressing system is secured to the first and/or second part of the vessel by releasable means such as lamination, including cold lamination, peelable adhesive or heat sealing. The invention will now be further described, by way of example only, with reference to the accompanying drawings, which are:- Fig. 1 An exploded perspective view of a first embodiment of a cell culture system according to the invention; Fig. 2 A perspective view of a part of the culture system shown in Fig. 1 ; Fig. 3 An exploded perspective view of a second embodiment of the invention; Fig. 4 A plan view of a part of the system shown in Fig. 3; Fig. 5 A cross-section along line 5-5 of Fig. 4; Fig. 6 An exploded perspective view of a third embodiment of the invention; Fig. 7 A plan view of a part of the system shown in Fig. 6 Fig. 8 A cross-section along line 8-8 of Fig. 7. Fig. 9 A perspective view of a further embodiment of the invention Fig. 10 A plan view of the system of Fig 9 Fig.11 A cross section along line 11-11 of Fig 10. Fig. 12 A perspective view of a part of a further embodiment of the invention. Fig. 13 A cross sectional view of the system shown in Fig. 12. In Fig. 1 , a cell culture flask 10 comprises a shallow base 11 and a deep "lid" 12. The lid 12 is moulded from a transparent grade of polystyrene which is not toxic to cells and has an upper wall 13 and a depending side wall 14. An access port 5 and closure 16 is located in the sidewall 14. Sidewall 14 includes a flange 17 around its lower peripheral edge. Shallow base 11 comprises a transparent film layer 18 which is at least as big as the area enclosed by peripheral flange 14 of the lid portion. Base 11 is formed from a relatively stiff polymeric film 19 such as 250μm thick polyethylene terephthalate to form a flat base for the flask. Base 11 is sealed to flange 14 of the lid portion to form a liquid-tight seal in such a way that it is peelable from flange 14 e.g. by heat sealing or by means of a peelable adhesive. A dressing system is peelably attached to film 19 as shown in Fig. 2a. The dressing system comprises a culture substrate 20 which forms a dressing and handle portion 21. The handle is detachable from the dressing by tearing along perforations 22 as shown in Fig. 2b. Dressing 20 has an upper surface i.e. the surface which is not adjacent film 19, to which cells may attach. This surface may comprise for example an ethylene vinyl acetate copolymer film which has been treated by corona discharge. Since only the surface of dressing 20 which is opposed to base 19 is to receive cells, the dressing may be a combination of more than one layer. The cell culture system is supplied with the dressing system attached to base film 19 of the flask 10 and base film 19 sealed to flange 17. The flask is sterilised. The flask is particularly suitable for and may be used in the preparation of a wound dressing which has a layer of cells attached to one surface, for a transfer of epidermal cells to areas of a patientin need. A suitable method of preparing such a dressing is described below. When a desired number of cells have attached to the dressing, the culture medium may be poured out of the vessel through port 15 and, if desired, the dressing system contained therein may be washed using e.g. normal saline solution. The base 19 may then be removed from the flask by peeling it away, giving access to the dressing system. Dressing 20 can then be removed from base film 19 by holding handle 21 and peeling. The dressing may then be applied to the patient, with the surface to which cells are attached facing towards the patient. Handle 21 may then be torn away along perforated line 22. Figs. 3-5 show a view of a second embodiment of the invention. In this form the vessel differs from that in Fig. 1 in that it includes a moulded base 23 which includes a raised portion 24 located in the central region of the base. Edge 25 of the raised portion is sized so as to form an interference fit around the lower edge 26 of sidewall 14 of the lid portion 12, such that the lower surface of flange 17 rests upon the edge region 27 of the base. Base 23 is moulded from a material which is not toxic to cells and which is preferably transparent. The dressing system 28 is located upon the raised central portion 24 of base 23 and comprises a dressing 20 having a handle region 21, and a support layer 29 in the shape of a frame. The support layer 29 is located between the dressing 20 and base 23. The support layer 29 is located between the dressing 20 and base 23. The support layer 29 includes a handle region 31. The dressing 20 is releasably attached to base 23 over its central portion in the area bounded by the frame 29, as shown in Fig. 5. The edges of dressing 20 are releasably attached to and supported by the frame 29. The flask is supplied with base 23 fitted in place to lid 12 by interference fit of edge 25 into wall 14. The edges of the flask are preferably shrink-wrapped or taped together to form a water-tight flask. When the dressing system is required to be removed for application to a patient, any overwrap is removed and the base 23 detached from lid 12, optionally using corners 30 as tabs or handles to assist in removal of base 23. The dressing system is then removed by lifting handles 21 and 31 and peeling dressing 20 away from base 23. The dressing may then be applied to a patient, by holding the frame uppermost and using it to manoeuvre the dressing onto the desired part of the body. Frame 29 and handle 21 may then be removed. The provision of a support layer 29 in this embodiment allows a more conformable and possibly delicate dressing 20 to be used because the dressing is held upon the support frame and thus is much less likely to wrinkle during application. Figs. 6-8 show a third embodiment of the invention. In this form, base 32, which is moulded from a suitable material, includes a lip 33 extending around the base adjacent the edge region 27 of the base. The outward-facing edge 25 of lip 33 forms an interference fit with wall 14 of lid portion 12 and, when together the edges may be further sealed by overwrapping with impermeable film, tape adhesive means, or heat sealing. The dressing system comprises a conformable dressing 20, having two handle portions 21 and a support layer 34 which is a continuous polymeric film (preferably transparent) which is relatively stiff compared with dressing 20. The support layer also has two handles 31 located beneath handles 21 of the dressing. The dressing 20 is releasably attached to support layer 34 in the region between the handles. Support layer 34 is releasably attached to base 32 at least in the region between handles 31. When the dressing system is ready to be removed from the flask, base 32 is detached from lid portion 12. The dressing system can then be removed from base 32 by pulling one of the handles 31 to lift the support layer 34, which carries dressing 20, away from the base. The handles 31 and 21 may then be used to assist in manoeuvring the dressing onto the patient and then support layer 34 is removed from the back of the dressing. Handles 21 may then be torn away from the remainder of dressing 20. In Figs. 9-11 a culture vessel 40 comprises a base 41 which has upwardly extending sidewalls 42 and a lid 43, which in this case is a transparent flexible film which is peelably adhered to a flange 44 extending outwardly from the sidewalls. A rib 45 extends from and around the interior surface of the sidewalls. A dressing system support 46 includes a relatively flat, dressing support portion 47 and a raised portion 48 extending around its peripheral edge. The support 46 is formed from a sheet of polymer which is semi-rigid, i.e, it can be deformed slightly by normal manual pressure. The support has a handle 49. A dressing system comprising a cell-culture substrate film 50 and a carrier layer 51 is laminated around its edges to the lower surface of the support 46. The cell-culture substrate 50 is exposed to the interior of the vessel 40 by means of a window extending through the support. The support is fitted into the vessel by locating raised edge 48 beneath rib 45 by deforming the support slightly. To remove the culture substrate, the peelable lid 43 is removed and, using handle 49, the support 46 carrying the dressing system is pulled away from rib 45. The dressing system may then be removed from the support 46 and applied to the patient. In Figs. 12 and 13, a support 52 comprises a dressing support portion 53 in the form of a frame disposed flat with respect to the base and a raised edge 54 which is angled slightly to form an obtuse angle with the dressing support portion. The frame and edge define a space through which nutrients etc may have access to a wound dressing system located beneath the support 52 The support is formed of resilient, semi rigid material such as a moulded polyester sheet. Base 55 includes a raised part 56 having an inwardly facing surface 57 which bears against the outward-facing surface 58 of edge 54 when the support is fitted to the base, as shown in Fig 13. Dressing system 59 is laid onto the central part of base 55 and held in place by support 53 being placed over the dressing system and held in place by the engagement between surfaces 57 and 58. Base 55 of course forms part of a vessel and may be integral with other parts of the vessel, e.g. sidewalls or may be assembled to the vessel separately. It will be appreciated that any of the flask embodiments described may be used with any of the dressing systems described. For example a dressing system incorporating a support layer may be attached to a peelable base. Any of the dressing systems shown may comprise one, two or no handles. Examples of manufacture and use of the invention are described below:- Example of preparation of a wound dressing A wound dressing having one surface to which cells are attached using a cell culture system according to the invention may be prepared as follows. A sample of human epidermal cells is prepared either from a biopsy of skin from the intended recipient of the dressing or from a commercial cell-line. A culture medium comprising Earle's Minimum Essential Medium (MEM) + 10% foetal calf serum was placed in a cell culture system vessel as described above. The vessel included a dressing system comprising a culture substrate materiai attached to the base of the vessel with a surface of the substrate material facing upwards into the vessel. The culture medium was made up as follows:- 348ml Earle's MEM (without L-glutamine), supplied by Gibco BRL 40 ml Heat-inactivated foetal calf serum 4 ml Penicillin/streptomycin (5000IU/ml-5000 μg/ml), supplied by Gibco BRL. 4 ml Non-essential amino acids. 4 ml L-glutamine (1 OOx) 299mM, supplied by Gibco BRL. Cells were then seeded into the medium at an approximate density of 10 6 cells per 3ml of medium. The vessel containing culture medium, cells and dressing system was then incubated at 37°C for 3 days in which time cells have attached to the cell-culture substrate material and have grown to sub-confluence. After this time, the culture medium was removed and the dressing system washed with saline solution. The dressing system was then removed from the vessel as described above. The dressing system thereby comprised a dressing comprising the culture substrate material which had a layer of cultured epidermal cells attached to one surface. Example of Manufacture of Cell Culture System. A vessel having a generally rectangular appearance and consisting of a flat rectangular wall and upstanding sidewalls is formed from rigid transparent polystyrene by injection moulding using suitable equipment familiar to those skilled in plastics processing. The moulded article includes an access port which is externally threaded to receive a screw top closure. The sidewalls include a flange extending outwardly from the edge of the sidewalls furthest from the flat wall. A peelable base for the flask is formed from 150μm thick "MELINEX" (trademark of ICI pic) PET film which is cut to size so as to be slightly larger in size than the area within the outer edge of the flange. A dressing system is formed by cutting a rectangular dressing shape from a sheet of ethylene-vinyl acetate film and forming a handle along one edge of the dressing by attaching a piece of adhesive tape to that edge. The dressing is then perforated along a line between the handle and the remainder of the dressing such that the handle may be detached by tearing along the perforated line. The dressing system is then attached to the PET base material by lamination. The peelable base PET is then adhered to the flange of the vessel using a peelable adhesive.

Claims: CLAIMS 1. A cell culture system comprising (a) a vessel having interior and exterior surfaces suitable for containing a liquid medium in which mammalian cells may be cultured; (b) a wound dressing system which comprises a culture substrate material which is not cytotoxic and having a first surface to which cultured mammalian cells may attach and a second, opposed surface; (c) means for releasably securing the dressing system to at least a part of the interior surface of the vessel such that the first surface of the substrate material is exposed to the interior of the vessel. 2. A cell culture system according to claim 1 wherein the means comprise an adhesive. 3. A cell culture system according to claim 2 wherein the adhesive means comprise a peelable adhesive. 4. A cell culture system according to claim 2 or 3 wherein the means are disposed on the second opposed surface. 5. A cell culture system according to claim 1 wherein the means comprise a heat seal. 6. A cell culture system according to claim 5 wherein the peripheral edge of the material is heat sealed to the part of the interior surface. 7. A cell culture system according to any preceding claim wherein the substrate material further comprises a handle portion. 8. A cell culture system according to claim 7 wherein the handle portion is detachable from the substrate material. 9. A cell culture system according to any preceding claim wherein the dressing system further comprises a support layer releasably attached to the culture substrate material. 10. A cell culture system according to claim 9 wherein the support layer is disposed on the second, opposed surface of the substrate material. 11. A cell culture system according to claim 9 or 10 wherein the support layer is in the form of a frame supporting the culture substrate material around at least a part of the edge regions of the substrate material. 12. A cell culture system according to claim 9 or 10 wherein the support layer is in the form a continuous sheet or film. 13. A cell culture system according to any of claims 9 to 12 wherein the support layer is releasably secured to part of the interior surface. 14. A cell culture system according to any preceding claim wherein the substrate materiai is a polyester, a polypropylene, a vinyl acetate blend or copolymer, a polyvinylidene chloride, a polystyrene, a polybutadiene or a polyethylene ionomer. 15. A cell culture system according to claim 14 wherein the vinyl acetate blend or copolymer is ethylene-vinyl acetate copolymer. 16. A cell culture system according to any of claims 1 to 13 wherein the substrate material is a hydrophilic polyurethane. 17. A cell culture system according to any preceding claim wherein the substrate material is a film. 18. A cell culture system according to any preceding claim wherein the first surface has been treated by corona discharge. 19. A cell culture system according to any of claims 1 to 17 wherein the first surface has been treated by plasma treatment. 20. A cell culture system according to any preceding claim wherein the substrate material is apertured. 21. A cell culture system according to any preceding claim wherein the vessel comprises at least first and second parts adapted to releasably fit together to form a substantially liquid-tight vessel. 22. A cell culture system according to claim 21 wherein the first part is a base and the second part is a lid. 23. A cell culture system according to claim 22 wherein the base comprises a lip formed around its periphery configured to form an interference fit with depending side walls of the lid. 24. A cell culture system according to claim 22 wherein the base comprises a raised central portion configured to form an interference fit with depending side walls of the lid. 25. The cell culture system according to claim 21 wherein the first part is peelable from the second part. 26. The cell culture system according to claim 25 wherein the first part is a lid and the second part is the base. 27. The cell culture system according to claim 25 wherein the first part is a base and the second part is the lid. 28. The cell culture system according to claim 25 wherein the first part is a wall of the vessel. 29. The cell culture system according to claim 28 wherein the culture substrate is disposed on the interior of the peelable wall. 30. The cell culture system according to claim 29 wherein the culture substrate comprises a support layer disposed on the second opposed surface which support layer is attached to the interior of the peelable wall. 31. The cell culture system according to claim 1 wherein the dressing system further comprises a support for supporting the culture substrate material which support comprises an engaging surface for resilently engaging a corresponding engaging surface disposed within the vessel. 32. The cell culture system according to claim 31 wherein the support comprise a dressing support portion for supporting the wound dressing system and an engagement portion comprising the engagement surface. 33. The cell culture system according to claim 31 or 32 wherein the engaging surface of either the support or vessel comprises a protrusion configured to engage the other one engaging surface. 34. The cell culture system according to any of claims 31 to 33 wherein the support has a raised peripheral edge one part of which is extended to form a handle. 35. The cell culture system according to claim 34 wherein the vessel comprises a retaining rib extending inwardly from the sidewalls of the vessel such that the raised peripheral edge locates beneath the retaining rib thereby bringing the engaging surface of the support into engagement with the engaging surface of the vessel. 36. The cell culture system according to claim 1 wherein the vessel comprises a raised central portion which defines an aperture in which the dressing system is received. 37. The cell culture system according to any of claims 31 to 36 wherein the support is disposed above the dressing system and holds the dressing system in a flat configuration against the base of the vessel. 38. A cell culture system according to any preceding claim wherein the vessel has a closable access port. 39. A cell culture system according to any preceding claim together with a batch of mammalian cells. 40. The use of a cell culture system according to any preceding claim. 41. A method of manufacturing a cell culture system comprising a vessel having a first and second part and a wound dressing system comprising a ceil culture substrate material which is releasably secured to at least one of the first and second parts of the vessel, the method comprising the steps of; (a) forming the first part of the vessel (b) forming the second part of the vessel (c) forming the wound dressing system (d) securing, by releasable means, the wound dressing system to the first part of the vessel and, (e) securing the first and second parts of the vessel together to form a liquid-tight vessel having a wound dressing system secured to an interior surface thereof

Inventors: BLOTT PATRICK LEWIS, DREWERY GEORGE ROBERT, MATTHEWS JANE BRIDGET, RICHARDSON MARK CHRISTOPHER, BLOTT, PATRICK, LEWIS, DREWERY, GEORGE, ROBERT, MATTHEWS, JANE, BRIDGET, RICHARDSON, MARK, CHRISTOPHER
Applicants: BLOTT PATRICK LEWIS, DREWERY GEORGE ROBERT, MATTHEWS JANE BRIDGET, RICHARDSON MARK CHRISTOPHER, SMITH & NEPHEW, BLOTT, PATRICK, LEWIS, DREWERY, GEORGE, ROBERT, MATTHEWS, JANE, BRIDGET, RICHARDSON, MARK, CHRISTOPHER, SMITH & NEPHEW, PLC
Application year: 1997
Main classification: C12M1
IPC codes: C12M1, C12M3