Apparatus and method for preparing tissue implants and devices, more particularly apparatus and method for processing tissue parts of an implant differently.
Various orthopedic procedures include replacing damaged native tissue with a tissue implant or device procured from another source. For instance, in a wide variety of procedures, autografts, allografts, and/or xenografts may be used to affect repair, replacement, or augmentation of damaged or otherwise non-functioning tissue within a patient. Prior to use within a patient, however, the tissue implant will typically be treated or processed to make the implant more suitable for implantation into the patient. In this regard, tissue implants may be subjected to processing to remove undesired tissue parts or components while maintaining desired tissue parts or components. For example, a tissue implant may be treated to remove fat and bone marrow tissue while maintaining the bone portion of the implant. The preparation of the tissue implants may be achieved through various processes including physical scrubbing, chemical treatment, or other processes known in the art.
One drawback of current processes for preparing tissue implants is that the processes are directed primarily to the preparation of homogeneous tissue implants, i.e., implants having a single type of tissue. In other words, the current processes maintain the desired tissue part but remove or effectively eliminate the functional aspects of other tissue parts surrounding the desired tissue part. Many orthopedic tissues, however, are inhomogeneous and have multiple tissue parts with distinctive physical, chemical, and biological properties, and which are desirable for certain types of tissue implants. Examples of such inhomogeneous tissue parts include bone-tendon-bone, osteochondral plugs, the meniscus with its red and white zones, and others. Treatment of inhomogeneous tissue parts using current processes destroy or severely diminish the unique properties of the tissue parts for which the processing method is not directed. By way of example, processing bone parts to remove fat and bone marrow tissue may diminish the usefulness of cartilage and tendons associated with the bone parts, even though the cartilage and tissue may be desired for the tissue implant.
Therefore, there is a need for improvements in a method and apparatus for preparing an inhomogeneous tissue implant so as to preserve the unique properties of multiple tissue parts.
Method and apparatus for differentially processing multiple tissue parts to preserve the properties of each of the tissue parts. In one embodiment, a method of preparing an implantable biological device having at least a first biological tissue part and a second biological tissue part includes exposing the first biological tissue part to a first preparation method and simultaneously substantially preventing exposure of the second biological tissue part to the first preparation method. In this embodiment, such is achieved by embedding the second biological tissue part in a material that substantially prevents exposure of the second biological tissue part to the first preparation method. The embedding material may include a gas, liquid, solid and/or a semi-solid. More particularly and without limitation, the embedding material may include wax, polystyrene, poly(methyl methacrylate), poly-alginate, agarose gel, combinations of these materials, and other materials. The method may further include exposing the second biological tissue part to a second preparation method, and in addition simultaneously substantially preventing exposure of the first biological tissue part to the second preparation method by embedding the first biological tissue part in a material that substantially prevents exposure of the first biological tissue part to the second preparation method. In one embodiment, the first tissue part is bone and the second tissue part may be cartilage, tendon, ligament, meniscus, periosteum, muscle, and/or other tissue parts. In another embodiment, the first and second tissue parts may be different sections of a homogeneous tissue.
In another embodiment, a method of preparing an implantable biological device having at least a first biological tissue part and a second biological tissue part includes exposing the first biological tissue part to a first preparation method and simultaneously substantially preventing exposure of the second biological tissue part to the first preparation method. In this embodiment, such is achieved by coating the second biological tissue part with at least one material that substantially prevents exposure of the second biological tissue part to the first preparation method. The coating material may include without limitation wax, polystyrene, poly(methyl methacrylate), combinations of these materials, and other materials. The method may further include exposing the second biological tissue part to a second preparation method, and in addition simultaneously substantially preventing exposure of the first biological tissue part to the second preparation method by coating the first biological tissue part in a material that substantially prevents exposure of the first biological tissue part to the second preparation method. In one embodiment, the first tissue part is bone and the second tissue part may be cartilage, tendon, ligament, meniscus, periosteum, muscle, and/or other tissue parts. In another embodiment, the first and second tissue parts may be different sections of a homogeneous tissue. In addition, the coating(s) may be selectively permeable to at least one component of a reagent used in the first and/or second preparation method.
In another embodiment, a method of preparing an implantable biological device having at least a first biological tissue part and a second biological tissue part includes exposing the first biological tissue part to a first preparation method and simultaneously substantially preventing exposure of the second biological tissue part to the first preparation method. In this embodiment, such is achieved by covering the second biological tissue part with a cover that substantially prevents exposure of the second biological tissue part to the first preparation method.
In one embodiment, the cover may include a first open end and a second closed end to define an interior cavity. The second biological tissue part may be disposed in the interior cavity of the cover and the first end of the cover sealed to substantially enclose the second tissue part inside the cover. The method may further include maintaining at least one preparation solution in the interior cavity of the cover. The cover may be selectively permeable to at least one component of a reagent(s) used in the first preparation method, or may be impermeable to reagent(s) used in the first preparation method.
In an alternate embodiment, the cover may include a first open end and a second open end to define an interior passage. The second biological tissue part may be disposed in the interior passage of the cover and the first and second ends of the cover sealed to substantially enclose the second tissue part inside the cover. The method may further include maintaining at least one preparation solution in the interior passage of the cover. The cover may be selectively permeable to at least one component of a reagent used in the first preparation method or be impermeable to the reagent used in the first preparation method. In the embodiments employing a cover, the first tissue part may be bone and the second tissue part may be cartilage, tendon, ligament, meniscus, periosteum, muscle, and/or other tissue parts. Alternatively, the first and second tissue parts may be different components of a homogeneous tissue. In addition, the method may further include exposing the second biological tissue part to a second preparation method, and in addition simultaneously substantially preventing exposure of the first biological tissue part to the second preparation method by covering the first biological tissue part in a material that substantially prevents exposure of the first biological tissue part to the second preparation method.
In another embodiment, a method of preparing an implantable biological device having at least a first biological tissue part and a second biological tissue part includes exposing the first biological tissue part to a first preparation method and simultaneously substantially preventing exposure of the second biological tissue part to the first preparation method. In this embodiment, such is achieved by positioning the first biological tissue part in a first chamber of an enclosure, and positioning the second biological tissue part in a second chamber of the enclosure that is substantially isolated from the first chamber. For example, the first biological tissue part may be exposed to a first processing reagent within the first chamber of the enclosure and the second biological tissue part may be exposed to a second processing reagent within the second chamber of the enclosure. Moreover, the temperature, pressure, and/or the concentration of the first and/or second reagents may be varied or otherwise manipulated in the respective first and/or second preparation methods. When temperature is manipulated in the first and/or second preparation methods, the first and second chambers may be thermally isolated from each other. In one embodiment, the first tissue part may be bone and the second tissue part may be cartilage, tendon, ligament, meniscus, periosteum, muscle, and/or other tissue parts. In another embodiment, the first and second tissue parts may be different components of a homogeneous tissue.
In one embodiment, an apparatus for preparing an implantable biologic device in a manner previously described includes an enclosure having a first chamber and a second chamber separated by a partition member that substantially isolates the chambers from one another. The partition member includes at least one aperture adapted to receive an implantable biological tissue having a first tissue part and a second tissue part. The biological tissue is received in the aperture so that a substantial portion of the first tissue part is within the first chamber and a substantial portion of the second tissue part is within the second chamber. Each of the first and second chambers includes an inlet and an outlet for exposing the respective tissue parts to at least one processing reagent, which may be the same or different for each chamber. The apparatus may further include a thermal control unit coupled to one or both chambers for controlling the temperature of the first and/or second reagent(s). A pump may also be operatively coupled to one or both chambers for controlling the pressure of the first and/or second reagent(s). The apparatus may further include valves for controlling the flow rate of the processing reagent(s) through the chambers.
In addition to exposing the tissue parts to reagents, the first and/or second preparation methods may include other processing steps. By way of example and without limitation, the first and/or second preparation methods may include agitation (e.g., shaker, vortex, tilt table), exposure to light/dark conditions (e.g., exposure to UV light), chemical crosslinking and/or other standard tissue processing steps.
These and other embodiments will become more readily apparent to those of ordinary skill in the art upon review of the following detailed description taken in conjunction with the accompanying drawings.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the summary given above, and the detailed description given below, serve to explain the invention.
Embodiments include methods and apparatus for preparing or processing an implantable biologic device having multiple tissue parts. For example,
In addition, the tissue implants are not limited to consisting of only biologic tissue, but may include artificial or synthetic components as well. Thus, a tissue implant as used herein may encompass not only natural/biologic implants but also hybrid implants having both biologic tissue and other artificial/synthetic components. By way of example, one such hybrid implant, as disclosed in WO 2007/025290 and assigned to the assignee of the present application, includes a tissue graft coupled to or grown on an artificial porous surface. Another hybrid implant may include a synthetic bone material, such as calcium phosphate, calcium sulfate, or the like, coupled to a soft tissue graft, such as tendon or ligament, to serve as an anchor.
The embodiments described below generally follow a similar algorithm for preparing the tissue implant.
In one embodiment, the embedding material 40 is a solid or semi-solid material such as, for example, wax, polystyrene, poly(methyl methacrylate), poly-alginate, agarose gel, combinations thereof, and other materials known to those of ordinary skill in the art. In addition, the embedding material 40 is not limited to a solid or semi-solid material but may also include a fluid (e.g., liquid or a gas). For example, one part of the tissue may be immersed in a liquid while the other part may be in another liquid that is immiscible with the first liquid (e.g., the first liquid is polar and the second is non-polar). As explained below, in some embodiments the embedding material 40 may be substantially non-reactive with the second tissue part 14 and which substantially prevents the second tissue part 14 from exposure to the first preparation method. It also may be desirable to employ an embedding material 40 that is relatively easy to remove (e.g., by physical or chemical means) from the second tissue part 14.
With the second tissue part 14 embedded in the material 40 and the first tissue part 12 positioned within the cavity 32, the first tissue part 12 may be processed using a first preparation method. For example, a processing reagent 42, such as acidic solution, base solution, detergents, organic solvent and enzyme solution, etc., may flow through the cavity 32 via the fluid inlet and outlet 34, 36, respectively, so as to treat the first tissue part 12. While container 30 includes an inlet and outlet that permits a fluid to flow through the cavity 32, the invention is not so limited as the inlet and outlet may be omitted and the container 30 adapted to hold or contain processing reagent 42 without flow-through capability. As noted above, the embedding material 40 protects the second tissue part 14 and substantially prevents exposure of the second tissue part 14 to the first preparation method. Thus, for example, the processing reagent 42 is not capable of substantially penetrating the embedding material 40 so as to reach and/or react with the second tissue part 14. After the first tissue part 12 has been treated for implantation, the second tissue part 14 may be removed from the embedding material 40. By way of example and without limitation, the embedding material 40 may be peeled from the implant 10, washed or dissolved using suitable solvents or solutions that are substantially non-reactive with the tissue implant in total or in part (e.g., water, salt solution, alcohol, chloroform, acetone, MeCl2), melted off the implant 10 using low heating that is not detrimental to the implant, combinations thereof, or other ways known to those of ordinary skill in the art.
Depending on the specific application, and as shown in
While the embedding materials 40, 44 were described above as being substantially non-reactive with the second tissue part 14 and first tissue part 12, respectively, the invention is not so limited. In particular, the embedding materials 40, 44 may include one or more components that treat the tissue parts embedded therein. Thus, for example, the embedding material 40 may include a component that treats the second tissue part 14 as the first tissue part 12 is being processed by the first preparation method. Likewise, the embedding material 44 may include a component that treats the first tissue part 12 as the second tissue part 14 is being processed by the second preparation method.
In one embodiment, the coating material 50 may be a solid or semi-solid material such as, for example and without limitation, wax, polystyrene, poly(methyl methacrylate), combinations thereof, and other materials known to those of ordinary skill in the art. As explained below, any suitable coating material 50 may be used which of itself is substantially non-reactive with the second tissue part 14 and which substantially prevents the second tissue part 14 from exposure to the first preparation method. In addition, the coating material 50 should be relatively easy to remove from the second tissue part 14. Moreover, the coating material 50 may be applied to the second tissue part 14 in any manner known to those of ordinary skill in the art. For example and without limitation, the coating material 50 may be sprayed on, brushed on, applied by dipping, etc. The coating material may have a typical thickness of 1 nm to 10 mm, but preferably less than 1 mm.
With the second tissue part 14 coated by the material 50 and the tissue implant 10 positioned within the cavity 32, the first tissue part 12 may be processed using a first preparation method. For example, a processing reagent 42, such as acidic solution, base solution, detergents, organic solvent and enzyme solution, etc., may flow through the cavity 32 via the fluid inlet and outlet 34, 36, respectively, so as to treat the first tissue part 12. While container 30 includes an inlet and outlet that permits a fluid to flow through the cavity 32, the invention is not so limited as the inlet and outlet may be omitted and the container 30 adapted to hold or contain processing reagent 42 without flow-through capability. As noted above, the coating material 50 protects the second tissue part 14 and substantially prevents exposure of the second tissue part 14 to the first preparation method. Thus, for example, the processing reagent 42 is not capable of substantially penetrating the coating material 50 so as to reach and/or react with the second tissue part 14. After the first tissue part 12 has been treated for implantation, the coating material 50 may be removed from the second tissue part 14. By way of example and without limitation, the coating material 50 may be peeled from the implant 10, washed or dissolved using suitable solvents or solutions that are substantially non-reactive with the tissue implant in total or in part (e.g., water, salt solution, alcohol, chloroform, acetone, MeCl2), melted off the implant 10 using low heating that is not detrimental to the implant, combinations thereof, or other ways known to those of ordinary skill in the art.
Depending on the specific application, and as shown in
While the coatings 50, 52 were described above as being substantially non-reactive with the second tissue part 14 and first tissue part 12, respectively, the invention is not so limited. In particular, the coatings 50, 52 may include one or more components that treat the tissue parts that are coated. Thus, for example, the coating material 50 may include a component that treats the second tissue part 14 as the first tissue part 12 is being processed by the first preparation method. Likewise, the coating 52 may include a component that treats the first tissue part 12 as the second tissue part 14 is being processed by the second preparation method.
In one embodiment, the cover 56 includes a first open end 58 and a second closed end 60 that defines an interior cavity 62. The cover 56 may be made from a material that is substantially non-reactive with the second tissue part 14 and which substantially prevents the second tissue part 14 from exposure to the first preparation method. For example and without limitation, the cover 56 may be formed from a material that is resistant to the aforementioned processing reagents or impermeable by big molecules (e.g., enzymes) or hydrophobic. The second tissue part 14 may be inserted into the cover 56 via the open end 58 and the open end 58 closed about the tissue implant 10 to form a seal thereat. For example, a clip 64, such as an elastic band, may be used to secure the cover 56 to the tissue implant 10 and form a seal along open end 58. Alternatively, a sealant, such as polyurethane or silicone, may be used to form the seal along open end 58. Those of ordinary skill in the art will recognize other ways to secure the cover 56 to the tissue implant 10 and form a seal therewith. The clip, sealant or other sealing elements also may be substantially non-reactive with the tissue and/or processing reagent(s) with which it is used.
With the second tissue part 14 disposed in the interior cavity 62 of cover 56 and the first tissue part 12 external to the cover 56, the tissue implant 10 may be positioned within the cavity 32 and the first tissue part 12 processed using a first preparation method. For example, a processing reagent 42, such as acidic solution, base solution, detergents, organic solvent and enzyme solution, etc., may flow through the cavity 32 via the fluid inlet and outlet 34, 36, respectively, so as to treat the first tissue part 12. While container 30 includes an inlet and outlet that permits a fluid to flow through the cavity 32, the invention is not so limited as the inlet and outlet may be omitted and the container 30 adapted to hold or contain processing reagent 42 without flow-through capability. As noted above, the cover 56 protects the second tissue part 14 and substantially prevents exposure of the second tissue part 14 to the first preparation method. Thus, for example, the processing reagent 42 is not capable of substantially penetrating the cover 56 so as to reach and/or react with the second tissue part 14. After the first tissue part 12 has been treated for implantation, the cover 56 may be removed from the second tissue part 14 by, for example, removing the clip 64 or removing the sealant from the open end 58.
Depending on the specific application, and as shown in
In one embodiment, the interior cavity 62 of the cover 56 (
In one embodiment, the cover 78 includes a first open end 80 and a second open end 82 that define an interior passage 84. The cover 78 may be made from a material that is substantially non-reactive with the second tissue part 14 and which substantially prevents the second tissue part 14 from exposure to the first preparation method. For example and without limitation, the cover 78 may be formed from a material that is resistant to the aforementioned processing reagents or impermeable by big molecules (e.g., enzymes) or hydrophobic. The second tissue part 14 may be inserted in the interior passage 84 of the cover 78 via one of the open ends 80, 82 and each of the open ends 80, 82 closed about the tissue implant 72 to form a seal thereat. For example, a clip 64 may be used to secure the cover 78 to the tissue implant 72 and form a seal along open ends 80, 82. Alternatively, a sealant, such as polyurethane or silicone, may be used to form the seal along open ends 80, 82. Those of ordinary skill in the art will recognize other ways to secure the cover 78 to the tissue implant 10 and form a seal therewith. The clip, sealant or other sealing elements may be substantially non-reactive with both the tissue and processing reagent(s) with which they are used.
With the second tissue part 14 disposed in the interior passage 84 of cover 78 and the first tissue parts 12 external to the cover 78 and positioned within the cavity 32, the first tissue parts 12 may be processed using a first preparation method. For example, a processing reagent 42, such as acidic solution, base solution, detergents, organic solvent and enzyme solution, etc., may flow through the cavity 32 via the fluid inlet and outlet 34, 36, respectively, so as to treat the first tissue part 12. While container 30 includes an inlet and outlet that permits a fluid to flow through the cavity 32, the invention is not so limited as the inlet and outlet may be omitted and the container 30 adapted to hold or contain processing reagent 42 without flow-through capability. As noted above, the cover 78 protects the second tissue part 14 and substantially prevents exposure of the second tissue part 14 to the first preparation method. Thus, for example, the processing reagent 42 is not capable of substantially penetrating the cover 78 so as to reach and/or react with the second tissue part 14. After the first tissue part 12 has been treated for implantation, the cover 78 may be removed from the second tissue part 14 by, for example, removing the clip 64 or removing the sealant from the open ends 80, 82.
Depending on the specific application, and as shown in
In one embodiment, the interior passage 84 of the cover 78 (
Though the tri-section tissue implant 72 described above was differentially processed using a covering technique, such tri-section tissue implants, or tissue implants with even more sections, may be differentially processed using any of the techniques described herein (e.g., embedding, covering, coating, and/or isolating).
With the first tissue part 12 substantially disposed in the first chamber 94 and the second tissue part 14 substantially disposed in the second chamber 96, the first tissue part 12 may be processed using a first preparation method and the second tissue part 14 may be processed using a second preparation method. For example, a first processing reagent 116, such as acidic solution, base solution, detergents, organic solvent and enzyme solution, etc., may flow through the first chamber 94 via the fluid inlet and outlet 100, 102, respectively, so as to treat the first tissue part 12. In a similar manner, a second processing reagent 118, such as acidic solution, base solution, detergents, organic solvent and enzyme solution, etc., may flow through the second chamber 96 via the fluid inlet and outlet 104, 106, respectively, so as to treat the second tissue part 14. Flow of the first and second processing reagents through the first and second chambers may be simultaneous or sequential, continuous or discontinuous in various embodiments. While each of the chambers 94, 96 includes an inlet and outlet that permits a fluid to flow through the chambers, the invention is not so limited as the inlets and outlets may be omitted and the chambers adapted to hold or contain processing reagents 116, 118 without flow-through capability. As noted above, the chambers 94, 96 are sealed at the partition member 98 so that the first tissue part 12 is not substantially exposed to the second preparation method and the second tissue part is not substantially exposed to the first preparation method. Such an apparatus 90 allows the first and second tissue parts 12, 14 to be prepared, at least in part, essentially at the same time. Those of ordinary skill in the art will recognize, however, that the tissue implant 10 may be processed sequentially in apparatus 90.
The apparatus 90 may further include additional elements for implementing the first and second preparation methods. For example, the first and/or second preparation methods may include varying or otherwise manipulating the pressure, temperature, concentration, and/or flow rate of the processing reagents 116, 118 through the chambers. To this end, the apparatus 90 may include a pump 120 associated with at least one and preferably both of the inlets 100, 104 to the first and second chambers 94, 96. The pump(s) 120 are capable of regulating the pressure of the processing reagents 116, 118 in the first and/or second chambers 94, 96. The apparatus 90 may also include a thermal control unit 122 associated with at least one and preferably both of the chambers 94, 96 for controlling the temperature of the first and/or second processing reagents 116, 118. The thermal control unit 22 includes a heat-generating element (not shown), such as a heating coil, for selectively heating the reagents in the first and/or second chambers 94, 96. The thermal control unit 22 may also include a temperature sensor (not shown) for monitoring the temperature of the first and/or second reagents and controlling the heat-generating element to maintain a desired temperature. The thermal control unit 22 may further include a capacity to cool the processing reagents in the first and second chambers 94, 96. Such thermal control units 22 are generally well known in the art. When temperature is manipulated as an aspect in either the first or second preparation method, the partition member 98 and/or sealing rings 114 may be made of a low thermally conductive material (i.e., an insulator) so as to minimize any heat transfer between the first and second chambers 94, 96.
To control the flow of the processing reagents 116, 118 through the chambers 94, 96 the apparatus 90 may further include a valve 124 coupled to at least one of the inlet or outlet of each of the chambers 94, 96. By adjusting the valves 124 between opened and closed positions, the flow rate of the processing reagents 116, 118 may be varied depending on the specific preparation method being used on the tissue parts. Such valves are also well known in the art. Moreover, as noted above, the concentration of components of the processing reagents 116, 118 may be varied depending on the specific preparation method being used. Accordingly, the fluid inlets 100, 104 to the chambers 94, 96 may be in fluid communication with a fluid reservoir 126, 128, respectively, that holds the processing reagents 116, 118 with the desired components and at the desired concentrations, or at bulk concentrations for achieving desired dilutions with water buffer solutions, alcohol, or other diluents.
While the present invention has been illustrated by a description of various preferred embodiments and while these embodiments have been described in detail, it is not the intention of the inventors to restrict or in any way limit the scope of the appended claims to such detail. While the embodiments described herein show a tissue implant having a first and second tissue part, the invention is not so limited. Embodiments of the invention may be used to prepare tissue implants with more than two tissue parts, with each part having a corresponding preparation method. Those of ordinary skill in the art will recognize how to modify the embodiments described herein to accommodate additional tissue parts. For example, the enclosure shown in
Furthermore, the various techniques, i.e., embedding, covering, coating, and isolation, may be used in various combinations to prepare a tissue implant. Also, while many of the apparatus shown and described herein illustrates only one tissue implant being processed, those of ordinary skill in the art will recognize that the apparatus may be configured to hold multiple tissue implants. Thus, additional advantages and modifications will readily appear to those skilled in the art. The various features of the invention may be used alone or in numerous combinations depending on the needs and preferences of the user.