IMPLANTABLE SYSTEMS AND STENTS CONTAINING CELLS FOR THERAPEUTIC USES

Abstract

An implantable system includes cells that produce and release a therapeutic agent, or agents, to a host in need. The system can include cells capable of eluting therapeutic agents in response to changing physiological conditions within a host. The system may comprise naked cells, encapsulated cells, or a mixture of non-encapsulating and encapsulated cells. The system may also comprise cells, and/or cell groups, of different origins. The implantable device may be placed intra-vascular, within bone marrow, within soft tissue, in the peritoneal cavity, or intra-hepatic, etc. The system can be comprised of a stent, or like devices. Such stents and like devices may optionally include port(s), catheter(s), and containment envelope systems for holding the above cells.

Claims

1. A medical device for implantation in a living host, said device containing cell components for delivering therapeutic agents to the host comprising a carrier supporting a plurality of biologically active cell components protected from the host immune system, said cell components adapted to deliver therapeutic agents in response to a stimulus in the physiology of the host.

2. A medical device of claim 1 wherein said carrier comprises a tubular stent for implantation in a lumen of the host, said stent having a lumen-wall contacting surface for securing said stent in said lumen and a lumen-exposed surface permitting flow through the lumen, said cell components located on said stent.

3. A medical device of claim 2 wherein said tubular stent has a mesh structure, said mesh structure having a collapsed state and an expanded state.

4. A medical device of claim 2 wherein said tubular stent includes barbs extending from said lumen-wall contacting surface for engaging said lumen wall.

5. A medical device of claim 3 wherein said tubular stent is composed of a pervious polymer.

6. A medical device of claim 3 wherein said tubular stent is composed of a porous alginate.

7. A medical device of claim 2 wherein a porous containment envelop is attached within said tubular stent, said porous containment envelop composed of an immuno-barrier and said cell components are disposed within said containment envelop.

8. A medical device for implantation in a living host, said device containing cell components for delivering therapeutic agents to the host comprising an elongated catheter having a tip for insertion into a living host, side holes in said tip for communicating with said host, a porous sac attached to said tip enclosing said side holes and forming a containment envelop between said sac and said tip, biologically active cells disposed in said containment envelop, said biologically active cells adapted to elute therapeutic agents through said sac in response to a stimulus.

9. A medical device of claim 8 wherein said catheter is composed of two lumen, one of said lumen providing nutrient to said containment envelop and the other lumen for removing waste from said containment envelop.

10. A medical device of claim 8 wherein said catheter is connected to a port providing a transcutaneous passageway, said port having a base for attachment to the host, said port having an inlet covered with a diaphragm, said inlet connected to an outlet, said catheter connected to said outlet.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0044] FIG. 1 illustrates a collapsed stent preloaded with encapsulated cells for intra-arterial deployment and having a loop for retrievably, according to an embodiment of the invention.

[0045] FIG. 2 illustrates the stent of FIG. 1 in expanded form, deployment in a blood vessel.

[0046] FIG. 3 illustrates an expanded intravenous stent with a loop for retrievably and fixating barbs, with an outer wall of titanium or Gore-tex.

[0047] FIG. 4 illustrates an expanded retrievable bone, hepatic, and peritoneal cell transplantation module with fixation barbs and containing a sac of cells, where the sac is made of an alginate or a porous polymer, according to an embodiment of the invention.

[0048] FIG. 5 illustrates an inner cell containment reservoir, composed of a porous polymer or alginate material, according to an embodiment of the invention.

[0049] FIG. 6 illustrates an implantable port that provides transdermal access to an inner cell reservoir (such as that of FIG. 11) through a single lumen catheter, according to an embodiment of the invention.

[0050] FIG. 7 illustrates a singular port that is implantable in subcutaneous tissue and that serves to access, replenish, and/or drain a cell containment envelope, according to an embodiment of the invention.

[0051] FIG. 8 illustrates a dual port that allows for flushing and/or simultaneous infusion of therapeutic cells into a containment envelope while removing old cells or expended therapeutic agent, according to an embodiment of the invention.

[0052] FIG. 9 illustrates a non-coring transdermal needle placed in a port, replenishing a containment envelope with a therapeutic substance, or cells according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0053] The present invention provides implantable systems for the treatment (including prevention) of a variety of disorders, such as, diabetes, leukemias, immune disorders, metabolic disorders, malignancies, hormone disorders, arthritis, hypertension, etc. The implantable systems of the present invention include a delivery device 10 comprising a carrier (e.g., stents, vascular grafts, stent graphs) and cells 20 (e.g., encapsulated cells, non-encapsulated cells, engineered cells), which can optionally be enclosed within containment vehicles 30. Such cells 20 are capable of responding to changing conditions within a host and producing one or more therapeutic agents in response to such conditions. The produced agents may have a therapeutic, preventative, or disease-modifying effect on the host.

[0054] The therapeutic agents are released from the cells of the delivery device upon the receipt of a stimulus, or contact of an endogenous signal or chemical, from the host (changes in blood glucose concentrations, changes in blood levels of a hormone, metabolic signaling agent, chemical signaling molecules, etc).

[0055] Cells 20 suitable for use in the present invention include a wide variety of cells that produce therapeutic agents. Such cells are able to secrete these agents upon the receipt of an endogenous signal received by the host. Suitable cells for use in the present invention typically include islets cells, endocrine cells, immune system cells, bone marrow cells, thyroid cells, mast cells, dermal cells, nervous system cells, skin cells, and other cells that would be recognized by one of skill in the art, whether they are autologous or allogeneic, genetically engineered or nonengineered. Mixtures of such cells can also be used.

[0056] There are a variety of disorders that can be treated using the systems and devices of this invention. Examples of these disorders include, but are not limited to: metabolic disorders, diabetes, arthritis, hypertension, nervous system disorders, immune system disorders, chronic pain, endocrine disorders, inflammations, amyloidosis, acute leukemias, chronic leukemias, myelodysplastic syndromes, stem cell disorders, myeloproliferative disorders, lymphoproliferative disorders, phygocyte disorders, inherited metabolic disorders, histiocytic disorders, erythrocyte abnormalities, immune disorders, platelet abnormalities, plasma cell disorders, malignancies (breast carcinoma, Ewing Sarcoma, neuroblastoma, renal cell carcinoma, etc.), hypothyroidism, hypoituitarism, hypogonadism, graph failure, graph versus host disease (GVD), veno-occlusive disease, Side effects form pre-transplant chemotherapy (mouth sores, hair loss, pancytopenia, neutropenia, infections, bleeding, infertility, cataracts, renal as well as lung and heart complications, and recurrent disease), and other disorders and diseases that would be recognized by one of skill in the art.

[0057] Therapeutic agents can be secreted by the cells contained in the devices described herein. Such cells are referred to herein as drug-eluting cells. Such cells may be useful for a wide-variety of functions such as: delivering pharmacoactive substances for treatment of local, regional, or systematic disease; promoting new cell production; adding to a depleted marrow cell line; activating cell function; buffering or blocking a specific cell dysfunction; altering, treating or influencing oncogenesis; contributing to enhancement of a local cell population; gene therapy; tumor specific vaccinations; delivering of a specific radionuclide labeled therapeutic agent (resulting in more efficacious local radiation dose with fewer or no systemic side effects; delivery of therapeutic agent to the epicenter of a tumor, and other functions as would be recognized by one of skill in the art.

[0058] The drug-eluting cells can be incorporated into the carrier 11 or incorporated into the coating of the device or stent. They can also be included within a containment apparatus 30. The apparatus can be coated on the carrier or incorporated into the carrier of the device or stent. The cells can be induced to release one or more therapeutic agents in response to a signal from the host. Such signals can embody a wide variety of physiologic events, chemicals, signaling agents, cellular messengers, inputs, etc. as would be appreciated by one of skill in the relevant art.

[0059] The modules and devices 10, shown in FIG. 1-4, herein can be percutaneously introduced using known and common radiological techniques and imaging devices (fluoroscopy, CAT scans, MRI, etc). The radiopaque nature of the devices described herein allows for follow-up imaging. The composition of the devices (e.g., titanium) allows for a biocompatible, nonferromagnetic structure. Implantation techniques may only require a simple local anesthetic and can be performed in minutes. The containment function of the module avoids rapid decrease in function and or cell population. Thus, the structural and unit integrity of the transplanted material is maintained. The required therapeutic response can be enhanced or altered by removal, replacement or addition of other modules as needed.

[0060] As used herein, a delivery device 10 includes: cells that produce one or more therapeutic agents, a carrier (e.g., stent, stent graph, vascular graft, bone graft, hepatic graph, etc.), optional containment vehicles, and other, optional, therapeutic and, or, non-therapeutic materials.

[0061] The term stent 11 refers to any device capable of being placed into contact with a wall of lumen L. FIG. 1 illustrates a collapsed stent according to an embodiment of the invention. The inner layer 13 of the stent can be made of a titanium mesh, for example. The outer layer 12 of the stent can also be a titanium mesh, or it can be made of pervious Gore-tex or other suitable material. Such a stent can be used for intra-arterial deployment in an embodiment of the invention. The diameter of the collapsed stent can be approximately 2-5 mm. FIG. 2 illustrates the stent of FIG. 1, in expanded form, as deployed in an artery lumen L. In an embodiment of the invention, the stent is pre-loaded with pancreatic islet cells.

[0062] Generally, when the device is shaped like a stent, it is designed in a tube-like fashion and has a lumen wall-contacting surface 12 and a lumen-exposed surface 13. The lumen-wall contacting surface is the outside surface of the tube while the lumen-exposed surface is the inner surface of the tube. After insertion by catheter, in a lumen L, the collapsed mesh tube, shown in FIG. 1, is expanded, as by a balloon, to remain in the lumen, as shown in FIG. 2. The stent may have a loop 14 for retrieving and/or fixing in place. Also, for positioning and retention, the stent may have barbs 15 that embed in the lumen walls. FIG. 3-4 illustrate an embodiment of the invention featuring pre-loaded encapsulated calls and fixation barbs 15 usable in hepatic and bone implantation. As before, both inner and outer lattices can be made of titanium.

[0063] The stent can generally include metallic or polymeric elements, or be combinations thereof. One of skill in the art can use of many varied materials to build a device, or devices, that can be used in the present invention.

[0064] FIG. 4 illustrates an expandable retrievable module for bone, hepatic, or peritoneal cell implantation. The module contains a sac 30 of cells. The sac 30 can be made of an alginate or a porous polymer material 31. Fixation barbs 15 are also shown and such barbs would be useful for bone or hepatic implantation.

[0065] As used herein the term port 40 refers to the device that allows transdermal infusion if cells, cell substrates, therapeutic agents, etc. into a reservoir or containment envelope within the devices or stents of the present invention. Such ports can be dual 41 or single 40. The dual port system 41 allows for the addition, or deletion of, cells, cell substrates, or therapeutic agents. The ports can be placed within the subcutaneous tissues S and therefore eliminate the need for trans-corporeal component(s). The ports can be made of plastic, titanium, or other materials known in the art and may optionally have a transdermal puncture piercing into the port by way of a traversing diaphragm 43.

[0066] As used herein the term catheter 50 refers to a device that is capable of communicating with the devices, port(s), stents, and containment device(s) as described herein. Intravascular placement can be performed via a femoral, jugular, cephlic, basilic, or subclavian venous approach. The catheter(s) tip 52 can be placed, among other locations, in major venous structure(s) such as the inferior vena cava or superior vena cava. The catheter 50 may be secured to the port 40 at the outlet 42.

[0067] As used herein the term containment envelope 32 refers to a structure that can be used as part of, or with, the devices, catheter(s) or stents of the present invention. The containment envelopes 32 can be composed of a porous polymer, alginate, or other materials known to one of skill in the art. Typically, such envelopes comprise a space that is created between the catheter's outer wall 51 and the containment envelope's inner wall 33. The space is where the cells, cellular components, or therapeutic agents rest. The containment envelope optionally creates an immuno-barrier capable of shielding contained cells from the host's immune system, while allowing for exchange of nutrients to the contained cells from surrounding body fluids. The containment envelope can also be referred to as a containment vehicle or reservoir.

[0068] In one embodiment of the invention, a stent may have cells that can be replenished. A sac 30 is located within the stent to be replenished by catheter. The reservoir can be made of a porous polymer or alginate material. The porous reservoir allows the transfer of nutrients from the surrounding medium to the cells, and permits the release of cells wastes through the reservoir wall.

[0069] In the illustrated embodiment of FIG. 6-7, an approximate rectangular base 44 is shown surrounding the port, and features perforations 45 around the perimeter of the base to allow suturing to subcutaneous tissue S. The catheter 50 is shown attached to the port at one end. The opposite end of the catheter connects to the reservoir shown in FIG. 7-9. The reservoir may in turn reside in a stent.

[0070] In an alternative embodiment of the invention, a dual port 41, shown in FIG. 8, can be used instead of a singular port. This configuration allows simultaneous access to the reservoir from two separate points. The dual port allows for flushing and/or simultaneous infusion of therapeutic cells into the reservoir while removing old cells or expended therapeutic agent. The dual port embodiment can be connected to a double lumen catheter 52. In this illustration, the catheter on the right is used for the provision of new cells into a reservoir. This process is facilitated by a presence of openings, or sideholes, 53 in the lower end of the catheter, such that cells can flow from the catheter on the right through the openings into the reservoir. The catheter on the left can be used to remove old cells or expended therapeutic agent. The removal process is likewise facilitated by the presence of openings 54 in the lower end of the catheter on the left. In the illustrated embodiment, the reservoir can be pre-loaded with cells prior to implantation.

[0071] FIG. 9 illustrates the use of a non-coring transdermal needle 60 in the port assembly 40. The needle can be used to replenish the reservoir or containment envelope at the distal end of the catheter. This assembly can be deployed, for example, with the catheter tip in the superior vena cava.