Abstract:
A medical device includes a carrier and an agent. The agent is formulated to control inflammation of biological tissue, such as heart tissue, and is releasably coupled to the carrier. The carrier is configured to be disposed in operative proximity to the biological tissue to be treated by the agent. In one embodiment, the carrier is configured to release the agent or otherwise deliver the agent to the biological tissue, thus controlling inflammation of the tissue. Also, a method to improve healing of biological tissue includes placing a medical device proximate to the heart of a patient, where the medical device has a carrier and an agent configured to control inflammation, the agent is releasably coupled to the carrier. In one embodiment, the method includes causing the agent to be released from the carrier.

Description:
BACKGROUND 
       [0001]    This invention relates generally to a medical device, and particularly to a medical device configured to be placed in or near the heart. This invention also relates to a method to improve healing of tissue. 
         [0002]    Inflammation is a natural and necessary part of a body&#39;s healing process. However, this process has been increasingly linked with pathological and detrimental conditions, and even with disease. The natural inflammatory process that occurs after a myocardial infarction results in removal of the existing myocardial scaffold and ultimately leads to scar formation—a mechanically and functionally inferior tissue. 
         [0003]    Systemic therapies that control inflammation of heart tissue or the biological tissue surrounding the heart have shown promise in treating heart disease. For example, better biological tissue may form if inflammation is controlled. However, such systemic therapies do not locally control inflammation of the heart tissue or the biological tissue surrounding the heart. Accordingly, there is a need for a device configured to locally control inflammation of heart tissue or the biological tissue surrounding the heart. 
       SUMMARY 
       [0004]    A medical device includes a carrier and an agent. The agent is formulated to control inflammation of biological tissue, such as heart tissue, and is releasably coupled to the carrier. The carrier is configured to be disposed in operative proximity to the biological tissue to be treated by the agent. In one embodiment, the carrier is configured to release the agent or otherwise deliver the agent to the biological tissue, thus controlling inflammation of the tissue. 
         [0005]    A method to improve healing of biological tissue includes placing a medical device proximate to the heart of a patient, where the medical device has a carrier and an agent configured to control inflammation, the agent is releasably coupled to the carrier. In one embodiment, the method includes causing the agent to be released from the carrier. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a schematic illustration of a medical device according to an embodiment of the invention. 
           [0007]      FIG. 2   a  is a perspective view of a medical device according to another embodiment of the invention. 
           [0008]      FIG. 2   b  is a cross-sectional view of the medical device of  FIG. 2   a  taken along line  2   b - 2   b.    
           [0009]      FIG. 2   c  is a cross-sectional view of a medical device according to another embodiment of the invention. 
           [0010]      FIG. 3   a  is the top view of a medical device according to another embodiment of the invention. 
           [0011]      FIG. 3   b  is the bottom view of the medical device of  FIG. 3   a.    
           [0012]      FIG. 3   c  is a cross-sectional view of the medical device of  FIG. 3   b  taken along line  3   c - 3   c.    
           [0013]      FIG. 4   a  is a perspective view of a medical device according to another embodiment of the invention. 
           [0014]      FIG. 4   b  is a cross-sectional view of the medical device of  FIG. 4   a  taken along line  4   b - 4   b.    
           [0015]      FIG. 5   a  is a perspective view of a medical device according to another embodiment of the invention. 
           [0016]      FIG. 5   b  is a cross-sectional view of the medical device of  FIG. 5   a  taken along line  5   b - 5   b.    
           [0017]      FIG. 6   a  is a perspective view of the medical device according to another embodiment of the invention. 
           [0018]      FIG. 6   b  is a cross-sectional view of the medical device of  FIG. 6   a  taken along line  6   b - 6   b.    
       
    
    
     DETAILED DESCRIPTION 
       [0019]    As illustrated schematically in  FIG. 1 , the medical device  100  includes an agent  120  that is releasably coupled to a carrier  130 . The carrier  130  is configured to retain the agent  120  upon the placement of the medical device  100 . The agent  120  is configured or formulated to control and/or reduce the inflammation of biological tissue, such as heart tissue. The term “heart tissue” is used herein to mean heart tissue and/or biological tissue surrounding or proximate to the heart, including but not limited to pericardium, epicardium, myocardium, and endocardium. 
         [0020]    The carrier  130  is configured to be disposed in operative proximity to biological tissue. In other words, the carrier  130  is configured to be disposed sufficiently close to biological tissue such that the agent  120  may treat the biological tissue. For example, in one embodiment, the carrier  130  is configured to be placed or otherwise disposed proximate to heart tissue. 
         [0021]    In one embodiment, the agent  120  is formulated to control and/or reduce inflammation of heart tissue such that the existing myocardial scaffold is not removed or otherwise deteriorated after a myocardial infarct. Accordingly, in such an embodiment, the formation of scar tissue in the heart tissue is controlled and/or reduced. 
         [0022]    In one embodiment, the agent  120  is configured to be released from the carrier  130  after the medical device  100  is placed or otherwise disposed proximate to the biological tissue. In another embodiment, the agent  120  is configured to be released from the carrier  130  in a controlled manner. For example, in one embodiment, the agent  120  is configured to be released from the carrier  120  at a constant rate over a period of time. In another embodiment, the agent  120  is configured to be released from the carrier  130  at a first rate for a period of time and at a second rate during another period of time. 
         [0023]    In one embodiment, the character of the agent  120  causes the agent  120  to be released from the carrier  130 . For example, in such an embodiment, the agent  120  is a coating that is configured to be placed on the carrier and degrade, dissolve, or otherwise separate from the carrier  130  at a constant rate over a period of time. In another embodiment, the carrier  130  is configured to release the agent  120 . For example, the agent  120  is disposed in a well of the carrier  130 . The carrier  130  includes a well cover that is configured to degrade or dissolve. Thus, when the well cover degrades or dissolves, the agent  120  is delivered to the patient. In another embodiment, the agent  120  is disposed within the carrier  130 . The carrier  130  is configured to degrade or dissolve to thereby deliver the agent  120  to the patient. 
         [0024]    In one embodiment, the agent  120  includes at least one of the group consisting of NSAIDs, pyrazolones, fenamate, diflunisal, acetic acid derivatives, propionic acid derivatives, oxicam, mefenamic acid, Ponstel, meclofenamate, Meclomen, phenylbutazone, Butazolidin, diflunisal, Dolobid, diclofenac, Voltaren, indomethacin, Indocin, sulindac, Clinoril, etodolac, Lodine, ketorolac, Toradol, nabumetone, Relafen, tolmetin, Tolectin, ibuprofen, Motrin, fenoprofen, Nalfon, flurbiprofin, Ansaid, carprofen, Rimadyl, ketoprofen, Orudis, naproxen, Anaprox, Naprosyn, piroxicam, and Feldene. In another embodiment, the agent  120  includes at least one of the group consisting of mesenchymal stem cells, aspirin in time released form, interleukins, hemeoxygenase, corticosteroids, tacrolimus, and cyclosporine. 
         [0025]      FIG. 2   a  is a perspective view of a medical device  200  according to an embodiment of the invention. The medical device  200  includes a carrier  245  and an agent  240  releasably coupled to the carrier  245 . 
         [0026]    In this embodiment, the carrier  245  is a tubular member, such as a stent. The carrier  245  has a first end portion  210  and a second end portion  220 . The carrier  245  defines a lumen  230  extending from the first end portion  210  to the second end portion  220 . The agent  240  is in the form of a coating that is releasably coupled to an exterior surface of the carrier  245  as shown in  FIG. 2   b.    
         [0027]    The agent  240  may be disposed on or otherwise releasably coupled to the surface of the carrier  245  via any know method, such as a dipping process or a spraying process. See, for example, U.S. Pat. No. 6,569,195, issued on May 27, 2003 and entitled “Stent Coating,” which is hereby incorporated by reference in its entirety. 
         [0028]      FIG. 2   c  is a cross-sectional view of a medical device  202  according to another embodiment of the invention. The medical device  202  includes a tubular carrier  255  and an agent  250 . As illustrated, the agent  250  is a coating that is releasably coupled to an inner surface of the carrier  255 . 
         [0029]      FIG. 3   a  is a top view of a medical device  300  according to another embodiment of the invention. The medical device  300  includes a carrier  310  and an agent  340 . The carrier  310  is configured to be placed on or adhered to surface tissue. The surface tissue may be surface tissue of the patient such as the skin, or surface tissue of the heart. 
         [0030]    In the illustrated embodiment, the carrier  310  includes material  330  that is configured to adhere to surface tissue. For example, the material  330  may be an adhesive such as glue. The bottom view of the device  300  is shown in  FIG. 3   b . As illustrated in  FIG. 3   b , in this embodiment, the material  330  is disposed along an outer perimeter of the carrier  310 . In other embodiments, the material is disposed at other locations of the carrier. 
         [0031]    In the illustrated embodiment, the agent  340  is coupled to an underside surface of the carrier  310 . Thus, once the agent  340  is released from the carrier  310 , the agent  340  contacts and/or penetrates the tissue. In other embodiments, the carrier is configured to release the agent such that the agent may contact and/or penetrate the tissue. A cross-sectional view of the medical device  300  of  FIG. 3   b  taken along line  3   c  is shown in  FIG. 3   c .  FIG. 3   c  illustrates the carrier  310  in relation to the agent  340  and in relation to the material  330 . 
         [0032]      FIG. 4   a  is a perspective view of a medical device  400  according to another embodiment of the invention. The medical device  400  includes a carrier  410  and an agent  420  releasably coupled to the carrier  410 . 
         [0033]    In another embodiment, the agent includes the material that is configured to adhere to the surface tissue. In yet another embodiment, the material that is configured to adhere to the surface tissue includes the agent. 
         [0034]    In the illustrated embodiment, the carrier  410  is a spherical body or a microsphere. The carrier  410  is configured to degrade in response to the medical device  400  being placed within the body of the patient. The agent  420  is released from the carrier  410  as the carrier  410  degrades. 
         [0035]      FIG. 4   b  is a cross-sectional view of the medical device  400  taken along line  4   b - 4   b  in  FIG. 4   a . The cross-sectional view shows the agent  420  in the carrier  410 . Although  FIG. 4   b  shows the agent  420  as granules, it is not necessary that the agent  420  be in granulated form. For example, in alternative embodiments, the agent is a solid, semi-solid, or liquid which fills the inner portion of the microsphere. 
         [0036]      FIG. 5   a  is a perspective view of a medical device  500  according to another embodiment of the invention. The medical device  500  includes a carrier  510  and an agent  520  releasably coupled to the carrier  510 . 
         [0037]    In this embodiment, the carrier  510  is configured to be implanted in a body of a patient. For example, in one embodiment, the carrier is an implantable plug.  FIG. 5   b  is a cross-sectional view of the medical device  500  taken along line  5   b - 5   b  in  FIG. 5   a . In this embodiment, the agent  520  is coupled to an exterior surface of the carrier  510 . 
         [0038]      FIG. 6   a  is a perspective view of a medical device  600  according to another embodiment of the invention. The medical device  600  includes a carrier  610  and an agent  620 .  FIG. 6   b  is a cross-sectional view of the medical device  600  taken along line  6   b - 6   b  in  FIG. 6   a . In this embodiment, carrier  610  is a solid tubular structure with the agent  620  coupled to an exterior surface of the carrier  610 . 
         [0039]    Although the illustrated medical device  500  and  600  illustrate the medical device as having a particular shape, it is not necessary that the medical device be so shaped. In other embodiments, the medical device has a different shape. 
         [0040]    In another embodiment of the invention, a medical device has a carrier and an agent releasably coupled to the carrier. In this embodiment, the carrier is a liquid that is configured to solidify in response to being disposed within a body of a patient, such as a solidifying spray solution. The agent is disposed within the carrier. In such an embodiment, the carrier is configured to dissolve or degrade to deliver the agent to the body of the patient. In one embodiment, the carrier is a liquid that is configured to be sprayed or injected into the heart tissue. 
         [0041]    In yet another embodiment, a medical device includes an injectable gel or injectable paste that may be injected into a body of a patient. 
         [0042]    While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.