Method of drug delivery to interstitial regions of the myocardium
A method of treating the heart and other body tissues by injecting a compound comprised of microsphere encapsulated macromolecule therapeutic agents into the myocardium, such that the microsphere size inhibits capillary transport of the compound but may permit lymphatic transport of the compound, and the compound releases therapeutic agents upon degradation of the microsphere.
1 . A method for interventional treatment of a patient having a lymphatic system and heart with a myocardium comprising:
providing a catheter having a tissue penetrating element disposed on its distal end and an inner lumen extending from its proximal end to its distal end;
providing a microdrug fluidic delivery system comprising a plurality of microspheres, said microsperes having an encapsulating layer and a therapeutic agent within the encapsulating layer, wherein said encapsulating layer is degradable when injected into the body tissue;
said microspeheres sized and dimensioned to prevent take up by the lymphatic system for a first time period;
said therapeutic agent comprising a genetic material;
injecting said microdrug interstitially to a depth within the myocardium to a first treatment site using the catheter;
treating the first treatment site for the first time period;
transporting the microdrug delivery system through a lymphatic system to a second treament site after the first time period;
treating a second treatment site within the patient with the microdrug delivery system.
2 . The method of claim 1 wherein the microspheres are less than 400 nm in size.
3 . The method of claim 1 wherein the microspheres are between about 220 nm to about 250 nm in size.
4 . The method of claim 1 wherein the first time period is between about 5 minutes to about 60 minutes.
5 . The method of claim 1 wherin the therapeutic agent is an angiogenic protein.
6 . The method of claim 1 wherein the therpeutic agent is an antiarrythmic agent.
7 . The method of claim 1 wherein the therpeutic agent is an antirestenosis agent.
8 . The method of claim 1 wherein the first treament site it the ventrical wall and the second treatment site is the atrium wall.
9 . A system for interventional treatment of a patient having a lymphatic system and a heart with a myocardium comprising:
a catheter having a tissue penetrating element disposed on its distal end and an inner lumen extending from its proximal end to its distal end, said tissue penetrating element adapted to penetrate the endocardium of a chamber of a heart to a depth withing the myocardium; and
a microdrug fluidic delivery system disposed within the catheter comprising a plurality of microspheres, said microsperes having an encapsulating layer and a therapeutic agent within the encapsulating layer, wherein said encapsulating layer is degradable when injected into the body tissue;
said therapeutic agent comprising a genetic material;
said microspeheres sized and dimensioned to prevent take up by the lymphatic system for a first time period.
10 . The system of claim 9 wherein the microspheres are less than 400 nm in size.
11 . The system of claim 9 wherein the microspheres are between about 220 nm to about 250 nm in size.
12 . The system of claim 9 wherein the first time period is between about 5 minutes to about 60 minutes.
13 . The system of claim 9 wherein the therapeutic agent is an angiogenic protein.
14 . The system of claim 9 wherein the therpeutic agent is an antiarrythmic agent.
15 . The system of claim 9 wherein the therpeutic agent is an antirestenosis agent.