Development of a microperforated nanocomposite balloon for intravascular anti-restenotic drug delivery

点击翻译按钮获取中文摘要

Hemodialysis is the most common treatment for kidney failure, requiring the passing of blood out of the body, through a filter, and back into the body. Almost 30% of hemodialysis patients undergo arteriovenous graft procedures involving the insertion of prosthetic shunts (i.e., synthetic tubes) between artery and vein, particularly in the forearm. With the hemodialysis patient population estimated to reach over 500,000 by 2020, the number of patients requiring grafts will reach over 150,000 (30% of 500,000) and most of these grafts will eventually clot. Clotting occurs in these grafts due to blockages that occur in the blood vessel at the outflow site of the graft. As a result, many hemodialysis patients require intervention to open up the narrowing, or stenosis, of the blood vessel. Currently, interventions for clotted grafts involve removal of the clot with a device followed by angioplasty of the vein. Once angioplasty is needed, the lesion will keep restenosing and often the patients need additional declot procedures and repeat angioplasty. While stents are routinely used to open up narrowed arteries, they cannot be implemented in this case. A more mechanically compliant structure is needed. Relatively new, drug-coated balloons (DCBs) are a possible solution. However, DCBs inherently exhibit sporadic and unpredictable drug delivery. Furthermore, DCB drug delivery is currently quite inefficient with much of the drug being lost downstream. This increases the potential for systemic toxicity. In addition, chemical agents (excipients) are needed to control diffusion of the drug coating. These excipients pose a risk of downstream embolism for the patient. A more efficient, safer method of intravascular anti-restenotic drug delivery is needed to improve efficacy and reduce risk of embolism. We propose to develop a nanocomposite-based polymer balloon with microperforations to enable pulsed-flow drug delivery to the lesion. Using our approach, drugs can be efficiently delivered directly to the diseased site reducing the potential for systemic toxicity. Our intravascular drug delivery system is capable of delivering drugs of almost any form, from lipophilic drugs to hydrophilic drugs and even combinations thereof.  -1-