The objective of the project is to demonstrate that it is feasible to fabricate a bioresorbable drug eluting poly (l-lactide) (PLLA) stent with appropriate mechanical properties using our newly developed novel rapid stent fabrication (RSF) system. This novel system is Computer Aided Design (CAD) based and has the capability to directly produce bioresorbable polymer stents by using polymer pellets and powders without any intermediate steps, such as making of polymer tubes and fibers. This will drastically reduce the processing time and the cost of the bioresorbable stent fabrication process. In this project, we will first optimize PLLA stent fabrication parameters in our RSF. Stents with single and double helical patterns will be fabricated and tested for their mechanical properties. The commonly used anti-inflammatory and anti-proliferative drug, rapamycin (sirolimus), and amorphous bioabsorbable polymer, poly-D,L-lactide, will be applied as drug/polymer coating in this phase I feasibility study. Mechanical properties, such as crimping and radial stiffness, acute recoil, foreshortening, will be tested. Fabricated drug elution stents will be sterilized using gamma-radiation or e-beam radiation and there in vitro drug elution profiles will be studied. The biodegradation behavior of these stents will also be characterized in vitro. Upon completion of this Phase I study, we plan to move forward by conducting a Phase II animal study in collaboration with a major stent manufacturer, such as Abbott Vascular.
Bioresorbable polymer stents are the focus of the next generation stent development. With all the benefits they can offer, bioresorbable stents may become a new standard of care in peripheral artery disease. Since currently there is no FDA approved bioresorbable stents on the market yet, there is a stronger demand for both stents and new fabrication technologies that can increase stent production efficiency and reduce stent development time and cost. Using our newly developed rapid stent fabrication (RSF) system, this project will demonstrate the feasibility of fabricating drug eluting bioresorbable poly(L-lactide) (PLLA) stents with appropriate mechanical properties and a drug-eluting profile of approximately 80% drug being released in 30 days. This novel system has the capability to directly produce bioabsorbable polymer stents by using polymer pellets and powders without intermediate steps, such as the making of polymer tubes and fibers. The commonly used anti-inflammatory and anti-proliferative drug, rapamycin (sirolimus), and amorphous bioasorbable poly-D,L-lactide will be applied as drug/polymer coating in this phase I feasibility study.