Paclitaxel prevents restenosis by blocking proper microtubal formation, thus it inhibits cell division and migration. It inhibits inflammatory processes. After balloon dilatation, injuries to the arterial wall stimulate inflammatory reaction, and the excretion of growth factors occurs as an important process along with the onset of cell division and the migration of smooth muscle cells. Paclitaxel inhibits platelet derived growth factor (PDGF) mediated vascular smooth muscle cell migration to the intima. Paclitaxel also inhibits extracellular matrix secretion and breakdown.
Paclitaxel selectively inhibits the proliferation of smooth muscle cells. The endothelium cells show a better resistance to Paclitaxel than the smooth muscle cells due to the different affinity of the connective structure on the cell surface. Paclitaxel does not influence non-proliferating cells as a result of cytokine and growth factor stimulation. The FREEWAY Paclitaxel-releasing PTA balloon dilatation catheter enhances a smooth re-endothelialization process.Neither direct contact to shellac-coated materials nor exposure to shellac extraction products impaired HDMEC and hSMC viability and function in vitro.
Shellac is a natural resin composed of shellolic and alleuritic acid.
The coating consists of a 1:1 mixture of Paclitaxel with shellac applied to the balloon by a micro-pipetting procedure in a clean room under sterile conditions.