Inkjet-printing technology was used to apply biodegradable and biocompatible
polymeric coatings of poly(D, L lactide) with the antiproliferative drugs
simvastatin (SMV) and paclitaxel (PCX) on coronary metal stents. A piezoelectric
dispenser applied coating patterns of very fine droplets (300 pL) and inkjet
printing was optimized to develop uniform, accurate and reproducible coatings of
high yields on the stent strut. The drug loaded polymeric coatings were assed by
scanning electron microscopy (SEM), atomic force microscopy (AFM) and transition
thermal microscopy (TTM) where a phase separation was observed for SMV/PLA layers
while PCX showed a uniform distribution within the polymer layers.
Cytocompatibility studies of PLA coatings showed excellent cell adhesion with no
decrease of cell viability and proliferation. In vivo stent implantation studies
showed significant intra stent restenosis (ISR) for PCX/PLA and PLA plain
coatings similar to marketed Presillion (bare metal) and Cypher (drug eluting)
stents. The investigation of several cytokine levels after seven days of stent
deployment showed no inflammatory response and hence no in vivo cytotoxicity
related to PLA coatings. Inkjet printing can be employed as a robust coating
technology for the development of drug eluting stents compared to the current
conventional approaches.