Biodegradable polymer films for releasing nanovehicles containing sirolimus.

To obtain novel biodegradable sirolimus-releasing polymer films that could release nanovehicles incorporating sirolimus, polyester, a water-soluble amphiphilic phospholipid polymer, and sirolimus were blended. The sirolimus-releasing polymer films were characterized by scanning electron microscopy and differential scanning calorimetry. Nanovehicles were formed with the phospholipid polymer chains and could be released from the sirolimus-releasing polymer films. The hydrodynamic diameter of the nanovehicles in phosphate-buffered saline was smaller than 20 nm. The nanovehicles substantially enhanced the carrier-mediated delivery of sirolimus and attenuated its degradation product. This study demonstrates that the delivery of sirolimus was enhanced by nanovehicles released from sirolimus-eluting materials.