Paclitaxel-polyurethane film for anti-cancer drug delivery: Film characterization and preliminary in vivo study

Polyurethane (PU) films incorporated with an anti-cancer drug paclitaxel (PTX) were prepared using a solvent casting method for potential applications to stent-based drug delivery and the local treatment of malignant tumors around gastrointestinal stents. The films were examined by scanning electron microscopy (SEM), and PTX micro-aggregates were observed when the drug loading was > 2.7 wt%. The in vitro release study revealed that the amount of drug released from the film was virtually independent and cumulative percentage release was inversely proportional to the drug loading. When plotted against the square root of time, the cumulative percentage release was initially linear, but the fraction of the linear region decreased with increasing drug loading, indicating that diffusion-controlled release is not applicable to the PTX molecules in micro-aggregates. When 1.25% PTX-PU films were placed under pre-existing CT-26 tumors in mice, tumor growth was slowed by an average of 65.5% compared to that in the control group.