RESUMEN
Objective: To prepare a mitomycin C (MMC)-eluting stent for biliary tract, and to observe the drug delivery from the stent. Methods: The mixed powder of MMC and polylactic glycolic acid (PLGA) was dissolved with their common solvent tetrahydrofuran (THF), with a drug concentration of 1%. The 6Fr biliary stent was soaked in the above solution for 10 min, and then was subjected to vacuum drying and was stored at room temperature. Then MMC-eluting stent was weighed and the MMC load was calculated. The MMC-eluting stents were soaked in 8 ml phosphate buffered saline (PBS, pH 7. 4) and placed in a shaker at a constant temperature of 37°C for 24 h soaking; then fresh PBS was changed every day for 30 days. The leaching solutions of the 1-30 days were subjected to chromatographic analysis to determine the concentrations of MMC. Results: MMC load on each stent was (216. 20 ± 2. 04) g, with the load per unit area being (0. 732 ± 0. 007) g/mm2. MMC could be released from the stent surface in a sustainable manner. The elution concentration of MMC was (1. 81 ± 0. 06) g/ml on first day and (1. 24 ± 0. 04) g/ml on the second day; then it fluctuated within 0. 61-0. 84 g/ml. The concentration of MMC began to decrease from the 21st day, and it was (0. 51 + 0. 01) g/ml on the 30th day. Conclusion: MMC-eluting biliary stents can be successfully prepared using polylactic acid as a drug carrier. In vitro study shows that the drug-eluting stents can sustainably and stably release MMC for over 30 days.