Preparation Of Triamcinolone-Eluting Stent And Application In Biliary Benign Stricture

ObjectiveProduce a new kind of biliary stent with Triamcinolone-eluting and observe the law ofdrug delivery from the stent evaluate the availability and safety in Biliary Benign Stricturemodel of rabbitMethodsPart Ⅰ: The powder both the Triamcinolone and polylactic glycolic acid (PLGA)dissolved in the common solvent tetrahydrofuran (THF) with a drug concentration of20%.6F biliary soaked in the above solvents. After10minutes, remove the vacuum drying, andstored at room temperature. Calculated the quality of the stent contained in Triamcinoloneby measuring changes in the quality. PBS buffer (PH7.4) diluted Triamcinolone for thestandard solution and analyzed the ultraviolet peak area at240nm. Triamcinolone-elutingstents soaked in PBS, placed in shaker with a constant temperature of37°C continuingsoaked48h, and then soaked in fresh PBS solution until40days. Standard PBS solutionsas the control group, the chromatographic analysis of specimens from the leaching solutionfor1-40days, calculated the concentration of Triamcinolone in the leaching solution. PartⅡ:36New Zealand rabbits were randomly divided into Triamcinolone-Eluting Stentgroup1（n=12），polyurethane stent group2（n=12）and control group3（n=12）. Throughthe duodenal papilla reverse insert stent into the common bile duct after fulgurizecholedochus. Control group only fulgurize choledochus common bile duct withoutspecial treatment. one month later. General conditions, survival of the animals andChanges in liver function were observed after surgery.observe. the histological changes ofbile duct after30days; immunohistochemistry SP method was used to measuretransforming growth factor-β1(TGF-β1) and α-Smooth muscle actin(α-SMA) expression.ResultsPart Ⅰ: The quality of Triamcinolone contained in the stent was detected. Triamcinolone on the stent of capacity was up to510μg; per unit area contained in the drugamount was1.63μg/mm2. Triamcinolone could be sustained-release from the stent surface.The first five days the quality release from the stent was180.61μg，is47.23%of the totalamount release from the stent then it fluctuated within1.85-3.51μg/ml.The concentrationof Triamcinolone begane to decrease from the23st day，and it was0.53μg/ml on the33thday，it can’t be detected in the later days.Part Ⅱ: Both of the two stent groups could effective prevent Biliary benige strictureformation after bile duct injuried.Stricture was improved in the two stent groups.Triamcinolone-Eluting Stent group total bilirubin fluctuate between0.61μmol/l and0.73μmol/l，polyurethane stent group total bilirubin fluctuate between0.54μmol/l and0.75μmol/l, there are no statistically significant between two stent groups(P＞0.05). totalbilirubin of the control group continued to rise. segment of the Stricture bile duct fromgroup1was expanded bigger than group2by histology observed. Inflammatory cellinfiltration, collagen fibers in the submucosal were observed from control group. Theimmunohistochemistry results showed that the stenosis bile duct of TGF-βl and α-SMAfrom group1expression were lower than group2,there have significant differencesbetween the two stent groups(P＜0.05).highest expression in the control group.ConclusionPart Ⅰ: Triamcinolone-eluting biliary stents can be successful prepared by polylacticglycolic acid as a drug carrier. In vitro study shows that the drug-eluting stents cansustainable and stable release of Triamcinolone over30days.Part Ⅱ: the new Triamcinolone-Eluting Stent is safe and provides enhanced localdrug delivery.it can inhibition the form of Biliary scar to a certain degree.