title: Study of biodegradable and self-expandable PLLA helical biliary stent in vivo and in vitro.
abstract: Biodegradable stents have advantages for the treatment of benign and malignant biliary stricture, especially eliminating the need for stent removal. In our present work, helical poly-l-lactic acids (PLLA) stent was fabricated and evaluated in vivo and in vitro. For in vivo study, bile duct injury canine models were made by transection of common bile ducts. Duct to duct anastomosis was done with helical PLLA biodegradable stents. Scanning electron microscopy (SEM) and histopathology were performed after three months. For In vitro study, sludge attachment assessment was performed. Polyethylene (PE) and PLLA membranes were immersed in human bile for two months. The samples were taken out and characterized by SEM. Self-expanding property of the helical stent was tested in 37 degrees Celsius water. The results demonstrate that the biodegradable stent had not only good biocompatibility, but also self-clearing effect to clear the attached sludge away. The self-expanding property facilitated stent implantation and also suggested possibility to be implanted endoscopically.
authors.affiliation: Department of Materials Science & Engineering, Tsinghua University, Beijing, 100084, Peoples Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Meng
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Ning
authors.initials: N
authors.lastname: Zhu
authors.forename: Qing-Yuan
authors.initials: QY
authors.lastname: Meng
authors.forename: Fu-Zhai
authors.initials: FZ
authors.lastname: Cui
authors.forename: Ying-Xin
authors.initials: YX
authors.lastname: Xu
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001647:Bile Acids and Salts / Q000494:pharmacology; D001652:Bile Ducts / Q000293:injuries* / Q000648:ultrastructure; D001672:Biocompatible Materials / Q000627:therapeutic use*; D001673:Biodegradation, Environmental; D001831:Body Temperature; D003135:Common Bile Duct / Q000601:surgery; D004285:Dogs; D005069:Evaluation Studies as Topic; D006801:Humans; D006965:Hyperplasia / Q000517:prevention & control; D066298:In Vitro Techniques; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D008567:Membranes, Artificial; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D015607:Stents; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D001647:Bile Acids and Salts; D001672:Biocompatible Materials; D008567:Membranes, Artificial; D011091:Polyesters; D011108:Polymers; D014867:Water; D019344:Lactic Acid; C033616:poly(lactide)