title: Prototype of biliary drug-eluting stent with photodynamic and chemotherapy using electrospinning.
abstract: BACKGROUND
  The combination of biliary stent with photodynamic and chemotherapy seemed to be a beneficial palliative treatment of unresectable cholangiocarcinoma. However, by intravenous delivery to the target tumor the distribution of the drug had its limitations and caused serious side effect on non-target organs. Therefore, in this study, we are going to develop a localized eluting stent, named PDT-chemo stent, covered with gemcitabine (GEM) and hematoporphyrin (HP).
  
  
  METHODS
  The prototype of PDT-chemo stent was made through electrospinning and electrospraying dual-processes with an electrical charge to cover the stent with a drug-storing membrane from polymer liquid. The design of prototype used PU as the material of the backing layer, and PCL/PEG blends in different molar ratio of 9:1 and of 1:4 were used in two drug-storing layers with GEM and HP loaded respectively.
  
  
  RESULTS
  The optical microscopy revealed that the backing layer was formed in fine fibers from electrospinning, while drug-storing layers, attributed to the droplets from electrospraying process. The covered membrane, the morphology of which was observed by scanning electron microscopy (SEM), covered the stent surface homogeneously without crack appearances. The GEM had almost 100% of electrosprayed efficiency than 70% HP loaded on the covered membrane due to the different solubility of drug in PEG/PCL blends. Drug release study confirmed the two-phased drug release pattern by regulating in different molar ratio of PEG/PCL blends polymer.
  
  
  CONCLUSIONS
  The result proves that the PDT-chemo stent is composed of a first burst-releasing phase from HP and a later slow-releasing phase from GEM eluting. This two-phase of drug eluting stent may provide a new prospect of localized and controlled release treatment for cholangiocarcinoma disease.
authors.forename: Min-Hua
authors.initials: MH
authors.lastname: Chen
authors.forename: Po-Chin
authors.initials: PC
authors.lastname: Liang
authors.forename: Kai-Chun
authors.initials: KC
authors.lastname: Chang
authors.forename: Jian-Yuan
authors.initials: JY
authors.lastname: Huang
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Chang
authors.forename: Fuh-Yu
authors.initials: FY
authors.lastname: Chang
authors.affiliation: Institute of Biomedical Engineering, National Taiwan University, No,1, Sec,1, Jen-Ai Rd,, Taipei 100, Taiwan. jmwong@ntu.edu.tw.
authors.forename: Jau-Min
authors.initials: JM
authors.lastname: Wong
authors.forename: Feng-Huei
authors.initials: FH
authors.lastname: Lin
mesh_terms: D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D054855:Drug-Eluting Stents; D004867:Equipment Design; D008855:Microscopy, Electron, Scanning / Q000379:methods; D010778:Photochemotherapy / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D000093542:Gemcitabine
chemical_list: D011108:Polymers; D003841:Deoxycytidine; D000093542:Gemcitabine