title: Bioresorbable drug-eluting magnesium-alloy scaffold: design and feasibility in a porcine coronary model.
abstract: OBJECTIVE
  Among three versions of bioresorbable magnesium scaffolds featuring different paclitaxel-elution kinetics, we determined the best-performing scaffold and compared it with established, paclitaxel-eluting, permanent stents TAXUS Liberté and eucaTAX.
  
  
  RESULTS
  Drug-elution kinetics in magnesium scaffolds were modulated by varying the composition of their bioresorbable poly(lactide-co-glycolide) coating loaded with paclitaxel. A 50:50 ratio of lactide to glycolide, or an 85:15 ratio and either high- or low-molecular-weight polymer was applied in the "50/50", "85/15H", and "85/15L" scaffolds, respectively. Seventy-three magnesium scaffolds (25 50/50, 24 85/15H, 24 85/15L) and 36 control stents (18 TAXUS Liberté, 18 eucaTAX) were implanted in coronary arteries of 50 Yucatan mini-pigs. Angiography, histomorphometry, and histopathology data were acquired at 28, 90 and 180 days. The best-performing magnesium scaffold, 85/15H, was equivalent to TAXUS Liberté and superior to eucaTAX regarding late luminal loss, intimal area, fibrin score, and endothelialisation. Intimal inflammation score was higher in 85/15H than in the control stents at 28 days, but this effect disappeared at later time points.
  
  
  CONCLUSIONS
  By selecting suitable paclitaxel-elution kinetics, it was feasible to develop a bioresorbable magnesium scaffold whose efficacy and healing characteristics in a porcine coronary model are comparable with those of established paclitaxel-eluting permanent metallic stents.
authors.affiliation: Biotronik SE & Co. KG, Erlangen, Germany.
authors.forename: Eric
authors.initials: E
authors.lastname: Wittchow
authors.forename: Nina
authors.initials: N
authors.lastname: Adden
authors.forename: Johannes
authors.initials: J
authors.lastname: Riedmüller
authors.forename: Claudine
authors.initials: C
authors.lastname: Savard
authors.forename: Ron
authors.initials: R
authors.lastname: Waksman
authors.forename: Marlen
authors.initials: M
authors.lastname: Braune
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry*; D000818:Animals; D002317:Cardiovascular Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000187:drug effects; D054855:Drug-Eluting Stents; D005240:Feasibility Studies; D005260:Female; D005355:Fibrosis; D007700:Kinetics; D008274:Magnesium / Q000737:chemistry*; D008297:Male; D008422:Materials Testing; D023421:Models, Animal; D008970:Molecular Weight; D058426:Neointima; D017239:Paclitaxel / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D062645:Percutaneous Coronary Intervention / Q000295:instrumentation*; D011098:Polyglactin 910 / Q000737:chemistry; D011474:Prosthesis Design; D013552:Swine; D013556:Swine, Miniature
chemical_list: D000497:Alloys; D002317:Cardiovascular Agents; D011098:Polyglactin 910; D008274:Magnesium; D017239:Paclitaxel