title: Electrospun rapamycin-eluting polyurethane fibers for vascular grafts.
abstract: OBJECTIVE
  To develop rapamycin-eluting electrospun polyurethane (PU) vascular grafts that could effectively suppress local smooth muscle cell (SMC) proliferation.
  
  
  METHODS
  Rapamycin (RM) was incorporated in PU fibers by blend electrospinning using three distinct blending methods. The drug release profiles and the bioavailability of RM-containing PU fibers in the form of fibrous mats and vascular grafts were evaluated up to 77 days in vitro.
  
  
  RESULTS
  RM-contained PU fibers generated by the three distinct blending methods exhibited significantly different fiber diameters (200-500 nm) and distinct RM release kinetics. Young's moduli of the electrospun fibrous mats increased with higher RM contents and decreased with larger fiber diameters. For all blending methods, RM release kinetics was characteristic of a Fickian diffusion for at least 77 days in vitro. RM-PU fibers generated via powder blending showed the highest encapsulation efficiency. The RM in grafts made of these fibers remained bioactive and was still able to inhibit smooth muscle cell proliferation after 77 days of continual in vitro release.
  
  
  CONCLUSIONS
  Electrospun RM-containing PU fibers can serve as effective drug carriers for the local suppression of SMC proliferation and could be used as RM-eluting scaffolds for vascular grafts.
authors.affiliation: School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Jingjia
authors.initials: J
authors.lastname: Han
authors.forename: Shady
authors.initials: S
authors.lastname: Farah
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Domb
authors.forename: Peter I
authors.initials: PI
authors.lastname: Lelkes
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D001672:Biocompatible Materials / Q000737:chemistry; D001807:Blood Vessel Prosthesis; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D004337:Drug Carriers / Q000737:chemistry; D055119:Elastic Modulus; D007166:Immunosuppressive Agents / Q000008:administration & dosage* / Q000494:pharmacology; D032342:Muscle Cells / Q000166:cytology / Q000187:drug effects*; D011140:Polyurethanes / Q000737:chemistry*; D020123:Sirolimus / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D007166:Immunosuppressive Agents; D011140:Polyurethanes; D020123:Sirolimus