title: Biodegradable nitric oxide-releasing poly(diol citrate) elastomers.
abstract: We have developed novel poly(diol citrate) elastomers, which are capable of providing localized and sustained release of nitric oxide (NO). The elastomer prepolymer was obtained by condensation of citric acid, 1,8-octanediol, and N,N'-bis(2-hydroxyethyl)ethylenediamine at 130 degrees C for 40 min. Films were prepared by solvent casting followed by crosslinking at 80 degrees C for 4 days. Mechanical properties were tested. NO-releasing expanded poly(tetrafluoroethylene) (ePTFE) vascular grafts were fabricated by coating the graft's lumen with the prepolymer and crosslinking it at 80 degrees C for 4 days prior to diazeniumdiolation. Samples were diazeniumdiolated via exposure to pressurized NO. Cell compatibility was assessed by monitoring the proliferation of porcine aortic smooth muscle cells (PASMC) on the elastomers. Degradation in phosphate buffer saline (PBS) (pH = 7) at 37 degrees C was evaluated for up to 6 weeks. The secondary amine-containing poly(diol citrate) films had a Young's modulus that ranged from 5.91 to 32.64 MPa, an ultimate tensile stress that ranged from 1.47 to 10.71 MPa, and an elongation at break from 200 to 260%, depending on the content of secondary amine in the feed monomer. These elastomers were degradable and compatible with PASMC. Furthermore, degradation rate was found to be independent of the content of secondary amines in the prepolymer. The NO release from diazeniumdiolated films and ePTFE grafts was sustained for two days. In conclusion, these novel diazeniumdiolated polyester elastomers may be useful in medical devices that require blood contact or control of cell proliferation.
authors: Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA.
authors: Haichao
authors: H
authors: Zhao
authors: M Concepcion
authors: MC
authors: Serrano
authors: Daniel A
authors: DA
authors: Popowich
authors: Melina R
authors: MR
authors: Kibbe
authors: Guillermo A
authors: GA
authors: Ameer
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000737:chemistry; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry; D002951:Citrates / Q000138:chemical synthesis* / Q000737:chemistry; D020724:Elastomers / Q000138:chemical synthesis* / Q000737:chemistry; D055595:Mechanical Phenomena / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D011138:Polytetrafluoroethylene / Q000494:pharmacology; D017550:Spectroscopy, Fourier Transform Infrared; D034421:Sus scrofa; D013696:Temperature
chemical_list: D001391:Azo Compounds; D001672:Biocompatible Materials; D002951:Citrates; D020724:Elastomers; D011108:Polymers; C452539:diazeniumdiolate; C513817:poly(1,8-octanediol citrate); D009569:Nitric Oxide; D011138:Polytetrafluoroethylene