title: Chitosan derivatives cross-linked with iodinated 2,5-dimethoxy-2,5-dihydrofuran for non-invasive imaging.
abstract: Radiopaque polymer derivatives were successfully prepared through surface diffusion mediated cross-linking of chitosan with iodinated 2,5-dimethoxy-2,5-dihydrofuran. The incorporation of iodine in 2,5-dimethoxy-2,5-dihydrofuran was validated by (1)H NMR and mass spectroscopy. The cross-linking of the glucosamine moieties of chitosan with the iodinated product was confirmed by (13)C NMR and energy-dispersive X-ray spectroscopy. Radiography analysis proved inherent opacity of the iodinated fibrous sheets and microspheres that were comparable to the X-ray visibility of aluminum hollow rings of equivalent thickness and commercially available radiopaque tape, respectively. Microscopic studies evidenced retention of the fiber/microsphere morphology after the iodination/cross-linking reactions. The effects of iodination/cross-linking on the mechanical and biodegradation properties of fibers were studied by nanoindentation and enzymatic assay, respectively. In vitro and in vivo studies established the nontoxic, biodegradable nature of radiopaque derivatives. Iodinated fiber mesh implanted in a rabbit model was significantly X-ray opaque compared to the uncross-linked fiber mesh and medical grade surgical swabs. Further, opacity of the iodinated mesh was evident even after 60 days, though the intensity was reduced, which indicates the biodegradable nature of the iodinated polymer. The opacity of the iodinated sutures was also established in the computed tomography images. Finally, the sufficient in vivo contrast property of the radiopaque microspheres in the gastrointestinal tract indicates its possible role in clinical diagnostics.
authors.affiliation: Biomaterials and Tissue Engineering Laboratory, School of Medical Science and Technology, Indian Institute of Technology Kharagpur , Kharagpur 721302, India.
authors.forename: Paulomi
authors.initials: P
authors.lastname: Ghosh
authors.forename: Manisit
authors.initials: M
authors.lastname: Das
authors.forename: Arun Prabhu
authors.initials: AP
authors.lastname: Rameshbabu
authors.forename: Dipankar
authors.initials: D
authors.lastname: Das
authors.forename: Sayanti
authors.initials: S
authors.lastname: Datta
authors.forename: Sagar
authors.initials: S
authors.lastname: Pal
authors.forename: Asit Baran
authors.initials: AB
authors.lastname: Panda
authors.forename: Santanu
authors.initials: S
authors.lastname: Dhara
mesh_terms: D000284:Administration, Oral; D000447:Aldehydes / Q000138:chemical synthesis* / Q000737:chemistry; D000818:Animals; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D048271:Chitosan / Q000737:chemistry*; D003287:Contrast Media; D003432:Cross-Linking Reagents / Q000737:chemistry*; D003952:Diagnostic Imaging / Q000379:methods*; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D054879:Halogenation; D006801:Humans; D008297:Male; D008863:Microspheres; D019919:Prosthesis Implantation; D066244:Proton Magnetic Resonance Spectroscopy; D011817:Rabbits; D051381:Rats; D012212:Rheology; D014057:Tomography, X-Ray Computed
chemical_list: D000447:Aldehydes; D003287:Contrast Media; D003432:Cross-Linking Reagents; D005663:Furans; D048271:Chitosan
keywords: 2,5-dimethoxy-2,5-dihydrofuran; X-ray opacity; covalent cross-linking; gastrointestinal tract; iodination; radiopaque sutures