title: Non-covalent crosslinkers for electrospun chitosan fibers.
abstract: Electrospun chitosan fibers have numerous potential in biomedical, food, and pharmaceutical applications. However, the mats formed are often not chemically stable in a wide range of pHs unless crosslinked. Here, we report on the use of glycerol phosphate (GP), tripolyphosphate (TPP) and tannic acid (TA) as a new set of non-covalent crosslinkers for electrospun chitosan fibers. Crosslinking with or without heat or base activation were performed either prior to (one-step or activated one-step) or after (two-step or activated two-step) electrospinning with either GP or TA. TPP crosslinking was performed in two-step and activated two-step. FESEM, FTIR and UV-vis transmittance at 600 nm were used to determine fiber surface morphology, chemical interactions and solubility in 1M AA (pH 3), water (~pH 6) and 1 M NaOH (pH 13), respectively. Crosslinking of chitosan with GP and TA yields fibers with a mean diameter range of 145-334 nm and 143-5554 nm, respectively. TPP crosslinking produced branched fibers with mean diameters of 117-462 nm range. Two-step chitosan-TA did not dissolve in 1M AA even after 72 h while all chitosan-TPP, activated two-step chitosan-TA and two-step heat activated chitosan-GP fibers survived in water after 72 h.
authors.affiliation: Materials Science and Engineering Department, Drexel University, Philadelphia, PA 19104, USA.
authors.forename: Marjorie A
authors.initials: MA
authors.lastname: Kiechel
authors.forename: Caroline L
authors.initials: CL
authors.lastname: Schauer
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D005994:Glycerophosphates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D011122:Polyphosphates / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013634:Tannins / Q000737:chemistry*; D014783:Viscosity
chemical_list: D003432:Cross-Linking Reagents; D005994:Glycerophosphates; D011122:Polyphosphates; D013634:Tannins; D048271:Chitosan; C005692:triphosphoric acid