title: Hybrid nanofibrous yarns based on N-carboxyethylchitosan and silver nanoparticles with antibacterial activity prepared by self-bundling electrospinning.
abstract: Hybrid nanofibrous materials with antibacterial activity consisting of yarns from N-carboxyethylchitosan (CECh) and poly(ethylene oxide) (PEO) that contain 5 wt% or 10 wt% silver nanoparticles (AgNPs) were prepared. This was achieved by electrospinning using formic acid as a solvent and as a reducing agent for silver ions. AgNO₃ was used as an Ag(+)-containing salt. Its concentration was selected to be 0.02 mol/L or 0.04 mol/L in order the content of the AgNPs in the electrospun nanofibers to be 5 wt% or 10 wt%, respectively. The self-bundling of the fibers into yarns with a mean diameter of ca. 35 μm was enabled only by using a grounded needle electrode. The reduction of the silver ions to an elemental silver was evidenced by UV-vis spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The transmission electron microscopy (TEM) analyses revealed that AgNPs formed at AgNO₃ concentration of 0.02 mol/L were with a mean diameter of 4±0.5 nm and were distributed uniformly within the fiber. The increase of AgNO₃ concentration to 0.04 mol/L led to the preparation of AgNPs with a higher mean diameter and a broader diameter distribution as well as to aggregate formation. The performed studies on the antibacterial activity of CECh/PEO/AgNPs fibrous materials against Staphylococcus aureus showed that at AgNPs content of 5 wt% the mats had bacteriostatic, and at AgNPs content of 10 wt%-bactericidal activity.
authors.affiliation: Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St. bl. 103A, 1113 Sofia, Bulgaria.
authors.forename: Hristo
authors.initials: H
authors.lastname: Penchev
authors.forename: Dilyana
authors.initials: D
authors.lastname: Paneva
authors.forename: Nevena
authors.initials: N
authors.lastname: Manolova
authors.forename: Iliya
authors.initials: I
authors.lastname: Rashkov
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D048271:Chitosan / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*; D055664:Electrochemical Techniques; D005561:Formates / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D057139:Nanofibers / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000737:chemistry; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D005561:Formates; D009942:Organometallic Compounds; C030544:formic acid; D012834:Silver; D011092:Polyethylene Glycols; D048271:Chitosan