title: Versatile photochemical surface modification of biopolyester microfibrous scaffolds with photogenerated silver nanoparticles for antibacterial activity.
abstract: A straightforward and versatile method for immobilizing macromolecules and silver nanoparticles on the surface of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) electrospun fibers is developed with the objective of designing a new functional material having significant antibacterial activity. The approach relies on a two-step procedure: UV photografting of poly(methacrylic acid) (PMAA) on the surface of PHBHV fibers according to a "grafting from" method, and complexation of in situ photogenerated silver nanoparticles (Ag NPs) by carboxyl groups from tethered PMAA chains. The photografting process is conducted through a photoinduced free-radical process employing a ketone-based photoinitiator in aqueous medium. Under appropriate conditions, the photogenerated radicals abstract hydrogen atoms from the PHBHV backbone, thus initiating the UV-mediated photopolymerization of MAA from the PHBHV microfibrous surface. The photochemical mechanism of the ketone photolysis is entirely described by the electron spin resonance/spin-trapping technique, and the modified PHBHV microfibrous scaffold is extensively characterized by ATR-FTIR spectroscopy, water contact-angle measurements, and mercury intrusion porosimetry. In a second step, the in situ synthesis of Ag NPs within the microfibrous scaffold is implemented by photoreduction reaction in the presence of both a silver precursor and a photosensitizer. The photoinduced formation of Ag NPs is confirmed by UV spectrophotometry and XPS analysis. SEM and TEM experiments confirm the formation and dispersion of Ag NPs on the surface of the modified fibers. Finally, a primary investigation is conducted to support the antibacterial activity of the new functionalized biomaterial against Staphylococcus aureus and Escherichia coli.
authors.affiliation: Université Paris-Est Créteil Val-de-Marne, Thiais, France. versace@icmpe.cnrs.fr
authors.forename: Davy-Louis
authors.initials: DL
authors.lastname: Versace
authors.forename: Julien
authors.initials: J
authors.lastname: Ramier
authors.forename: Daniel
authors.initials: D
authors.lastname: Grande
authors.forename: Samir Abbad
authors.initials: SA
authors.lastname: Andaloussi
authors.forename: Pierre
authors.initials: P
authors.lastname: Dubot
authors.forename: Nelly
authors.initials: N
authors.lastname: Hobeika
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Malval
authors.forename: Jacques
authors.initials: J
authors.lastname: Lalevee
authors.forename: Estelle
authors.initials: E
authors.lastname: Renard
authors.forename: Valerie
authors.initials: V
authors.lastname: Langlois
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D053768:Metal Nanoparticles; D008826:Microbial Sensitivity Tests; D055668:Photochemical Processes; D012834:Silver / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods; D013499:Surface Properties; D054457:Tissue Scaffolds; D014466:Ultraviolet Rays
chemical_list: D000900:Anti-Bacterial Agents; D012834:Silver
keywords: biopolymers; electrospinning; photochemistry; photogenerated silver nanoparticles; poly(3-hydroxybutyrate-co-3-hydroxyvalerate)