title: Electrospun cellulose acetate composites containing supported metal nanoparticles for antifungal membranes.
abstract: Electrospun cellulose acetate composites containing silver and copper nanoparticles supported in sepiolite and mesoporous silica were prepared and tested as fungistatic membranes against the fungus Aspergillus niger. The nanoparticles were in the 3-50nm range for sepiolite supported materials and limited by the size of mesopores (5-8nm) in the case of mesoporous silica. Sepiolite and silica were well dispersed within the fibers, with larger aggregates in the micrometer range, and allowed a controlled release of metals to create a fungistatic environment. The effect was assessed using digital image analysis to evaluate fungal growth rate and fluorescence readings using a viability stain. The results showed that silver and copper nanomaterials significantly impaired the growth of fungi when the spores were incubated either in direct contact with particles or included in cellulose acetate composite membranes. The fungistatic effect took place on germinating spores before hyphae growth conidiophore formation. After 24h the cultures were separated from fungistatic materials and showed growth impairment only due to the prior exposure. Growth reduction was important for all the particles and membranes with respect to non-exposed controls. The effect of copper and silver loaded materials was not significantly different from each other with average reductions around 70% for bare particles and 50% for membranes. Copper on sepiolite was particularly efficient with a decrease of metabolic activity of up to 80% with respect to controls. Copper materials induced rapid maturation and conidiation with fungi splitting in sets of subcolonies. Metal-loaded nanomaterials acted as reservoirs for the controlled release of metals. The amount of silver or copper released daily by composite membranes represented roughly 1% of their total load of metals. Supported nanomaterials encapsulated in nanofibers allow formulating active membranes with high antifungal performance at the same time minimizing the risk of nanoparticle release into the environment.
authors.affiliation: Department of Chemical Engineering, University of Alcalá, Alcalá de Henares, Madrid 28871, Spain.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Quirós
authors.affiliation: Department of Chemical Engineering, University of Alcalá, Alcalá de Henares, Madrid 28871, Spain.
authors.forename: Soledad
authors.initials: S
authors.lastname: Gonzalo
authors.affiliation: Department of Chemical Engineering, University of Alcalá, Alcalá de Henares, Madrid 28871, Spain.
authors.forename: Blanca
authors.initials: B
authors.lastname: Jalvo
authors.affiliation: Department of Chemical Engineering, University of Alcalá, Alcalá de Henares, Madrid 28871, Spain; Madrid Institute for Advanced Studies of Water (IMDEA Agua), Parque Científico Tecnológico, Alcalá de Henares, Madrid E-28805, Spain.
authors.forename: Karina
authors.initials: K
authors.lastname: Boltes
authors.affiliation: Department of Chemical Engineering, University of Alcalá, Alcalá de Henares, Madrid 28871, Spain.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Perdigón-Melón
authors.affiliation: Department of Chemical Engineering, University of Alcalá, Alcalá de Henares, Madrid 28871, Spain; Madrid Institute for Advanced Studies of Water (IMDEA Agua), Parque Científico Tecnológico, Alcalá de Henares, Madrid E-28805, Spain. Electronic address: roberto.rosal@uah.es.
authors.forename: Roberto
authors.initials: R
authors.lastname: Rosal
mesh_terms: D001234:Aspergillus niger / Q000187:drug effects*; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D003300:Copper / Q000494:pharmacology*; D005659:Fungicides, Industrial / Q000494:pharmacology*; D053768:Metal Nanoparticles; D012834:Silver / Q000494:pharmacology*
chemical_list: D005659:Fungicides, Industrial; C005062:acetylcellulose; D012834:Silver; D003300:Copper; D002482:Cellulose
keywords: Cellulose acetate; Electrospinning; Fungistatic membranes; Mesoporous silica; Nanometals; Sepiolite