The rapid spreading of resistance among common bacterial pathogens towards the misused antibiotics/disinfectant agents has drawn much attention worldwide to bacterial infections. In light of this, the present work aimed at the realization of core-shell nanoparticles possessing remarkable antimicrobial properties thanks to the synergistic action of the metal core and the disinfectant shell. Copper nanoparticles stabilized by benzalkonium chloride were prepared, characterized, and implemented in poly-vinyl-methyl ketone to obtain nanoantimicrobial composite coatings. Bioactivity tests are reported, proving the excellent disinfectant properties of the proposed nanomaterials, as compared to one of the well-known and strongest silver-based nanoantimicrobials. Applications are also briefly described.

Bio-plastics are starting to graduate from the 'emerging technology' stage to market acceptance as everyday materials. In the present study, nanocomposite coatings embedding copper nanoparticles (CuNPs) were developed as new active packaging for fresh dairy products. In order to combine the bioactivity of CuNPs with a biodegradable polymer matrix, copper nanoparticles were satisfactorily incorporated into polylactic acid (PLA). Two different routes were carried out to prepare active films by picosecond-pulsed laser ablation. The nano-materials were characterized by UV-Vis spectroscopy and X-ray Photoelectron spectroscopy. Copper release was also measured through atomic absorption analyses. To assess the antimicrobial effects of nanocomposite systems, both in vitro and in vivo tests were carried out. The active polylactic acid films showed good antibacterial activity. In fiordilatte samples stored at 4 degrees C during 9 days, proliferation of main spoilage microorganisms was delayed with a consequent preservation of sensory attributes. These results represent a step forward in the possible application of copper in the food packaging industry.Industrial relevance: Bio-plastics with active properties represent the most emerging technology in food packaging field. Results from the current paper demonstrate that antimicrobial films of PLA embedding copper nanoparticles could be developed and applied to fresh dairy products as fiordilatte. In fact, the in vivo test confirmed the antimicrobial effects on fiordilatte spoilage, without compromising sensory attributes. Results could gain great importance from the industrial dairy sector. (C) 2013 Elsevier Ltd. All rights reserved.

Research on the nanomaterials containing one or more transition metals is growing tremendously, thanks to the large number of preparation processes available and to the novel applications that can be envisaged in several fields. This review presents an overview of the selected studies in the field of antimicrobial textiles, employing bioactive nanophases of elements/compounds such as silver, copper, or zinc oxide. In addition, the history of use of these antimicrobials and their mechanism of action are shortly reported. Finally, a short description is provided of the deposition/preparation methods, which are being used in the authors' labs for the development of the textiles modified by the novel nanoantimicrobials.

A new type of nanomaterial has been developed as antibacterial additive for food packaging applications. This nanocomposite is composed of copper nanoparticles embedded in polylactic acid, combining the antibacterial properties of copper nanoparticles with the biodegradability of the polymer matrix. Metal nanoparticles have been synthesised by means of laser ablation, a rising and easy route to prepare nanostructures without any capping agent in a liquid environment. As prepared, nanoparticle suspensions have been easily mixed to a polymer solution. The resulting hybrid solutions have been deposited by drop casting, thus obtaining self-standing antibacterial packages. All samples have been characterized by UV-Vis spectroscopy, X-ray photoelectron spectroscopy and electro-thermal atomic absorption spectroscopy. Ion release data have been matched with bioactivity tests performed by Japanese Industrial Standard (JIS) method (JIS Z 2801:2000) against Pseudomonas spp., a very common Gram-negative microbial group able to proliferate in processed food.

Copper-containing nanomaterials have been developed as antimicrobial additives for food packaging applications. These nano-antimicrobials are composed of copper nanoparticles (CuNPs) embedded in poly-lactic acid (PLA), which has been selected as a biodegradable polymer matrix. Copper nanostructures have been synthesized by laser ablation following two different protocols: (I) one-pot synthesis in presence of PLA and (II) in absence of polymer matrix. In the latter route, the as prepared CuNPs suspension has been subsequently mixed to a PLA solution. The resulting dispersions have been directly drop-cast on several substrates. Nanoantimicrobials have been characterized by UV-Vis and x-ray photoelectron spectroscopies, and transmission electron microscopy. The kinetics of copper release in aqueous solution from antimicrobial nanomaterials have been studied by means of Electro-Thermal Atomic Absorption Spectroscopy. Finally, preliminary biological tests have been performed on Pseudomonas species by JIS methods (Japanese Industrial Standard, JIS Z 2801:2000).