S. Torrengo

Sustained in vitro release and cell uptake of doxorubicin adsorbed onto gold nanoparticles and covered by a polyelectrolyte complex layer

Gold nanoparticles functionalized with doxorubicin and stabilized with multilayers of degradable polyelectrolyte were allowed to age in aqueous medium in vitro in order to show the possibility of drug release in cellular environment. The chemico-physical characteristics of the nanoparticles are reported. The observed release of doxorubicin (DOX) was pH-dependent, and it increased in acidic environment. Cell uptake of nanoparticles and drug release were monitored by laser scanning confocal microscopy. Data showed that drug-bearing nanoparticles delivered DOX into the nuclei of A549 cells, leading to pronounced cytotoxic effects to this lung tumor cells. Our results suggest that gold nanoparticles conjugated with doxorubicin could be used as a pH-triggered drug releasing carrier for tumor drug delivery.

Synthesis and characterization of PMMA-based superhydrophobic surfaces

Recently, superhydrophobic surfaces are gaining much interest because they may be employed in a series of applications, spanning from the realization of self-cleaning surfaces to microfluidics to special water-impermeable tissues allowing perspiration. It is well-known that superhydrophobicity strictly depends on the combination of superficial micro- and nano-structures. Then, key factors in the process of surface synthesis are the parameters which will define the surface conformation. In this work, we deal with the fabrication of polymer-based superhydrophobic surfaces. We developed a new method to have a good control of the structure of the synthesised surface. A high stability of the superhydrophobic character during time was obtained. Moreover, the synthesis process is green and easily transferable to industry for large production.

XPS Characterization of Iron Oxide and Gold Nanoparticles for Tumor Care

Superparamagnetic iron oxide nanoparticles (SPIO) have a wide range of applications, including high-density magnetic storage, catalytic and separation processes, magnetic resonance imaging (MRI), in vivo imaging of tumor progression. One advantage is that they are sufficiently inert to be injected to the human body without significant counter effects. For these reasons, SPIO are utilized as carriers to target tumor tissues with the aim to visualize the extension of the malignant affection and to cure it. A mimetic coating is needed to overcome the immune system and ensure a sufficient long life to allow SPIO to reach the tumor tissue. In addition, gold nanoparticles were functionalized and coated with the same mimetic film. Differently from iron oxide NPs, those based on gold may be utilized to perform Surface Enhanced Raman Spectroscopy (SERS) to obtain spatial and chemical information. In this work, we present preliminary results on iron oxide and gold-based NPs synthesized in our laboratories. A full characterization was performed by means of XPS to study both the chemical composition of the SPIO nanoparticles, of their mimetic coatings, and to get structural information.

XPS Study of In Situ One-Step Amination of Nanocrystalline Diamond Films

In the present work two different in situ amination of hydrogenated nano-crystalline diamond surfaces were studied. The effects of an UV irradiation in pure ammonia gas were compared to those produced in a mixture of pure ammonia gas with a small amount of pure oxygen. In situ XPS analysis was used to study the evolution of surface terminations from “C-H” to “CNH2”. As we will show in this work, the grafting of NH2 functional groups to the diamond surface is mediated by oxygen indicating that oxygen plays a crucial role in the process of amination.

Synthesis of Carbon Nanotubes/Gold Nanoparticles Hybrids for Environmental Applications

Multi-walled carbon nanotubes were chemically cut by acid treatments and then deposited on 2-aminoethanethiol-modified gold substrate by the application of an external electric field. 2-aminoethanethiol-capped gold nanoparticles were then covalently bonded to the nanotubes to exploit their plasmon resonances. Reaction intermediates as well as the final products were analyzed by X-Ray Photoelectron Spectroscopy, Atomic Force Microscopy and Scanning Electron Microscopy. The synergetic interaction between carbon nanotubes and gold nanoparticles leads to an efficient signal enhancement in Raman spectra. This is of particular interest for the detection of toxic molecules dangerous for the environment.