Noble metal nanoparticles networks stabilized by rod-like organometallic bifunctional thiols

Rod-like organometallic dithiol containing square-planar Pt(II) centers, i. e., trans,trans-[(H3COCS)Pt(PBu3)(2)(C equivalent to C-C6H4-C6H4-C equivalent to C)(PBu3)(2)Pt(SCOCH3)] was used as bifunctional stabilizing agent for the synthesis of Pd-, Au-, and AgNPs (MNPs). All the MNPs showed diameters of about 4 nm, which can be controlled by carefully modulating the synthesis parameters. Covalent MNPs stabilization occurred through a single S bridge between Pt(II) and the noble metal nanocluster surfaces, leading to a network of regularly spaced NPs with the formation of dyads, as supported by SR-XPS data and by TEM imaging analysis. The chemical nature of NPs systems was also confirmed by EDS and NMR. Comparison between SR-XPS data of MNPs and self-assembled monolayers and multilayers of pristine rod-like dithiols deposited onto polycrystalline gold surfaces revealed an electronic interaction between Pt(II) centers and biphenyl moieties of adjacent ligands, stabilizing the organic structure of the network. The possibility to obtain networks of regularly spaced MNPs opens outstanding perspectives in optoelectronics

Truffle farming and nanomaterials: a new technology for the optimization of the mycorrhization process and release of "helper" microorganisms

Truffle farming is synonymous with specialized plantations where the quality of the starting material, that is the plant with the mycorrhiza, determines its productivity and economic sustainability. The mycorrhizal phase still represents a crucial point in the process and the study of the rhizospheric microbiome in the process of mycorrhizal symbiosis through the action of 'helper' microorganisms is of crucial importance. The TANA project is part of this complex context, in which research groups from the University of Tuscia, Sapienza, in collaboration with the start-up Nanomnia, thanks to funding from LazioInnova regional funding agency for innovation of Regione Lazio, have proposed a new synergistic approach for the enhancement and optimization of truffle farming processes thanks to the combined use of nanotechnologies. Indeed, numerous inorganic compounds, bacteria and viruses contribute to the complexity of the soil biota; among these, bacteria are the most abundant and many of them are classified as MHB (mycorrhiza helper bacteria) because they are able to stimulate the formation of mycorrhizal symbiosis and its vitality. In this context, nanomaterials can act as carriers for bioactive species and at the same time can be effective in stabilizing and protecting encapsulated molecules / microorganisms (fungi and bacteria), favoring their gradual release into the environment. The study of inorganic nanoparticles and polymer / nanoparticle composites, to be used as carriers of microorganisms in the soil, has the main purpose of improving the development of the rhizosphere by providing a consistent source of fungi and bacteria capable of interacting with the root system and the microbiome of the soil. Polysaccharides are among the most stable and most efficient biomaterials to meet the needs that the encapsulation of microorganisms requires. Among these, alginate, a natural polymer extracted from brown algae, is the most used because it is non-toxic to humans and the environment, inexpensive and suitable for encapsulating living cells. It is therefore possible to prepare alginate beads with a controlled diameter and, with a simple methodology, also create formulations by encapsulating mycorrhizogenic fungi and MHB bacteria at the same time. Furthermore, it is possible to encapsulate inorganic nanoparticles (AgNPs) which at low doses show beneficial effects on the growth and development of the rhizosphere thanks to a slow controlled release. The specific objective of TANA is therefore to develop a new biotechnological manufacturing product based on the use of nanotechnologies, functional to the truffle supply chain for Tuber melanosporum (precious black truffle) in the process phase that concerns the production of high quality mycorrhized plants, for productive plantations

Acrylates-based hydrophilic co-polymeric nanobeads as nanocarriers for imaging agents

Acrylates-based co-polymeric nanoparticles (PNPs) are widely used in nanomedicine applications due to their tunable hydrophilic surface, physical and chemical versatility. Particularly attracting is their use as nanocarriers for imaging agents. Herein, methyl methacrylate (MMA) and N,N-dimethylacrylamide (DMAA) monomers were used to synthesize hydrophilic p(MMA-co-DMAA) nanoparticles in the 200–600 nm size range via surfactant-free radical emulsion polymerization technique. Different MMA/DMAA molar ratios, temperatures, and reaction times were investigated to evaluate their role in determining the average particle size, polydispersity, and optimizing surface properties of PNPs. Nanoparticles formation, stability (in water and culture medium for cell growth), swelling behavior, structural features and molecular weights were assessed by spectroscopic, non-spectroscopic, and chromatographic techniques. Morphological profiles confirming spherical-shaped NPs were obtained at solid state via microscopies (FESEM, AFM). To use such colloids as potential imaging agents, PNPs were loaded with Y3+(aq) ions by the addition of aqueous solutions of YCl3 at different concentrations, and results compared with p(MMA-co-AA)-DTPA NPs (AA = acrylic acid) functionalized with DTPA chelating agent. Yttrium ions loading percentage was ca. 90% for both p(MMA-co-DMAA) and p(MMA-co-AA)-DTPA, with negligible release (<15%) over a month. Parallelly, optical imaging nanoprobes were obtained by physical encapsulation of fluorescein isothiocyanate isomer I (FITC) dye during the synthesis process, and the spontaneous FITC incorporation was evaluated by spectroscopic studies and fluorescence microscopy. Cytotoxicity studies on pristine and yttrium-loaded nanoparticles were done in vitro on human glioblastoma T98G cell line within 24 h of treatment. Transmission electron microscopy (TEM) studies on cancer cells treated with NPs confirmed an active uptake of PNPs through multiple endocytic pathways to reach the perinuclear region of the cell. Overall, this work elucidated the role of synthetic parameters for a rational design of hydrophilic PNPs as nanocarriers for imaging agents with potential applications in theranostics