In this work PEGylated polyester-based nanoparticles (NPs) for drug delivery applications were synthetized through emulsion free radical polymerization. These NPs are produced starting from functionalized macromonomers whose average chain length can be tuned in a controlled way. Since the degradation of these NPs occurs through the hydrolysis of side chains, by tuning their length it is possible to obtain NPs with a controllable degradation time, comparable to data obtained with NPs internalized into cells. The long-term colloidal stability of these NPs in isotonic environment has been assessed through dynamic light scattering measurements and their degradation rate in cell medium has been proved to be fast and controllable. The NP behavior in gastric and intestinal solution was also studied.

Efficient application of stem cells to the treatment of neurodegenerative diseases requires safe cell tracking to follow stem cell fate over time in the host environment after transplantation. In this work, for the first time, fluorescent and biocompatible methyl methacrylate (MMA)-based nanoparticles (fluoNPs) were synthesized through a free-radical co-polymerization process with a fluorescent macromonomer obtained by linking Rhodamine B and hydroxyethyl methacrylate. We demonstrate that the fluoNPs produced by polymerization of MMA-Rhodamine complexes (1) were efficient for the labeling and tracking of multipotent human amniotic fluid cells (hAFCs); (2) did not alter the main biological features of hAFCs (such as viability, cell growth and metabolic activity); (3) enabled us to determine the longitudinal bio-distribution of hAFCs in different brain areas after graft in the brain ventricles of healthy mice by a direct fluorescence-based technique. The reliability of our approach was furthermore confirmed by magnetic resonance imaging analyses, carried out by incubating hAFCs with both superparamagnetic iron oxide nanoparticles and fluoNPs. Our data suggest that these finely tunable and biocompatible fluoNPs can be exploited for the longitudinal tracking of stem cells.

The electrochemical behavior of magnetite (Fe3O4) aggregates with submicrometric size is investigated. Specifically, cyclic voltammetry tests were performed in both acidic (pH ∼ 4.5) and alkaline (pH ∼ 12.8) solutions, exploiting a conventional three-electrode cell. In the first case, the working electrode was made of a glassy carbon substrate loaded with magnetite nanoaggregates, forming a continuous film. In a second configuration, magnetite nanoaggregates were dispersed in solution, kept under stirring, as a fluidized electrode. The latter approach showed an increase in the electrochemical response of the particles, otherwise limited by the reduced active area as in the former case. Electrochemical-atomic force microscopy (EC-AFM) investigation was carried out in an acidic environment, showing the topography evolution of nanoaggregates during the electrochemical characterization. X-ray diffraction (XRD) analysis was carried out to evaluate the microstructural variation in the Fe3O4 electrodes after cathodic polarization tests in an alkaline environment.

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Over the last few years, oil companies have devoted much effort to decrease the amount of water that is pumped up with oil, especially from mature reservoirs, where the water production is huge. In addition to reducing the profit margin, the water extracted from an oil field is polluted by different organic and inorganic compounds and must be properly treated before being discharged or reinjected. Alternatively, it must be disposed of with high treatment and/or disposal costs. To overcome costs associated with water treatment/disposal, mechanical and chemical strategies aimed at reducing the amount of extracted water (i.e., water shut-off) are applied. Among them, hydrophilic polymeric micro-and nanogels are promising materials that are gaining increasing interest. They are three-dimensional networks able to retain water by increasing in size and thus creating a physical barrier to the water flowing. In this work, nano-and microabsorbent particles made up of crosslinked poly(methacrylic acid-co-oligo(ethylene glycol) methyl ether methacrylate) p(MAA-co-OEGMA) were synthesized via inverse suspension polymerization in Lamix, an aromatic-free hydrocarbon blend. The formulation was optimized in terms of OEGMA mole fraction to achieve a high swelling in seawater and hence high efficacy in the water shut-off. Finally, the suspension was modified to be produced on a ton scale and injected into an open-hole, partially depleted oil reservoir for a first pilot field test. One-year monitoring was conducted by evaluating the oil productivity as well as the water fraction (i.e., water cut) under conventional extraction procedures. This trial assessed a 30% decrease in the water cut, as well as an increase in the oil production from 5 to 30 m 3 /day. This confirmed the developed microgels as a promising tool for water shut-off.