Fluorogenic hyaluronan nanogels for detection of micro- and nanoplastics in water

Environmental pollution from plastics is exponentially increasing due to human activities. While larger microplastics can be detected with various methods, retrieving micron-sized fragments and nanoplastics remains challenging. Yet, these smaller-sized plastics have been raising considerable toxicological concern. Here, we show that a poorly emissive hyaluronan functionalized with rhodamine B (HA–RB) adheres with high affinity to various microplastic surfaces, becoming brightly emissive. Micro- and nanoplastics (MNPs) can be successfully detected with size as small as the diffraction limit of confocal microscopy (ca. 250 nm). FLIM images show that the fluorescence lifetime of the dye moieties changes according to the plastics, making possible a discrimination of the nature of MNPs based on lifetime. HA–RB, compared to previous reports, eliminates false-positive results caused by formation of dye aggregates, resulting in a higher S/N ratio which allows the unequivocal detection of nano-sized fragments

PluS Nanoparticles Loaded with Sorafenib: Synthetic Approach and Their Effects on Endothelial Cells

Silica nanostructures are widely investigated for theranostic applications, since relatively mild and easy synthetic methods allow the fabrication of multi-compartment nanoparticles (NPs) and to finely modulate their properties. Here, we report the optimization of a synthetic strategy leading to brightly fluorescent silica NPs with a high loading ability – up to 45 molecules per NP – of Sorafenib, a small molecule acting as antiangiogenic drug. We demonstrate that these NPs can efficiently release the drug and they are able to inhibit endothelial cell proliferation, migration and network formation. Their lyophilization can endow them with long shelf stability while, once in solution, they show a much slower release compared to analogous micellar systems. Interestingly, Sorafenib released from PluS NPs completely prevented endothelial cell responses and post-receptor MAPK signaling ignited by VEGF, one of the major player of tumor angiogenesis. Our results indicate that these theranostic systems represent a promising structure for anti-cancer applications since NPs alone have no cytotoxic effect on cultured endothelial cells, a cell type to which drugs and exogenous material are always in contact once delivere

Tandem Dye-Doped Nanoparticles for NIR Imaging via Cerenkov Resonance Energy Transfer

The detection of the Cerenkov radiation (CR) is an emerging preclinical imaging technique which allows monitoring the in vivo distribution of radionuclides. Among its possible advantages, the most interesting is the simplicity and cost of the required instrumentation compared, e.g., to that required for PET scans. On the other hand, one of its main drawbacks is related to the fact that CR, presenting the most intense component in the UV-vis region, has a very low penetration in biological tissues. To address this issue, we present here multifluorophoric silica nanoparticles properly designed to efficiently absorb the CR radiation and to have a quite high fluorescence quantum yield (0.12) at 826 nm. Thanks to a highly efficient series of energy transfer processes, each nanoparticle can convert part of the CR into NIR light, increasing its detection even under 1.0-cm thickness of muscle

modelling and control of a free cooling system for data centers

Abstract Data centers are facilities hosting a large number of servers dedicated to data storage and management. In recent years, their power consumption has increased significantly due to the power density of the IT equipment. In particular, cooling represents approximately one third of the total electricity consumption, therefore efficiently cooling data centers has become a challenging problem and it represents an opportunity to reduce both IT energy costs and emissions environmental impact. The efficiency of computers room air conditioning (CRAC) systems can be increased using both advanced control techniques and new free cooling technologies, such as the indirect adiabatic cooling (IAC), that is the humidification of air under adiabatic conditions. Water sprinkled by spray nozzles humidifies and cools down the air taken from the outside, which then cools down the computers room air by means of a crossflow heat exchanger. In this way, the process air temperature is economically reduced and the cooling process is effective even when the outside temperature is warmer than that desired in the computers room. Beside the traditional approach, that improves energy efficiency of CRAC systems through advanced hardware design, nowadays advanced control systems offer the opportunity to improve both efficiency and performance by mostly acting on software components. In particular, a model-based paradigm can result very useful in the design of the controller. This approach involves three main steps: plant modelling, controller design, and simulations. In this paper, First-Principle Data-Driven (FPDD) techniques have been considered in the modelling phase, in order to obtain a model as simple as possible but accurate enough. All the main components of the plant, such as fans, spray nozzles, heat exchanger, and the computers room have been taken into account and they have been calibrated exploiting real data. The dynamics of the computers room variables (e.g. temperature) are slower than those of the components of the cooling system, due to higher thermal inertias of the computers room. Therefore, fans, heat exchanger, and spray nozzles are described by static models, whereas the computers room is described by a LTI dynamic model. Once obtained a model of the plant, a simulation environment based on Matlab/Simulink is designed accordingly. The developed control system is hierarchical: a supervisor determines the best combination of CRAC water and process air flows which minimizes the total power consumption, while satisfying the cooling demand. This system energy management problem is formulated as a non-linear optimization problem, subject to internal air condition requirements and system operating constraints. The optimization problem is repeatedly solved at each supervision period by using a population based stochastic optimization technique (Particle Swarm Optimization). Results of simulations show that the proposed control system is effective and minimizes the input electric power while satisfying both the data center thermal load and system operating constraints

Effect of anabolics on bovine granulosa-luteal cell primary cultures.

Granulosa cell tumours are observed with increased frequency among calves slaughtered in Northern Italy. The use of illegal anabolics in breeding was taken into account as a cause of this pathology. An in vitro approach was used to detect the possible alterations of cell proliferation induced by anabolics on primary cultures of bovine granulosa-luteal cells. Cultures were treated with different concentrations of substances illegally used in cattle (17beta-estradiol, clenbuterol and boldione). Cytotoxicity was determined by means of MTT test, to exclude toxic effects induced by anabolics and to determine the highest concentration to be tested. Morphological changes were evaluated by means of routine cytology, while PCNA expression was quantified in order to estimate cell proliferation. Cytotoxic effects were revealed at the highest concentrations. The only stimulating effect on cell proliferation was detected in boldione treated cultures: after 48 h treated cells, compared to controls, showed a doubled expression of PCNA. In clenbuterol and 17beta-estradiol treated cells PCNA expression was similar to controls or even decreased. As the data suggest an alteration in cell proliferation, boldione could have a role in the early stage of pathogenesis of granulosa cell tumour in cattle

Core–Shell Pluronic-Organosilica Nanoparticles with Controlled Polarity and Oxygen Permeability

Nanostructured systems constitute versatile carriers with multiple functions engineered in a nanometric space. Yet, such multimodality often requires adapting the chemistry of the nanostructure to the properties of the hosted functional molecules. Here, we show the preparation of core-shell Pluronic-organosilica "PluOS" nanoparticles with the use of a library of organosilane precursors. The precursors are obtained via a fast and quantitative click reaction, starting from cost-effective reagents such as diamines and an isocyanate silane derivative, and they condensate in building blocks characterized by a balance between hydrophobic and H-bond-rich domains. As nanoscopic probes for local polarity, oxygen permeability, and solvating properties, we use, respectively, solvatochromic, phosphorescent, and excimer-forming dyes covalently linked to the organosilica matrix during synthesis. The results obtained here clearly show that the use of these organosilane precursors allows for finely tuning polarity, oxygen permeability, and solvating properties of the resulting organosilica core, expanding the toolbox for precise engineering of the particle properties

Preparation of Non-Toxic Fluorescent Peptide-Coated Silica/PEG Nanoparticles from Peptide-Block Copolymer Conjugates

Peptide-decorated nanosystems have demonstrated higher stability and improved cellular uptake as compared to bare NPs and appear highly promising in diagnostics and theranostics of cancer. Herein, we discuss the preparation and structural characterization of peptide-functionalized silica/PEG NPs, starting from peptide–block copolymers, prepared in turn by conjugation of the peptides to block copolymers before NP formation. This synthetic design allowed full control of density and composition of peptide surface coverage. Preliminary experiments support the low toxicity of the fluorescent peptide–NPs and their ability of cell internalizatio

Effect of anabolics on bovine granulosa-luteal cell primary cultures.

Granulosa cell tumours are observed with increased frequency among calves slaughtered in Northern Italy. The use of illegal anabolics in breeding was taken into account as a cause of this pathology. An in vitro approach was used to detect the possible alterations of cell proliferation induced by anabolics on primary cultures of bovine granulosa-luteal cells. Cultures were treated with different concentrations of substances illegally used in cattle (17beta-estradiol, clenbuterol and boldione). Cytotoxicity was determined by means of MTT test, to exclude toxic effects induced by anabolics and to determine the highest concentration to be tested. Morphological changes were evaluated by means of routine cytology, while PCNA expression was quantified in order to estimate cell proliferation. Cytotoxic effects were revealed at the highest concentrations. The only stimulating effect on cell proliferation was detected in boldione treated cultures: after 48 h treated cells, compared to controls, showed a doubled expression of PCNA. In clenbuterol and 17beta-estradiol treated cells PCNA expression was similar to controls or even decreased. As the data suggest an alteration in cell proliferation, boldione could have a role in the early stage of pathogenesis of granulosa cell tumour in cattle

Interaction between Engineered Pluronic Silica Nanoparticles and Bacterial Biofilms: Elucidating the Role of Nanoparticle Surface Chemistry and EPS Matrix

Nanoparticles (NPs) are considered a promising tool in the context of biofilm control. Many studies have shown that different types of NPs can interfere with the bacterial metabolism and cellular membranes, thus making them potential antibacterial agents; however, fundamental understanding is still lacking on the exact mechanisms involved in these actions. The development of NP-based approaches for effective biofilm control also requires a thorough understanding of how the chosen nanoparticles will interact with the biofilm itself, and in particular with the biofilm self-produced extracellular polymeric matrix (EPS). This work aims to provide advances in the understanding of the interaction between engineered fluorescent pluronic silica (PluS) nanoparticles and bacterial biofilms, with a main focus on the role of the EPS matrix in the accumulation and diffusion of the particles in the biofilm. It is demonstrated that particle surface chemistry has a key role in the different lateral distribution and specific affinity to the biofilm matrix components. The results presented in this study contribute to our understanding of biofilm-NP interactions and promote the principle of the rational design of smart nanoparticles as an important tool for antibiofilm technology.Science Foundation Irelan