Synthesis and biological assay of GSH functionalized fluorescent quantum dots for staining Hydra vulgaris

Quantum dots (QDs) have been used extensively as fluorescent markers in several studies on living cells. Here, we report the synthesis of conjugates based on glutathione (GSH) and QDs (GSH-QDs) and we prove how these functionalized fluorescent probes can be used for staining a freshwater invertebrate called Hydra vulgaris. GSH is known to promote Hydra feeding response by inducing mouth opening. We demonstrate that GSH-QDs as well are able to elicit biological activity in such an animal, which results in the fluorescent staining of Hydra. GSH-QDs, once they reach the gastric region, are internalized by endodermal cells. The efficiency of GSH-QD internalization increases significantly when nanoparticles are coadministrated with free GSH. We also compared the behavior of bare QDs to that of GSH-QDs both in the presence and in the absence of free GSH. The conclusions from these series of experiments point to the presence of GSH binding proteins in the endodermal cell layer and uncover a novel role played by glutathione in this organism

Positive Negative Arrays of Organic Light Emitting Diodes by a Surface Tension driven approach

A surface-tension-driven technique to pattern molecular arrays of organic light-emitting diodes by using a metallic grid to induce the geometrical confinement was presented. The technique enables the controlled replication of the micrometer-scale template, allowing the fabrication of arrays of OLED pixels of a well-defined geometry. The principle of this approach is the controlled dewetting of the molecular compounds in the feature of the template, allowing to realize either negative or positive patterns. The molecular TPD-patterned layer was realized by taking advantage of the combination of both liquid instability, following the dewetting phenomena, and geometrical confinement, induced by a template mes

Bioconjugation of Rod-Shaped Fluorescent Nanocrystals for Efficient Targeted Cell Labeling

In the present work, we report a three-step approach for the functionalization of CdSe/CdS core/shell and CdSe/CdS/ZnS double-shell quantum rods (QRs) with either biotin or folic acid. We carried out an in vitro study on cultured cells and fixed tissue sections in which the biofunctionalized QRs were compared with the more traditional CdSe/ZnS quantum dots (QDs), which were also functionalized with either biotin or folic acid. The QR and the QD samples exhibited the same specificity toward the targeting cells. In addition, due to the enhanced photoluminescence of the QRs with respect to QDs, a lower amount of rods was required to image cells. In immuno-localization experiments on rat brain tissue sections, biotin-functionalized QRs have shown the typical protein localization patterns expected both for neuronal enolase NSE and actin, confirming the specificity of the interaction of QRs with avidin, and the feasibility of these materials as fluorescent probes in tissue staining. In this specific targeting study, we could assess via the MTT test, a cell viability assay, the lower toxicity of the CdSe/CdS/ZnS QRs with respect to CdSe/CdS QRs

Magnetic nanobeads decorated by thermo-responsive PNIPAM shell as medical platforms for the efficient delivery of doxorubicin to tumour cells

Medical nanoplatforms based on clusters of superparamagnetic nanoparticles decorated with a PNIPAM thermo-responsive shell have been synthesized and used as drug carriers for doxorubicin (DOXO), a common chemotherapeutic agent. The nanosystem here developed has a total diameter below 200 nm and exploits the temperature responsive behaviour of the PNIPAM polymeric shell for the controlled loading and release of DOXO. The system has been tested in vitro on tumour cells and it clearly demonstrates the effectiveness of drug polymer encapsulation and time-dependent cell death induced by the doxorubicin release. Comparative cellular studies of the DOXO loaded nanoplatform in the presence or absence of an external magnet (0.3 T) showed the synergic effect of accumulation and enhanced toxicity of the system, when magnetically guided, resulting in the enhanced efficacy of the system

Family-Centered Care to Improve Family Consent for Organ Donation

The need for organ donation has increased over time, but the shortage of available donors is the major limiting factor in transplantation. Organ donation refusal from relatives of potential donors with brain death significantly reduces organ availability. We report a brief analysis about family conflicts in decision-making and causes for refusing donation; moreover, we describe new family-centered strategies in the intensive care unit (ICU) and our systematic communication approach between medical staff and patients’ relatives. In 2016 we conducted a single-center, non-randomized, controlled and before and after study in our ICU, an 18-bed intensive care unit (ICU) of a university hospital. We compared the rate of consent for organ donation before and after the introduction of the new communication approach. The application of a new communication approach between medical staff and relatives of brain-dead patients was associated with a significant increase in the rate of consent to donation. The positive results of the 3-year period 2013–2015 have been confirmed in the 2-year period 2016–2017. Our results highlight the importance of empathy and counselor support of relatives in the ICU

Nonlinear absorption and gain in InGaAs/GaAs quantum wells

We present a detailed study of the excitonic nonlinearities in InGaAs/GaAs multiple quantum wells based on both stationary and transient pump-and-probe transmission spectroscopy. Bleaching of the excitonic resonance and free carrier gain have been observed. A quantitative analysis of the observed nonlinearity is provided by means of a rigorous solution of the Bethe–Salpeter equation for the investigated heterostructures

Multifunctional nanostructures based on inorganic nanoparticles and oligothiophenes and their exploitation for cellular studies.

The combination of materials that possess different properties (such as, for instance, fluorescence and magnetism) into one single object of nanoscale size represents an attractive challenge for biotechnology, especially for their potential relevance in biomedical applications. We report here the preparation of novel bifunctional conjugates based on the linkage of inorganic nanoparticles to organic oligothiophene fluorophores (OTFs). In comparison to the organic dyes commonly used in bioimaging and more similarly to colloidal quantum dots, OTFs have broad optical absorption spectra, and therefore OTF fluorophores emitting at different colors can be excited with a single excitation source, allowing for easier multiplexing analysis. In this work we show the preparation of OTF-nanoparticle conjugates based on gold and iron oxide nanoparticles and their characterization using different techniques such as gel electrophoresis, photoluminescence spectroscopy, dynamic light scattering, and so on. In addition, by performing an in vitro study on human tumor cells we show that OTF-nanoparticle conjugates emitting at different colors can be used for multiplexing detection. Also, in the case of iron oxide-OTF conjugates, once uptaken by the cells, we show that they preserve both their fluorescent and their magnetic properties

Perfluorinated compounds (pfcs) in river waters of central Italy. Monthly variation and ecological risk assessment (era)

Perfluorinated compounds (PFCs) are a wide class of emerging pollutants. In this study, we applied the US EPA method 533 for the determination of 21 PFCs in river water samples. In particular, this method was used to investigate the presence of the target PFCs in six rivers in central Italy during a 4-month-long monitoring campaign. In 73% of the analyzed samples, at least some of the target PFCs were detected at concentrations higher than the limit of detection (LOD). The sum of the 21 target analytes ( n-ary sumation 21PFCs) ranged from 4.3 to 68.5 ng L-1, with the highest concentrations measured in the month of June, probably due to a minor river streamflow occurring in the warmer summer months. Considering the individual congeners, PFBA and PFPeA, followed by PFHxA and PFOA, were the predominantly detected compounds. Short- and medium-chain PFCs (C4-C9) prevail over the long-chain PFCs (C10-C18), likely due to the increased industrial use and the higher solubility of short-chain PFCs compared to long-chain PFCs. The ecological risk assessment, conducted by using the risk quotient method, highlighted that the risk for aquatic environments associated with PFBA, PFPeA, PFBS, PFHxA and PFOA was low or negligible. Only for PFOA, there was a medium level of risk in two rivers in the month of June. With regard to PFOS, 54% of the river water samples were classified as "high risk" for the aquatic environment. The remaining 46% of the samples were classified as "medium risk.

Acidic pH-responsive nanogels as smart cargo systems for the simultaneous loading and release of short oligonucleotides and magnetic nanoparticles.

Smart materials able to sense environmental stimuli can be exploited as intelligent carrier systems. Acidic pH-responsive polymers, for instance, exhibit a variation in the ionization state upon lowering the pH, which leads to their swelling. The different permeability of these polymers as a function of the pH could be exploited for the incorporation and subsequent release of previously trapped payload molecules/nanoparticles. We provide here a proof of concept of a novel use of pH-responsive polymer nanostructures based on 2-vinylpyridine and divinylbenzene, having an overall size below 200 nm, as cargo system for magnetic nanoparticles, for oligonucleotide sequences, as well as for their simultaneous loading and controlled release mediated by the pH

Pathogenesis and clinical approaches to anticonvulsant hypersensitivity syndrome: current state of knowledge.

Anticonvulsant hypersensitivity syndrome (AHS) is a rare, but severe and potentially fatal, adverse reaction that occurs in patients who are treated with commonly used older anticonvulsant drugs (phenytoin, carbamazepine and phenobarbital) and/or with some newer agents (lamotrigine). Paediatric patients are at an increased risk for the development of AHS for the higher incidence of seizure disorder in the first decade of life. Hypersensitivity reactions range from simple maculopapular skin eruptions to a severe life-threatening disorder. AHS is typically associated with the development of skin rash, fever and internal organ dysfunctions. Recent evidence suggests that AHS is the result of a chemotoxic and immunologically-mediated injury, characterized by skin and mucosal bioactivation of antiepileptic drugs and by major histocompatibility complex-dependent clonal expansion of T cells. Early recognition of AHS and withdrawal of anticonvulsant therapy are essential for a successful outcome. In vivo and vitro tests can be helpful for the diagnosis that actually depends essentially on clinical recognition