On the shuttling across the blood-brain barrier via tubule formation: Mechanism and cargo avidity bias

The blood-brain barrier is made of polarized brain endothelial cells (BECs) phenotypically conditioned by the central nervous system (CNS). Although transport across BECs is of paramount importance for nutrient uptake as well as ridding the brain of waste products, the intracellular sorting mechanisms that regulate successful receptor-mediated transcytosis in BECs remain to be elucidated. Here, we used a synthetic multivalent system with tunable avidity to the low-density lipoprotein receptor-related protein 1 (LRP1) to investigate the mechanisms of transport across BECs. We used a combination of conventional and super-resolution microscopy, both in vivo and in vitro, accompanied with biophysical modeling of transport kinetics and membrane-bound interactions to elucidate the role of membrane-sculpting protein syndapin-2 on fast transport via tubule formation. We show that high-avidity cargo biases the LRP1 toward internalization associated with fast degradation, while mid-avidity augments the formation of syndapin-2 tubular carriers promoting a fast shuttling across.

Combinatorial entropy behaviour leads to range selective binding in ligand-receptor interactions

From viruses to nanoparticles, constructs functionalized with multiple ligands display peculiar binding properties that only arise from multivalent effects. Using statistical mechanical modelling, we describe here how multivalency can be exploited to achieve what we dub range selectivity, that is, binding only to targets bearing a number of receptors within a specified range. We use our model to characterise the region in parameter space where one can expect range selective targeting to occur, and provide experimental support for this phenomenon. Overall, range selectivity represents a potential path to increase the targeting selectivity of multivalent constructs.

Green Plasmonic Nanoparticles and Bio-Inspired Stimuli-Responsive Vesicles in Cancer Therapy Application

: In the past years, there is a growing interest in the application of nanoscaled materials in cancer therapy because of their unique physico-chemical properties. However, the dark side of their usability is limited by their possible toxic behaviour and accumulation in living organisms. Starting from this assumption, the search for a green alternative to produce nanoparticles (NPs) or the discovery of green molecules, is a challenge in order to obtain safe materials. In particular, gold (Au NPs) and silver (Ag NPs) NPs are particularly suitable because of their unique physico-chemical properties, in particular plasmonic behaviour that makes them useful as active anticancer agents. These NPs can be obtained by green approaches, alternative to conventional chemical methods, owing to the use of phytochemicals, carbohydrates, and other biomolecules present in plants, fungi, and bacteria, reducing toxic effects. In addition, we analysed the use of green and stimuli-responsive polymeric bio-inspired nanovesicles, mainly used in drug delivery applications that have revolutionised the way of drugs supply. Finally, we reported the last examples on the use of metallic and Au NPs as self-propelling systems as new concept of nanorobot, which is able to respond and move towards specific physical or chemical stimuli in biological entities.

A new laccase-mediator system facing the biodegradation challenge: Insight into the NSAIDs removal

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely found pollutants in the aquatic environment and the currently available treatments for their removal are usually associated with some drawbacks. The aim of this research was to apply a laccase-mediator system for the degradation of some commonly used NSAIDs, namely diclofenac (DCF), naproxen (NAP) and ketoprofen (KP). The biocatalyst was obtained by direct immobilization on chitosan beads of a periodate-oxided laccase from Trametes versicolor. A preliminary study aimed to optimize DCF degradation in the presence of 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonicacid) diammonium salt (ABTS) as mediator. It turned out that pH 3 and a 1:1 M ratio for ABTS:drug were the best experimental conditions under which DCF was degraded at 90% after 3 h. In addition, an efficient reuse of the biocatalyst for up to 5 cycles emerged. DCF was further mixed with naproxen and ketoprofen to test whether laccase was still able to eliminate DCF and eventually act on the other compounds. At just 0.02 U of laccase activity, diclofenac was completely degraded within 3 h, while an almost complete removal for naproxen (∼90%) and a partial removal for ketoprofen (30%) occurred in 7 d when drugs were added at high concentrations (78.5 μM, 98 μM and 108 μM, respectively). After 7 d of degradation, transformation products of diclofenac, identified as hydroxylated compounds, disappeared. Naproxen products were, instead, reduced to very small amounts.

Cocaine profiling: Implementation of a predictive model by ATR-FTIR coupled with chemometrics in forensic chemistry

In this study, a strategy based on Infrared Spectroscopy with Fourier Transformed and Attenuated Total Reflectance associated with chemometrics (ATR-FTIR) is proposed to identify the chemical "fingerprint" of cocaine samples. To this end, standard mixtures of cocaine and cuttings at differents ratio were investigated in order to develop a multivariate classification model to simultaneously predict the composition of the samples and to obtain a profile of adulteration of cocaine seizures. In addition, the application of a Partial Least Squares (PLS) and Principal Component Regression (PCR) calibration approaches were found to be a useful tool to predict the content of cocaine, caffeine, procaine, lidocaine and phenacetin in drug seizures. The achieved results on real confiscated samples, in cooperation with the Italian Scientific Investigation Department (Carabinieri-RIS) of Rome, allow to consider ATR-FTIR followed to chemometrics as a promising forensic tool in such situations involving profile comparisons and supporting forensic investigations.