Barbara Capone

Novel hybrid Fe ₃ O ₄ superparamagnetic nanoparticles with polyoxazoline coatings enable the selective adsorption of pollutants and heavy metals, offering a refined and versatile solution for cutting-edge water purification. Graphical abstract background via Canva.com.

This study investigates the behavior of a biocompatible polyoxazoline (PO) polymer in water. POs are of interest for biological applications due to their biocompatibility and thermoresponsive behavior, making them ideal polymers for developing smart materials. This study focuses on PAmOx, a macromolecule that has recently been used to develop nanoscale tools for water remediation. However, despite the significant interest in the applications of PAmOx, its behavior in water and its thermal response remain to be thoroughly characterized. To address such a gap, we present a combined computational and experimental study of PAmOx's properties in aqueous solution. UV–Vis experimental results reveal a distinct transition temperature of 40°C, which is consistent with the thermoresponsive nature of numerous POs. Above this temperature, significant macromolecular aggregation occurs. Computational results demonstrate that, while temperature has no impact on hydration at the single‐chain level in water, an increase in temperature promotes aggregation by enhancing hydrophobic effects. Crucially, during aggregation, interchain hydrogen bonds replace polymer‐water interactions, thereby stabilizing the aggregate by maintaining an almost constant number of hydrogen bonds per monomer.

Organic wastewater compounds (OWCs) employed in human activities are, nowadays, commonly detected in surface water, groundwater, and drinking water. In particular, pharmaceuticals have caused great concern because after their consumption, traces of metabolites are excreted and reach the water resources either directly or after inefficient treatment. Despite this, these compounds are not regulated in drinking water, and existing toxicity data are inadequate to assess potential risks from chronic low-dose exposure. Considering the necessity to find new efficient, reusable, and biocompatible systems to remove organic pollutants from wastewater, the adsorption process has been found to be the most effective and economical because it is simple, highly efficient, regenerative, and scalable and does not produce intermediates that can increase the toxicity of the parent contaminants. Prompted by these reasons, in this research, an adsorbed medium composed of graphene oxide and an amine-oxazoline-based polymer (poly­(2-(3-(amino)­propyl))-2-oxazoline) was synthesized and employed in several adsorption experiments targeting nonsteroidal anti-inflammatory drugs such as ibuprofen (1), aspirin (2), ketoprofen (3), and benzoic acid (4). The specific interaction between acidic moieties of drugs and basic domains of the polymer has been investigated by targeting both acid compounds and pharmaceutical products free of carboxylic groups. Also, the influence of several parameters, including initial concentration, liquid-phase composition, pH, and reusability, has been investigated. Results show that the maximum adsorption capacity for ibuprofen (1), aspirin (2), ketoprofen (3), and benzoic acid (4) for experiments conducted in water, at the maximum initial concentration explored (90 mg L–1) and at natural pH equilibrium (pH ∼ 4), are, respectively, 37.4, 27.5, 43.5, and 26.0 mg g–1. These findings suggest that the prepared GO-pAmOx material has significant potential for adsorbing these drugs in water and good versatility for all investigated acid compounds and maintains high reusability. Notably, the reduction in adsorption capacity after ten adsorption cycles was only 1%.

Self-assembled nanostructures of tip functionalised anisotropic particles can be tuned by choosing aspect ratio, inteaction strength range or density.

[This corrects the article DOI: 10.1021/acsomega.3c02921.].

The urgency to find complementary therapies to current SARS-CoV-2 vaccines, whose effectiveness is preserved over time and not compromised by the emergence of new and emerging variants, has become a critical health challenge. We investigate the possibility of jamming the opening of the Receptor Binding Domain (RBD) of the spike protein of SARS-CoV-2 with small compounds. Through in silico screening, we identified two potential candidates that would lock the Receptor Binding Domain (RBD) in a closed configuration, preventing the virus from infecting the host cells. We show that two drugs already approved by the FDA, mithramycin and dihydroergotamine, can block infection using concentrations in the μM range in cell-based assays. Further STD-NMR experiments support dihydroergotamine's direct interaction with the spike protein. Overall, our results indicate that repurposing of these compounds might lead to potential clinical drug candidates for the treatment of SARS-CoV-2 infection.

The design of nano-functionalised membranes or channels, able to effectively adsorb pollutants in aqueous solutions, is a topic that is gaining a great deal of attention in the materials science community. With this work we explore, through a combination of scaling theories and molecular dynamics simulations, the adsorption of spherical non-deformable colloidal nanoparticles within planar polymeric brushes. Our strategy is twofold: first, we generalise the Alexander-de Gennes theory for planar homopolymeric brushes to the case of diblock copolymer brushes, then we map the adsorbing homopolymeric brushes onto a diblock copolymer system, where the adsorbed colloids and all interacting monomers are considered monomers in bad solvent and we apply the generalised scaling theory to this effective diblock copolymer. This allows the prediction of the average conformation of the grafted substrate, i.e. its average height, as a function of the amount of loaded particles, as well as the introduction of a continuous mapping between a homopolymeric brush, the fraction of loaded particles and the average height of the adsorbing substrate.

The rich and complex phase diagram typical of anisotropic biological or synthetic nanoparticles, has brought a great deal of interest over the equilibrium phase behaviour of non-spherical colloids. Amongst the class of anisotropic nanoparticles, hard spherocylindrical colloids have been, over the years, extensively studied because of their optical properties, for their rich phase diagrams, and their important industrial applications, as model particles for biological systems (viruses), or for example as potential drug carriers having the ability of surviving the attacks of the immune systems. As real anisotropic nanoparticles are often polydisperse in size and/or in shape, unveiling the effect of such a perturbation over their equilibrium phase diagram is of paramount importance. This work focuses on the effects of polydispersity over the full equilibrium phase diagram of hard spherocylindrical colloids (HSCs). Previous studies showed that a polydispersity in L alters the equilibrium phase diagram of HSCs. With this work we determine, both theoretically as well as computationally, the effects due to a generic polydispersity, namely in D, in L and, in both ones, on the equilibrium phase diagram and introduce a viable theoretical generalisation of the Onsager theory that allows us to get some insight into the observed phase behaviour.