Protein–nanoparticle hybrids represent entities characterized by emerging biological properties that can significantly differ from those of the parent components. Herein, bovine serum amine oxidase (i.e., BSAO) was immobilized onto a magnetic nanomaterial constituted of surface active maghemite nanoparticles (i.e., SAMNs, the core), surface-modified with tannic acid (i.e., TA, the shell), to produce a biologically active ternary hybrid (i.e., SAMN@TA@BSAO). In comparison with the native enzyme, the secondary structure of the immobilized BSAO responded to pH variations sensitively, resulting in a shift of its optimum activity from pH 7.2 to 5.0. Conversely, the native enzyme structure was not influenced by pH and its activity was affected at pH 5.0, i.e., in correspondence with the best performances of SAMN@TA@BSAO. Thus, an extensive NMR study was dedicated to the structure–function relationship of native BSAO, confirming that its low activity below pH 6.0 was ascribable to minimal structural modifications not detected by circular dichroism. The generation of cytotoxic products, such as aldehydes and H2O2, by the catalytic activity of SAMN@TA@BSAO on polyamine oxidation is envisaged as smart nanotherapy for tumor cells. The present study supports protein–nanoparticle conjugation as a key for the modulation of biological functions.

No abstract

<p>With the unprecedented urbanization in the last decades, massive solid wastes containing potentially toxic elements (PTEs) have been generated and dumped, which can be detrimental to soil health and affect flora and fauna. To minimize the exposure risks, delivering in-situ or ex-situ sustainable management of solid wastes continues to be one of the biggest public health challenges worldwide. Concurrently, in-situ high-performance solidification/stabilization<sup>©</sup> (S/S) has been proposed as a remediation strategy to prevent the release of pollutants in the stockpile sites, with ordinary Portland cement (OPC) being conventionally used as a cost-effective binder. However, growing concerns related to the substantial greenhouse gas emissions associated with the OPC production process and the limited PTEs retention capacity of OPC make the application of OPC under scrutiny. In this work, we examined the feasibility of minimizing the use of OPC in the S/S process of pyrite ash, a typical Pb and sulfate-rich solid waste generated in the sulfuric acid production industry. Four alternative binders (CEM/IIIB, calcium aluminate cement, white-steel-slag and ground-granulated blast-furnace slag mixture, and alkaline-activated ground-granulated blast-furnace slag) were tailored as solutions alternative to conventional OPC, with the aim of mitigating the anthropogenic CO<sub>2</sub> emissions and promoting the PTEs retention. The experimental characterization and geochemical modeling of the stabilized products revealed the different interactions between the applied binder scenarios and pyrite ash, which clarifies the roles of hydration products and the binding systems’ microstructures on the Pb and sulfate leachability. Further, we evaluated the cradle-to-gate carbon footprint and cost analysis associated with each binder-pyrite ash system. Overall findings underscore that applying these alternative binders could be pivotal in the envisaged carbon-neutral scenario and offer technical benefits in future field trials if the growth of the cement-free roadmap continues.</p>

The musk fragrance Galaxolide® (HHCB) is widely used in personal care and household products. Its large use leads to a continuous release of the compound into aquatic environments. Although some studies on the presence of HHCB in ecosystems and biota have been conducted, limited data about its effects on organism biomarkers are available. This study aimed at investigating both cellular and biochemical effects of HHCB in the clam Ruditapes philippinarum. Mussels were exposed for 7, 14 and 21 days to 100 ng/L and 500 ng/L of HHCB in seawater, and the effects on haemocyte parameters and antioxidant enzyme activities in the gills and digestive gland were evaluated. In addition, the neurotoxic potential of HHCB and its capacity to cause oxidative damage to proteins were assessed. Overall, our results demonstrated that exposure to HHCB was able to induce changes in biomarker responses of mussels, mainly at the cellular level.