Bioengineered Surfaces for Real-Time Label-Free Detection of Cancer Cells

Biosensing technology is an advancing field that benefits from the properties of biological processes combined to functional materials. Recently, biosensors have emerged as essential tools in biomedical applications, offering advantages over conventional clinical techniques for diagnosis and therapy. Optical biosensors provide fast, selective, direct, and cost-effective analyses allowing label-free and real-time tests. They have also shown exceptional potential for integration in lab-on-a-chip (LOC) devices. The major challenge in the biosensor field is to achieve a fully operative LOC platform that can be used in any place at any time. The choice of an appropriate strategy to immobilize the biological element on the sensor surface becomes the key factor to obtain an applicable analytical tool. In this chapter, after a brief description of the main biofunctionalization procedures on silicon devices, two silicon-based chips that present an (i) IgG antibody or (ii) an Id-peptide as molecular probe, directed against the B-cell receptor of lymphoma cancer cells, will be presented. From a comparison in detecting cells, the Id-peptide device was able to detect lymphoma cells also at low cell concentrations (8.5 × 10−3 cells/μm2) and in the presence of a large amount of non-specific cells. This recognition strategy could represent a proof-of-concept for an innovative tool for the targeting of patient-specific neoplastic B cells during the minimal residual disease; in addition, it represents an encouraging starting point for the construction of a lab-on-a-chip system for the specific recognition of neoplastic cells in biological fluids enabling the follow-up of the changes of cancer cells number in patients, highly demanded for therapy monitoring applications

Cellular Interaction of Human Eukaryotic Elongation Factor 1A Isoforms

Besides its canonical role in protein synthesis, the eukaryotic translation elongation factor 1A (eEF1A) is also involved in many other cellular processes such as cell survival and apoptosis. We showed that eEF1A phosphorylation by C-Raf in vitro occurred only in the presence of eEF1A1 and eEF1A2, thus suggesting that both isoforms interacted in cancer cells (heterodimer formation). This hypothesis was recently investigated in COS-7 cells where fluorescent recombinant eEF1A isoforms colocalized at the level of cytoplasm with a FRET signal more intense at plasma membrane level. Here, we addressed our attention in highlighting and confirming this interaction in a different cell line, HEK 293, normally expressing eEF1A1 but lacking the eEF1A2 isoform. To this end, His-tagged eEF1A2 was expressed in HEK 293 cells and found to colocalize with endogenous eEF1A1 in the cytoplasm, also at the level of cellular membranes. Moreover, FRET analysis showed, in this case, the appearance of a stronger signal mainly at the level of the plasma membrane. These results confirmed what was previously observed in COS-7 cells and strongly reinforced the interaction among eEF1A isoforms. Moreover, the formation of eEF1A heterodimer in cancer cells could also be important for cytoskeleton rearrangements rather than for phosphorylation, most likely occurring during cell survival and apoptosis

Promotion effect of rare earth elements (Ce, Nd, Pr) on physicochemical properties of M-Al mixed oxides (M = Cu, Ni, Co) and their catalytic activity in N2O decomposition

A series of M-AlOx mixed oxides (M = Cu, Co, Ni) with the addition of high loadings of rare earth elements (REE, R = Ce, Nd, Pr; R0.5M0.8Al0.2, molar ratio) were investigated in N2O decomposition. The precursors were prepared by coprecipitation and subsequent calcination at 600\ua0\ub0C. The obtained mixed metal oxides were characterized by X-ray diffraction with Rietveld analysis, N2 sorption, and H2 temperature-programmed reduction. Depending on the nature of REE and the initial M-Al system, R cations could be separately segregated in oxide form or coordinated with the transition metal cations and form mixed structures. The addition of Ce3+ consistently led to nanocrystalline CeO2 mixed with the divalent oxides, whereas the addition of Nd3+ or Pr3+ resulted in the formation of their respective oxide phases as well as perovskites/Ruddlesden–Popper phases. The presence of REE modified the textural and redox properties of the calcined materials. The rare earth element-induced formation of low-temperature reducible MOx species that systematically improved the N2O decomposition on the modified catalysts compared to the pristine M-Al materials by the order of Co > Ni > Cu. The Ce0.5Co0.8Al0.2 catalyst revealed the highest activity and remained stable (approximately 90% of N2O conversion) for 50\ua0h during time-on-stream in 1000\ua0ppm N2O, 200\ua0ppm NO, 20 000\ua0ppm O2, 2500\ua0ppm H2O/N2 balance at WHSV = 16 L g−1\ua0h−1

Chapter 9: Silica-based Nanovectors: From Mother Nature to Biomedical Applications (Book chapter)

Diatomite is a natural porous silica material of sedimentary origin, formed by remains of diatom skeletons called “frustules.” The abundance in many areas of the world and the peculiar physico-chemical properties made diatomite an intriguing material for several applications ranging from food production to pharmaceutics. However, diatomite is a material still rarely used in biomedical applications. In this chapter, the properties of diatom frustules reduced to nanoparticles, with an average diameter less than 350 nm, as potential drug vectors are described. Their biocompatibility, cellular uptake, and capability to transport molecules inside cancer cells are discussed. Preliminary studies of in vivo toxicity are also presented.Peer reviewe

Editorial for Special Issue “New Insights in Stability, Structure and Properties of Porous Materials”

Porous materials (such as zeolites, clay minerals, and assemblies of oxide nanoparticles) are of great importance for the progress in many technological and environmental fields, such as catalysis, adsorption, separation, and ion exchange, because of their unique pore topologies, tunable structures, and the possibility of introducing active reaction sites. The major goal of this special issue is to provide a platform for scientists to discuss new insights in the stability, structure, and properties of porous materials, as well as in innovative aspects in their processing and applications. The emphasis is on the relationships between the structure and/or chemical composition and the specific physical properties of these materials, as well as their role in mineralogical, technological, green, and sustainable processes. With this special issue of Minerals, we have endeavored to provide an up-to-date selection of high-quality original and review papers concerning the physical, chemical, and structural characterization of porous materials, the synthesis of crystalline phases with pores in the appropriate range, structure–property relationships at ambient conditions but also at high temperatures and/or at high pressures, adsorption, and diffusion of mobile species in porous materials, host/guest interactions and confinement effects, ion exchange, modeling in geological and environmental processes, and new insights in processing and applications. In total, eight fashionable contributions reflect both the diversity and interdisciplinary of modern mineralogy, bridging together experimentalists and computational approaches

Pressure-induced hydration in acidic cation-exchanged zeolites: an Exafs study at Ga k edge

The catalytic property of zeolites is one of the more exploited for several type of reactions in the industrial field and the number of reactions catalysed by them has been extended. Moreover, new multicomponent polyfunctional catalysts with specific properties have been developed. The future applications of zeolite catalysts could target the synthesis of fuel from renewable biomass to increase the energy sources availability while decreasing CO2 emissions. The origin of the catalytic property of these materials resides in the presence of active acidic sites of two different nature, Brønsted and Lewis acid sites. In this proposal we intend to monitor the effect of pressure-induced hydration on four Ga-exchanged different zeolites topology (ferrierite, mordenite, ZSM-12 and L characterized by different Si/Al ratio) possessing both Bronsted and Lewis acidity. The water molecules that are the nearest neighbours of metal cation form the primary hydration sphere, protons of water molecules directly bonded to hydrated cations can form relatively strong hydrogen bonds and they are of acidic nature due to hydrolysis reaction. The acidity of the cations depends on its charge (oxidation number) and on the water-complex formed. These information can be obtained by a detailed EXAFS study at the Ga K-edge