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Miriam HANUSKOVA

Personale tecnico amministrativo
Dipartimento di Ingegneria "Enzo Ferrari"

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Pubblicazioni

2022 - Characterisation of potentially toxic natural fibrous zeolites by means of electron paramagnetic resonance spectroscopy and morphological-mineralogical studies [Articolo su rivista]
Giordani, M.; Mattioli, M.; Cangiotti, M.; Fattori, A.; Ottaviani, M. F.; Betti, M.; Ballirano, P.; Pacella, A.; Di Giuseppe, D.; Scognamiglio, V.; Hanuskova, M.; Gualtieri, A. F.
abstract

This study explored the morphological, mineralogical, and physico-chemical features of carcinogenic erionite and other possibly hazardous zeolites, such as mesolite and thomsonite, while also investigating the interacting capability of the mineral surface at the liquid/solid interface. Extremely fibrous erionite is K+ and Ca2+-rich and shows the highest Si/Al ratio (3.38) and specific surface area (8.14 m2/g). Fibrous mesolite is Na+ and Ca2+-rich and displays both a lower Si/Al ratio (1.56) and a smaller specific surface area (1.56 m2/g). The thomsonite composition shows the lowest values of Si/Al ratio (1.23) and specific surface area (0.38 m2/g). Electron paramagnetic resonance data from selected spin probes reveal that erionite has a homogeneous site distribution and interacts well with all spin probes. The surfaces of mesolite and thomsonite are less homogeneous and closer polar sites were found through consequent interaction with the probes. The mesolite surface can also clearly interact but with a lower strength and may represent a potential health hazard for humans, though with a lower degree if compared to erionite. The thomsonite surface is not inert and interacts with the probes with a low-grade capability. We can expect small fragments of thomsonite to interact with the biological environment, though with a low-grade intensity.

2022 - Preliminary Assessment of Rice Husk Ash (RHA) as Functional Interphase Agent in Sustainable Composite Systems for Structural Strengthening [Relazione in Atti di Convegno]
Sola, Antonella; Signorini, Cesare; Hanuskova, Miriam; Zapparoli, Mauro
abstract

Over the last few years, the effectiveness of textile-reinforced mortar (TRM) composite systems for structural retrofitting has led to the widespread adoption of these materials in the practice and to the issue of up-to-date design guidelines. Nonetheless, the weak interfacial bonding that is frequently observed between matrix and fibres is likely to cause inconsistent failure modes and, generally speaking, to severely limit the reinforcing potential of the textile. A promising solution to tackle this issue consists in treating the surface of the reinforcing fibres with a functional coating to improve the adhesion at the interphase. In this paper, a pilot study is presented to assess the effectiveness of a fully sustainable polymer coating, consisting in polyvinyl alcohol (PVA) loaded with with rice husk ash (RHA) or with a 50/50 mixture of RHA and silica fume (SF). The coating was applied on basalt fabrics to reinforce TRM coupons that were mechanically tested under uni-axial tensile loads. The mechanical properties of the TRM samples were significantly increased by up to 20%, and the peak load was attained at a higher deformability level, which is a clue of the enhanced ductility of the reinforced elements.

2021 - Characterization and assessment of the potential toxicity/pathogenicity of Russian commercial chrysotile [Articolo su rivista]
Di Giuseppe, D.; Zoboli, A.; Nodari, L.; Pasquali, L.; Sala, O.; Ballirano, P.; Malferrari, D.; Raneri, S.; Hanuskova, M.; Gualtieri, A. F.
abstract

Today, cancer is one of the main health issues faced in the workplace, with asbestos an important carcinogen in the occupational environment. Among the asbestos minerals, chrysotile is the main species of socio-economic and industrial relevance. Although chrysotile asbestos is classified as a "carcinogenic substance"by the International Agency for Research on Cancer (IARC), this fiber is still mined and used in Russia. The effective health hazard posed by the Russian commercial chrysotile has not been quantitatively assessed to date. In this work, the potential toxicity/pathogenicity of Russian chrysotile was quantitatively determined using the fiber potential toxicity index (FPTI) model. This model was applied to a representative commercial chrysotile from the Orenburg region, Russia, whose morphometric, crystal-chemical, surface activity, and biodurability related parameters were determined. We have quantitatively assessed that the toxicity/pathogenicity potential of Russian chrysotile (FPTI = 2.4) is lower than that of amphibole asbestos species but higher than the threshold limit set for "safe"mineral fibers (FPTI = 2.0), although it does not contain impurities of amphibole asbestos. Differences with other chrysotile samples were discussed, and it was found that the investigated Russian commercial chrysotile shares several features with the Italian Balangero chrysotile, indicating that widespread concern on commercial Russian chrysotile is justified.

2021 - Characterization of fibrous wollastonite NYAD G in view of its use as negative standard for in vitro toxicity tests [Articolo su rivista]
Di Giuseppe, D.; Scognamiglio, V.; Malferrari, D.; Nodari, L.; Pasquali, L.; Gualtieri, M. L.; Scarfi, S.; Mirata, S.; Tessari, U.; Hanuskova, M.; Gualtieri, A. F.
abstract

Today, despite considerable efforts undertaken by the scientific community, the mechanisms of carcinogenesis of mineral fibres remain poorly understood. A crucial role in disclosing the mechanisms of action of mineral fibres is played by in vitro and in vivo models. Such models require experimental design based on negative and positive controls. Commonly used positive controls are amosite and crocidolite UICC standards, while negative controls have not been identified so far. The extensive characterisation and assessment of toxicity/pathogenicity potential carried out in this work indicate that the commercial fibrous wollastonite NYAD G may be considered as a negative standard control for biological and biomedical tests involving mineral fibres. Preliminary in vitro tests suggest that wollastonite NYAD G is not genotoxic. This material is nearly pure and is characterized by very long (46.6 µm), thick (3.74 µm) and non-biodurable fibres with a low content of metals. According to the fibre potential toxicity index (FPTI) model, wollastonite NYAD G is an inert mineral fibre that is expected to exert a low biological response during in vitro/in vivo testing.

2019 - Bile salt-coating modulates the macrophage uptake of nanocores constituted by a zidovudine prodrug and enhances its nose-to-brain delivery [Articolo su rivista]
Dalpiaz, A.; Fogagnolo, M.; Ferraro, L.; Beggiato, S.; Hanuskova, M.; Maretti, E.; Sacchetti, F.; Leo, E.; Pavan, B.
abstract

We have previously demonstrated that the ester conjugation of zidovudine (AZT) with ursodeoxycholic acid (UDCA) allows to obtain a prodrug (U-AZT) which eludes the active efflux transporters (AET). This allows the prodrug to more efficiently permeates and remains in murine macrophages than the parent compound. Here we demonstrate that U-AZT can be formulated, by a nanoprecipitation method, as nanoparticle cores coated by bile acid salt (taurocholate or ursodeoxycholate) corona, without any other excipients. The U-AZT nanoparticles appeared spherical with a mean diameter of ∼200 nm and a zeta potential of ∼−55 mV. During the incubation (5 h) in fetal bovine serum, the ursodeoxycholate-coated nanoparticle size did not change. Differently, taurocholate-coated particle size was firstly reduced and then increased up to 800 µm, thus suggesting the high aptitude of these nanoparticles to interact with serum proteins. The in vitro uptake of taurocholate coated particles by murine macrophages was strongly higher than that of ursodeoxycholate-coated particles or free U-AZT (∼500% and ∼7000%, respectively). AZT was also detected in macrophages following the prodrug uptake, with the greatest amounts observed after the taurocholate-coated nanoparticle incubation. As macrophages in the subarachnoid spaces of cerebrospinal fluid (CSF) constitute one of the most unreachable HIV sanctuaries in the body, we also tested the ability of taurocholate-coated nanoparticles (i.e., nanoparticles highly internalized by macrophages) to reach them after their nasal administration in the presence or absence of chitosan. The results indicate that chitosan allowed to obtain a relatively high uptake (up to 4 µg/ml) of U-AZT in CSF. Taking into account that chitosan may promote the direct brain nanoparticle uptake, these findings can be considered an initial step toward the in vivo targeting of the subarachnoid macrophages by U-AZT prodrug.

2019 - Characterization and assessment of the potential toxicity/pathogenicity of fibrous glaucophane [Articolo su rivista]
Di Giuseppe, D.; Harper, M.; Bailey, M.; Erskine, B.; Della Ventura, G.; Ardit, M.; Pasquali, L.; Tomaino, G.; Ray, R.; Mason, H.; Dyar, M. D.; Hanuskova, M.; Giacobbe, C.; Zoboli, A.; Gualtieri, A.
abstract

In California, the metamorphic blueschist occurrences within the Franciscan Complex are commonly composed of glaucophane, which can be found with a fibrous habit. Fibrous glaucophane's potential toxicity/pathogenicity has never been determined and it has not been considered by the International Agency for Research on Cancer (IARC) as a potential carcinogen to date. Notwithstanding, outcrops hosting fibrous glaucophane are being excavated today in California for building/construction purposes (see for example the Calaveras Dam Replacement Project - CDRP). Dust generated by these excavation activities may expose workforces and the general population to this potential natural hazard. In this work, the potential toxicity/pathogenicity of fibrous glaucophane has been determined using the fibre potential toxicity index (FPTI). This model has been applied to a representative glaucophane-rich sample collected at San Anselmo, Marin County (CA, USA), characterized using a suite of experimental techniques to determine morphometric, crystal-chemical parameters, surface reactivity, biodurability and related parameters. With respect to the asbestos minerals, the FPTI of fibrous glaucophane is remarkably higher than that of chrysotile, and comparable to that of tremolite, thus supporting the application of the precautionary approach when excavating fibrous glaucophane-rich blueschist rocks. Because fibrous glaucophane can be considered a potential health hazard, just like amphibole asbestos, it should be taken into consideration in the standard procedures for the identification and assessment of minerals fibres in soil and air samples.

2017 - Conveying a newly designed hydrophilic anti-human thymidylate synthase peptide to cisplatin resistant cancer cells: are pH-sensitive liposomes more effective than conventional ones? [Articolo su rivista]
Sacchetti, Francesca; D'Arca, Domenico; Genovese, Filippo; Pacifico, Salvatore; Maretti, Eleonora; Hanuskova, Miriam; Iannuccelli, Valentina; Costi, Maria Paola; Leo, Eliana Grazia
abstract

Context: LR-peptide, a novel hydrophilic peptide synthetized and characterized in previous work, is able to reduce the multi-drug resistance response in cisplatin (cDPP) resistant cancer cells by inhibiting human thymidylate synthase overexpressed in several tumors, including ovarian and colon-rectal cancers, but it is unable to enter the cells spontaneously. Objective: The aim of this work was to design and characterize liposomal vesicles as drug delivery systems for the LR peptide, evaluating the possible benefits of the pH-responsive feature in improving intracellular delivery. Materials and methods For this purpose, conventional and pH-sensitive liposomes were formulated, compared regarding their physical-chemical properties (size, PDI, morphology, in vitro stability and drug release) and studied for in vitro cytotoxicity against a cDDP-resistant cancer cells. Results and discussion Results indicated that LR peptide was successfully encapsulated in both liposomal formulations but at short incubation time only LR loaded pH-sensitive liposomes showed cell inhibition activity while for long incubation time the two kinds of liposomes demonstrated the same efficacy. Conclusions Data provide evidence that acidic pH-triggered liposomal delivery is able to significantly reduce the time required by the systems to deliver the drug to the cells without inducing an enhancement of the efficacy of the drug.

2015 - Enhanced anti-hyperproliferative activity of human thymidylate synthase inhibitor peptide by solid lipid nanoparticle delivery [Articolo su rivista]
Sacchetti, Francesca; Marraccini, Chiara; D'Arca, Domenico; Pela', Michela; Pinetti, Diego; Maretti, Eleonora; Hanuskova, Miriam; Iannuccelli, Valentina; Costi, Maria Paola; Leo, Eliana Grazia
abstract

Recently, octapeptide LSCQLYQR (LRp), reducing growth of cis-platinum (cDDP) resistant ovarian carcinoma cells by inhibiting the monomer–monomer interface of the human enzyme thymidylate synthase, has been identified. As the peptide is not able to cross the cell membrane it requires an appropriate delivery system. In this work the application of SLNs, biocompatible and efficient tools for the intracellular drug transport, applied especially for lipophilic drugs, was exploited for the delivery of the hydrophilic peptide LRp. SLNs formulated in the absence/presence of small amount of squalene showed dimensions below 150 nm, negative zeta potential and good stability to the freeze-drying process. Even though the particles formulated with squalene exhibited a less ordered crystal lattice and a lower surface hydrophobicity, a rapid drug release from these nanocarriers occurred as a result of the relevant expulsion of the drug from the lipid core during lipid crystallization. On the contrary, SLNs formulated in the absence of squalene were able to incorporate more stably the peptide showing considerable cytotoxic effect on cDDP resistant C13* ovarian carcinoma cell line at concentration 50 times lower than that used previously with a marketed delivery system. From the cell cycle analysis by the propidium iodide test in SLNs-peptide treated cancer cells an increase of apoptosis percentage was observed, indicating that SLNs were able to carry efficiently the peptide until its enzymatic target.

2015 - Nanoencapsulation of an hTS inhibitor octapeptide against ovarian cancer in solid lipid matrix [Abstract in Atti di Convegno]
Sacchetti, Francesca; Marraccini, Chiara; Cannazza, Giuseppe; Iannuccelli, Valentina; Hanuskova, Miriam; Maretti, Eleonora; Costi, Maria Paola; Leo, Eliana Grazia
abstract

New octapeptides able to reduce the growth of platinum-resistant cells by inhibiting the enzyme human thymidylate synthase (hTS), cannot cross the cell membrane alone and require an appropriate delivery system. In the aim to transport hTS inhibiting LR octapeptide (LR-op) into the cells, Solid Lipid Nanoparticles (SLNs) were developed and evaluated in vitro. The optimized SLNs were formulated in the absence and presence of squalene (7S and 7Sq) both in the LR-op loaded and unloaded form. All the SLNs produced had dimensions below 150 nm, negative Zpotential and a good stability both in suspension and after freeze-drying. Only the sample obtained in the absence of squalene showed to stably incorporate the LR-op promoting its cell internalization, as demonstrated by in vitro studies on C13* ovarian carcinoma cell line.

2014 - Development and characterization of PLGA nanoparticles as delivery systems of a prodrug of zidovudine obtained by its conjugation with ursodeoxycholic acid [Articolo su rivista]
Dalpiaz, Alessandro; Contado, Catia; Mari, Lara; Perrone, Daniela; Pavan, Barbara; Paganetto, Guglielmo; Hanuskova, Miriam; Vighi, Eleonora; Leo, Eliana Grazia
abstract

The main purpose of this study was to investigate the effect of the Pluronic F68 coating on the loading, release and stability of PLGA nanoparticles embedded with a prodrug of zidovudine, an anti HIV agent, obtained by its conjugation with ursodeoxycholic acid. The mean diameter of the nanoparticles prepared by nanoprecipitation or emulsion/solvent evaporation methods was determined using both photon correlation spectroscopy and sedimentation field–flow fractionation (SdFFF) and resulted about 600 nm with a relatively high polidispersity. The nanoparticles obtained by emulsion/solvent evaporation method were not able to control the prodrug release while the nanoparticles obtained by nanoprecipitation were able to control the release of the prodrug, showing a burst release of about 50%. The presence of the Pluronic coating did not substantially modify the kinetics of the drug release nor the extent of the burst effect which was instead only influenced by the preparation parameters. The prodrug incorporated in the nanoparticles was more stable in the rat liver homogenates than the free prodrug and no influence of the Pluronic coating was observed. Considering the different potential applications of nanoparticles coated and uncoated with Pluronic, both of these nanoparticle systems could be useful in the therapies against HIV

2014 - Energy-Based Assessment of Optimal Operating Parameters for Coupled Biochar and Syngas Production in Stratified Downdraft Gasifiers [Relazione in Atti di Convegno]
Allesina, Giulio; Pedrazzi, Simone; LA CAVA, Emma; Orlandi, Michele; Hanuskova, Miriam; Fontanesi, Claudio; Tartarini, Paolo
abstract

Biochar represents a valuable solution for carbon sequestration. Infact, it has aroused the interest of the scientific community due to its resistance to the degradation and its potential of soil improving. Stratified downdraft gasifier reactors are characterized by extreme design simplicity and it was proved that are able to operate with non-homogeneous feedstock. On the other hand, stratified reactors dispose a higher amount of char when compared to other downdraft gasifier. This work is aimed at characterizing the char produced through downdraft stratified reactors. Particular conditions which maximize both the quality and the amount of syngas and biochar was investigated. The whole system was evaluated through a composed coefficient Ip (performance index) which takes into account the energy content in the gas stream and the characteristics of the char produced. A lab-scale reactor, able to operate under different conditions, was designed considering the requirements of this work. It was implemented with a sophisticated heating system which allow us to control the reactor surface temperatures independently zone to zone. Results shown the capability of stratified gasifiers to be used for biochar disposal. Results outlined the Ip trend as function of the SV of the gasifier. and tar production was considered to find the more suitable condition.

2014 - Facile synthesis of B-type carbonated nanoapatite with tailored microstructure [Articolo su rivista]
Gualtieri, M. L.; Romagnoli, M.; Hanuskova, M.; Fabbri, E.; Gualtieri, A. F.
abstract

Nanolime and a phosphate-based chelating agent were used to synthesize B-type carbonated apatite. Developed Rietveld refinement strategies allowed one to determine process yield, product crystallinity as well as structural (unit cell) and microstructural (size, strain) parameters. The effect of synthesis temperature (20-60 °C) as well as Ca/P ratio (1.5-2.5) and solid content (10-30 wt%) of the starting batch on these properties were investigated. FTIR, TEM and gas adsorption data provided supporting evidence. The process yield was 42-60 wt% and found to be governed by the Ca/P ratio. The purified products had high specific surface area (107-186 m2/g) and crystallinity (76-97%). The unit cell parameters, correlated to the degree of structural carbonate, were sensitive to the Ca/P ratio. Instead, temperature governed the microstructural parameters. Less strained and larger crystals were obtained at higher temperatures. Long-term aging up to 6 months at 20 °C compensated for higher crystal growth kinetics at higher temperature. © 2014 Elsevier Inc.

2014 - Inhaled Solid Lipid Microparticles to target alveolar macrophages for tuberculosis [Articolo su rivista]
Maretti, Eleonora; Rossi, Tiziana; Bondi, Moreno; Croce, Maria Antonietta; Hanuskova, Miriam; Leo, Eliana Grazia; Sacchetti, Francesca; Iannuccelli, Valentina
abstract

The goal of the work was to evaluate an anti-tubercular strategy based on breathable Solid Lipid Microparticles (SLM) to target alveolar macrophages and to increase the effectiveness of the conventional tuberculosis (TB) therapy. Rifampicin loaded SLM composed of stearic acid and sodium taurocholate were characterized for aerodynamic diameter, surface charge, physical state of the components, drug loading and release as well as drug biological activity on Bacillus subtilis strain. Moreover, SLM cytotoxicity and cell internalization ability were evaluated on murine macrophages J774 cell lines by MTT test, cytofluorimetry and confocal laser microscopy. SLM exhibited aerodynamic diameter proper to be transported up to the alveolar epithelium, negative charged surface able to promote uptake by the macrophages and preserved drug antimicrobial activity. The negligible in vitro release of rifampicin indicated the capacity of the microparticle matrix to entrap the drug preventing its spreading over the lung fluid. In vitro studies on J774 cell lines demonstrated SLM non-cytotoxicity and ability to be taken up by cell cytoplasm. The microparticulate carrier, showing features suitable for the inhaled therapy and for inducing endocytosis by alveolar macrophages, could be considered promising in a perspective of an efficacious TB inhaled therapy by means of a Dry Powder Inhaler device.

2014 - The zeta potential of mineral fibres [Articolo su rivista]
Pollastri, Simone; Gualtieri, Alessandro; Gualtieri, Eva Magdalena; Hanuskova, Miriam; Cavallo, Alessandro; Gaudino, Giovanni
abstract

For the first time, the zeta (ξ) potential of pathogenic mineral fibres (chrysotiles, amphiboles and erionite) was systematically investigated to shed light on the relationship between surface reactivity and fibre pathogenicity. A general model explaining the zeta potential of chrysotile, amphiboles and erionite has been postulated. In double distilled water, chrysotiles showed positive values while crocidolite and erionite showed negative values. In contact with organic solutions, all fibres exhibited negative values of zeta potential. The decrease of the surface potential is deemed to be a defensive chemical response of the macrophage cells to minimize hemolytic damage. Negatively charged surfaces favour the binding of collagen and redox activated Fe-rich proteins, to form the so-called asbestos bodies and prompt the formation of HO via the reaction with peroxide (H2O2+e(-)→HO+HO(-)). An additional mechanism accounting for higher carcinogenicity is possibly related to the Ca(2+) sequestration by the fibres with surface negative potential, impairing the mitochondrial apoptotic pathway. It was also found that with a negative zeta potential, the attractive forces prevailed over repulsions and favoured processes such as agglomeration responsible of a tumorigenic chronic inflammation.

2013 - Application of heating microscopy on sintering and melting behaviour of natural sands of archaeological interest [Articolo su rivista]
Montanari, F.; Boschetti, C.; Miselli, P.; Hanuskova, M.; Baraldi, P.; Leonelli, C.
abstract

In antiquity, beach sand was one of the main raw materials for glass-making and for the production of other vitreous materials, like Egyptian blue and faience. During the 1st century AD, glass and pigments manufacturing industry was active along the Gulf of Naples, Italy, where we sampled four littoral sands. Samples were analyzed with different techniques: chemical analysis was performed by means of X-Ray Fluorescence (XRF) and mineralogical analyses with X-Ray Powder Diffraction (XRPD) and Raman Spectroscopy. The complete sintering to melting thermal behaviour of the four sands was studied by heating microscopy or hot-stage microscope (HSM) equipped with an high resolution camera capable to collect sample profile during heating. The effect of the grain size on the sintering curves, which were automatically elaborated by specimen profile transformation, was also investigated. Finally, some deductions about the granulometry effect and the presence of alkaline and alkaline-earth oxides on sintering and melting behaviour were drawn. All the four sands were found suitable for highly sintered manufacts rather than glasses, to reach complete amorphous materials the addition of fluxes was necessary.

2013 - Design flexibility influencing the in vitro behavior of cationic SLN as a nonviral gene vector [Articolo su rivista]
Vighi, Eleonora; Montanari, Monica; Hanuskova, Miriam; Iannuccelli, Valentina; Coppi, Gilberto; Leo, Eliana Grazia
abstract

In this paper SLN were prepared using stearic acid as main lipid component, stearylamine as cationic agent and protamine as transfection promoter and adding phosphatidylcholine (PC), cholesterol (Chol) or both to obtain three different multicomponent SLN (SLN-PC, SLN-Chol and SLN-PC-Chol, respectively). Cytotoxicity and transfection efficiency of the obtained SLN:pDNA complexes were evaluated on three different immortalized cell lines: COS-I (African green monkey kidney cell line), HepG2 (human hepatocellular liver carcinoma cell line) and Na1300 (murine neuroblastoma cell line). Samples were characterized for the exact quantitative composition, particle size, morphology, zeta potential and pDNA binding ability. All the three SLN samples were about 250-300nm in size with a positive zeta potential, whereas SLN:pDNA complexes were about 300-400nm in size with a less positive zeta potential, depending on the SLN composition. Concerning the cell tolerance, the three samples showed a level of cytotoxicity lower than that of the positive control polyethylenimine (PEI), regardless of the cell lines. The best transfection performance was observed for SLN-PC-Chol on COS-I cells while a transfection level lower than PEI was observed on HepG2 cells, regardless the SLN composition. On Na1300 cells, SLN-Chol showed a double efficiency with respect to PEI. Comparing these results to those obtained with the same kind of SLN without PC and/or Chol, it is possible to conclude that the addition of Chol and/or PC to the composition of cationic SLN modify the cell tolerance and the transfection efficiency of the gene vector in a manner strictly dependent on the cell type and the internalization pathways.

2013 - Effect of drying method on the specific surface area of hydrated lime: A statistical approach [Articolo su rivista]
Romagnoli, Marcello; Gualtieri, Eva Magdalena; Hanuskova, Miriam; Rattazzi, Andrea; Polidoro, Costantino
abstract

Lime putty is a traditional binder, experiencing a new advent in the preservation of historical buildings. Recently it was shown that lime putty microstructure evolves with ageing time, generally resulting in a continuous quality improvement, but possibly also passing a minima/maxima. Hence, periodical quality checks during ageing are needed to optimize quality and avoid excessive storage. The specific surface area (SSA) of lime putty is a potentially valuable parameter for quality control as it influences the workability and setting of lime mortars. Gas adsorption and the Brunauer–Emmet–Teller (BET) theory is a popular method for its determination, requiring a dry powder. Generally, freeze-drying is used for powder preparation as this method is assumed to diminish particle aggregation. However, no systematic investigation of the effect of powder preparation method on BET SSA has previously been reported. In addition, reproducibility evaluations of such methods are also lacking. This work was aimed to fulfil these gaps, using both calcitic and dolomitic lime putties. Freeze-drying was compared to heat-induced drying (105 °C) under air as well as at low pressure. In addition, sample microstructure was evaluated using X-ray Powder Diffraction data and Rietveld refinements as well as Electron Microscopy techniques (SEM, TEM). It was statistically proven that freeze-drying, compared to the other dehydration methods, resulted in a 20–35% higher BET SSA for calcitic lime putties consisting mainly of nanoparticles. Instead, BET SSA of a dolomitic lime putty containing micrometre-sized hexagonal platelet crystals was not influenced by drying method. No statistically significant difference in phase composition was found between the samples dried by the different methods, excluding carbonation of the hydroxides as influencing factor. Finally, high reproducibility of BET specific surface area was obtained regardless of drying method which is an important characteristic of a standard test method for quality control.

2013 - Porcelain stoneware with pegmatite and nepheline syenite solid solutions: Pore size distribution and descriptive microstructure [Articolo su rivista]
Kamseu, E.; Bakop, T.; Djangang, C.; Melo, U. C.; Hanuskova, M.; Leonelli, C.
abstract

Investigations correlating the pore size distribution-cumulative pore volume to the microstructure are used to compare the efficiency of two solid solutions of pegmatite and nepheline syenite as fluxing agents for the design of porcelainized stoneware. Particularly the fusibility of the two solid solutions was modified by adjusting the CaO content of the bodies. As results, the pegmatite based flux produced an extended viscous phase capable on embedding the crystalline phases and close open porosity as from 1175°C. Conversely, the bodies with nepheline syenite remained relatively porous up to 1225°C although the similar results of the mechanical strength at this temperature. The investigations on microstructure, pores size distribution and cumulative pore volume indicated almost complete reduction of the open pores in the pegmatite based bodies and the development of a band of closed pores ranged between 0.080 and 0.9μm showing P series as a more compact structure. For the nepheline syenite based bodies, the incomplete reduction of the open pores and the relative absence of the band of pores between 0.080 and 0.9μm were ascribed to the difference in fusibility and the viscosity of the glassy phases. These differences were interpreted in term of the differential action of CaO in Na2O-Al2O3-SiO2 and K2O-Al2O3-SiO2 on the amount and viscosity of the liquid phase formed already described in the literature. © 2013 Elsevier Ltd.

2012 - Natural raw materials in "Traditional" ceramic manufacturing [Articolo su rivista]
Manfredini, Tiziano; Hanuskova, Miriam
abstract

New typologies of ceramic tiles represent well all the innovations in body and glaze compositions, preparation of powders, application of new integrated industrial strategies, and consequently rational utilization of all the necessary raw materials available. Italy is a representative example of growing of the ceramic tile industry, being one of the larger producer of wall and floor tiles in the world. The optimal utilization of minerals and raw materials is directly proportional to the level of knowledge about the ceramic materials and the effects of minerals and their impurities on the process and on the properties of the end-products. The same mineral can be used for simple, bulk products, but after small modification it may well be used for high quality products.

2011 - Structural investigation and intracellular trafficking of a novel multicomposite cationic solid lipid nanoparticle platform as a pDNA carrier [Articolo su rivista]
Vighi, Eleonora; Leo, Eliana Grazia; Montanari, Monica; Mucci, Adele; Hanuskova, Miriam; Iannuccelli, Valentina
abstract

Background: The ability to efficiently cross cellular barriers and accomplish high-level transgene expression is a critical challenge to broad application of nonviral vectors, such as cationic solid lipid nanoparticles (SLN).Aims: This study aims to design and characterize in vitro multicomposite SLN as a novel platform for pDNA delivery.Results/Discussion: The distribution of each component (stearic acid, stearylamine, phosphatidylcholine, cholesterol, protamine and Pluronic F68) in the SLN matrix was studied by electron spectroscopy for chemical analysis and NMR in order to establish its influence on SLN cytotoxicity and transfection efficiency. Multicomposite SLN mediated the expression of enhanced green fluorescent protein in a way comparable with the positive control,but inducing a lower cytotoxicity. Moreover, the carrier exhibited the ability to enter the nucleoli, probably as a result of the synergic action of the nuclear localization signal of protamine and the flexibility of the lipid matrix owing to the phosphatidylcholine. Conclusion: The multicomposite SLN showed good transfection efficiency and negligible cytotoxicity, both crucial factors for an efficient gene-delivery system. Considering the fact that nucleolihave emerged in recent years as important targets in many fields, this novel carrier could have significant future therapy involvements whenever there is a requirement to overcome subcellular barriers. However, further work needs to be carried out in order to fully characterize the formulation, to elucidate where alternative colloidal structures might exist and play a role in obtaining the results presented.

2010 - Thermal conductivity of fired clays: Effects of mineralogical and physical properties of the raw materials [Articolo su rivista]
Gualtieri, M. L.; Gualtieri, A. F.; Gagliardi, S.; Ruffini, P.; Ferrari, R.; Hanuskova, M.
abstract

The physical, chemical and mineralogical properties of representative commercial Italian clays were investigated by X-ray powder diffraction and Rietveld refinements, laser granulometry, X-ray fluorescence spectroscopy and calcimetry. The clays were used to prepare bricks by both extrusion and uniaxial pressing. The effective thermal conductivity of the fired bricks was determined and correlated with physical and mineralogical properties of the raw materials. Unfortunately, the complex nature of the system with many influencing parameters and interactions did not allow linear correlations with single parameters. Hence, a multiple linear regression approach was attempted and a statistically valid model was built for extruded samples. Although the model cannot be regarded as conclusive, due to the system complexity and the limited number of observations, the results gave some indications regarding the role played by the raw materials properties on the effective thermal conductivity of the bricks. The pore forming effect of organic material decreases the thermal conductivity of the bricks. On the contrary, the thermal conductivity increases with decreasing particle size, possibly due to an increased sintering rate and/or improved particle packing. © 2010 Elsevier B.V.

1998 - L’analisi granulometrica per la caratterizzazione delle polveri ceramiche. Parte I: aspetti teorici [Articolo su rivista]
Hanuskova, Miriam; Romagnoli, Marcello
abstract

Nell'articolo vengono riportate le basi teorico-pratiche dell'analisi granulometrica al fine di caratterizzare polveri di materie prime utilizzate in ceramica.

1998 - L’analisi granulometrica per la caratterizzazione delle polveri ceramiche. Parte II: aspetti applicativi [Articolo su rivista]
Hanuskova, Miriam; Romagnoli, Marcello
abstract

Nell'articolo vengono riportati esempi di applicazione dell'analisi granulometrica a polveri ceramiche. Si riportano esempi di curve e possibili effetti.