The purpose of this work was the assembly of multicomponent nano-bioconjugates based on mesoporou... more The purpose of this work was the assembly of multicomponent nano-bioconjugates based on mesoporous silica nanoparticles (MSNs), proteins (bovine serum albumin, BSA, or lysozyme, LYZ), and gold nanoparticles (GNPs). These nanobioconjugates may find applications in nanomedicine as theranostic devices. Indeed, MSNs can act as drug carriers, proteins stabilize MSNs within the bloodstream, or may have therapeutic or targeting functions. Finally, GNPs can either be used as contrast agents for imaging or for photothermal therapy. Here, amino-functionalized MSNs (MSN-NH 2 ) were synthesized and characterized through various techniques (small angle X-rays scattering TEM, N 2 adsorption/desorption isotherms, and thermogravimetric analysis (TGA)). BSA or lysozyme were then grafted on the external surface of MSN-NH 2 to obtain MSN-BSA and MSN-LYZ bioconjugates, respectively. Protein immobilization on MSNs surface was confirmed by Fourier transform infrared spectroscopy, ζ-potential measurements, and TGA, which also allowed the estimation of protein loading. The MSN-protein samples were then dispersed in a GNP solution to obtain MSN-protein-GNPs nano-bioconjugates. Transmission electron microscopy (TEM) analysis showed the occurrence of GNPs on the MSN-protein surface, whereas almost no GNPs occurred in the protein-free control samples. Fluorescence and Raman spectroscopies suggested that proteins-GNP interactions involve tryptophan residues.
Herein we provided the first proof of principle for in vivo fluorescence optical imaging applicat... more Herein we provided the first proof of principle for in vivo fluorescence optical imaging application using monoolein-based cubosomes in a healthy mouse animal model. This formulation, administered at a non-cytotoxic concentration, was capable of providing both exogenous contrast for NIR fluorescence imaging with very high efficiency and chemospecific information upon lifetime analysis. Time-resolved measurements of fluorescence after the intravenous injection of cubosomes revealed that the dye rapidly accumulated mainly in the liver, while lifetimes profiles obtained in vivo allowed for discriminating between free dye or dye embedded within the cubosome nanostructure after injection.
Current Opinion in Colloid & Interface Science, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Mesoporous silica nanoparticles (MSN) were synthesised and functionalised with triethylenetetrami... more Mesoporous silica nanoparticles (MSN) were synthesised and functionalised with triethylenetetramine (MSN-TETA). The samples were fully characterised (transmission electron microscopy, small angle X-ray scattering, Fourier transform infrared spectroscopy, thermogravimetric analysis, zeta potential and nitrogen adsorption/desorption isotherms) and used as carriers for the adsorption of the antimicrobial drug sulphamethizole (SMZ). SMZ loading, quantified by UV–Vis spectroscopy, was higher on MSN-TETA (345.8 mg g−1) compared with bare MSN (215.4 mg g−1) even in the presence of a lower surface area (671 vs. 942 m2 g−1). The kinetics of SMZ adsorption on MSN and MSN-TETA followed a pseudo-second-order model. The adsorption isotherm is described better by a Langmuir model rather than a Temkin or Freundlich model. Release kinetics showed a burst release of SMZ from bare MSN samples (k1 = 136 h−1) in contrast to a slower release found with MSN-TETA (k1 = 3.04 h−1), suggesting attractive int...
A dynamic, rheological, and structural characterization of aqueous gel-like systems containing hy... more A dynamic, rheological, and structural characterization of aqueous gel-like systems containing hydroxypropyl guar gum (HPG), borax and glycerol is presented in this paper. The role of glycerol, which is introduced as a plasticizer in the formulation, is investigated by means of B NMR and H NMR PGSTE measurements in order to clarify its contribution to the gel network formation and its interaction with borax, with whom it forms a complex. The effect of gels components on the rheological behaviour and on the activation energy related to the relaxation process of the system was assessed by means of rheology. The results obtained suggest that the mechanical properties of these gels can be tuned and controlled by modulating the formulation in a wide range of compositions. Moreover, a structural characterisation has been also carried out by means of Small Angle X-ray Scattering (SAXS) to highlight the role of the various components on the mesh size of the network. The structural and mecha...
Different 10 mM buffers at the same nominal pH affect specifically the adsorption of lysozyme on ... more Different 10 mM buffers at the same nominal pH affect specifically the adsorption of lysozyme on ordered mesoporous silica. It emerges that specific buffer effects should be considered within ‘Hofmeister phenomena’.
Penetration Enhancer-Containing Vesicles: Does the Penetration Enhancer Structure Affect Topical Drug Delivery?
Current Drug Targets, 2015
The aim of this study was to elucidate the influence of the edge activator structure on the prope... more The aim of this study was to elucidate the influence of the edge activator structure on the properties of novel deformable liposomes, Penetration Enhancer-containing Vesicles (PEVs), capable of delivering drugs to the skin. The PEVs were prepared by testing five different amphiphilic penetration enhancers as edge activators in the bilayer composition, together with soy phosphatidylcholine and oleic acid. The penetration enhancers contained the same lipophilic tail (one or more C8-C10 carbon chains) and different hydrophilic heads. Conventional phospholipid liposomes were prepared and used as a control. Lidocaine was chosen as a model drug. Liquid and gelified PEVs were obtained, depending on the penetration enhancer used. The vesicular systems were characterized by measuring size distribution, zeta potential, incorporation efficiency, and monitoring these parameters over 90 days. Accelerated ageing tests were also performed to check the stability of the dispersions. The effects of the different nature of the edge activator on the features of the obtained PEVs were assessed by TEM, SAXS and WAXS, rheological, and deformability studies. Higher interactions of the most lipophilic penetration enhancers with the lipid bilayers and a consequent higher stability and elasticity of the obtained PEVs were observed. In vitro experiments through pig skin confirmed the superior potential as carriers for lidocaine of the PEVs prepared with the most lipophilic penetration enhancers, even in comparison with commercial EMLA cream.
Colloids and surfaces. B, Biointerfaces, Jan 17, 2015
We present here an innovative, fluorescent, monoolein-based cubosome dispersion. Rather than embe... more We present here an innovative, fluorescent, monoolein-based cubosome dispersion. Rather than embedded within the monoolein palisade, the fluorescent imaging agent, namely dansyl, was conjugated to the terminal ethylene oxide moieties of the block copolymer Pluronic F108. We discuss the physicochemical and photophysical properties of this fluorescent Pluronic and of a cubosome formulation stabilized by a mixture of dansyl-conjugated and non-conjugated Pluronic, also including an anticancer drug (quercetin). Furthermore, we performed biocompatibility tests against HeLa cells to assess internalization and cytotoxicity features of this nanoparticles aqueous dispersion. Cryo-TEM, SAXS, and DLS analysis, proved the bicontinuous cubic inner nanostructure and the morphology of this fluorescent cubosome dispersion, while photophysical measurements and biocompatibility results basically validate their potential use for theranostic nanomedicine applications.
In this paper we report on the fabrication and characterization of a potentiometric biosensor for... more In this paper we report on the fabrication and characterization of a potentiometric biosensor for the detection of triglycerides. This is constituted by a lipase immobilized on a mesoporous Si matrix. Prototypes, realized on 1 × 1 cm n +-type silicon wafers, show a very high enzymatic activity. Moreover the properties of these biosensors have been shown to be stable in a several months time interval, clearly showing their advantages with respect to traditional triglycerides detection systems. The Michaelis Menten curve is obtained to demonstrate the absence of diffusion problems. Potentiometric measurements are also shown.
The water self-diffusion coefficients were determined by means of the Fourier transform pulsed gr... more The water self-diffusion coefficients were determined by means of the Fourier transform pulsed gradient spin-echo NMR technique in three-and four-component W/O systems based upon perfluoropolyether (PFPE) oils and an anionic surfactant with a PFPE hydrophobic chain. In order to investigate the structural changes associated with microemulsion formation, the study has been performed by varying the water content within the monophasic isotropic region of the phase diagram, which is located at relatively low water content (<30% by weight). The addition of water to oil-surfactant mixtures, at constant mass ratio O/S, was found to cause the transition to a water-in-oil droplet structure in most of the systems, in agreement with light scattering and conductivity results recently reported. The effects of composition (01.9 ratio), molecular weight of the oil, and ionic strength of the water phase have been examined. In particular the effect of the oil chain length on the droplet formation has been clarified. The effects of water-soluble (ethanol) and oil-soluble (long chain PFPE) alcohols were also investigated. The cosolvent effect of ethanol, well-known in hydrocarbon systems, and the cosurfactant behavior of the PFPE alcohol have been ascertained in PFPE systems. A quantitative interpretation of NMR self-diffusion coefficients enabled the evaluation of the amount of water in droplets in the range of composition where continuous water and water in droplets coexist. Good agreement was found between our NMR results and those obtained by applying the hydration/partial dissociation concept to conductivity data.
Targeted liquid crystalline nanoparticles with a reverse hexagonal inner structure as diagnostic ... more Targeted liquid crystalline nanoparticles with a reverse hexagonal inner structure as diagnostic and therapeutic tools in oncology.
Acyl migration and hydrolysis in monoolein-based systems
Progress in Colloid Polymer Science, 2002
The extent of acyl migration and hydrolysis phenomena in glycerol monooleate/water based systems ... more The extent of acyl migration and hydrolysis phenomena in glycerol monooleate/water based systems and how they are affected by acetic acid and oleic acid has been examined. To facilitate analysis and interpretation of the data, samples with a low water content, 2–5 wt%, which form a liquid reverse micellar, L2, phase, were chosen. Acyl migration and hydrolysis were monitored versus
International journal of molecular sciences, Jan 8, 2018
Ordered mesoporous silica (OMS) is a very interesting nanostructured material for the design and ... more Ordered mesoporous silica (OMS) is a very interesting nanostructured material for the design and engineering of new target and controlled drug-delivery systems. Particularly relevant is the interaction between OMS and proteins. Large pores (6�?�9 nm) micrometric particles can be used for the realization of a drug depot system where therapeutic proteins are adsorbed either inside the mesopores or on the external surface. Small pores (1�?�2 nm) mesoporous silica nanoparticles (MSNs), can be injected in the blood stream. In the latter case, therapeutic proteins are mainly adsorbed on the MSNs’ external surface. Whenever a protein-OMS conjugate is prepared, a diagnostic method to locate the protein either on the internal or the external silica surface is of utmost importance. To visualize the fine localization of proteins adsorbed in mesoporous silica micro- and nanoparticles, we have employed specific transmission electron microscopy (TEM) analytical strategies based on the use of go...
Perfluoropolyether Carboxylic Salts in Water: Liquid Crystals by Optical Microscopy and NMR
The Journal of Physical Chemistry, 1994
Page 1. J. Phys. Chem. 1994, 98, 7591-7598 7591 Perfluoropolyether Carboxylic Salts in Water: Liq... more Page 1. J. Phys. Chem. 1994, 98, 7591-7598 7591 Perfluoropolyether Carboxylic Salts in Water: Liquid Crystals by Optical Microscopy and NMR Maura Monduzzi,&amp;#x27; Alba Chittofrati,? and Viviana Bosellit Dipartimento Scienze ...
A frequency-dependent 14N and 13C NMR relaxation study of the micellar region formed by a very lo... more A frequency-dependent 14N and 13C NMR relaxation study of the micellar region formed by a very long zwitterionic surfactant, viz., 6-(dimethyleicosylammonio)hexanoate (CAH), is presented. As a starting point the binary phase diagram of C&/D20 is determined. The phase diagram is similar to those found for shorter chain ionic surfactants with bulky head groups. The NMR relaxation data show a dependence upon the magnetic field strength and are discussed in terms of the two-step model of relaxation. The frequency dependence found at low frequencies in the 14N data is assumed to be caused by the rotational tumbling of the micelle, while it is argued that the frequency dependence found at high frequencies in the 13C relaxation data is caused by a local motion. The analysis of the data yields a radius of the micelle which is slightly shorter than an extended Czo chain, pointing to a situation where the methylene groups in the head-group dipole are embedded in the micelle. Moreover, the local motions in the head-group region are slow as compared to the corresponding motions in single-chain ionic surfactants.
Current Opinion in Colloid Interface Science, Oct 1, 1998
Significant advances have been attained in the characterization of microstructure and microstruct... more Significant advances have been attained in the characterization of microstructure and microstructural transitions of surfactant aggregates in terms of shape, dimension, and connectivity, in both micellar and liquid crystalline phases and microemulsion systems. Fluorocarbon surfactants display a variety of phase behavior as large as that of hydrocarbon surfactants. The presence, however, of fluorine atoms in the surfactant molecules provides peculiar performances that are of great industrial interest.
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