Sonia Casolari

Organometallic building blocks for crystal engineering. Synthesis, structure and hydrogen bonding interactions in [Fe(η5-C5H4CH2(CH3)OH)2], [Fe(η5-C5H3(CH3)COOH)2], [Fe(η5-C5H4CH(CH3)NH(η5-C5H4CH(CH3))] and in the diaminecyclohexane salt [Fe(η5-C5H4COO)2]2−[(1S,2S)-(NH3)2C6H10]2+·2[H2O]

Abstract The novel ferrocene-based compounds [Fe(η5-C5H4CH(CH3)OH)2] (1), [Fe(η5-C5H3(CH3)COOH)2] (2), [Fe(η5-C5H4CH(CH3)NH(η5-C5H4CH(CH3))] (3) and the diaminecyclohexane salt [Fe(η5-C5H4COO)2]2−[1S,2S-(NH3)2C6H10]2+·2[H2O] (4) have been synthesised and their molecular and supramolecular structures determined by single-crystal X-ray diffraction. The hydrogen bonding networks established by the COOH, CH(CH3)OH, and COO(−) groups have been studied and the structural parameters compared with those available for the prototypical dicarboxylic acid [Fe(η5-C5H4COOH)2].

Hollow-fiber flow field-flow fractionation and multi-angle light scattering investigation of the size, shape and metal-release of silver nanoparticles in aqueous medium for nano-risk assessment.

Due to the increased use of silver nanoparticles in industrial scale manufacturing, consumer products and nanomedicine reliable measurements of properties such as the size, shape and distribution of these nano particles in aqueous medium is critical. These properties indeed affect both functional properties and biological impacts especially in quantifying associated risks and identifying suitable risk-mediation strategies. The feasibility of on-line coupling of a fractionation technique such as hollow-fiber flow field flow fractionation (HF5) with a light scattering technique such as MALS (multi-angle light scattering) is investigated here for this purpose. Data obtained from such a fractionation technique and its combination thereof with MALS have been compared with those from more conventional but often complementary techniques e.g. transmission electron microscopy, dynamic light scattering, atomic absorption spectroscopy, and X-ray fluorescence. The combination of fractionation and multi angle light scattering techniques have been found to offer an ideal, hyphenated methodology for a simultaneous size-separation and characterization of silver nanoparticles. The hydrodynamic radii determined by fractionation techniques can be conveniently correlated to the mean average diameters determined by multi angle light scattering and reliable information on particle morphology in aqueous dispersion has been obtained. The ability to separate silver (Ag(+)) ions from silver nanoparticles (AgNPs) via membrane filtration during size analysis is an added advantage in obtaining quantitative insights to its risk potential. Most importantly, the methodology developed in this article can potentially be extended to similar characterization of metal-based nanoparticles when studying their functional effectiveness and hazard potential.

WORKING WITHOUT ACCUMULATION MEMBRANE IN FLOW FFF. EFFECT OF SAMPLE LOADING ON RECOVERY

ABSTRACT Steric/hyperlayer flow field-flow fractionation (St/Hyp/FlFFF) is suitable for the separation and characterization of micrometer-sized particles. In this technique, an ultrafiltration membrane is commonly used as the surface of the accumulation wall. St/ Hyp/FlFFF has been recently tested in membraneless mode and an improvement in performance was found. Recovery was also improved and second-order effects were reduced. In the framework of St/Hyp/FlFFF optimization, the effect of sample loading is a problem of a certain importance. For quantitative purposes, the conversion of peaks into mass particle size distributions is of prime importance and, therefore, the conditions in which there is no effect of sample loading on recovery should be investigated. In this paper, systematic work was performed in order to study the effect of sample loading on recovery. We have found the conditions in which recovery is independent of sample loading. For these conditions, the limit of detection for various micrometer-size standard polystyrene particles was calculated. The absolute sample recovery was calculated by applying a quantitative method for single-run analysis in FFF with UV/Vis detectors.

Chiral–achiral ligand synergy: activation of a zirconium–BINOL Lewis acid complex by the addition of 4-tert-butylcalix[4]arene

4-tert-Butylcalix[4]arene activates the enantioselective allylation of aldehydes catalyzed by a new zirconium–BINOL Lewis acid system allowing the use of less than 2% of the catalyst.

Gelatin Porous Scaffolds as Delivery Systems of Calcium Alendronate

The systemic administration of bisphosphonates (BPs) for the treatment of metabolic diseases characterized by abnormal bone loss suffers from several adverse side effects, which can be reduced by implementation of alternative modes of administration. In this work, glutaraldehyde cross-linked gelatin scaffolds are proposed as delivery systems of calcium alendronate monohydrate (CaAL•H2 O). The 3D highly porous scaffolds display a relevant interconnected porosity (>94%), independently from CaAL•H2 O content (0, 3, and 6 wt%). At variance, pore size varies with composition. The relative increase of the number of smaller pores on increasing BP content is in agreement with the parallel significant increase of the compressive modulus and collapse strength. The scaffolds exhibit a sustained CaAL•H2 O release profile, and a significant amount of the drug is retained in the scaffolds even after 14 d. In vitro tests are carried out using cocultures of osteoblast (OB) and osteoclast (OC). The evaluation of differentiation markers is performed both on the supernatants of cell culture and by means of quantitative polymerase chain reaction. The results indicate that BP containing scaffolds support osteoblast proliferation and differentiation, whereas they inhibit osteoclast viability and activity, displaying a promising beneficial role on bone repair processes.

Hybrid gravitational field-flow fractionation using immunofunctionalized walls for integrated bioanalytical devices

In this work, the biospecific recognition antigen–antibody reaction was implemented in gravitational field-flow fractionation (GrFFF), a flow-assisted separation technique for micron-sized particles, in order to realize a hybrid immunomodulated GrFFF system in which two different principles are combined to achieve highly versatile fractionation. Micron-sized polystyrene beads coated with horseradish peroxidase (HRP) were used as a model sample, and anti-HRP antibodies were immobilized on the accumulation wall of the GrFFF channel. Ultrasensitive chemiluminescence imaging was employed to visualize the beads during elution and to optimize experimental conditions. The same principle was then applied to real biological samples composed by Yersinia enterocolitica and Escherichia coli cells. Results show the possibility to modify the elution of selected sample components and even to retain them into the channel. The hybrid immunomodulated GrFFF system is a step towards the development of a module that could be integrated in a lab-on-a-chip-based point-of-care testing device which includes sample pre-analytical cleanup and analysis.

Strontium-Substituted Hydroxyapatite-Gelatin Biomimetic Scaffolds Modulate Bone Cell Response

Strontium has a beneficial role on bone remodeling and is proposed for the treatment of pathologies associated to excessive bone resorption, such as osteoporosis. Herein, the possibility to utilize a biomimetic scaffold as strontium delivery system is explored. Porous 3D gelatin scaffolds containing about 30% of strontium substituted hydroxyapatite (SrHA) or pure hydroxyapatite (HA) are prepared by freeze-drying. The scaffolds display a very high open porosity, with an interconnectivity of 100%. Reinforcement with further amount of gelatin provokes a modest decrease of the average pore size, without reducing interconnectivity. Moreover, reinforced scaffolds display reduced water uptake ability and increased values of mechanical parameters when compared to as-prepared scaffolds. Strontium displays a sustained release in phosphate buffered saline: the quantities released after 14 d from as-prepared and reinforced scaffolds are just 14 and 18% of the initial content, respectively. Coculture of osteoblasts and osteoclasts shows that SrHA-containing scaffolds promote osteoblast viability and activity when compared to HA-containing scaffolds. On the other hand, osteoclastogenesis and osteoclast differentiation are significantly inhibited on SrHA-containing scaffolds, suggesting that these systems could be usefully applied for local delivery of strontium in loci characterized by excessive bone resorption.