Biomedical subjects

Giuseppe Gigli

Publications and source records attributed to Giuseppe Gigli.

6 recordsLinked to original sources

PubMed2005

Emission properties of printed organic semiconductor lasers.

We investigated the emission properties of a distributed-feedback resonator based on an organic semiconductor patterned by a novel printing technology. We observed the peak splitting of the photonic bandstructure of the periodic grating and extracted the effective refractive index of the outcoupled guided modes. The laser works at the second diffraction order, exhibiting narrow single-mode emission at 637 nm, with a threshold as low as 37 microJ/cm2. The results suggest that direct printing is a promising fabrication technique for optically confined integrated optoelectronics.

Journal Article↗

PubMed2005

Microfluidic motion for a direct investigation of the structural dynamics of glass-forming liquids.

Glass-forming liquids, polymer solutions, and biofluids have additional inertial and elastic macroscopic degrees of freedom that are related to the elasticity of the molecular coils and affect the determination of the structural dynamical parameters. In this work, we propose a new approach for the direct evaluation of the fundamental material parameters (viscosity, fragility, glass transition temperature) of a viscoelastic liquid in a capillary flow inside a microfluidic device. The proposed technique substantially reduces the complexity of the theoretical analysis and provides an evaluation of the most relevant functional parameters of the fluid dynamics. Moreover, the approach allows the investigation of localization phenomena in geometrical confined systems, such as those required in miniaturized devices.

Microfluidic Analytical Techniques↗

PubMed2004

Rapid soft lithography by bottom-up enhanced capillarity.

The growing demand for new solutions to pursue the trend of micro- and nanoelectronics predicted by Moore's law is stimulating the development of new high-resolution, low-cost lithographies. Here we demonstrate that several bottom-up approaches can be used to increase the throughput of soft lithography by exploiting the enhanced hydrophilicity, the low viscosity, and the fragility of the employed materials. In particular, the customized functionalization of the involved surfaces to improve the wettability to polymer fluids and the dramatic decrease of the viscosity of polymer compounds as the temperature is increased, together with the good thermal stability of the functionalized surfaces, allow a faster filling of elastomeric channels, up to almost an order of magnitude with respect to conventional microfluidics.

Journal Article↗

PubMed2003

Solid-state supramolecular organization, established directly from powder diffraction data, and photoluminescence efficiency of rigid-core oligothiophene-S,S-dioxides.

The "rigid-core" material 3,5-dimethyl-2,3'-bis(3-methylthiophene)-dithieno[3,2-b:',3'-d]thiophene-4,4-dioxide (DTTOMe4) has the highest photoluminescence ever reported for thiophene-based molecules in the solid state. We report the structure of this material, determined directly from powder X-ray diffraction data using the Genetic Algorithm method for structure solution, followed by Rietveld refinement, and the structural properties are discussed in relation to the structures of the corresponding subsystems DTTO and DTTOMe. While the crystal structures of the latter compounds contain cofacial dimers, the crystal structure of DTTOMe4 comprises layers of molecules aligned in an antiparallel fashion. Intermediate neglect of differential overlap with single configuration interaction (INDO/SCI) calculations on the intermolecular interactions in the three crystal structures show that the different solid-state photoluminescence efficiencies of DTTOMe4, DTTOMe, and DTTO cannot be correlated with the different types of dipole-dipole alignment in the solid state. Instead, photoluminescence efficiencies correlate well with the rate of formation of nonradiatively decaying charge-transfer pairs upon photoexcitation. Because of larger intermolecular distances in DTTOMe4, the photoluminescence is less effectively quenched by charge-transfer processes than in DTTOMe and DTTO.

Journal Article↗

PubMedDate not supplied

Self-assembled extracellular matrix protein networks by microcontact printing.

Physiological patterns of the extracellular matrix protein, laminin-1, were obtained on glass substrates by physisorption-assisted microcontact printing. Besides the well-retained antigenicity confirmed by indirect immunofluorescence assays, we investigated the supramolecular organization of the proteins by atomic force microscopy. We found the characteristic protein self-assembling in polygonal networks with well-defined sub-100 nm quaternary structures of laminin. The formation of these physiological mesh-like protein matrices was obtained by means of one-step soft lithography without any preliminary functionalization of glass, which can be exploited for many possible applications for cell cultures and biomolecular devices.

Coated Materials, Biocompatible↗

PubMedDate not supplied

Bright oligothiophene N-succinimidyl esters for efficient fluorescent labeling of proteins and oligonucleotides.

The synthesis of multicolor fluorescent oligothiophene N-succinimidyl esters (TSEs) is reported, and their optical properties are discussed with the aid of ab initio calculations. The esters were coupled to proteins and to 3'-amino-modified oligonucleotides in mild conditions and with similar modalities. A comparative study of the bioconjugate of IgG1 anti-CD3 antibody labeled with a blue fluorescent TSE and with fluorescein isothiocyanate (FITC) is reported, showing that the former achieves higher photoluminescence intensity and optical stability than the latter. Fluorescence resonance energy transfer experiments with TSE-labeled oligonucleotides and examples of cellular imaging via TSE-labeled proteins are reported.

Antibodies, Monoclonal↗