Single-Cell Photothermal Analysis Induced by MoS2 Nanoparticles by Raman Spectroscopy

Two-dimensional nanomaterials, such as MoS2 nanosheets, have been attracting increasing attention in cancer diagnosis and treatment, thanks to their peculiar physical and chemical properties. Although the mechanisms which regulate the interaction between these nanomaterials and cells are not yet completely understood, many studies have proved their efficient use in the photothermal treatment of cancer, and the response to MoS2 nanosheets at the single-cell level is less investigated. Clearly, this information can help in shedding light on the subtle cellular mechanisms ruling the interaction of this 2D material with cells and, eventually, to its cytotoxicity. In this study, we use confocal micro-Raman spectroscopy to reconstruct the thermal map of single cells targeted with MoS2 under continuous laser irradiation. The experiment is performed by analyzing the water O-H stretching band around 3,400 cm−1 whose tetrahedral structure is sensitive to the molecular environment and temperature. Compared to fluorescence-based approaches, this Raman-based strategy for temperature measurement does not suffer fluorophore instability, which can be significant under continuous laser irradiation. We demonstrate that irradiation of human breast cancer MCF7 cells targeted with MoS2 nanosheets causes a relevant photothermal effect, which is particularly high in the presence of MoS2 nanosheet aggregates. Laser-induced heating is strongly localized near such particles which, in turn, tend to accumulate near the cytoplasmic membrane. Globally, our experimental outcomes are expected to be important for tuning the nanosheet fabrication process

Editorial: Nanobiophotonics and Related Novel Materials Aimed at Biosciences and Biomedicine

Editorial on the Research Topic Nanobiophotonics and Related Novel Materials Aimed at Biosciences and Biomedicin

A combinatorial approach to gene expression analysis: DNA microarrays.

The microarray technology is based on analytical tools that parallelize the quantitative and qualitative analysis of nucleic acids, proteins and tissue sections one of its more recent evolutions-. By miniaturizing the size of the reaction and sensing area, microarrays allow to assess at the activity of thousands of genes in a given tissue or cell line at once in a rapid and quantitative way, and to carry out serial comparative tests in multiple samples. These tools, that stem from the innovations resulting from the technological improvements and knowledge arising from the genome sequencing projects, can be considered as a combinatorial technique that can rapidly provide significant information about complex cellular pathways and processes within one or few ‘‘mass scale’’ and comprehensive testing of a biological sample’s composition

One- and two-photon time-resolved fluorescence of visible and near-infrared dyes in scattering media

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Extracellular vesicle-based nucleic acid delivery: Current advances and future perspectives in cancer therapeutic strategies

Extracellular vesicles (EVs) are sophisticated and sensitive messengers released by cells to communicate with and influence distant and neighboring cells via selective transfer of bioactive content, including protein lipids and nucleic acids. EVs have therefore attracted broad interest as new and refined potential therapeutic systems in many diseases, including cancer, due to their low immunogenicity, non-toxicity, and elevated bioavailability. They might serve as safe and effective vehicles for the transport of therapeutic molecules to specific tissues and cells. In this review, we focus on EVs as a vehicle for gene therapy in cancer. We describe recent developments in EV engineering to achieve efficient intracellular delivery of cancer therapeutics and avoid off-target effects, to provide an overview of the potential applications of EV-mediated gene therapy and the most promising biomedical advances

Influence of the medium length on high-order harmonic generation

We study high-order harmonic generation using a 110 fs Ti:sapphire laser loosely focused into a variable-length gas cell filled with neon or argon at 5 mbar pressure. The harmonic intensity is recorded as a function of the medium length, varying between 2 and 21 mm. Several cases are examined, the 17th and the 29th harmonic in argon, and the 29th and 51st harmonic in neon, at the same intensity 4 x 10(14) W cm(-2). We find that the length which maximizes the harmonic yield varies from 10 mm to more than 20 mm. We discuss the different effects affecting the photon yield of the high-order harmonics

Plasma-Induced Frequency Chirp of Intense Femtosecond Lasers and Its Role in Shaping High-Order Harmonic Spectral Lines

We investigate the self-phase modulation of intense femtosecond laser pulses propagating in an ionizing gas and its effects on collective properties of high-order harmonics generated in the medium. Plasmas produced in the medium are shown to induce a positive frequency chirp on the leading edge of the propagating laser pulse, which subsequently drives high harmonics to become positively chirped. In certain parameter regimes, the plasma-induced positive chirp can help to generate sharply peaked high harmonics, by compensating for the dynamically-induced negative chirp that is caused by the steep intensity profile of intense short laser pulses.Comment: 5 pages, 5 figure

Measurement of the two-photon absorption cross-section of liquid argon with a time projection chamber

This paper reports on laser-induced multiphoton ionization at 266 nm of liquid argon in a time projection chamber (LAr TPC) detector. The electron signal produced by the laser beam is a formidable tool for the calibration and monitoring of next-generation large-mass LAr TPCs. The detector that we designed and tested allowed us to measure the two-photon absorption cross-section of LAr with unprecedented accuracy and precision: sigma_ex=(1.24\pm 0.10stat \pm 0.30syst) 10^{-56} cm^4s{-1}.Comment: 15 pages, 9 figure

Regulatory Interplay between miR-181a-5p and Estrogen Receptor Signaling Cascade in Breast Cancer

he efficacy and side effects of endocrine therapy in breast cancer (BC) depend largely on estrogen receptor alpha (ERα) expression, the specific drug administered, and treatment scheduling. Although the benefits of endocrine therapy outweigh any adverse effects in the initial stages of BC, later- or advanced-stage tumors acquire resistance to treatments. The mechanisms underlying tumor resistance to therapy are still not well understood, posing a major challenge for BC patient care. Epigenetic regulation and miRNA expression may be involved in the switch from a treatment-sensitive to a treatment-resistant state and could provide a valid therapeutic strategy for ERα negative BC. Here, a hybrid lysine-specific histone demethylase inhibitor, MC3324, displaying selective estrogen receptor down-regulator-like activities in BC, was used to highlight the interplay between epigenetic and ERα signaling. MC3324 anticancer action is mediated by microRNA (miRNA) expression regulation, indicating an innovative function for this molecule. Integrated analysis suggests a crosstalk between estrogen signaling, ERα interactors, miRNAs, and their putative targets. Specifically, miR-181a-5p expression is regulated by MC3324 and has an impact on cellular levels of ERα. A comparison of breast tumor versus healthy mammary tissues confirmed the important role of miR-181a-5p in ERα regulation and points to its putative predictive function in BC therapy